gt-40 crate engine dyno wtf

stang619 said:
can you explain the way rich part im not really understanding where or at what point its too rich and the timing is at 14 deg ...

As an example my friend took his car into Xotic Motorsports to have a few base pulls made. He made 299rwhp and like 330tq. His AFR from 4500rpm's up was between 11.0 and 11.7 . the tuner told us that on (NA) set ups they shoot for an AFR of 12.5 to 13.5. and on boosted cars they go for 11.0 to 12.0. After my buddy backed off his fuel preasure the AFR was around 12.7 to 13.3 if i remember right, but his horsepower came up to 314rwhp and im not sure how his torque was affected. Leaner makes more power to a point. Going to lean will cause alot of other problems.
 
just4bob50 said:
As an example my friend took his car into Xotic Motorsports to have a few base pulls made. He made 299rwhp and like 330tq. His AFR from 4500rpm's up was between 11.0 and 11.7 . the tuner told us that on (NA) set ups they shoot for an AFR of 12.5 to 13.5. and on boosted cars they go for 11.0 to 12.0. After my buddy backed off his fuel preasure the AFR was around 12.7 to 13.3 if i remember right, but his horsepower came up to 314rwhp and im not sure how his torque was affected. Leaner makes more power to a point. Going to lean will cause alot of other problems.
thanks man...by the way ive been reading bout other guys making 260 with almost identical setups but with iron heads or another guy with almost same ccombo except he has the 315 bhp crate engine hes making 265 untuned...dont you guys think my max of 254 at 4800 rpm is kind a low on the rpm range... shouldnt i be maxing out at 5500 or so??? Most people (including me ) think im bout 25- 30 hp low
 
91ghp5.0 said:
thats what i thought. so why is he dissapointed w/ 290? thats just about right...even w/o the carb.

He dynoed in the 254rwhp range and 290rwtq range.

The 340hp rating of the gt40 engine is based on no accessories and with a carb. I think he should be proud of the 254rwhp number he got. It isn't much more stepped up than a 93 Cobra motor and they dyno 230rwhp or so.
 
5spd GT said:
He dynoed in the 254rwhp range and 290rwtq range.

The 340hp rating of the gt40 engine is based on no accessories and with a carb. I think he should be proud of the 254rwhp number he got. It isn't much more stepped up than a 93 Cobra motor and they dyno 230rwhp or so.

my bad, i misread the torque for the HP on the last run. i think those are pretty darn good numbers! throw some bolt ons/exhaust on there and you're set!
 
5spd GT said:
He dynoed in the 254rwhp range and 290rwtq range.

The 340hp rating of the gt40 engine is based on no accessories and with a carb. I think he should be proud of the 254rwhp number he got. It isn't much more stepped up than a 93 Cobra motor and they dyno 230rwhp or so.
how can i be proud when people with the the 315 bhp engine are making more power 265 untuned and guys wiht iron headed gt 40 crates making 260 untuned and some guys with the 340 bhp making 300rwhp? I think im short bout 30 hp and will find out why
 
Get the 24's, Christ I have 24's on my 325 stroker with the F/P just tunred up a bit higher than stock. There is no need for 30's with your motor. It is better to use a smaller injector and turn up the F/P rather than getting a bigger injector and turning down the F/P.
 
gt40x heads, are far superior to gt40 irons, there damn near as good as some of the others. But as i said, and rick re-inforced, the valve trains on them are a bit screwy. Ford is not known to do good valve jobs, or pay much attention to how tight guides are, and spring seat pressures are pretty much random. For $250, it's well worth it to take them to a head shop and have them valve jobbed, bowl blended, and spring seat pressure set.
I'm telling you to look into the valve train issue, BD went as far as to call his Ford guys and ask them what the hell they where doing.

The cobra intake is not the best in stock form for this setup either.
I've seen this combo except with a true gt40 intake, make over 300rwhp and run in the 11's. It took about 30 runs of practice, but my buddy got it there.

So if you do the heads, get either the FP adjusted better or run 24's, possibly use a better intake, it should be around 300 rwhp.
 
2000xp8 said:
gt40x heads, are far superior to gt40 irons, there damn near as good as some of the others. But as i said, and rick re-inforced, the valve trains on them are a bit screwy. Ford is not known to do good valve jobs, or pay much attention to how tight guides are, and spring seat pressures are pretty much random. For $250, it's well worth it to take them to a head shop and have them valve jobbed, bowl blended, and spring seat pressure set.
I'm telling you to look into the valve train issue, BD went as far as to call his Ford guys and ask them what the hell they where doing.

The cobra intake is not the best in stock form for this setup either.
I've seen this combo except with a true gt40 intake, make over 300rwhp and run in the 11's. It took about 30 runs of practice, but my buddy got it there.

So if you do the heads, get either the FP adjusted better or run 24's, possibly use a better intake, it should be around 300 rwhp.
Ill definitely look into doing the heads ,try to lean out my a/f a lil ,what would be the best intake for my application? Also if its possible, can you talk to your bro with 300 at the wheels and see what his fp, timing ,and may be a dyno sheet if available ...thanks for all your help man
 
stang619 said:
Ill definitely look into doing the heads ,try to lean out my a/f a lil ,what would be the best intake for my application? Also if its possible, can you talk to your bro with 300 at the wheels and see what his fp, timing ,and may be a dyno sheet if available ...thanks for all your help man
I'd use an rpm intake, might be a tad on the big side, but it will keep you from buying another intake if you have the heads ported later on.
Or my guys swear that the true gt40 intake is a solid peformer. They also have sent out cobra's to be extrude honed, which works well, but is not cheap.

Sorry, my friend is about 5 combos past his x head engine, but his #'s i believe were 316 rwhp, all his tuning was done at the track, he's a true track junky. It only went to the dyno for refernce numbers, not a change on a thing at the dyno.
If you had 24's, 38lbs would probably be the place to start.

I have 30's in my car, if you plan on keep them, i'll start it up and pull the vacumm to see what the guys have the pressure at, and you can pull a few more lbs out than what i have.
 
256rwhp * 1.15 (% drivetrain loss) = 296fwhp.
dyno headers vs stock headers and full exhaust = 20easyhp.
no accessories vs full accessories = 10easyhp.
12:1a/f vs 13.5 a/f = 10easyhp.
carb vs long runner intake = 5easyhp.
k'n'n filter and stock intake track vs no filter = 5easyhp
msd vs stock ingnition = negligable at this power level.

add that all up, bam! 346hp.
 
here you go Ron

ron2hz.webp
 

Attachments

  • ron2hz.webp
    ron2hz.webp
    2.8 KB · Views: 126
2000xp8 said:
Ford is not known to do good valve jobs, or pay much attention to how tight guides are, and spring seat pressures are pretty much random. For $250, it's well worth it to take them to a head shop and have them valve jobbed, bowl blended, and spring seat pressure set.
are you talking about porting the heads??
 
well i got a leak down/compression test ... the shop said i look good ...what you think??found oil on my plugs though, on all the threads and burntoil on the tips of a few...the shop thinks its my heads ... ford racing said they havent had any issues with these heads and they think its my leaking intake gasket seal causeing the oil on plugs and low dyno numbers...what you guys think??? Im waiting to have the shop do the seal on my intake for the 4th time now so i can rule that out now ... here the numbers 1 5% 150 2 5% 155 3 4% 160 4 3% 150 5 10% 150 6 10% 155 7 8% 150 8 12% 150