Plenums, Do They Run Lean On Rear Cylinders?

[Redback]

Well I think im convinced. I just ordered a Plazmaman Plenum. Thanks for the info guys.

[F6R]

Not done it on one of these yet, as the provision to 3D trim the cylinders is not there yet, and I dont know if it is even coded into the oak. There is no closed loop individual lambda trimming to the best of my knowledge, but there is individual cylinder knock control.

The The last GTR I did which still ran the stock intake went like this:

Cyl 6 needs an increase of 6% by 5000 at 200kpa abs and 12% by 8000, but needs a reduction of 16% at 50kpa abs below 3000 tapering to zero by 150kpa abs and 5000rpm

Cyl 5 needs a reduction of 12% at 50kpa abs below 3000 tapering to zero by 150kpa abs and 5000rpm

Cyl 4 is neutral

Cyl 3 needs an increase of 3% by 8000rpm from 5000 at 200kpa

Cyl 2 needs 5% by 5000rpm at 200kpa and 9% by 8000 at same pressure

Cyl 1 is neutral

This sorts the fuelling out. There is still cylinder temperature to deal with, which I use high speed EGT's for.

Edited 13/10/10 06:42 PM by F6R

[Boosted1]

aaron from DTM in geelong has a turbo EL falcon, he has done individual cylinder sensors on his exhaust ports. I beleive its for two resons mentioned above. but would this only be nessasary if you are pushing the upper limits? ie 500>

[IH8TOADS]

F6R the PCM does both, it's there. Rapid the BA/BF has that table but I wouldn't touch it unless you have data to back up why you're making the change.

[DUS12]

I got pyro bosses in each runner, dont tune so close to the edge and you wont have a problem, easy

[turbotrana]

Some good info here. Innovate do a lambda setup that allows you to datalog every cylinder and is being used by alot of serious tuners. I know that EGT sensors were the main thing to use years ago (pre cheap lambda)and would certainly aid in comparing cylinders if datalogged. But I'd say there are less than a handfull of Ford Turbo tuners that use either.

Most just use a lamda in the tailpipe on a non load dyno. that's why we see so many melted pistons on highly strung engines. I am sure Nizpro would know the variances in cylinders.

[F6R]

The trouble with an EGT is that it is less specific about whether there is a timing or fuelling issues causing the variation in temperature. Lambda is more specifically mixture related - well timing can change mixture slightly, but that's another thing.

I know there are tables for individual bank trimming in the oak, but certainly with regards to the turbo engine, the function is disabled and the tables are empty.

I struggle to see how closed loop individual fuel trimming can work on these engines when it comes out and straight into a blender. It'd be one hell of a task to map that with both O2's downstream as they are.

[IH8TOADS]

You make some good points F6R. Being time window based would make it possible....accuracy could be debated. The second O2 is not used in the closed loop fuel trimming.

[Smoke them tyres]

The trouble with an EGT is that it is less specific about whether there is a timing or fuelling issues causing the variation in temperature. Lambda is more specifically mixture related.

I struggle to see how closed loop individual fuel trimming can work on these engines when it comes out and straight into a blender.

Absolutely spot on.

The car actually has 2 "blenders".....the exhaust manifold that collides the flows AND the turbine which swirls the flow.

Edited 15/10/10 09:39 AM by Smoke them tyres

[F6R]

True that. 2 blenders!

Second O2 is just there to tell you the cat is misbehaving I think..... could be wrong.