Dyno results status post Kooks long tube header installation

[jgibby]

Well, I just got back from Carolina chassis dyno. Here are the results after having done Kooks long tubes and catted X-pipe.
425 whp.
402 wtq.

Since the car is an automatic, what does this equate to at the flywheel, anyone have any ideas?

The guy who ran the dyno said I was a bit lean at 12.6, but according to his datalog all my other paratmeters were good. I have been driving the car hard for a week now on the Brenspeed mail order 93 octane tune. Car runs very strong, No strange noises, no check engine lights. I contacted Dave at brenspeed and he said that that Saleen did not route the fuel vacuum pump line correctly on these cars and said he would send me a kit to correct this and only takes 10 minutes to install. He said this should drop down my A/F ratio a little. He also said that an a/F of 12.6 measured at the tailpipe was not dangerously lean. I've heard of guys running a/Fs of 14 with no issues, even though those were on naturally aspirated cars. I'm only running 4 pounds of boost with my setup, so does anyone here think that 12.6 is an outrageous a/F? I've seen newer model mustangs throw engine codes right and left for the smallest deviation so i expect that if I had a real issue i would have had a light come on by now. BTW, Anyone considering doing Kooks header should do it in my opinion.
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2007 GT California Special
Saleen SC with 475 hp upgrade, Kooks long tube headers and X-pipe with high flow cats, Magnaflow Magnapack

 

[stangzilla100]

nice dyno #'s. the a/f is a little lean, but the tailpipe method may be the problem. but that is real good for 4 psi, better than the eforce.

 

[BCB00GT]

Just curious - your signature says the 475hp kit which comes with the 3.87" pulley as oppose to the 4" pulley. Are you running the 3.87" pulley? If so, that pulley is rated at 5.5# I believe.

Definitely change the vac connection/routing. Also, I would think you would want to be a little more richer - too lean.

 

[TBrad]

Since the car is an automatic, what does this equate to at the flywheel, anyone have any ideas?

It's in the range of...12% to 18%

So...

425 RWHP = 476HP at the flywheel.

Or can be as high as

425 RWHP = 501HP at the flywheel.

Every car will be different depending on various loads on the engine (Power steering, A/C, etc), transmission efficiency, drive train components (lengths, rotating masses, etc.) and configurations.

There really is not a truly accurate formula besides pulling the motor and running it on an engine dyno.


What were your numbers before the header install?

 

[jgibby]

Just curious - your signature says the 475hp kit which comes with the 3.87" pulley as oppose to the 4" pulley. Are you running the 3.87" pulley? If so, that pulley is rated at 5.5# I believe.

Definitely change the vac connection/routing. Also, I would think you would want to be a little more richer - too lean.

I have Brenspeed sending me the parts to change the vac routing. Wouln't that drop the power some?

 

[Gearbanger 101]

Just curious - your signature says the 475hp kit which comes with the 3.87" pulley as oppose to the 4" pulley. Are you running the 3.87" pulley? If so, that pulley is rated at 5.5# I believe.

Opening things up on the exhaust end will often result in a drop in manifold pressure on the intake side. Its not a bad thing, it only means he's moving the spent exhaust gases out more efficiently. Making as much, or more power, with the least amount of manifold restriction is the ideal situation.

 

[BCB00GT]

Just trying to find out the pulley size. I know headers can lower the boost, but at such a low boost level, that would be about 1/3 less. Still would like to know the pulley size.

 

[jgibby]

Just trying to find out the pulley size. I know headers can lower the boost, but at such a low boost level, that would be about 1/3 less. Still would like to know the pulley size.

It's the 3.87 pulley, Do headers really lower boost? Do you think I need to up the boost maybe to 7 lbs?

 

[NastyStang113]

It's the 3.87 pulley, Do headers really lower boost? Do you think I need to up the boost maybe to 7 lbs?

Headers can lower boost but it's not a matter of being correlated to loosing power because you've lost boost. It's a matter of making the system more efficient.

 

[Gearbanger 101]

It's the 3.87 pulley, Do headers really lower boost? Do you think I need to up the boost maybe to 7 lbs?

Need to, no...but you have the option at this point. Again, lowering boost pressure by opening up the exhaust side isn't a bad thing. It doesn't mean you're losing power, only that you're evacuating spent exhaust gases more efficiently. The fact that you picked up horsepower by doing so, even while manifold pressure drops says that they're doing their job.

I’d be less worried about upping the blower speed to recapture boost numbers at this point than I would pushing the stock short block too hard with excessive power levels.

 

[jgibby]

Need to, no...but you have the option at this point. Again, lowering boost pressure by opening up the exhaust side isn't a bad thing. It doesn't mean you're losing power, only that you're evacuating spent exhaust gases more efficiently. The fact that you picked up horsepower by doing so, even while manifold pressure drops says that they're doing their job.

I’d be less worried about upping the blower speed to recapture boost numbers at this point than I would pushing the stock short block too hard with excessive power levels.

I wouldnt think increasing the boost by 2 psi would be that dangerous, but I could be wrong about that. Brenspeed will readjust my sct tune to match the new boost level.

 

[Gearbanger 101]

I guess that all depends on how capable you think your stock short block is at handling the power levels. 2psi with that set up could mean as much as 35-45hp. You're already knocking down 475-500hp at the crank now, are you willing to bet your engine that another 40-50hp isn't going to push it over the edge?