Roman

Does a flat six actually have any reason to sound different than a straight six? 

As in, arent they both even firing order? 

Wonder if the "flat six sound" is more "air cooled sound" 

Hello darkness my old friend (entropy)

I think black holes form in the universe, when someone figures out you can connect an alternator up to the wheel, that then feeds its power back to an electric motor that spins the wheel 

Your car has a way bigger engine and an equally big turbo hanging off it.
I think the only way you'll be seeing my tail lights, is if you're parked behind me when it's blown to smithereens. 
 I'll be absolutely over the moon to just get the car down the end of the strip to be honest.
I'm not sure if I'll be able to fit the big cams in by December as there's possibly still a few curveballs to contend with.

I think drag racing is one of the few things where sometimes it feels like you're missing out when you're participating.
Because when you're lining up you dont get to watch all of the other cars run.
Super keen to see yours there!
God I cant wait to get to the point where I can hoon nightspeed events and do some track days again.
I'm only about 35 minutes away from Hampton Downs now, and about 40 to Meremere.

New exhaust sounds legit! 

Excited to see this back up and running again, so much cool South Island stuff to do. 

Reckon you'll run it up Coronet Peak? 

 

Must feel nice to ask someone else that for a change

Will require some sort of positioning signal, as otherwise it doenst know the frequency of firing injectors.
However are you wanting to use one for something else? 

You could probably put it into a test mode or generate a fake signal easy enough.

For now I think I'll just leave the alternator where it is and work around it. 

Relocating alternator can maybe be a future-Dave scope creep activity.
Once I've got a 2nd engine and some garage space I'll do some scheming. 

Looking at my manifold on the drivers side, I keep wondering if it's long enough... seems short. 
Think it's something like 980mm per runner, give or take. 

But then looking at how far back I'd have to run the manifold on this side if they go straight back, it's huge haha.

What I'm currently thinking is that I'll try take up as much space as possible still in the engine bay by running the first pipe as far foward and down as I can. 
Then the second pipe can sit on top, so the third pipe can extend out further so it can run past the other two to make up the length. 

But I've run out of straight sections so will need to order some more.
Bend #2 might need to get a bit wiggly to get enough length in it.

@h4nd Seems like a belt slip nightmare. Same belt has to run the waterpump, so not keen on any risks. 

Will just make the manifold work around it. 

As per the Echo having your day ended because of alternator or waterpump problems is a whole bunch of no fun. 

Ahh yeah! 

HKS does quite a few with that design:




Something else interesting that HKS does, is they make 4-1 manifold for the Altezza that links the pipes together into pairs.
Not sure if this is some sort of tuned length thing, perhaps it makes it behave more like a 4-2-1. 

But interestingly it's linking the cylinders which are not 360 degree separated. (should be 1&4 and 2&3 if evenly spaced)




Then even further off topic, but the S1000RR bike has exhaust valves that open or close based on rpm, that link pairs of cyls together.




It seems that HKS is the biggest mainstream sort of company that has experimented with this kind of stuff. Might be interesting to have a dig through their back catalogue. Seems the "HKS hi power" ones usually have that design.

Those pistons turned out so cool.

Cant wait to see how this goes! 

Yeah agree. Im sure there is many an engine that has gone boom when the water ran out. 

Just another cause of engine anxiety! 

Yeah 100%
A lot of the vitz bolt on supercharger kits are non intercooled, and a similar design to SCs I think...
they run so damn hot that they end up making about the same power as a standard motor haha.
They absolutely fly once a water meth setup is added, but it's a whole lot nicer and easier to just have a good intercooler on it.
 

Yeah stuff like that is perfect use for it. 
You should check out what Matt Gill has been up to, he's been seeing how far he can push the SC12 and SC14. 
His SC14 setup ran a 13.6 at the drags on a 195 street tyre which is awesome!
Must be making some good power, think he said he ran a 105 or 106mph over the line when the car was colder.
I've always shit talked SC12/14 setups but he's making it work really well.

https://www.instagram.com/garagedori_nz/

27 minutes ago, Rhyscar said:

Yeah I was wondering how that might change it. So say your Lambda is still on target (around 1 for example), but ignition timing is too advanced and you're not getting complete combustion, then in reality what the O2 sensor is reading is mostly combustion in cylinder (say 80-90%) and the remainder in the exhaust manifold with whatever air is left over... Wouldn't that provide some real weird/unstable Lambda readings? 

Bit of a tangent, however, thinking about that further, it's interesting to start understanding how wide the tuning window is in a lot of non-WOT scenarios... because coming in/out of corners or balancing the car on the throttle is such a common occurrence that it would make sense to optimize that for the WOT that comes after it. My experience racing tells me it's the bit before/after WOT that sets good drivers apart from average one... So given the choice, I'm picking you want to keep fuel as rich as possible without power loss.. but what is the 'ideal' end of the ignition range for partial throttle? Retarded or advanced?

I dont think its a case that there is still oxygen present by the time the air/fuel comes past the sensor. 
So much as that a motor never capitalizes on 100% of the expansion energy from the gas. 
Which starts expanding once it's ignited, but doesnt stop expanding until well after it's left the engine.

Like if you took a 500cc combustion chamber's worth of air and fuel. When you combust it, the air and fuel wants to expand to a size of say... 3 square meters (or whatever)
So to use all of that energy you'd need something like a 10 meter long stroke length. 

So thats part of why even if your ignition timing is optimized, exhaust gas still comes out with lots of energy and is hot loud and chaotic.
When you retard the timing you're pushing the expansion curve further out the arse end of the engine. 

In terms of ignition timing, and part throttle. The more densely packed the cylinder is, the less time it takes for the air/fuel mix to ignite from one molecule to the next.
So to get the peak pressure happening at the correct time (about 14 deg ATDC) you need less ignition advance when the cylinder is fuller. 
As you reduce the amount of air and fuel in the cylinder, by closing the throttle a bit more. You need to increase the timing to account for that it burns slower and expands slower.
So just try think about it that way, best ignition timing is always just to get the strongest pressure happening after TDC - You only ever ignite the fuel before TDC because it takes so long to start expanding.

Getting the part throttle tuning right is absolutely critical for the crisp throttle response.
With e-throttle it's easy, as you can just set it so that 100% pedal is only 80% throttle, and do some runs exactly the same each time and dial it in. 
However it might be useful to make some mechanical stoppers for your pedal or throttles so that you can get some repeatable results for tuning part throttle.
When I had the echo setup with lots of repeat runs on part throttle, it was insane how much more punchy the car was on transient conditions.

I would be looking to optimize ignition, fuel, and cam timing everywhere you can for what gives the best power. 
Then if you do feel like trimming the power back out of it, I'd keep the VVT at or close to it's full throttle angle, because there is some mechanical latency. 
But then just trim some power back out by pulling the ignition timing out a little. 
But I doubt you'd need or want to do that.

8 minutes ago, Rhyscar said:

I'm pondering if I make a change to my exhaust. Its not very loud, but god dammit its raspy. If a muffler can tame the 3S rasp then it'll make any car sound good!

It might sound a little different once you get the fuel and ignition dialled in a bit better. 
As if you have too little ignition timing (which is safe place to start for tuning) then there is more gas still expanding and with lots of energy in it while coming out the exhaust.
Probably wont solve the issue enough to your liking but you'll probably notice some amount of difference.

57 minutes ago, GARDRB said:

Would printed flanges with 50mm of the initial pipe integrated that you could slip your tube into make sense or not financially viable?

This might work if I knew exactly where my pipes need to go. (in terms of angles etc) 
But it's been too hard trying to come up with a design that works made from regular bend sections in a model. 
I dont know the actual orientation I'd need, one of the pipes needs to start its bend as soon as possible so that would need to be incorporated. 
This new flange though will make life waaaayyyyy easier than before.
Especially once I've got one runner down to the collector fully made. 

This is another awesome sounding one, a destroked BMW straight six... But this one is turbo so once again its throwing out Maester's rule book on what's needed to sound high pitched. 
I'm still both excited that the Carina might sound cool at full chat and also terrified that it's going to sound unfixably awful for some reason.
Seems like a real lottery! 
 

Yeah metal printing would definitely be cheaper for some of those parts! 

Looks like their collector was metal printed? Or cast maybe. 

A good trick for idle stuff that someone told me.
Is to give the engine enough air to get it cold starting at the rpm you want and at the air/fuel ratio you want. 
Then when it heats up, pull timing and possibly fuel out until the rpm drops to your idle target, rather than reducing the air amount.

This way as soon as you put your foot down a little, like to roll off the line.
You've got a lot of torque instantly available so it stops it bogging.