[staples87]

Originally Posted by 7WSM

The AF looks to be a little rich. Most of the guys I know that do DI cars run it a little close to 12.5-13.

So if you tuned a car at 11.5-11.8 a/f and then 12.5-13 a/f and it was a difference of say "3-5whp", why wouldn't you run it a little richer and safer? ESPECIALLY when you're running a bigger blower with a lot more boost than stock. Timing is what makes the most difference in power, not air fuel ratio (unless it's extremely rich or extremely lean). Rule of thumb on pump gas is 11s on forced induction, 12s-13 on NA. E85 allows you to run a lot leaner, safer. Methanol mixed 50/50 allows you to run a little leaner as well, but a lot of people don't want to rely solely on methanol because if the pump fails or a nozzle becomes clogged at wide open, that could cost you your engine.

[BAD MOOOFOOO]

We can speculate all day long but without a before and after on the same Dyno Dynamics machine it's kind of pointless. He also mentioned really high ambient temps which also makes a difference.


I would recommend the OP go to a different shop with a Dynojet and see what you get. (or dare I suggest a drag strip and see what your MPH is)

[GT-ER]

Originally Posted by BAD MOOOFOOO

We can speculate all day long but without a before and after on the same Dyno Dynamics machine it's kind of pointless. He also mentioned really high ambient temps which also makes a difference.


I would recommend the OP go to a different shop with a Dynojet and see what you get. (or dare I suggest a drag strip and see what your MPH is)

This is my plan.

Originally Posted by staples87

So if you tuned a car at 11.5-11.8 a/f and then 12.5-13 a/f and it was a difference of say "3-5whp", why wouldn't you run it a little richer and safer? ESPECIALLY when you're running a bigger blower with a lot more boost than stock. Timing is what makes the most difference in power, not air fuel ratio (unless it's extremely rich or extremely lean). Rule of thumb on pump gas is 11s on forced induction, 12s-13 on NA. E85 allows you to run a lot leaner, safer. Methanol mixed 50/50 allows you to run a little leaner as well, but a lot of people don't want to rely solely on methanol because if the pump fails or a nozzle becomes clogged at wide open, that could cost you your engine.

I agree!

Originally Posted by staples87

Yeah that's plenty of timing for 16-17psi, so that's good you're not getting any knock retard. If you have HP Tuners and can log, I would enable MAP in kPA and do a log. Keep an eye on wide open throttle to see if the number starts to drop off, especially in the higher RPMs. That would tell you that the engine is struggling to breath in the upper range. This would be a simple way of trying to figure out.

I have several logs. I monitor my engine pretty often. I just added another degree so it's doing 22-23 now. 0KR. I'll run it for a while like this to see if I get any KR during multiple runs but so far so good.


The map numbers I've logged will keep climbing all the way to redline.