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Discussion Starter · #1 ·
Chris - When I originally put my vortech on my car 2 years
ago I had a SHM chip burned. I have added LT's, un-catted
h-pipe, accufab single blade TB,Pro-M 80 meter,42 lb injectors,
FMU 4:1 recal. I dynoed at 503 hp but was a little concerned
with the big dip at about 5600 then back up. Should I have
a new chip and get rid of the FMU?I have attached the Dyno run.

Thank You,
Pete
 

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Hey Pete, did you ever get this question answered? I also had my car built and tuned by SHM to between 547 and 521rwhp with a 2.62" pulley that slipped all the time. Now i'm adding long tubes and a bigger blower. Curiously, your trap speed seems low for the rwhp you dyno at, as does mine...

dave
 

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DaveRam said:
Hey Pete, did you ever get this question answered? I also had my car built and tuned by SHM to between 547 and 521rwhp with a 2.62" pulley that slipped all the time. Now i'm adding long tubes and a bigger blower. Curiously, your trap speed seems low for the rwhp you dyno at, as does mine...

dave
OMG.....who the hell invited you here Rammer? Probably that inbreed Cobra Killer. Oh well, welcome to insanity my friend.

Scott
VT
 

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Discussion Starter · #6 ·
DaveRam-My 118 mph was when I made 440 Hp with a 3.60 pulley, I now use a 3.33 pulley, I hope to get to the track soon.


Pete
 

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Pete, when i had 483rwhp on SHM's Dynojet, i trapped at 117. Then i dynoed at SHM at 547rwhp but could never get the belt to last with the 2.62" at the track. Now with an RR 2.80" pulley, the trap is at 119. My traps have never jived with trap speeds at the track like other people. As far as the FMU, i still have mine as SHM seemed to want to keep it, even though i have 42#s. It must be a 'play it safe' viewpoint.

dave
 

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Discussion Starter · #8 ·
What calibration FMU are you using, I use a 4:1 with the
42lb injectors. Im not getting any belt slip with the 3.33. When I
dynoed it hit 14lbs of boost at 6500 RPM.

Pete
 

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Dave,
I'm pretty sure your FMU is set at 4:1. With your cars weight and your hp, you should be trappin' @ a buck 23. (123 mph). However, with your trap speed of 119mph, you work out to approximately 500 rwhp. SO, it could be that the belt is slipping under load at the track, that wasn't present on the dyno. Even varying driving styles "shouldn't" effect mph. Hp is Hp, and weight is weight, so the car "should" trap 122-124 no matter whose driving. Driving style and suspension effects ET, but not really mph. With the JT on there, you should be able to pulley it up and still achieve that same boost level, thus ending your dreaded belt slippage issue. I'm hoping that's the case anyway. Take care.

Scotty
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Pete, Scotty is correct. I have the 4:1 FMU kit. I was getting 14psi with the 2.87" pulley and then 16-17psi with the 2.62". We never saw any signs of slippage on the dyno, but on the street, i was shredding belts unexpectedly. We then recently went with the 2.80" RR pulley and the shredding disappeared. So did 3psi!

Scotty, according to the calculator at Modular Depot, with a 119 trap and 3680lbs, I'm making 421rwhp. The Corral calculator says 494hp but doesn't specify drivetrain losses or not. I hope to make some serious gains with the JT!!!

Dave

P.S. Are you in bed already??
 

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DaveRam said:
Scotty, according to the calculator at Modular Depot, with a 119 trap and 3680lbs, I'm making 421rwhp. The Corral calculator says 494hp but doesn't specify drivetrain losses or not. I hope to make some serious gains with the JT!!!

Dave

P.S. Are you in bed already??
:confused:
Why the hell did you ask me if I was in bed already?? You're sick....:p Anyway, 421 seems low. Go to www.prestage.com to get the calculators I used.

Bye.
Scott
:evil
 

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Scotty, how did you find that Prestage site? I think most calculators use RWHP unless stated because 'effective horsepower' is that power actually moving the mass (car) to a certain speed in a certain distance. Force= mass*acceleration. Power=Force*Distance therefore, Power=mass*acceleration*distance.

Dave
 

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correction: Work=Force*Distance. Power=Work/time!!Therefore Power=mass*accel*distance/time. Yeah, that's it!!!

dave
 

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hey Einstein, stick to dentistry! LOL
 
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