Hey everyone. I need to pick the brains of you savvy motor guys and gals out there. About a year ago, I purchased a set of Dart Pro1 LS1 heads (225cc), a Comp cam (.600/.600, .228 duration, 114 deg. lobe sep), and Dynatech Supermaxx long tubes and high-flow cats for my 2004 GTO. The components were installed by a friend of my brother (highly recommended). I then had it taken to Xtreme Horsepower in N. Richland Hills, TX for the tune and dyno. Now, I'm assuming that most GTO's run about 290-305 rwhp from the factory depending on if the motor was a "ringer" or not. My dyno sheet read 363 rwhp and 347 ft. lbs of torque. After driving it for almost a year, I took it back to have bigger injectors put in (42 lb Ford Motorsport flow-matched) and re-tuned. The dyno sheet read 361 rwhp/353 ft. lbs of torque. Both the mechanic and the tuner said that there's something wrong with that head/cam combo. They said it should be producing more than that. To be honest, I was a little dissapointed in the result of my almost 5 grand spent.

Now my question is, is the cam that I'm using the right cam for the heads? If not, then what cam do you guys and gals suggest for me to use? Any help is greatly appreciated. Thanks!!

 

Got the dyno sheet? do you know your A/F and timing? did it get knock retard? is it a high stall unlocked A4? mustang dyno?

Just a little more info and you should get more answers

 

hay i have almost the same setup and i put 420hp with no hassle???

i was wondering why you use the 42# if you are not runing NOS or FI ???

i think its not the combo your combo should work fine and should put 400 at least.

and as asmodeus said your dyno sheet will explain alot of things and your A/F ratio

plus timing.

so tell us man this thread seems to be intrested.

 

Asmodeus,

The Dyno was a Dyno Dynamics dyno. As far as the A/F goes, I talked to the guy who did the motorwork and he said it was at 14.4 or 14.5 throughout the entire RPM range. As far as the knock retard, he said it lost no more than 1 to 1 1/2 degrees. The timing he couldn't really tell me, he only said that he put the cam in straight up, which I guess the cam by the way it's made gives a little bit of timing. I hope this clears things up.

 

How big CC are the heads? That IMO is very low for that setup...

William

 

William,
I put all the info in the beginning of the post, but so you don't have to read, here ya goClicky

 

doesnt the a/f seem a little too lean throughout the entire powerband...i thought most NA guys were shooting for like 12.5's?

 

My car was smoking too much with it running that rich. I don't need the spy hunter thing going on.....

 

"I talked to the guy who did the motorwork and he said it was at 14.4 or 14.5 throughout the entire RPM range"

either someone is confused...you misinterpreted whta he was saying...or the tuner has NO idea what he's doing.

the A/F is way too high....

if it was smoking...that means something else was wrong.

 

+1 you want to run around 12.5 or so A/F, not 14+, thats way too lean. Also, with the ethanol based gas now you cant throw as much timing at the car either. You really need to find out if his A/F readings are off...also, for what its worth I made more power than you on a stock headed 98 ls1 camaro (worst flowing heads of all ls1 vehicles) with a 232/238 cam.

 

The AFR sounds like the car needs more fuel. It is well accepted that the DD dyno reads about 12% lower than dynojets if left at the 0 correction factor. So factor that in for comparison purposes with other peoples #'s. Anyhow I would trouble shoot that AFR and take it to the track. Your MPH will tell you where you are at HP wise. mario

 

hmmm...

i think you need to get that A/F to 13.2 because most of the NA cars run with simillar
AFR 5% more or less and it will get you there,but if you still have that smoke?thats mean somthin wrong inside the engine like lifter failuer or so?

anyway tell us man if you know the problem it could help alot of us in the futuer.
(and find a good tuner for the god sake)

 

Thanks for all the help everyone! I'll keep everyone informed on what's going on. I have some work and research to do!