Roman's 4GR V6 Toyota Carina

[Roman]

I've been chipping away at a bunch of tasks and tidying things up, after the excitement of first drive has faded.
But one thing on my mind which is - Man I honestly hate how it sounds at the moment.
It's not right for the car at the moment and not very pleasant overall.

This car has only had two objectives... Do a shitload of rpm, and sound cool. 
I've been fixated on sorting out the nuts and bolts of getting the motor fitted and running.
Then dealing with some "shitload of rpm" problems. 
But the current noise even just idling. Just seems so discordant to the rest of the car.
It sounds like a straight piped AU Falcon or lil johnnys RB20DE. 
Honestly, I have looked up on youtube some straight piped falcons and RB20s and it sounds just the same haha.

How to improve? 
Here's what I'm hoping: 
-Will sound better once I've got the fuel map sorted a bit better, and some cam overlap chucked in there
-Will sound better once trumpets are on (was just bare throttles currently)
-Will sound better once it's doing a full throttle nang up the road
-Will sound better with big cams in it
-Might try keeping the 2-1 pipes smaller diameter, (currently 3") then flare out to 3" 
-Will try some different muffler options 
-Might try splitting exhaust back out to 2 pipes 
-Smaller tip diameters on the muffler (currently 1x 3" in, 2x 3" out)

Ideally want to get rid of the bassy exhaust note a bit.

Given the variety of sounds that I've heard from 2GR exhausts, I dont think it's an insurmountable problem. 
If I had a broader vision for the car than the two factors above, I could forgive it for sounding a bit "meh". 
But this is the one thing that will drive me mad if it's not right. 
Currently sounds way worse than a prius motor did - Surely that's a fairly low bar to set! haha.

Still stoked to do some skids in it, but really looking forward to getting the tune more dialled in and seeing where the torque/power ends up with current setup.
Then cant wait to chuck the big cams in and see how it compares.

I will go back to listening to Alfa 155 DTM noises while my faith in V6 wavers...

[Roman]

I have started dialling in fuel a bit better with 2 or 3 full throttle runs so far.  No cam advance, just setting a baseline. 

The shape of the fuel map / power curve is absolutely hilarious when there is no cam advance.
So the peak VE (105%) is at around 5500, secondary peak 7000rpm 103% so pretty good for the dunga stock cams and no cam timing adjustments yet.
Gave it a run to 8300rpm. Good news is that as expected the bank to bank difference narrows down as rpm/throttle opening goes up.

But.

At 2000rpm full throttle, its only around 55% VE max. It can only half fill the cylinder, so it must be bouncing a big bunch of the air back out.
Still sucks until around 4500rpm then starts to wake up.

It's also quite gross coming just off idle, as I think it's gaining a huge amount of throttle area quite quickly. 
Possibly also because I've got a secondary air source that bypasses the throttles (PCV line and brake booster) so it does weird stuff where more air comes into the throttles, but then the reduced vacuum means less PCV. or something. Dunno. 
It's getting better but it's been the hardest motor to tune so far. 
I think mainly because the injector position sucks.
Will definitely look at doing some explorative drilling on my old heads to see if I can mount the injectors further down.

It will be interesting to see how the exhaust cam timing will like to be adjusted as well, as I've never played around with that before.

This graph isnt suggestive of final powerband at all. I am just posting it because it's comical to see how much this engine sucks shit with fixed cam timing.

I suspect that the home position of the cam is hugely far back, so it's working kinda like the atkinson cycle on the 1NZFXE.
So its trying to reduce pumping losses as much as possible by having the cam intake timing incredibly delayed.
People say that the Mark X gets exceptionally good fuel economy for a big barge, so this is probably one of its tricks. 
It's also probably why it cranks over fairly easily with 12:1 comp as well.
I bet it would read surprisingly low on a compression test.

The low end should jump up by heaps with even say 10-15 degrees of intake cam timing added.

[Roman]

Exhaust noise stuff 

Alright alright alright.

So, for this motor I've always envisioned it having a more high pitched racey sorta sound.
Kinda like a motorbike with more cyls. 
What I've got at the moment is like a gluggy V8 sort of sound coming out, even when it's revving out nicely.
So in order to fix this I think I need to somehow quantify what "good noise" and "bad noise" actually is. 

So any engine has a fundamental exhaust frequency that relates to the number of pulses coming out of the exhaust.
So for example. A 4 cyl engine doing 8000rpm.
What is the frequency of the exhaust pulses coming out of the engine. 

8000rpm x 4 cyls 
divided by 2 because each cyl only fires once per 720 deg. 
Then divide by 60 to convert from rpm to hz. 

8000 x 4 /2 /60 = 266hz

Then another example, a V12 engine doing 6000rpm.

6000 x 12 / 2 / 60 = 600hz 

So obviously a V12 is going to sound higher pitched, as it's got more events going on. 
So that's one thing that you cant change about the motor. 
With some excel nerding we can figure out what sort of freq a 4, 6, 8, 10, 12 cyl motor naturally makes at a variety of rpm:





There's a youtube plugin called "Youtube Musical Spectrum" which is meant for guitar nerds to reverse engineer stuff I think. 
But it's also helpful for visualizing exhaust noise.

If we start with some known examples of good sounding stuff and look at the frequency plot which now overlays at the bottom of the screen.

This 6 cyl BMW sounds quite nice:
Can see that there's a big spike around 350hz which suggests it's doing around 7000rpm at this point. 




This BMW V12 sounds good. Can see there's a big spike around 375ish hz, which suggests it's likely doing under 4000rpm at the point this video is freeze framed.



This 4AGE starlet is running just under 10k rpm, sounds nice, and sitting at around 320hz which matches the tacho.




What you will notice about the cars above, is that the bulk of the noise matches the engine's rpm frequency.
There's almost nothing going on below 200hz but I think most importantly. All of the extra frequencies are higher than the engine's natural tone, not lower.

Now, lets look at some cars that sound..... well..... not so good. 
This is a BMW straight six motor that does have a 6-1 exhaust manifold, but doesnt sound as cool as you'd expect.
300hz so its doing around 6000rpm which matches the tacho.
Difference to the above plots?
There's a messy distribution of frequencies, and a lot of them are happening below the RPM frequency.



This is the Zonda that was ruined by the crappy double exit aftermarket exhaust: 
650hz so its likely doing around 6500rpm. But look at all of the frequencies happening below that point.




This is my carina which is sounding like a puddly arse at the moment:
(Fuck you, Chicken)
400hz = 8000rpm, but then lots of frequency peaks below that point and nothing above it.



This is the awful sounding exhaust of a V16 engine that was made from 4x 4cyl motors:
You can see its absolutely howling with a 1khz rpm frequency, but its got lots of yuck stuff happening under that.




Now, lets go back to an earlier carina video where it sounded better. I just had a coby hotdog muffler stuffed into the bum of open headers:
400hz, so the motor is doing ~8000rpm. 
But there are hardly any frequencies happening lower than the engine rpm.




So this is all interesting, but what can we do with this information?
Well, I think the deeper frequencies can only exist in a few different scenarios:

-Two adjacent pressure waves collapse into a big single one, halving the frequency. (like subaru boxer unequal header noise, or v8 firing order noise)
Possible causes for this happening in the carina could be an unequal length 2-1 section, or unequal length 3-1 on each bank. But I dont think this is the issue.

-There is some length or diameter of the exhaust that can cause a standing wave at lower hz than the engine pulse frequency. So maybe a muffler + pipe length is working as a helmholtz resonator or something like that.

I think the key to the nice high pitched noise that you hear from the likes of the Zonda, LFA, etc. 
Comes from realizing that a large diameter pipe allows frequencies lower than engine rpm to resonate. 
So to get the flow they need, instead of having one big honking pipe at the exit. 
They have multiple smaller pipes. 
This seems to be the case with almost all of the other cars that sound nice too. 


Exhaust outlets of high rpm cars that sound good:
Zonda with its signature 4 exit pipe.



The LFA has 3x pipes, again not  huge:




The V12 Mercedes has only 2 tips, but seems fairly small:



This V10 Audi which sounds absolutely crazy has 4x quite small exhaust tips:

 



Based on the above my current theory is that a smaller diameter pipe must act like a low pass filter and eliminates any frequencies lower than engine rpm.

My current muffler has 2x 3" exits, and an empty chamber section in the rear part of the exhaust just before that. 
I'm guessing this is what is responsible for making it resonate at those lower frequencies in a gross way. 
If I covered up one of the exits, the tone improves straight away.

So I am going to cut the back end off my fancy muffler. Then I will make it so I can have a flanged section where I can bolt on different outlet configs. 
I think having 3 or 4 small outlet pipes (so equivilent area or slightly more, of a single 3" pipe) will end up a lot more high pitched how I want.
This way I can also test if it needs some long pipe lengths after the muffler to make it work.
Fingers crossed I manage to figure something out without 3 zillion iterations.

A single 3" pipe has a cross sectional area of 7 square inches
So to have the same cross sectional area with two pipes, they would need to be 2" each. I've got some 2" pipe here already.
To get the same area with 3 pipes, would need to be 0.87" each. I dont have any pipe that small, but I do have some 1.5" pipe that I made the extractors with. will try that.
Will be interesting to see how the pitch changes, if at all. 
Hopefully have some setups to test this coming week.

[Roman]

I havent had a chance to do much exhaust testing, apart from trying some gatling gun looking ends.

So this still has same cross sectional area as a single 3" pipe but it has longer pipe bits which protrude in, and has bellmouths on the entrances so it's hopefully not too restrictive.
Surprisingly, it does in fact sound a bit better even at idle.
God bless PLA and duct tape.
Changing the tips is not getting the sound I need/want (Didnt think it would be that simple, but best to rule out the easiest possibilities first)
I cant show some nerdy stuff about wavelengths etc because it was incredibly windy at the time.



Some ethrottle junk turned up in the post.
I gave it a test and it works great!
A single motor could pull open both banks, no problem.
So having 1 motor per bank and it should be super snappy.



I've got an ethrottle pedal from a Toyota Aqua wired in, and have the ECU running one bank through the onboard ethrottle. 
For the second bank my dashboard now doubles as an ethrottle controller, and runs an H bridge to power the 2nd motor. 
So a high priority CAN message gets sent at 200hz containing ethrottle target (throttle %) and actual throttle %.
Then it applies a PID routine to output a frequency to the H bridge to give it some juice.
It's all wired up and just needs PID settings locked in with some testing once it's operational.

Since I currently need to run ethrottle from the same microcontroller that does dash stuff. 
I need to make sure I'm not hogging the processor for half a second (or whatever) with screen updates or something. 
Currently my code has just been running in a loop, updating the screen every time it can after receiving some CAN data.
I never checked how quick this is, but its zillions fast. 
I've now cut it down to a fixed refresh rate of 50hz for screen refresh, 200hz for ethrottle PID routine. Then the rest of the time it just sits there collecting CAN frames. 
It's managing to catch 20+ lots of can frames in between each PID routine so there shouldnt be any issue getting the relevant ethrottle data from the ECU in time.
I've added some other bits and pieces to the code to make it easier to draw features, change color scheme and so on. 
It's still not quite the aesthetic I want but it will do for now.
I've ordered a Teensy 4.1 (rather than my 4.0) as this has an onboard SD car slot. Meaning I can load gifs and bitmaps onto the SD card so it can display them on the screen. 
Once that turns up I'll have the 4.0 as a dedicated ethrottle unit, and 4.1 just for the dash. 

I've drawn up some new pulleys that can sit underneath the fuel rails without bonking into anything.
New one looks like this. No holes or anything, as I dont want to have any chance of snagging on something or jamming while it's further down in the guts of the intake setup.


So all of this stuff can go up on the wall of shame, and make way for an airbox.





Alsoooooo some Kelford cams turned up! 
Exciting.
Big cams are the make or break for this project, so it's exciting to finally have them.
Am I completely full of shit about this motor revving out good? Lets see. Haha.
Lots to do at the moment but very busy.
The plan from here is to finish the ethrottle setup. Then get a decent full throttle fuel map / VVTI map sorted on the factory cams.
So I've got a good baseline for comparison.
Its incredibly annoying how much of the motor you need to take apart to swap cams.
If it was easier, I'd probably just do it straight away. Haha.

[Roman]

I havent really driven the car anymore, because I've had a clusterfuck of small inter-related issues which are causing things to not be fun. 

So firstly the bank to bank imbalance was a pain - So I went back to setting up double e-throttle.
After a bunch of hours, and admittedly was very close to having it running good.
I decided it was quite un-fun to try make my own ethrottle controller, so I am using a borrowed G4+ Xtreme just as a 2nd throttle controller. Ha.
It's not doing anything except for actuating the throttle, and receiving throttle position target over canbus.
So once this was all going. I tried adjusting each bank individually to try get lambda to match bank to bank. 
Still sucks, even when the motor is at steady state.
Still got some other issues somehow.

So I pulled the fuel rails off and printed a test rig to double check injector data. 
Yep it was all good, no issues. 

Sooooo what else could it be? Maybe individual throttle balancing. 

Ages ago I tried to print a little throttle balancer thingy, but my printer was acting up.  



But went back up the priority list.
It's a little tube that I can plonk on top of each throttle, and it'll give me an airflow reading through a MAF that I've stuffed in there.

Like so:



This worked GREAT! 

My previous guesses with the screwdriver were massively wrong. 
On one bank, all 3 throttles were being fed air by only 1, back through the balance tubes. The other 2 throttles werent flowing any air at all through the throttle plate. 
It only took about 10 minutes to get everything balanced up, and now it's all matching a lot better, and idle is now really nice.

I've just printed a version 2.0 that has a smaller internal pipe size so it pushes the voltage readings a bit further up the scale, so its a bit more sensitive. It works well enough as is, but not making much use of the range available.
I will also add a capacitor to the output so it smooths the signal a bit.

My ethrottle pedal that was from the Echo, has a weird pivot point height and pedal height when fitted to Carina.
So it's quite awkward. But it's working at least.
However I think I will try adapt the sensor onto the normal pedal instead. 

Hopefully now it'll start feeling like the car responds and acts a bit better when trying to dial in the fuel.

 

Edit: some paddock tuning

 

 

[Roman]

Airbox activities.

I wasnt sure how to start on this or what might fit with bonnet yet. So just start with making a base plate that clears the rails etc.

Then the goal is to have a filter, or at least the air inlet. Running over radiator.

Dipping into my bucket-o-filters i found this one which fills the gap pretty well.

A few more top part tests then printed one with a flange on the front. So i can test the shape and start dipping it down.

Mainly just need to work around the radiator cap area.

It looks like i will have a pinch point to the bonnet about where the flange is. So decided to start making it wider as soon as the fuel rails finish.

This is current scheme thats just started on the printer.

Im not sure what the lid will look like yet, but will try use as much head height as possible.

Im not 100% sure how I will make the final version yet. Possibly thin nylon print with carbon smooshed over the top.

 

[Roman]

Found an easier option I think.

Rather than running the super long wide filter, and having it directly over radiator. I guess it's easier to put it a little close to the motor, and then any flexi join etc that's needed, isnt critical to sealing filtered air in.

I found this other filter in my bucket, which looks like a good size and means everything fits within my printer's width:

 

So now I'm printing the front part to hold it on and dip it down a little. 
It looks like I've got more room around the radiator cap than I first thought, so will un-scoop some of that area. 

Might add some ridges that run front to back to add rigidity to the whole thing. But for now, make sure it all fits. 
Then figure out how much of a roof I can put on it, and how to hold it all together.
This has been fun to make some fairly quick progress on for once.

[Roman]

"This has been fun to make some fairly quick progress on for once."
I just had to say it, didnt I? 
Okay as per chat thread, there's a bit of a change of plans to make everything work betterer. 
I dont have nearly as much bonnet clearance as I would have hoped.
I've decided that remaking the fuel rails will help remedy this, but also solve a bunch of other problems at the same time.
The existing fuel rails sit high, meaning the airbox has to be quite narrow. So it shrouds the trumpets a bit:


So there are a few considerations for a version 2 version 3 fuel rail setup.
-Last ones looked kinda cool when I modelled them, and I was excited to print some gratuitously bendy looking shapes. But ended up weird looking. I will keep it simpler now.
-This time I will be more considerate for the person that needs to machine the fuel rail later. This means having a flat base that is perpendicular to the direction of drilling needed, so it's easy to clamp down.
-The fuel feed fittings will now be on the same plane as the injector holes. Not located in the long end which makes it very difficult to secure to drill/tap.
-I need to keep the fuel rail high enough that I have clearance for my cable pulleys to be able to move at least 90 degrees.
-I need to keep the top of the fuel rail flush with the underside of a wider flatter airbox.
-Make sure that fuel dampers can fit this time. I suspect this might solve some weird behavior with fuel at particular rpm/load combos.
-I will add some fixing points so the airbox can mount on the rails. So all of the intake stuff locks together a bit and makes the whole assembly a lot more rigid.

After some farting around juggling the above criteria back and forth. has ended up like this.

New fuel rail shape is a bit simpler. It has some fixing points that I will fit studs to, for holding the airbox on.




 

 

 

 

The throttle pulleys are a tight fit underneath, but will be able to rotate more than 90 degrees.








It is kind of annoying to be redoing things, again. However this solves a whole bunch of issues so I'm happy to do it.
Thankfully none of this impedes other progress. As there's lots I can carry on with while still having no airbox and using the current fuel rails.
 

[Roman]

I borrowed some proper corner scales.
I was kinda thinking lots of little extra bits would add up.
Even though the V6 is technically about sameish weight as a 3SGE. 

I was super stoked to see these numbers! 
This is with no passenger seat, otherwise full interior.
Not sure on gas tank level.
Heavy 15" wheels with semi slicks on. 
Full glass. Lithium battery.

There are still some easy wins in the weight department yet. But super happy for it to be this already.




For some context, this weighs about same as a gen 1 MX5.

[Roman]

Another motor?  Be rude not to

A friend had a customer's car come in with a seized 2GRFSE engine.
It was deemed uneconomical to try and repair, so they replaced it.
Being the local V6 weirdo, I was asked if I would like the seized engine for V6 activities. 
Why, yes I would! Thanks.



I've mostly stripped it down, and found nothing particularly wrong so far. 
It turns over smoothly except for a small portion of rotation where it "sticks" for some reason. I found a broken chain tensioner, but this looks to be a symptom rather than cause.
With the chain fully off, it still does the same thing.
With a camera stuck down the spark plug holes, all of the bores are looking good as best I can tell. 
I am guessing either it's a main bearing that is stuffed, or maybe a piston has cracked a ringland, so it jams when it first starts going up (or down)
But it's looking though its still going to be a useable engine with a minor fix hopefully.

So, what to do with this motor? 
Well, it looks like a good candidate for destroking with the 5GR or 2MZ crank. 
Hopefully the heads and the bores are 100% okay on this motor. 
As the crank and rods get binned anyway.
Once I've confirmed its all okay, I'll just put it mostly back together and park it in the corner of the garage for now.
The only "downside" of this motor is that the ports on intake and exhaust are incompatible with my existing manifolds.
However it'll be no stress to make some new ones later on to test.

Throttle Pulley problems

It seems I messed up my measurements for cable length for the dual ethrottle setup.
So it's now working amazingly, and both banks are getting to target and really quickly. However I can only reach about 70% throttle before it runs out of cable pull.  
So my pulleys are off with Dad to cut them down a bit with the CNC machine, so I can reach full travel. 
Ahhhh well shit happens.

Airbox stuff

Height of airbox to the bonnet is still the main issue I'm contending with. Rhys had a suggestion to try trumpets that are parallel to the roof of the airbox, to gain a bit more clearance. Good idea!
So just printing some of these out.






Thermal camera side quest

I last had a thermal camera about 10 years ago. Technology has come leaps and bounds since then. 
My last one was very low resolution, and limited to either 5hz or 10hz refresh rate.
It could only read up to 200ish degrees, which wasnt hugely useful for things like brakes or exhaust stuff.

My new one is a little device the clips into the bottom of my phone. 
It can record video at 25hz, has 256*192 resolution, and scales up to 600 degrees C. 
Considerably cheaper than last time too. Bloody awesome! 
The thing about it that will be absolutely magnificent though.
Is that I've confirmed it works with a decent quality USB-C extension cable.
So this means I can mount the tiny device somewhere in my engine bay, wheel area, brake area, or whatever else. 
Then record and view results from in the cabin. Gonna be awesome.
But obviously I need to have all of the bread and butter parts of the car sorted before this will be much use.

Although 256*192 resolution seems low for a modern type of camera. 
It's awesome when you think about what it's replacing. 
If you put a temp sensor into something, you only have 2 datapoints. temperature and time. 
This has over 50,000 datapoints instead of 1.
So instead of "radiator is hot at this particular spot" you can now see the temperature gradient across the whole thing. 

Interesting to see the temp gradient on this SW20 radiator, which has both its inlet and outlet mounted at the top of the radiator.



It's cool to be able to see the exhaust pipes without maxxing out the sensor instantly. 
The bright areas are because of the different emissivity of the material, not because my welds are bad. That's my story, and I'm sticking to it.

 

[Roman]

2GRFSE pull down 

I finished pulling the 2GRFSE to bits, and found that the total sum of damage was: 
1x exhaust VVT pulley starting to push its guts out
1x chain tensioner broken 
2x big end bearings damaged
1x big end journal on crank looking damaged

So the great news here is, all of the damage is confined to bolt on stuff, or, relating to the crank/rods that I am planning to bin anyway. 
Perfect! 
If anyone has a 2MZFE motor kicking around, or just the crank, let me know. Keen.

Exhaust noise rambling part 2

I thought I would try come up with some practical testing methods for further isolating and confirming what "good noise" is, and isnt.
So I can quickly make some iterations and see if they meet objectives or not.
Keeping in mind that this is nothing to do with what makes best power, just sounds "better".
At this stage this is just testing at a constant idle speed. Which obviously isnt indicative of full throttle performance, or noise. 
However I'd prefer if it does not sound like a clattery bag of dicks at idle too. So its a relevant test.
I will do some medium and full load testing once my ethrottle setup is sorted properly.

For a TL;DR version of this considerably overlength post.
Here's a video of me just putting a Coby hotdog muffler on or off the back of a 2" exhaust pipe. It sound different with it on or off. The end.
 

 

 

 

 

Rest of post here:

 

 

I bought a decent microphone to clip on top of my DLSR so that it's hopefully recording as accurately as possible. 
I pulled all of the exhaust off back to open manifolds.
Below is a time plot visualization of the exhaust frequency from WinVNC.
The big peaks and troughs correlate to the pulse of gas coming out of the exhaust, the small wriggly bits are maybe reflected waves scooting around at speed of sound.
I can confirm that "wriggly noise" sounds yuck.




Now 2-1 section back on.
This sounded considerably better. Interestingly all of the wriggly stuff is gone. Sounds way less like a tractor.
I think the improvement in noise isnt from any sort of tuned length to do with the 2-1. Simply that the extra exhaust length or maybe the merge is eliminating a lot of the grotty frequencies.




Then in order to test the biggest range of mufflers that I've got sitting around, and see a single smaller pipe changes the noise by much.
I made a little test pipe that steps the exhaust down from 3" to 2".
My welding is getting a bit better.

With just this next section on, it sounded super yuck again. More tractor noises. 



Then biff a coby on it, and it sound nice again. Its interesting to note that I am recording everything at a fixed volume level - So the amplitude of the "gas pulse" sound was indeed bigger with the muffler on. Not just a trick of recording.



Then a second one up the bum. Not hugely different by ear.



Next just try stuffing the end of it into a 3.5" Adrenalin R. By ear, makes absolutely zero difference if I take it off or back on.



Then stuff the back of it into the 3" Adrenalin R muffler with the dual exit. Again, by ear, virtually zero difference to noise.




Just to give some continuity to the videos I showed previously using the Youtube spectrum analyzer, and also in case there werent enough pointless graphs in this post yet.
Here are same things again, but viewed through the youtube spectrum analyzer.

You can see that the gas pulse frequency is at around 65hz (sorry typo on post) which looking at my previous table equates to ~1100rpm for a 6 cyl car so that checks out.
Then you can see the peaks and troughs of the yuck stuff higher up that makes it sound like a tractor.

Its definitely interesting that although the general consensus for "f1 sound" exhaust has been to increase the frequency. But having all of these higher frequencies present is what makes it sound like absolute shit.




Then stuffing the coby onto the end, gas pulse is much bigger and considerably less yuck stuff further up.




Then I put a 2nd one on, and its a bit worse again. However this might be because the end of the pipe is touching the ground. Although, didnt seem to make any difference by ear when I lifted it up a bit more.




Then a human centipede of coby>adrenalin>adrenalin




Just the 3.5" 



Then just the double exit






Conclusion: 
I am thinking that straight out of the engine, the noise is primarily a large amplitude gas pulse (rpm dependent) but heavily sprinkled with a chaotic mess of frequencies. 
The best noise will probably come from stripping away the chaotic frequencies. Conditioning the pulse back to a single sine wave ideally. 
So I will aim to have this happening up the front of the car. Before bothering with the back half, make a front half exhaust that cuts away the chaos.
Then once this is done, the rear half of the exhaust can be fine tuned with pipe length/diameter/muffler type/whatever to push and pull the sine wave around to whatever sounds best.

But it seems there's no point trying to tune the sound at the back of the car if you still have all of the chaotic frequencies present.


It was interesting that the Adrenalin R stuff didnt seem to do anything meaningful. At idle speed at least. 
I suspect that a muffler starts working once the amplitude of the gas pulse somehow exceeds the cross sectional area of the pipe.
A 3" ID muffler can just have a bunch of low amplitude noise just waltz right out the back unimpeded.
But more of the noise gets forced into the packing when it's a smaller diameter pipe.

 

[Roman]

I got my throttle pulleys machined down to a smaller size, so they can open the throttles all of the way (Thanks Dad!)
So this is all now working GREAT. and it's super snappy.

So I started doing some tuning to try figure out the area just off idle, and why its such a bag of crap. 
I found that adding considerably more ignition timing helped a lot, and increasing injection timing to around 600deg (usually 400)
However, at a fairly early stage I managed to blitz one of my ethrottle motors with about 100 amps too many haha. 
It still worked, but smelled funky. Well, it ended up crapping itself. So I've ordered another one but it's still a few weeks away which is annoying.

Since I couldnt do anything else meaningful for that stuff, I figured probably a good idea to take all of the exhaust completely off and check it. 
I found a worst case scenario leak for my extractors on both sides. 
There were signs of a small leak coming from somewhere between the 3 pipes, up the middle of them. Blargh!
Impossible to get to this to fix it without cutting everything up. 
I was fretting about it for longer than it actually took to fix. 
I cut off the collectors just slightly up past the 3x pipes. Then fully welded both halves, flattened it off, then welded back together. 
No more leaks and it solved what one of the ticking noises from the motor was. 
Even if these extractors eventually crack or something. I'm still absolutely stoked to have made these myself.




My new fuel rails turned up, but I havent had them machined yet. But fits a lot better. 







Given the available space I think I'm gonna give up on having a front feed airbox.  So thinking dual sides instead.
I guess these could both rejoin around the front and grab some air from on top of the radiator. Or I could have air intakes behind the headlights, and go back to a full height radiator. Which probably isnt a bad plan.




I cant fit the entire thing on my printer but I can do half at a time. 
So just banging one out to test fit.





2GRFSE Scheming 
"Since I am doing this, may as well do this"
Since I need a custom rod for the 2GR destroke scheme.
Has made me consider piston options. 
The factory piston is typical Toyota stuff, fairly big and chunky/strong. 
But for high rpm the lighter the better... No point in reinventing the wheel if something else already exists? 
I found a 94mm piston from a 400cc quad bike that runs 10k rpm from factory. 
Cheap and easily available, and nice and light! 
It has a 22mm pin so might even fit the 2GR rod (apart from that the rod is too short)
So I've ordered one of these to test fit and see what sort of compression ratio will be achievable.



A destroked 2GR doesnt end up tooooooo far off the geometry of the Opel Calibra DTM car which was absolutely hectic.
I wonder if you could grind the journals down to lose another 9mm stroke out of it... Would only need 4.5mm taken off one side I think?

 

 

Just to be 100% clear though, none of the above are detracting from getting the car onto the dyno ASAP! 
Once my ethrottle motor turns up, its ready to go.

2GR Destroke comparison for future scope creeping:

[Roman]

My ethrottle motor turned up, finally! 
I got everything as well balanced as I could then went for a little bit of a trundle up the road.

I have got a few issues to sort out.
I've been stupidly sick with Influenza B though so everythings been happening in slow motion recently. 

The exhaust VVT pulleys end up floating away from target even when there's no duty applied to the solenoid. 
It's unlikely to be an actual problem as people say it tends to like 10+ degrees of exhaust retard anyway.
But it's interesting that there's probably no way I can force the pulleys to 0 degrees at high rpm. 
It's likely just because of the stiff valve springs, or maybe with a thicker oil it would stay on target (using 5w30 currently)
Maybe the chain stretches, or the cam chain tensioner that goes just between intake and exhaust pulleys starts to get pushed in.
I'm not sure why the signals are so jiggly but I can add some extra smoothing to it so the PID isnt going crazy trying to get to target.
Not a huge problem, but interesting that it is a problem

EDIT: A 2GR guy on facebook told me that it helps to set the minimum duty cycle to the solenoid, greater than zero. So will try that.



General engine health:
Fuel pressure stays dead flat, and oil pressure is looking good, at least to ~7000rpm.
As expected, pressure drops off a little when engine is running hotter.
But I've got enough of a shape there to start adding in some oil pressure alarm / shut down features.




I've got a bit of an AFR imbalance between banks still. However at least now I can trim each motor independently as needed.
It looks like part of this is caused by the VVTI PID settings for the intake pulleys not quite being right on default settings, causing airflow differences. 
Again, this is likely due to having much stiffer valve springs fitted rather than junk PID values by default.
Interesting it looks like left and right banks will need different PID settings. I suspect that this is because on one bank, that cam angle sensor is assigned as trigger 2. Then the other bank, its a regular digital input. 
I suspect that they get treated a little different and with different priority perhaps. It will take a little bit of mucking around to adjust the settings per bank and get them tracking nice, but hopefully not too bad.




I didnt do much in the way of full throttle stuff, as was mainly a bit of a shakedown to test a variety of things were okay. 
With the exhaust leaks at the collectors fixed, the car is sounding MUCH MUCH better.
Today is the first time where I've driven it, and come back with a smile on my face because the overall experience was fun and it sounded cool.
It will still sound better with an X pipe and so on, but I'm at least happy enough for now.


Not much full throttle or high rpm activity so far, however the indicated power figures from virtual dyno seem about right for a healthy standardish engine.
More of a health check indicator than full on performance indicator at this stage.
Still need to optimize fuel map, VVT settings, and ignition timing. So should pick up a bit everywhere once all that's dialled in.
No trumpets fitted at the moment either.
The 4GR usually makes around 212hp at 6400rpm and 179 ftlb (at engine)
Hopefully we'll be sitting somewhere around the 250whp mark with the big cams in and a bunch more rpm.




so, yeah! 
On the whole, super happy that things are finally getting to the fun stage of the project.
Where I can road tune it (to make graphs)
and take it to the dyno (to make graphs)
and then take it racing (to make graphs)

And now I can add the cruise control switch back in, which is bloody excellent.

EDIT: I had a reply from one of the 2GR tuner guys on Facebook, who said its normal to need different PID values for each of the four cams.
Even when cams and springs are stock.
So will just carry on setting that up and treat it as normal that they're a bit wonky currently.

[Roman]

Alright! 
So straight after that run, my 2nd ethrottle motor also shat itself. 
Then some other bullshit that we dont need to discuss.

Lets just get straight to the part today where it went for a decent run up the road! 
 

I've still not optimized the VVT so there's still probably a bit more in it up top. 
But the fuel map starts falling off around 8k on factory cams.

This plot below tracks pretty well to my previous run, shows exact same torque figure at nearly same rpm.
The peak torque figure at the wheels sanity checks pretty well against the factory ~190 ft lb at the engine.
Virtual dyno isnt an exactamundo power figure but it's proven pretty decent in the past. 

I need to adjust the clutch, tidy wiring, bunch of other little jobs but generally speaking.

FIZZ LEVEL FOR BIG CAM INSTALL IS SET TO MAXIMUM BLAST

[Roman]

Had a little bit of time for testing today, so did some VVT sweeps to see what sort of cam timing it likes.
So using MegalogViewerHD (Great program) 
Can collate the full throttle runs into a single XY plot. Basically which ever cam timing setting runs leanest, provided the most air into the engine.
The colour scale shows how much cam advance. I only did 3 tests where I added 10 deg timing or subtracted 5 over the base result, so this isnt comprehensive but gets it into ballpark.
It looks as though it still might like a little more cam advance at peak rpm, but I havent tried that yet.
As you can see it's currently hideously lean around 6000rpm either way, so fuel map has been updated to suit.

It still wants 20 degrees advance right to 7000rpm which is a good sign. 10 deg was best result near 9000rpm but 15 deg might be even better.




Thennnnn the bad news... The virtual dyno results from these runs were considerably worse than yesterday.
It was showing around 190hp and 140 ftlb. 
Was this because these runs were in 2nd gear instead of 3rd? Are these the real power numbers? fuck. haha.

Going through the logs, I found that one of the banks had no VVT movement at all. 
So that explains it!
I tested the solenoid, makes a buzzing noise, so working fine. 
Pulled the cover off to have a look, which is probably a good idea anyway after first big rpm buzz. 
Everything fine. Cool.



I looked a little further into the ECU settings to look for clues.
Ahh... damnit. problem found. 



Obviously should be set to "Exhaust RH" not "Exhaust LH".
Previously I was using the default PID settings for the VVT pulleys. 
This was first time where these extra options were shown.

Quick vid:
 

 

[Roman]

"Since I've got the rocker cover off already" 

Escalated into a full blown fuck around for 3 whole days swapping cams over. haha. 




I tested on the factory cam timing, and both intake and exhaust side will end up hitting pistons into valves if run that way. 
So you need to go 1 tooth back on the intake cams, and one tooth forward on the exhaust cams.
Then everything clears. I have a set of pulleys here that are locked in the fully advance position for testing, but it took a bunch of iterations with different pulleys and some lifters locked so they cant squish down.

So this must just be a problem caused by running 2GR cams in a 4GR right? Nope. The 2GR guys have to do the exact same thing to make it clear the pistons. 
It really begs the question as to why the cams just dont come with the pin rotated around, so it all works on factory timing marks? 

I'm guessing they just kept the same cam centerline as the OEM one, then pushed the duration out in both directions. Kinda weird.

Anyway! 

My laptop is dead and its absolutely pissing down for the next day or three so I cant really do anything further now. But it's all running.
Current goal, now that big cams are in. Is to get to @kpr 's dyno and see how it goes! 

It still idles really nice so far without any changes to anything tune related. But cant do any full throttle stuff until I can amend the tune.

 

[Roman]

Dyno Day booked!

I've been doing a little bit of road tuning, however, it's so damn noisy I feel bad hooning around annoying people. 
So I'll sort a quieter exhaust a bit later on. But for now the easiest thing is going to be to go to KPR's Northland dyno facility and try beat it into shape. 
So will be heading there on Thursday which is exciting.

So I've been sorting a few issues.

Yesterday I had a heart stopper when I realized that one of the VVT pulleys wasnt moving at all.
It was one on the exhaust side, and I'd not entered any values into that table yet.
The solenoid was good, wiring was good(well, functional), cam angle sensor was good... But no movement. So could only be something mechanical. 
Thinking back, I realize I made a mistake which jammed the pulley into place. I did similar on the 1NZ, but, it's a lot easier to access the locking pin with the 1NZ pulley while the pulley is in place.
Thankfully by blasting some compressed air into the chambers, and doing a dodgy partial disassembly while in place.
I managed to unjam the locking pin.
Big relief as I do not have the brain juice at the moment for completely pulling this motor apart again.
So fingers crossed everything is good for Thursday! 


How's it gonna go?!

I've been talking shit about this project for the last few years, running to 10k rpm and all that.
This is pretty much the point where all of the main ingredients of my initial concept are all in place. Exciting!
But I'm also nervous about whether it's going to fall on its face or just blow up again or whatever. Haha. 
If the powerband at the moment isnt supporting mega rpm I'll not ring its tits off just yet.
After all of the work on this and headaches getting this far.
I at least want to drive it a bit and get to some events. 
I am mentally drained from project work. I want to have some fun with it finally.

My gut feeling for this first dyno run: (aka preloading with excuses)
-My intake runners are probably a lot too short. I've done the best I can while trying to not hit the bonnet, but it's probably going to perform significantly better with another ~200mm of intake length. 
I dont have enough time to print some other runner lengths up to try.
But, regardless. I am just super keen to get a baseline result recorded. 

-I suspect that having the cam timing 1 tooth back is going to be fairly punishing on midrange power, so it will probably have the cam timing maxxed out at 40 degrees for a fair bit of a the powerband. 
Hopefully not, but will be interesting to see. Longer runners might address that even with the cam timing position where it currently is.
Again, it's something I can improve on later but it's a hell of a lot of work to fit the right sized stoppers in the pulleys, to run them on the factory timing marks again.

I am Hopeful that it will have peak torque at or higher than 6000rpm, and peak power 8500ish or higher. 
So far it's felt really flat with the new cams, but, I've not done any further driving so the cam timing has been dreadful. So makes sense.

Anyone want to pitch in some guesses?
Hp@rpm and torque@rpm.
Closest guess wins... ahh... some broken engine parts that I'll leave on your doorstep.

I am guessing ~250hp @ 8500   180 ft lb @ 6000



 

[Roman]

Dyno day was great! 

TL;DR: 220 whp with a few issues, lots of 9000rpm runs, needs a few changes made
 

The day started out with investigating a bank to bank AFR imbalance, which turns out was caused by me not plugging an injector on properly. Woops...
Then we tried to do some VVTI timing sweeps, starting from zero degrees advance and run it in 5 degree increments. 
Nope. Absolutely not. Haha. The cam timing at 0 degrees advance is so bad, that the car can barely even spin the rollers.
So we put in a starting point cam advance map and went from there trimming it up and down.

As expected, once the ideal exhaust cam angle was found, it was pretty pointless moving it around any further.
But now I know what sort of angle works for that. 

We did a bunch of runs getting the fuel and VVT dialled in, and was stuck around 200whp without the ignition timing optimized. 
Then added some timing, and was up to around 220. Which is still a fair bit short of expectations. But it was revving out nicely to 9000. 
No point going out past that (yet?)

One of the issues that I was somewhat expecting, but not this bad.
Is that the intake cam timing is pinged right to maximum advance right up to 6000rpm. 
So everywhere below that, it's losing power currently. So I'll need to retime the gears and put some stoppers in. But it's an absolute prick of a thing to do.

Thankfully KPR has a absolute plethora of intake trumpets lying around so we bodged some stuff together. Haha.
Some amazing results with the long trumpets! 

Gained 15kw at around 6500and some gains through most of the powerband.

I suspect part of the reason it picked up so much though is that 6000-6500ish and below is where we cant advance the cam far enough. 
So with a little bit shorter runner it would probably/maybe be starting out from less of a bad spot. So you wouldnt necessarily see that 15kw jump as the worst result improves.

 

The longest trumpets were 195mm, and next size down was 100. So it looks like a 140-150mm trumpet will plonk that big torque blob right onto the 7000-9000rpm region which will be great.
But we didnt have anything to test at that length. So it's on the to-do list. 
It's really good to now know what it likes for overall runner length.
As now I can plan around that if I need to make any major revisions to my intake situation.
I've got some gross transitions from ITB to the head, which I suspect is possibly also a limiting factor at the moment.

There's been so many different elements to get this motor in the car and running, that it was honestly great to have a full day of wailing on it and nothing go wrong. Even if power was not quite to expectation yet.
That's how it goes with NA motors though, needs testing and sometimes lots of revisions to get things right. But this is coming right into the fun part of the project for me.
Bloody good!

All of the tuning was done in 4th gear, but 5th is 1:1 ratio where you have a bit less drivetrain loss.
So it had a final run in 5th gear, but the roller speed got too high near the end and dyno didnt like it. 
But makes the numbers look a little better. Haha.


 

[Roman]

Alright so whats next? 

With the Echo, I tried a whole bunch of different intake runners, and found that the motor was fairly insensitive to it. 
Like you could change the runner length and see differences, but then once you move the cam timing to suit. It was like you're 99% back to normal.
I was kinda figuring it would be the same deal here, and this is part of how I've shot myself in the foot with the overall design of my intake.
As I've committed multiple sins to try and get the throttles sitting below the bonnet height. But there's no point in this anymore, as the runner length it needs is stupidly longer than that.
I was so surprised to see a 15kw jump from runner length!
It was so cool to see.

One of the issues that I caused for myself, by trying to fit everything under the bonnet height.
Was trying to get the BWM throttles mounted as low down as possible. 
So my intake manifold transitions from a very oval shape, into two separate almost rectangle shapes. In only a very short vertical space (about 22-25mm ish)

So I've actually got a fairly gross transition happening here, which is I'm guessing part of what is limiting the high rpm situation at the moment. 
The throttles acutally have a 48mm or 50mm throttle plate, which is fine. But then taper down quite hard towards the exit. 
48mm throttle should be okay, but not a 42mm circle area at the exit. As well as a bunch of gross transitions in multiple planes.
This is the shape inside my manifold:






So I guess my options are to see if I can bore out the bottom side of the throttles to a larger shape, or, bin them and try something else. Not sure yet. 



Some other interesting things noticed while sifting through the logs. 

Exhaust VVT doing pooz

One of my exhaust VVT pulleys has a spaz at low rpm, and comes right when there's enough oil pressure. 
I can probably get it to work by further tweaking PID values on that pulley, but, the fact it's so different makes me think it's probably hosing more oil out than the others.
(They naturally leak oil during operation)
The motor was fairly insensitive to exhaust cam timing, and we found what was about the best spot for it overall.  
So I'll probably just put some fixed timing pulleys on it, as this eases my headache of piston to valve clearance on that side, for an amount of advance that it doesnt use anyway.

The other three were tracking nicely, but this one was a bit dumb.

Battery Voltage

My battery voltage is doing weird stuff, seems to nosedive at 6700ish. Maybe it hates spinning faster? Could make an underdrive pulley for it I guess. Although I'm not sure if I can get the diameter too much smaller without causing belt slip.



Some of the 2GR guys have said they dont see their alternator doing the same, when doing more than factory RPM. So could be a wiring issue or something.

Oil Pressure
With the 2ZZ engines, there's been a history of oil pump issues (sort of, sometimes) 
So it makes sense to fit an aftermarket billet pump and I'm all for that. 
Good investment as it's cheaper than a new engine, and solves a known issue. 
What I'm not sold on though, is just throwing money at parts when there's no case to justify it. 
I dont think there are any documented cases of the GR engine oil pumps having issues like cracking.
There's no pressure drop either.
All of the 2GR people in FB land are in a big fizz currently about fitting an aftermarket oil pump.
Now that one has been recently released. 
But I'm not seeing a good reason for it.
And most of the 2GR people are worried about doing 7500rpm or something Haha.
Maybe if my pump gear eventually fractures, I'll get one.
But stock looks fine to me so far. 




Hydraulic lifter situation 

It's very hard to diagnose issues with hydraulic lifters squashing down from the force of stiffer valve springs and/or more rpm. 
I'm not sure what I can do to check it apart from watching it with a camera perhaps. 
But that's not going to be very practical. 
The GR motors have an almost identical valvetrain layout to the Coyote 5 litre DOHC V8 engines. Which are popular in America for tuning up, and some guys are running big rpm with them. 
Which is great because a lot of their testing might be relevant information here. 
The Coyote hydraulic lifters are a direct swap fit into the GR motor. So any of their solutions for solid lifters or whatever is likely the same deal. 
I'll do a bit of internet sleuthing to see if I can find any articles about before/after for those guys switching to solid lifters.
Then maybe there's a product I can just buy that will work straight away too.
If they cost zillions though, maybe I'll just try make some or look into making solid ones out of the dozens of hydraulic ones I've got sitting around.

Standard heads this time 

On the first motor I spent ages porting the heads, and it seemed like it would be very worthwhile. As the cut to the port / seat is absolutely shocking:




But with this 2nd motor, I didnt want to reuse the old heads, and decided too much work right now to port them. 
But I'll do that at some point, at least around the bowl area. Probably only bother with that gross stuff on the intake side this time. The rest wasnt so bad.

Overall there's still a lot of scope for improvement here, so I'm not super disheartened about ~220 whp. 
In saying this though, since the motor plateaus at 220 over several thousand rpm. It will be pretty much bang on that for an entire gear shift.
But it will be better when its a bit pointier up towards peak rpm. Haha.
It's still about 40hp better off than with the 2 litre motor in the car, and average power will already be considerably higher as it doesnt lose power on gear shift. 
Will keep working on ramping these numbers up though! 

[Roman]

The BMW throttles, I'm definitely not going to be able to get them bored out enough to be worth the trouble. 
Even if I do, they wont fit on my manifold anymore. So either way I'm remaking stuff. 
So probably end up hanging on the wall of shame and/or onselling just the throttles etc.
Anyone want some? Good for a smaller CC motor with a more normal port shape.

Anyway,
I'm back to the same old same old. Trying to solve throttle situation.
Looking on ebay, aliexpress, where ever else.
Seeing if there are any good solutions for a decent throttle size I've not thought of yet. 
Doesnt look like it, just circling the drain again...
Until! Holy shit! 
How absolutely perfect is this. 



It turns out that OBX has apparently shut up shop.
So they've got a bunch of stuff on ebay for half price. 
Their full 350Z kit is fairly garbage because the cast lower manifold part doesnt fit properly, and so on. 
But they obviously have a whole bunch of the throttles on their own to sell. Sweet!

51mm throttle set! For fairly decent price for brand new stuff. (about $700 landed) 
I'm perilously broke in terms of car budget right now, but this seemed too good to miss. 
So I've borrowed some $$$ to make sure I didnt miss out on getting a set.
As I've not found or seen anything else that was going to work very well. 

I've started modelling up a new pair of manifolds which will fit these, and cross them over running flat. 
This is so far working out really well. 

-The angle of the runner into the port can now be absolutely excellent, with no horrible transitions or shape changes. 
-Bonnet height is not going to be an issue at all anymore, not even close. 
-I can have as much room as I could dream for, for runner length, outer injectors, dual stage runners, or whatever other obnoxiously unnecessary crap I can come up with. Awesome!
-I've wanted to look at the idea of fitting small, well atomizing injectors in pairs per cylinder. Having one spray down each separated port. So now I can easily fit a fuel rail in the right place to do that.

I was running to 79% duty cycle with the 302cc BMW injectors. 
So fitting a pair of injectors from a prius or similar which are around 220cc. But have zillions of tiny holes (16 I think) 
means atomization should be incredibly better. Which will likely be a helpful attribute when the injectors are still a fair distance from the valves. 
Instead of 4 injector holes per cylinder, it will have 32. Bloody good. Haha.

This solves an incredible number of my problems all at once. 
Still a few things to sort out. But should be good! 

Will be exciting to see the difference on the dyno from last time. Will get a variety of trumpet lengths printed before the next trip up.
Wont be any time too soon though. New manifolds and fuel rails (again...) is a fair bit of pocket money.
But this feels like its heading in the right direction.