dual injection is just a long overdue solution to carbon build up?

[Ryephile]

Originally Posted by arghx7

It's relevant for the life of all components connected to the exhaust system. In aftermarket performance tuning you're not so concerned about catalytic converter life or cat lightoff though.

You're right, and the reason I ignored it in my reply you got spot-on.

You seem like you know what you're talking about. Do you do calibration?

[ryridesmotox]

Originally Posted by Ryephile

My advice would be to throw away the EGT gauge and get a good set of datalogging for RPM, Ignition, IAT, MAF/MAP, WBO2, fuel rail pressure, injector duration, throttle angle, and cam phasing.

I have that... It's called HP tuners. I also have a gauge that switches between alot of those as well. I don't use EGT gauges for tuning I was just asking a question about cylinder temps since the EGTs are a reflection of how efficient an engine, to include a turbo, is doing 'work'. I guess I was just a little confused with your response is all... You second one cleared it up though, thanks

Originally Posted by arghx7

This is true only if by "leaner" you mean that the engine-out AFR is leaner than lambda=1, meaning leaner than 14.7:1 on pure gasoline.

Yea depending on the tuner for my current car, you will see as much as .86 lambda at WOT according to the wideband in the exhaust manifold.

[arghx7]

.86 lambda (about 12.6:1 AFR on 100% gasoline), if that is a mostly accurate value, is significantly leaner than what you would expect on most comparable port injected engines. On a completely stock calibration for a typical boosted port injected engine it would probably be closer to .70 lambda, or 10.3:1 on 100% gasoline. On a performance tune it would be closer to .78 lambda, or 11.5:1 on 100% gasoline.

[ryridesmotox]

Originally Posted by arghx7

.86 lambda (about 12.6:1 AFR on 100% gasoline), if that is a mostly accurate value, is significantly leaner than what you would expect on most comparable port injected engines. On a completely stock calibration for a typical boosted port injected engine it would probably be closer to .70 lambda, or 10.3:1 on 100% gasoline. On a performance tune it would be closer to .78 lambda, or 11.5:1 on 100% gasoline.

Yep, the beauty of a direct injection motor. But I also run on ethanol from time to time and that is run much richer. My 100% gasoline tune is not at .86 lambda, I am about the gasoline tune to be my daily driver econo tune.

[Ryephile]

I found a nice article differentiating Cylinder Head Temps versus Exhaust Gas Temps:

http://www.jpitech.com/press_releases/Bush_Article.pdf

Yes, it's related to small aircraft engines, but it's still relevant.


Regarding ryridesmotox's AFR's at WOT; 0.86 Lambda sounds reasonable with your LNF [DI] engine as long as you're not excessively knocking.

[ryridesmotox]

Originally Posted by Ryephile

Regarding ryridesmotox's AFR's at WOT; 0.86 Lambda sounds reasonable with your LNF [DI] engine as long as you're not excessively knocking.

Yea it dialed it pretty good... I haven't had mine on the logs in a while to see but I'll hook it up and see what she's doing... It usually holds at around .87-.88 at wot. On the 91 octane I have here in commi-fornia is lame.