i have a 3.7 blower 7.25 Crank makes 13 psi with truck hat on and 15 off. @ 15 it made 644 unlocked and 700 locked..

What do u guys make

 

what u guys making vs. what u ran at the track.. i went 10.51@128, 10.55@132, 10.7@132 last weekend at 3900 pounds..

 

I don't have a F1A but I do have a 402 with a YSi. My trans setup is a 4L60,
I see around 22 psi and make around 860-900 to the wheels unlocked.

Car weighs 3640lbs with me.

Times in the sig.

 

your only making 700rwhp with a 3.7 pulley? what rpm you shifting at.
i would think you'd make more then 15psi with a 3.7.

 

What compression ratio? what size intercooler pipe

shifting at 7k.... doesnt ramp at all floor it at 2k and it flashes up and hit 15psi without inlet hat and holds it till redline..

 

Block, gaskets and heads?

.

 

10.25 compression, when I ran 8.8's it was the a LS2 block. I know have an iron block.

I'm using LS9 gaskets.

 

I figured you would be making more power and seeing better track times with a 402 and F1A procharger. Not trying to put you down, but maybe something is wrong?

 

I wish I knew what to check or change it is very aggravating

 

What's your pulley combo?

 

Funny , I have the same problem in almost identical engine and box combination.

I have posted on the other thread asking question and just bumped into your thread.

I have just bought and installed a new F1A , coming from a worn out D1-SC , the dyno graph and boost was almost identical between the 2 blowers.

Hard to believe considering the F1A is rated at 175 hp more and 175 CFM higher air flow.

Something must be wrong cause that makes no sense to me.


The F1A is almost maxed out with the 3.9 on the blower and 7.5 crank 8 rib

Showed 635 hp at 16 psi @ 7000 rpm no pipe on the back through a 4L80E and 3000 rpm converter un locked.

The D1 was maxed with a 3.4 pulley.

I believe that there maybe be a pound or so slip here and there even tho i have gone up 1/2 inch bigger on the pulley , but still the HP out put is no where near the 750 - 800 i was expecting , this is also with 17* timing on pump fuel.

I need to run some tests at this stage and take it from there.

Keep me posted on your progress please,

P.S how old is your F1A ?

cheers

 

I solved my problem after running a test i learnt that my current intercooler is a massive restriction with my combination.

24 psi in 16 psi out.

cheers

 

Wow that sounds less like an IC and more like a Cork.

I remeber when Procharger 1st came out with IC'd Centris.

I thought if you lost more than 2-4 lbs boost the IC was a restriction!?

 

what kind of intercooler/size etc. were you running??

 

Something doesn't sound right, I would have expected more out of that combo.

This comment tells you right there, something like belt slip maybe, since blowers don't flash to 15psi and hold.

 

It is a large 600 X 300 X 100 custom job rated at 1000HP, clearly since thats all i could ever make with it .

 

well he is running a 7.25. crank pulley. he needs a bigger one. hed have to go to a smaller pulley to get the blower rpm up. in going to a smaller pulley....the belt wont hold as much since the diameter goes down.


so we have small crank pulley.
belt slip
possible IC restriction
heavy heavy car.

 

410CI, TH400, 12lbs (7.25/3.400 with belt slippage) Have a Dan Schoneck cog setup, but have to buy new pullies and a belt. Right now it's just got two very small 4rib serpentine style belts which isn't doing much good.

Has been 6.10 best ET and 113MPH best at 3,750lbs.

 

I ran every test i could on mine. Even took intercooler off and put a 3" pipe in place... still only picked up 3 psi.. so i took it all off and im.trading it for a big 85mm turbo setup

 

nice !