A/F ratio question
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Teching In
Joined: Dec 2007
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From: Bradenton, FL
A/F ratio question Got the car on the dyno. On motor, A/F was at 12.0. On a 75 shot, it went to 12.8-12.9. On 100 shot, went to 13.0-13.1. I know it's a little lean, but would this be safe to run, or no?
Any suggestion on tuning? Pull timing, ect...?
Any suggestion on tuning? Pull timing, ect...?
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Joined: Jun 2005
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Is it wet or dry sys?
A safe rule of thumb with good race gas is to pull out 1.5-2 degrees for every 50hp increase. "If you push timing to the ragged edge there's not much of a performance improvement, but the engine will be much more prone to detonation," says ZEX. "
A safe rule of thumb with good race gas is to pull out 1.5-2 degrees for every 50hp increase. "If you push timing to the ragged edge there's not much of a performance improvement, but the engine will be much more prone to detonation," says ZEX. "
Last edited by bluecamaroz28; Apr 28, 2008 at 12:40 PM.
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Thread Starter
Teching In
Joined: Dec 2007
Posts: 26
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From: Bradenton, FL
01'
Converter/Gear/exhaust
Wide Band on a dyno.
I have HP tuners, but am not going to put it back on the dyno to verify a/f. I was kinda over-priced and under-served where I went. Also, the tuner did not have any suggestions for me to help with the a/f ratio, that is why I am on here. Nozzle placement is strait at the MAF, about 9-10 inces away.
I spent all this money on a kit, I would hate to just take it back off. I do not want to spend any more money on dyno time, especially if I do not know how to tune it for nitrous. I was under the assumption that the MAF would pick up the nitrous and add the extra fuel. Also, the car only picked up 55 h.p. and 50 tq to the wheels with the 100 pill. (Which I'm not complaining about because it was to the wheels, but I was expecting a tad more.)
On motor I was at 26* timing, when I sprayed, I brought it down to 25* (Stock). I will be going to 27* when I am on motor.
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Verdad Gallardo stall,gear,exhaust would have been fine on a simple tune with hptuners. since all that really needed changing was the gears.
you should have gotten more than 55hp even if the kit was rated at the engine. but that could also be the dyno is off.
get a new wideband for >$300 since you already have hptuners and try to do it yourself. dry tuning is not hard if you can consistently get the spray to be read by the maf. that's the tough part.
a lot of people on here say 3-4 inches from the maf. myself, i'd say 4-5 and get the spray to hit the lid or each other in a dual nozzle so that it disperses more of a cloud when it hits the maf. i had poor results when i sprayed directly at a descreened maf. your biggest problem is the nozzle location with a dry. dual nozzles will help. basically what you have to do is log the maf hertz being read by the maf on spray that is above na readings and bump up the amount of grams of air that it represents to get the pcm to feed more fuel. the maf needs to be reading more hertz and consistenly the.
keep an eye out for kr with your timing. i'd take timing down just to be safe. it won't be that much of a lost in hp.
leave the nitrous on the car and hang on for the nx maf. they said about 6 weeks. or get the hsw interface for now.
you should have gotten more than 55hp even if the kit was rated at the engine. but that could also be the dyno is off.
get a new wideband for >$300 since you already have hptuners and try to do it yourself. dry tuning is not hard if you can consistently get the spray to be read by the maf. that's the tough part.
a lot of people on here say 3-4 inches from the maf. myself, i'd say 4-5 and get the spray to hit the lid or each other in a dual nozzle so that it disperses more of a cloud when it hits the maf. i had poor results when i sprayed directly at a descreened maf. your biggest problem is the nozzle location with a dry. dual nozzles will help. basically what you have to do is log the maf hertz being read by the maf on spray that is above na readings and bump up the amount of grams of air that it represents to get the pcm to feed more fuel. the maf needs to be reading more hertz and consistenly the.
keep an eye out for kr with your timing. i'd take timing down just to be safe. it won't be that much of a lost in hp.
leave the nitrous on the car and hang on for the nx maf. they said about 6 weeks. or get the hsw interface for now.
Thread Starter
Teching In
Joined: Dec 2007
Posts: 26
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From: Bradenton, FL
Thanks.
I am not too great with HP Tuners, I am still a newbe. So I should make a WOT rip NA and check the Hz reading from the MAF on HPT, then do the same with the spray. Find a point between the N/A Hz readings and the spray Hz readings and bump up the amount of Grams of air that Hz reading represents from that point up? That sounds easy enough. I'm going to pick up my own Wideband like you suggested cause I can see that Dyno becoming very expensive, very quickly. Plus I will need it for a future cam swap as well.
Thanks for you help.
I am not too great with HP Tuners, I am still a newbe. So I should make a WOT rip NA and check the Hz reading from the MAF on HPT, then do the same with the spray. Find a point between the N/A Hz readings and the spray Hz readings and bump up the amount of Grams of air that Hz reading represents from that point up? That sounds easy enough. I'm going to pick up my own Wideband like you suggested cause I can see that Dyno becoming very expensive, very quickly. Plus I will need it for a future cam swap as well.
Thanks for you help.
get the wideband first so that you know your a/f on and off the spray to tune. everything else you typed is pretty much what you'll have to do. sounds easy but the nozzle(s) location is the hardest part to ensure that the maf reads the nitrous correctly and consistently. that's why a lot of people on here have been waiting for the nx maf. good luck.
