Air Fuel Vs Psi
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Originally Posted by 05Z33
BTW-max TQ on VQ's for 95% of people is at 4800rpm's
5700 for me @11.5A/F
After seeing what happen to Nexx, I wouldn't want to run 12 on my A/F.
5700 for me @11.5A/F
After seeing what happen to Nexx, I wouldn't want to run 12 on my A/F.
like I said this is a very complexed issue. No tuners will give their timing numbers and for good reason. (we wouldnt need them if they did...lol)
But:
the more boost the lower AF in general. I bet the stock pontiac GTP with 5psi is running like 13.. I will run a google search to see what it has...
keep the comments coming... this is good stuff.
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Extremely well put together article on tuning, O2, timing, injectors, etc.
All on a Pontiac GTP (Supercharged)
All on a Pontiac GTP (Supercharged)
Originally Posted by 4SHIZZIL
After seeing what happen to NEXX you should know that 12psi is nuts.
like I said this is a very complexed issue. No tuners will give their timing numbers and for good reason. (we wouldnt need them if they did...lol)
But:
the more boost the lower AF in general. I bet the stock pontiac GTP with 5psi is running like 13.. I will run a google search to see what it has...
keep the comments coming... this is good stuff.
like I said this is a very complexed issue. No tuners will give their timing numbers and for good reason. (we wouldnt need them if they did...lol)
But:
the more boost the lower AF in general. I bet the stock pontiac GTP with 5psi is running like 13.. I will run a google search to see what it has...
keep the comments coming... this is good stuff.
Originally Posted by 4SHIZZIL
the more boost the lower AF in general. I bet the stock pontiac GTP with 5psi is running like 13.. I will run a google search to see what it has...
keep the comments coming... this is good stuff.
keep the comments coming... this is good stuff.
I don't really think you base your A/F with boost. If this is the case then people who're running high boost (10-20si) should run 10's since mid boost (7-9psi) are running mid to low 11's A/F. I think it is more on the timing control. You set your target A/F and as you increase boost then you retard more timing.
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Originally Posted by 05Z33
I'm not hitting 12 psi I'm at 9 psi. My air fuel is 11.5. Nexx had his A/F not psi at 12 when he blew his motor.
Originally Posted by NEXX
Originally Posted by NEXX
FS: Vortech Polished Tuner Kit with 2.87 pulley, CHEAP!!
--------------------------------------------------------------------------------
My car is down at Forged getting a TT and built motor installed. Has the GTM Pulley mod for no belt slip and easily puts out 12psi. Its polished for the extra bling everyone seems to like. You'll need some injectors, fuel pump, gauges and some sort of engine management to finish off the job and I'm sure Sharif would be happy to install everything for a very reasonable price. All lines have been upgraded to higher grade steel braided. This is for a DE motor.
Asking $2600 + 3% paypal.
FS: Vortech Polished Tuner Kit with 2.87 pulley, CHEAP!!
--------------------------------------------------------------------------------
My car is down at Forged getting a TT and built motor installed. Has the GTM Pulley mod for no belt slip and easily puts out 12psi. Its polished for the extra bling everyone seems to like. You'll need some injectors, fuel pump, gauges and some sort of engine management to finish off the job and I'm sure Sharif would be happy to install everything for a very reasonable price. All lines have been upgraded to higher grade steel braided. This is for a DE motor.
Asking $2600 + 3% paypal.
who really has the right numbers....only blown motors will tell.
lol
Originally Posted by 4SHIZZIL
Hmmm but his sold his SC with this thread:
like I said, its a balance of boost timing that makes things bad or not. I am sure with race gas and meth you can run 15 or 16 AFs...
who really has the right numbers....only blown motors will tell.
lol
like I said, its a balance of boost timing that makes things bad or not. I am sure with race gas and meth you can run 15 or 16 AFs...
who really has the right numbers....only blown motors will tell.
lol
even with a race gas you shouldn't run 15's A/F. Fuel burn the fastest at around 11.1 and slow down as you go up or down of that number. I don't remember the exact # but there is a range on the A/F ratio between the best lean TQ and best Rich TQ that tuner try to follow or come close. If I'm not mistaken 11.5 is the Richest best TQ and somewhere around 13:1 for best lean TQ so most tuner tune around mid to low 12's to be in the middle. Turbo charger are usually around the 11.5:1 just for added safety and extra cooling. Like I said I think it is more on the Timing side and not boost that will dictate your A/F ratio.
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Originally Posted by athenG
even with a race gas you shouldn't run 15's A/F. Fuel burn the fastest at around 11.1 and slow down as you go up or down of that number. I don't remember the exact # but there is a range on the A/F ratio between the best lean TQ and best Rich TQ that tuner try to follow or come close. If I'm not mistaken 11.5 is the Richest best TQ and somewhere around 13:1 for best lean TQ so most tuner tune around mid to low 12's to be in the middle. Turbo charger are usually around the 11.5:1 just for added safety and extra cooling. Like I said I think it is more on the Timing side and not boost that will dictate your A/F ratio.
thanks man, just trying to get my head around this. I have some that say running 11.5-12.0 is fine with my Vortech SC (8psi), then others who swear things will go boomb!
I side with my tuner (JE Import Performance) because he is in it to make money to drive his own 350 (v8) drift monster...not to just have a big checking account. I said conservative daily driven....thats what he gave me.
thanks for the knowledge bro. Much appreciated.
Any Others?
Originally Posted by athenG
even with a race gas you shouldn't run 15's A/F. Fuel burn the fastest at around 11.1 and slow down as you go up or down of that number. I don't remember the exact # but there is a range on the A/F ratio between the best lean TQ and best Rich TQ that tuner try to follow or come close. If I'm not mistaken 11.5 is the Richest best TQ and somewhere around 13:1 for best lean TQ so most tuner tune around mid to low 12's to be in the middle. Turbo charger are usually around the 11.5:1 just for added safety and extra cooling. Like I said I think it is more on the Timing side and not boost that will dictate your A/F ratio.
Originally Posted by JCstart
the magic number with a turbo setup is 11.7....
mine is running mid 11's past 3psi at WOT.
I'm up at 12 before 3psi WOT. I have timing pulled 9 degrees at high rpms. 93 vpower, no knock. running 12.1psi.
i think just under 11.5 is safe on mine. with my timing pulled that far i haven't heard knock and it runs great. I think i'm safe enough that i have a good bit of a safety net before i detonate.
I'm up at 12 before 3psi WOT. I have timing pulled 9 degrees at high rpms. 93 vpower, no knock. running 12.1psi.
i think just under 11.5 is safe on mine. with my timing pulled that far i haven't heard knock and it runs great. I think i'm safe enough that i have a good bit of a safety net before i detonate.
like said before, raw AFR dont mean much without being within the context of timing.
You can look at most of the shop build dynos and they waver along the 12:1 ratio with probably 14-16 degrees of timing.
You can look at most of the shop build dynos and they waver along the 12:1 ratio with probably 14-16 degrees of timing.
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LOL
Edit:
By the way.. this thread is old..
Last edited by athenG; Jul 7, 2009 at 03:27 PM.
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