I lost HP?

[FriedRice]

Ok who has ever heard of this? I got a 99 cobra with a 01 eng. Put on a bassani cat-less X-pipe,mac fenderwell cold air pipe and dyno'ed it. The numbers were 287 rwhp. After that i did 4:10's steeda underdrive pullies and a magnaflow catback. Re-dyno'ed it at 282 rwhp. WTF:cuss: The air fuel curve changed by 2 points first dyno run was a 12:1 then after the other mods it went lean to a 14:1 ratio. The guys at the dyno were at a loss of words. Anyone got an idea what happened?:cryying:

 

[103]

Did you get the dyno done on a dynojet? I've been told that if you have steeper gerars than stock, the number will come out lower than it should. Just a thought.

-103

 

[Booyah]

Originally posted by FriedRice
Ok who has ever heard of this? I got a 99 cobra with a 01 eng. Put on a bassani cat-less X-pipe,mac fenderwell cold air pipe and dyno'ed it. The numbers were 287 rwhp. After that i did 4:10's steeda underdrive pullies and a magnaflow catback. Re-dyno'ed it at 282 rwhp. WTF:cuss: The air fuel curve changed by 2 points first dyno run was a 12:1 then after the other mods it went lean to a 14:1 ratio. The guys at the dyno were at a loss of words. Anyone got an idea what happened?:cryying:

You are way to lean for some reason. They need to check all your O2 sensors and maybe reset your computer to compensate for all your mods.

 

[FriedRice]

Check O2 sensors, what exactly sre they checking? How can you test those? To reset my computer just disconect the bat for 30 mins right?

 

[FriedRice]

Originally posted by 103
Did you get the dyno done on a dynojet? I've been told that if you have steeper gerars than stock, the number will come out lower than it should. Just a thought.

-103

yep got it dyno'ed on a dyno jet 1200hp