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boost life
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On pump gas over say 18psi ,you might here the intoxicating sound called boom. If you are running say 15ish psi and not in it for Long , you might get a pass depending on setup
 

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hks is the best get the full kit
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On pump gas over say 18psi ,you might here the intoxicating sound called boom. If you are running say 15ish psi and not in it for Long , you might get a pass depending on setup
That's what I wanna hear.

Thanks.
 

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AFR and octane level are quite related. on stock ecu, low octane, and high AFR, you are going to get a lot of time pulled and just losing power, and probably break things. with race fuel/meth and the afr you mentioned will probably give you a good 10% more HP. I started my tuning not knowing much about the octane requirements. at bpu, 15 psi and tried to get afr to 11 instead of 10 and i could feel the timing pull. now with meth, 17 psi, 11.0 afr, this car is pretty insane. get your octane up before playing with afr.
 

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Master Shit Fixer
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I realize a low AFR is correct for WOT, but can someone explain why 14.7 is perfect for idle and steady-state driving, and running rich is correct for WOT? I'm looking for a technical answer. Why isn't stoiciometric the right answer all the time?
 

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Thanks, Nick.

OK, so it's extra fuel to cool the combustion gases, which decreases the probability of knock. That implies there will be unburned fuel left over, that exits through the exhaust, right?
 

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12 AFR on E85 is fine, but a 12 AFR on 93 octane gasoline is a bit too lean.

If you are mixing the fuels like E85, methanol etc the stoich point will change so AFR is not always the best measure. I would look at using lambda with those fuels it will make your life easier.
 

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You mentioned lambda being the more accurate way of tuning. I actually have meth injection and been using AFR to 11.0 when injecting meth water. Stoic AFR of meth is like 6. How would you tune it in lambda?
 

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You mentioned lambda being the more accurate way of tuning. I actually have meth injection and been using AFR to 11.0 when injecting meth water. Stoic AFR of meth is like 6. How would you tune it in lambda?
Someone feel free to chime in and correct me if I'm wrong but running meth/water you'd still be looking at the same lambda as if you where only tuning for gas. You arn't removing gas from the tune. You are adding the meth on top of it. I think generally you want to see approx .5 afr lower when spraying meth. So if you're running 11.7:1 on only gas. You should see about 11.2:1 with meth injection. I don't work in Lambda but I imagine if your goal in lambda for a/r is say .8. You'd probably run something like a .76 with meth injection.

Lambda isn't more accurate it's just different and easier to switch back and fourth, especially when you're talking cars running both e85 and pump tunes.

Edit post: sorry I should clarify for anyone reading this. That adding meth on top of the fuel is the safe way, but I suppose it would make more power to lean out the mixture slightly. You'd just be risking the engine more so if the meth ever stopped or didn't spray the same volume as usual.
 
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