Roman

I really like what you're doing with the new engine. But I think you may have gone a bit far with lightening the crank

Starting on a new mould for some 4AGE ITB trumpets but learning from some previous mistakes. Problems from the past are that I've had too little draft angle on some parts that are quite long. Also that some of the excess untrimmed parts end up folding over something and locking the part in place. Also trying to use only 2 pieces when theres no reason not to use more if it makes life easier. Annndddd I think it will be a good idea to add some tabs so I can twist the halves relative to each other to try get the part free. Previously I've damaged the moulds by needing to smash a screwdriver in (or whatever) to get the halves apart. Hopefully this will help! I'm hoping I can make at least four, or even eight from the one set of moulds. I'll also try drill some little holes in the moulds, fill them with wax and then so afterwards I can use some compressed air to blow the halves apart hopefully if they are stuck. The center part of the bell shape still needs to be dissolved out, but cant think how else to get that sweet sweet return angle on it. Worth it... Fingers crossed! Fingers crossed!

I've modelled some different bell shapes before, and compared to ideal they all get Vena Contracta a whole bunch more and reduced flow. But the flow rate at which it happens to a large degree needs to be very high. They way I figure it, if a cylinder is 500cc then an intake runner just needs to provide 500cc of air before the valves shut, then it has the whole rest of the cycle to "recharge" So a poor shape is probably less of an impact than if it was steady state flow like on front of a turbine or something. To be honest I have no idea if this will be any better or worse but that's the fun Thankfully in this case the numbers for fuel to reach AFR doesnt leave much to interpretation so its easy to compare. Especially if peaks and troughs move around. The idea is to have enough combos ready to try out that I can put together quickly for a dyno session to do some comparisons.

Thats some sweet power, love the airbox setup! Do you know how long your total intake length is, down to the valves? Also interesting that with an engine with totally different (everything) it still comes on power at around ~5300rpm.

Soooooo for a while now I've had an obsession with getting a "proper" bellmouth geometry on something. I successfully made a big one for the big single throttle but I really need a different radiator arrangement to make it work so its been on the back burner. But the geometry to give completely straight flow is massively massive compared to what is usually used, so its a problem when you have 4x throttles close together. With the space that is available, you have to trim down the sides of each trumpet by this much to fit 4 alongside each other. (Obviously dont need to trim front or rear but lazy modelling) So it looks like you lose most of the useful area of the bell... And looks like it would be prone to "stealing" air and maybe fuel from adjacent cylinders? Not so good. Probably better just having a smaller radius on each. Either way, I printed out a full sized bellmouth (without trimmed sides) so I can size it up in the engine bay. As it turns out that thanks to having a brake booster I've got zero room for a trumpet this big anyway on the rear and hitting the bonnet on the front will be a problem too. I've seen those cool kits where people have all of those parts you can clip together to help build an exhaust manifold. So I thought I'd try the same thing here but for an intake. So printed some parts so I can try some combos for a single runner. Base piece, a bell, 3 x straight 20mm sections and 3 x 10 degree sections. Also pictured is the bellmouth provided with the ITB kit, for an indication on how rediculous the bigger one is haha. Unlike those fancy exhaust kits though mine doesnt actually clip together because aint nobody got time for that. Also, turns out printing the straight ones was a waste of time as there's not even enough room for just the bends. Neither front or rear really fits. pooz. So I'm reprinting the bend parts with 15 degrees per segment and a bit tighter radius to see how much that helps. Based on what looks like will fit though, tipping the trumpets slightly towards the front of the engine bay is actually pretty cool because it allows more useful bellmouth area per runner. A lot more! Most of the air comes from around the sides rather than straight ahead so will be interesting to see how this goes. The question is, is the efficiency gain of the big bell worth the efficiency loss from the bend. And is the bend worth the extra runner length gained. And does any of this make a difference when you're trying to wheeze through a 45mm throttle. And the biggest question of all, will I actually finish making any of this? Some preliminary nerding seems to look like the bellmouth partially shrouding the entrance shouldnt be an issue so long as there's a bit of gap. The colour scale on this, red is 101.3kpa and green is 101.0kpa so pretty minimal loss hopefully EDIT: Just found what the factory BMW S14 engine runners look like, makes me feel like I might be on the right track. Even if the big bellmouth isnt necessary, perhaps there is a real life benefit to having them staggered to allow more clear air around each runner than you can get with straight pipes that are butted up to each other.

Great stuff! Now the fun part begins

Hahahaha looking at some sweet sweet waveforms while driving. The dream

Yeah partly because this adaptor retains the first part of the intake manifold. So its ports > ali manifold > adapter > throttles > trumpet Which isnt a bad thing as that first part of the manifold handles the transition from circular shape to the port shape and does a nice job of it by the looks.

Current manifold lengths as follows: Valves to end of adapter: 205mm Throttle body height: 74mm Trumpet length: 83mm Giving a total current length from valve to bellmouth of 362mm Which is surprising! A lot longer than I expected. The standard intake manifold is approx 40-50mm longer than this (with a bend) Can easily go another ~70mm longer if I put about a 30 deg bend in the runners to avoid the bonnet. So will give this a hoon.

Just been thinking about this over last few days, even though I have comparatively heaps of space I want to try runners as long as I can so space is still an issue haha. Just been thinking, perhaps you could solid mount your airbox to the body of the car, and then just have some rubber gaskets around the trumpets so they can move relative to it? Thinking I might do something along these lines, probably easiest way to ensure theres enough space around the brake booster etc.

Thank you! Yours seems to have the 5500rpm curse as well. Haha. I think we have definitely established a trend here. Also I must disclaimer that since im using a redtop engine its lower comp, slightly less aggressive cams and no exhaust vvti. So its not exact apples for apples but results still applicable if not magnified for a dual vvti engine.

Without a throttle body in the way will also be interesting to try so different inlet pipe diameters and lengths. I think i remember glenn saying around 4" dia was best So much to do so little time! Start with the trumpets though

If you have two cars but largely the same except for engines, then they need to be different enough that its not a hard decision to take which one for a drive. I dont think a v6 turbo isn going to feel hugely different to a 1uz in terms of power delivery etc. Turbo rotary and then each car has its own completely different charm! or a high strung turbo hyabusa engine or something. Something as completely different to a 1uz as possible.

Yep im keen as to try staged injection again, as i can print some trumpets with injector bosses in them. 100% keen on a carbon airbox too, if a small enough pipe works nice to allow a maf it will be on there for sure! Then i just need one of those bmw ethrottle motors and ill be back in business.

That would be really intetesting actually, or even per cyl map sensor that can see when the pressure waves peak relative to tdc... might give some clues to best cam angle when a maf isnt available. Im hyped on some runner lenth experiments right now though! 17kw gain from runner lengthening is a crazy big improvement.

I still havent had much time to play with the tune more, but got it tidied up a bit. Basically it still just falls on its face at around 5500rpm. After refining the existing map a bit more though I am less convinced that cam timing is going to help that hugely. After its peak at 5500rpm it loses about 11% cylinder fill by 7500rpm, which is an uncharacteristically aggressive drop in torque. I'm getting more convinced the throttles themselves are a mass flow restriction, and this is why torque drops after this point. But it could be something else too. Possibly the stupid inlet/outlet shape on the blacktop throttles causing turbulence or something. So thought I'd head to the internetz and see if there are similar trends on other beams ITB setups using blacktop throttles. This is the first result I find... 180hp ATW with the peak torque at 5500rpm falling on its face after that. And comparatively garbage below 4000rpm too. Almost exactly how my setup has responded! I'd describe as "small to medium length" trumpets fitted on this one: Second result that I looked up looked almost identical to the above... Hmmm. Around about same length trumpets too. Found another link which didnt have RPM scale on the dyno, only KPH as was rolling road so cant tell what RPM things are happening at. But it looked to have initially results similar to the above. But then they put on longer and longer trumpets made more power everywhere. Ended up with a 17kw gain using 110mm trumpets after starting with 35mm. So I think I'll try print some trumpets as long as will fit. Will add a curve if need be. Another thing which is quite different to the plenum setup. On a stinking hot day with the air being drawn from right at the back of the hot engine bay it lost considerably more power to heat soak. Like, Virtual Dyno and fuel map says 25-30hp kind of loss. Really flat power from then onwards yuck. I'm not sure if that can be completely accounted for just from reduced air density, but somethings making it lose a lot of power when very hot! Is this all dissapointing so far? No way, all the indicators are there that there are good results to be found with some further testing. I know the engine has the cams etc capable of making max torque up to at least 6500rpm - There's likely just one variable holding it back currently. It might be the throttle ID, it might be the trumpet shape, it might be the overall intake tract length, or lack of airbox, or something else. All of these things I will be able to test and prove/disprove one by one. What a time to be alive / have a 3D printer

Haha yes I see... 94 KPA at only 34% throttle hahaha. Needs a MAF

Thanks. Looks like my wideband is starting to pack up, tuning from a fresh start is always hard on them. So no more ITB progress for a while, but so far it's looking like standard plenum might still be the winner by a smidge. I dont want to make any sweeping statements just quite yet though. As it might pull a few tricks out of the bag once the cam timing has been optimized. Getting it right for the standard plenum makes a huge difference in airflow through the powerband, so I wont be surprised to see the same here. It's a bit trickier doing this without a MAF but still doable. I'm looking forward to seeing how different it might end up (or not) Excited to try some different runner lengths and different style bellmouths though!

Okay so I've always been a big proponent for the factory inlet manifold, as, well, it's a bloody good design and most people just get rid of it because they cant fit it, or they think its ugly. Both of which are valid reasons, but both of which do not apply to me because it fits and I dont care. However! The GC @NicT has a 3D printing company called https://www.facebook.com/volumetricNZ, and makes some nifty manifolds and trumpets, printed from some fancy pants Carbon Fibre Nylon material. So here we are: The saddest part was having to unplug about 6 sensors in order to make this work haha. So the basic gist of the setup now, is: -Modelled fuel equation, differential fuel pressure taken from fuel pressure sensor and MAP sensor -MAP sensor connected to one throttle body only -FPR connected to one throttle body only -Brake booster currently disconnected from vaccuum (This shall change because its bloody scary) -No MAF or Ethrottle or cruise control (Blargh) So first impressions are that this has increased the volume of my car by at least double It's unsociable to say the least, hahaha. You can hear exactly when the cam starts to advance and introduce overlap as it gets about twice as loud again! Which I guess makes sense as there's an accoustically open path to the exhaust manifold when overlap is present. So I've given it a quick tune up, and there are some interesting observations. (By which I mean uninteresting graphs) Firstly, having the MAP sensor connected to just one TB is an absolute shit show. Because of the individual pulses in it, the MAP signal under steady conditions looks like this: Since this is something that happens once every 720 degrees, the severity of the pulses diminishes with RPM, and also goes away as the throttle opens (which makes sense as this reduces the amplitude of the pulses when there's less vaccum) So on this graph the bigger the bulge is up and down, the worse the problem is... Can see it's mostly stable by say 30% throttle Then if we look at an RPM plot we can see we're needing to go to around 5000rpm+ in order to get a stable MAP signal. It was quite funny, my Closed Loop Lambda wasnt working because it has a TPS delta threshold, it would only start working above around 6000rpm. So if wanting to do a TPS / MAP blend, I guess you'd need to only use the MAP in high RPM or high load regions. What is also interesting is that people report that with ITB you dont get very good vacuum signal generally speaking, which is why MAP sensor sucks with it. When connected to 1 runner only this is very much not the case, it pulls better vaccum than my plenum does. Right down to ~20kpa! But as per above it's MAP quality that's the issue. When teeing all 4 into a vaccum cannister you average out the signal but it also ends up a lot lower I guess. Also, I've had to forgo my lovely smooth looking MAF based fuel map, and go back to an Alpha N abomination which I guess you could just say is typically ugly for that load axis. Still very much a work in progress, but you can see pretty clearly how with ITB above a certain throttle position you're almost getting a full amount of air already. In this case the kink happens somewhere around 40% throttle, so I'll add some more resolution to that area so I can smooth the curve a bit nicer. Another unexpected thing is that it looks like max torque is now around 5500rpm, previously 6500ish with the plenum. People talk about ITB being for high rpm power but this looks like either it makes good midrange :OR: it's a mass flow restriction at higher rpm and power tapers off at that point. Still cant draw any conclusions on that one until I've refined the map a bit. One thing that's clear from looking at the logs though is that the cam timing wants to change. I see dips in the fuel logs which correspond to high amounts of intake cam advance. The standard plenum loves having right up to 50 deg cam timing it looks like this is going to want 35-40 max. All of the places with the high overlap/advance and it starts losing power. I think this is why there's the dip after 5500rpm onwards, too much cam timing everywhere. Not sure why yet. But I'll do a full sweep of cam angles and see what it shows. Maybe draw a graph? Who knows. According to Virtual Dyno, at current point in time it's making somewhere in the region of 180hp ATW at 8100rpm and max torque at 5300rpm. Which seems about right . Will see how it pans out with some cam timing optimization, looks like there's still something left in it yet. The overwhelmingly standout thing about this though is just the absolute bloody racket it makes. haha! It drives surprisingly nice at part throttle, but if I'm going to keep ITB I'll need to figure out an E-throttle solution. Cant go back from having cruise control then losing it. TL;DR: Added some things and make a bloody racket. Engine bay still looks like shit. Car still draws graphs.

^^^Thats pretty much everything you need! Just need to know which byte of the can frame is the ID, probably 7 if 0 is already info. In other news, read a really good tip to stop those infuriating situations where you use = instead of == If you mean to write: if (engineSpeed == 7) But you accidentally write: if (engineSpeed = 7) Then you're in the shit because it makes the Engine Speed 7. But if you swap the order of your variable and the constant: if (7 == engineSpeed) Then if you accidentally use if (7 = engineSpeed) 7 can never become your variable so the code doesnt show a positive result 100% of the time. I have screwed myself over with this one, multiple times hahhaa.

When I went to the dyno I found absolutely nothing adding a whole bunch of timing all through the rpm range, and not a single blip of knock. When I had staged injection running with a blocked injector it just wheezed but nothing blew up. This motor has put up with heaps of punishment haha. Youre right there are no knock issues on my engine with 98 so I might need to run on some 91 to torture test it. Triggers and RPM are nice and stable!

It's also a bit of a moot point as I can run 50 deg timing well past MBT and not get any knock during cruise conditions. God bless lean burn haha

Yeah well another annoyance is things like cutting over ripple strips at trackday can trigger knock sensor. Audio detection of knock is a bit ghetto really which is why I'm really hoping I can see ion sensing data with some decent resolution. My understanding is that some modern BMWs have a knock detection system that uses just ion sensing. Some preliminary looky-loos with a scope have shown what looks to be indication of knock on the coilpack return signals. But useless if you can only see it on a scope and not in a device which can process it! So just need to make some more progress on hooking it all up.

Not using Speeduino but I've got a spare Teensy 3.6 here that I've mounted the audio processing board on. Will fit my spare canbus backpack on it. Will be able to use the audio processing for some knock detection, and hopefully some ion sensing with a burst reading on the ADC on a single cylinder just past an ignition event. Hoping there's an rpm/load range where there's something interesting from the ion sensing, at the resolution and frequency I'm able to measure it. one thing on the Link G4+ I've thought is a bit so-so is its knock detection. I think its silly to detect knock, pull timing, and then just slowly creep the value back up until it knocks again then do same thing over and over. Like it never builds up a "smart" table it just does the same dumb thing over and over. IT might knock on the same load/rpm 1500 times and it will never change its behaviour. Even if you never turn the engine off (it doesnt store the table) the table it generates even if you ran the engine for say 10 hours doesnt actually show you anything useful as it might be half way through its pull knock / advance timing again in each cell. So I want to make a long term trim table for knock like OEM stuff does. Every time it registers short term knock it will take say 0.5 degrees off the long term table. Then the next time it gets to that same region it is already 0.5 degrees less total timing instead of just banging its head against the wall over and over.

You only need to know the can frame id that contains vehicle speed, and then which of the bytes contain speed. As this is the only one that yku need to pick out to modify. Everything else you can just tell to pass straight on through as is. Keep in mind that you also need a transciever on the teensy to interact with canbus. (Sounds stupid and it is)There is a dual can backpack board available for it if you google.