Hp Problem?

[Tim03cobra]

I bought a 2008 GT500 with the KB 2.8H stage 3 kit already installed. I currently have the 3" pulley and the p1 program installed. I have stock exhaust and drag radials. Here is the problem. When i had it dynoed it made 610 rwhp on a Dyno jet and last night it ran 122mph in the quarter. Both numbers seem low to me. The old owner said it made 680 rwhp. I currently have 3300 miles on the car. Do you think something is off on the Hp numbers and trap speed? Kenne Bell says it should be making close to 700 rwhp. I also posted this in the KB tech area and didn't get any replys. Thanks Tim

 

[venom04svt]

honestly 610 seems way low...you should be at around 17psi with that pulley size and should be at least at 675 or more... 122 is still a lil low for even 610 i would expect more of 127-129 or so....need more info from your slip tho... 60 foot...etc

 

[Alloy Snake]

Needs to be checked out for sure-2.2 Eatons are running better times than that with pulleys,Possible belt slip.When it was on the dyno did anyone look at the tune?Look at what your Lightning was running-Those are good numbers.

 

[Tim03cobra]

Here is the time slip numbers.
R/T .068
60' 1.995
330' 5.216
1/8 7.812
MPH 95.63
1000 10.006
1/4 11.863
MPH 122.29
Thanks Tim
The first 2 runs were high 12's @ 114 then i let it cool off with ice on the blower. The car weight is 4155 with me in it.

 

[skyhighsd]

Heat soak? You didnt really post any info, was the car cold when you dyno'ed it was it straight off of the street, was it 100* and humid as hell out could have been a lot of reason. What did the dnyo sheet look like, A/F, timing, boost ect....... Your car needs some more mods to pull real good numbers out all of the time IMO. Overall the numbers are low but need more info. and I take you are running the kb tunes due to the fact you said p1?

 

[Leonard 95]

I would probably talk to John Lund and get a tune from him and work from there, 610rwhp seems really low. I take it you ran at Thunder Valley? Weather was pretty nice here in Oklahoma yesterday.

 

[Tim03cobra]

Heat soak? You didnt really post any info, was the car cold when you dyno'ed it was it straight off of the street, was it 100* and humid as hell out could have been a lot of reason. What did the dnyo sheet look like, A/F, timing, boost ect....... Your car needs some more mods to pull real good numbers out all of the time IMO. Overall the numbers are low but need more info. and I take you are running the kb tunes due to the fact you said p1?

The car sat about 30 minutes before the dyno was done. The temps were in the high 80's. The A/F went lean past 5500 rpm using the KB tunes. Do i need to get a custom tune? They were using a tailpipe sniffer for the A/F. What other mods keep the numbers more consistant? Thanks Tim

 

[Tim03cobra]

I would probably talk to John Lund and get a tune from him and work from there, 610rwhp seems really low. I take it you ran at Thunder Valley? Weather was pretty nice here in Oklahoma yesterday.

Do you have a number for John Lund? And yes, I was at Thunder Valley. Thanks Tim

 

[blkGT500nCA]

Do you have a number for John Lund? And yes, I was at Thunder Valley. Thanks Tim

Jon Lund:beer:

 

[Leonard 95]

As for other mods, I would get the tune from Lund and a revan racing heat exchanger if you don't have one already. You should be in the 650rwhp pretty easy.

 

[Tim03cobra]

Thanks or the info. Tim

 

[skyhighsd]

First thing I would do is have a bung put in the exhaust so that they are not using a tailpipe sniffer and go from there I bet that alone will make a difference in the A/F readings. Agree'd you will have a better tune from Lund then you have now thats a good start also. Get a good heat exchanger and get rid of those cats, that will help you out a lot and then from there its all about the money.....lol

 

[09Troublemaker]

First thing I would do is have a bung put in the exhaust so that they are not using a tailpipe sniffer and go from there I bet that alone will make a difference in the A/F readings. Agree'd you will have a better tune from Lund then you have now thats a good start also. Get a good heat exchanger and get rid of those cats, that will help you out a lot and then from there its all about the money.....lol

x2 on all points

 

[rdsnk46]

Sounds like the car was hot and pulling timing, Take 2 Jon Lunds and call m e in the morning.

 

[Tim03cobra]

Sounds like the car was hot and pulling timing, Take 2 Jon Lunds and call m e in the morning.

I think i'll take it to a different place and have it dynoed. :beer: