210-215 roller and a/f ratios with meth???

[turbov6joe]

Last year we put this cam in my dad's motor with a set of Champion ported irons and intake, a GTQ70 turbo, 86pph injectors and meth injection. We were having trouble with the tune, specifically with commanded a/f ratios. After a rather disappointing day at the track Lonnie Diers mentioned that this cam likes a leaner a/f ratio due to the duration on the exhaust side. We started leaning it out and ended up right at 11.7 out the back door before we ran out of time....the car was getting faster. My question is this, for those that have knowledge of this cam, what a/f ratios are you having the best luck with while squirting meth? We need to know just how lean you guys are having good luck with?

TIA

 

[SS_Sean]

Posting in only one forumn helps.

http://www.turbobuick.com/forums/engine-tech/254900-comp-210-215-roller-cam-tuning.html

 

[Razor]

Joe,
You tune what the motor tells you it likes. Same thing with wide band sensors. Not all read the same. Its just a "more" accurate sensor.

Remember if you ask Buick guys what "O2" to tune with.. some guys will say 680's and some say 820's. If the car likes to be leaned out.. it likes that. As long as you have "No Knock" keep leaning her out. Just watch your EGT's and make sure they are in line.

I went to a dyno session a few months ago. The car had an AEM guage, an AEM computer, and had the shops Dynojet WB sensor in the tail pipe. All three sensors read differently. They all tracked the same.. just different numbers. In the end the spread was over 1 point AF between the NGK in the tail pipe and the AEM one.

So your 11.7 could technically be someone elses 10.7. hope this makes sense.

Just like timing. some cars like 18 degree's some like 27 degree's.

Tune for what makes the most power, then back it down a notch. This is what most of my higher end shops do.

HTH

 

[turbov6joe]

Posting in only one forumn helps.

Umm, I don't think so. Thanks for keeping track and bringing it to my attention.

 

[turbov6joe]

Joe,
You tune what the motor tells you it likes. Same thing with wide band sensors. Not all read the same. Its just a "more" accurate sensor.

Remember if you ask Buick guys what "O2" to tune with.. some guys will say 680's and some say 820's. If the car likes to be leaned out.. it likes that. As long as you have "No Knock" keep leaning her out. Just watch your EGT's and make sure they are in line.

I went to a dyno session a few months ago. The car had an AEM guage, an AEM computer, and had the shops Dynojet WB sensor in the tail pipe. All three sensors read differently. They all tracked the same.. just different numbers. In the end the spread was over 1 point AF between the NGK in the tail pipe and the AEM one.

So your 11.7 could technically be someone elses 10.7. hope this makes sense.

Just like timing. some cars like 18 degree's some like 27 degree's.

Tune for what makes the most power, then back it down a notch. This is what most of my higher end shops do.

HTH

I feel ya Julio. We both know all cars are different, I was looking for some reference a/f numbers to compare with my data. What concerns me is that this cam profile is requiring us to go a completely different direction in tuning.