i have the 3.40 blower pulley and 7.25 crank pulley with the SDCE 8 rib kit . im told my pulley combo is spinning the blower to 57000, max is 62000. Why am i only making 5 psi? pulley combo should make 10 - 10.5 psi from the formula i found on here last night

few more details on setup.
402 ci tsp block , 317 heads with SS valves no porting or polishing
90 mm fast intake, 90 mm Nick Williams TB
d1sc procharger with the FMIC and Procharger Race valve. i am running the stock maf with combo'd sd tune

 

Is there a wastegate on that system?

 

nope just a race valve. watsegate isnt needed with this system

 

You check for boost leaks everywhere? Belt slip? I have a buddy with a similar combo and his makes like 13-14psi on max impeller so you should be a little higher then 5 lol.

 

Haven't noticed any belt powder. And no haven't checked for boost leaks. But will today. Felt good about that part

 

Same pulley combo I'm running (Stock motor though). When I first got mine on the dyno it only made 8#s and I felt like the belt was tight already. Well I cranked down some more on it and was able to get 9#s. Still showing some slip though and cranked on it some more to get 10.5 #s and the belt was silly tight.

I ended up getting a SDCE setup and although it never went back on the dyno, my boost gauge showed 15ish and the belt isn't like a guitar string.

Try to tighten it some more if you haven't. Also check for leaks.

 

I'm going to make a guess that it is your FAST 90mm intake, as they are well known for leaking under boost. Bob

 

if its not the belt slipping then id be with bob in saying the intake.

 

yeah man i'd say you have a boost leak

 

Anyone know of a way
To check the intake for boost leaks?

 

bump to the top

 

What Cam?

 

http://www.dsmtuners.com/forums/arti...et-tester.html

 

The only question I would have with that is what about when the cam has both intake an exhaust valves open? Isn't boost going to be bled off there?

The reason I'm asking is because I too have a FAST 90 and in the process of installing a D1 as well.

 

Epp blower cam

 

great point, i guess you'd want to loosen up the rockers.

 

Make sure the procharger is rotating in the right direction. if backwards, your only going to get is about 5lbs. Seen it happen to a corvette.

 

how could i check that????

 

Look at the way the fins of the impeller curve and compare it to the direction of the compressor housing, or take a pic and post it.

 

http://m61.photobucket.com/albumview...A20%2BqIIWk%3D