Help any ideas?
08-03-2007, 07:14 PM
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Help any ideas? A few years ago after I built my 99 FRC I took it to Speed Inc. to be tuned. Result= 415 rwhp and an afr of 12.5 across the board. Today with only change being a ti Z06 cat back (now) vs a Borla(then) 350 rwhp with an afr of 15 !!!!!!! I know the differences between dynos (dynojet vs mustang) and the like but what could cause the afr? When I say no other changes the car still has the same plugs in it! I figured with the old plugs and more restrictive exhaust (maybe) it would be richer not majorly lean!!!! No ses lights or anything car runs fine I just thought something might be up because I could swear I heard some detonation but everyone said I was crazy, guess not. Thanks guys.
08-03-2007, 07:22 PM
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lol...thats pretty strange. You're right, it should have went richer with the different exhaust.
The only thing I can think of is the altitude of the dyno...did you dyno in Colorado the 1st time and Miami the 2nd time??? lol...jk
The only thing I can think of is the altitude of the dyno...did you dyno in Colorado the 1st time and Miami the 2nd time??? lol...jk
08-04-2007, 08:39 AM
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Fuel pump or a fuel issue of some sort.
I had the same thing happen; should have been 340 HP, Dynoed at 270 HP and AFR was 15.1. I was logging fuel pressure and found the pressure dropped to 35 PSI and did not recover.
Dyno again and watch your fuel pressure.
I had the same thing happen; should have been 340 HP, Dynoed at 270 HP and AFR was 15.1. I was logging fuel pressure and found the pressure dropped to 35 PSI and did not recover.
Dyno again and watch your fuel pressure.
08-09-2007, 03:14 PM
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Agreed....check your fuel pressure...something is way wrong there.....dont get on it either...dont want to hurt it! Do any tuning on a mustang dyno....A lot better to have a load on the car than just the free spinning well...real street type testing for a street car
08-15-2007, 12:33 PM
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A little update. Checked the fuel pressure 58-60 and no drop during a neutral rev. Checked with a scanner and no codes were found. I took the MAF off and there was a film of something on it? I have a dry blackwing filter don't know what could be on the MAF? I cleaned it so we will see.