Blownramair

Okay guys... Having trouble getting boost... I ran the car last october at Norwalk and made 9.5lbs with a FMIC and a D1SC Procharger... I wanted to get the boost up around 12-15psi, so i put this SDCE tensioner on... Now i got 6psi... SDCE sent me a new crank pully and new blower pully to reach 12psi... So why am i only seeing 6psi on the dyno??? I have had problems with this procharger from day 1 and ready to say hell with it and go N/A or Turbo... What do i gotta do? I have had, no joke, approx. 40 1/4mile passes on this D1, could the blower be broken already? No leaks are present, however when i dynoed the car i took the acordian air filter off and just left that pcv wire that plugs into the plastic hat unplugged, i did not cover it up... is that my problem? I highly doubt it tho... Have any of y'all had this problem or am i just the unlucky one... I am soo frustrated, it's not even funny... Any help would be apprecited... Here's a condensed list of my hundreds of mods.

2000 Trans Am
W2W 346 blower motor
D1sc Procharger
Griffin FMIC
F.A.S.T. 900HP forced induction fuel system kit
C10 Fuel
Turbo 400 Trans with 4000converter
3" ypipe to 4" dumped over axel

kp

iTrader: (34)

What size pulleys do you have?

I have pretty much the same stuff you do (dont know what kind of cam you have) and 15psi of boost with a 7.25/3.7 pulley @ 6700 is no problem under 2000' DA.

You either have a major boost leak, bypass valve isnt closing, pipe isnt tight, something. Balancer can be slipping on the crank too, FAST intakes (if you have one) are known to leak, pcv issues, but only getting 6psi is a major problem somewhere. My bypass valve (vortech mondo) stuck wide open and I still had 10psi of boost..

You have all the right parts, just have to step back and see whats going on..

FWIW I have over 200 passes + a couple thousand street miles on this D1 and I bought it used, still works fine.

APD*98SS

Did you do the math on the pulleys vs engine speed? If the new set up has a lower blower impeller speed then you need more engine speed to get more air into the blower...

Blownramair

Did the math on the pully's and the my MAX impeller speed on the D1sc is 55,000rpms... When i ran 9.5lbs of boost my max boost was at 6700rpms and the blower was no where near maxed out impeller wise... Now with 6lbs my max boost is at 5600rpms, then it just stays consistant at 6lbs until redline, i cant explain that? Yes, i have a FAST intake but cant see a leak on any of the head gaskets/ intake... Do you know where they usually leak on the intakes? My BOV is what procharger recommended for my setup and i know that isnt staying open, no slippage on the belt is visible ( dont see any belt dust on the alternator, any pully's or any sign of HP increase/ decrease flutter on the dyno graph ). Anything else y'all can steer me to looking at? I appreciate your help!

Jayson

98Z28MASS

iTrader: (6)

maybe they just sent you the wrong belt?

98Z28MASS

iTrader: (6)

did you measure it before installing it?

Mark98SS

iTrader: (1)

The big vacuum fitting on the back of the manifold could be the problem. It does not have any kind of locking clip as it does on a LS1 or LS6 intake, just kind of pushes in. My setup is exopied to the manifold.

MrDude_1

iTrader: (4)

my guess is your crank pulley is spinning on the crank now. is it pinned?

Blownramair

Thanks for your replies everyone... The SDCE 8rib belt is the correct one and size, so that's ruled out... I am still having a tough time finding a leak anywhere... I have never seen this before, especially on my car... Lots of people in the shop said that FAST intake is not the most efficient intake to use under boost... I think im gonna rip that off regardless and have a fab shop custom build me an intake... Plus the polish will look alot better Other than that, no obvious leaks are present... but i'm still looking... I appreciate all of your thoughts and inputs guys... thanks for help... As soon as i find the problem, i will let y'all know so we can get a grasp on this thing! Take r' easy...

Jayson

MrDude_1

iTrader: (4)

is your crank pulley pinned to the crank, or is it just pressed on like stock?

Blownramair

I believe it is pressed on like stock... sdce sent a new crank pulley with the kit, as i assume you know... As of now, i am leaning towards a boost leak... im almost positive that the belt drive system is not the problem..

wicked_95z

iTrader: (8)

I would put my money on that. Ive had it happen twice. I was only seeing about 4 psi instead of 8

kp

iTrader: (34)

If you put an ATI balancer on and the crank isnt keyed it may loosen up on you, down side is it will tear up your crank. Quick check is to see if the balancer bolt is loose or not.

A D1SC moves a ton of air and to loose 5psi would be a huge leak.

MrDude_1

iTrader: (4)

if i were a betting man, the pulley spinning on the crank is where i would put my money...
you did change the crank pulley.. you arnt showing the belt slipping. the bigger belt is capable of spinning the crankpulley on the crank... and like kp just said, 5psi would be a huge leak.. theres no way you can have that 6psi on the dyno, and have the other 5psi worth of air at that volume pour out without you hearing it.

thats just my thoughts on it...


edit:
i never believed that sucker would ever spin loose, but after having it happen to a friend with his ASP pulley, i now realize how easy it is....

kp

iTrader: (34)

Once you get the belt to stop slipping the crank pulley will spin if it isnt pinned/keyed. That belt is turning 50-60hp at high impeller speeds and non-keyed, press fit balancer wont handle it.

I have alse seen people drop the key out of the blower by accident when swapping pulleys and they slip pretty well too

Black LS1 T/A

My vote is crank bolt backed out, too.

If you are going to spin a blower more than 10 PSI, I highly recommend pinning the crank or go home.
STOP! Check it NOW! You may be wallowing out the end of your expensive crankshaft as we speak!

EPP

iTrader: (22)

Some great suggestions here on this thread, let us all know what you find out about the crank pulley. Bob

wicked_95z

iTrader: (8)

Mine was keyed and I still spun the keyway off so anything is possible

Blownramair

First, I want to thank you all again for your thoughts and inputs, I dont know what i'd do without ls1tech... Secondly, If i key/ pin the crank pulley to the crank will i run the risk of tearing up my callies crankshaft? That doesnt sound to appealing, LoL.

When i get back home from the weekend, that is the first thing I will check and let y'all know what happen and hopefully some good hp numbers... Till then I left y'all with some pictures if you were curious of my setup, enjoy. Once again, thank you!

Jayson

kp

iTrader: (34)

Very nice looking setup.

NOT pinning or having a key in the crank runs the risk of tearing it up.

Most aftermarket cranks are cut for a key and so is the ATI balancer, they do that for a reason. If your crank isnt cut for one then you can drill from the front and install a pin.

And just having it pinned/keyed is no guarantee it wont come loose. I always paint a mark on the balancer bolt/damper so I can see if anything is moving. I have seen stock balancers crack around where the pins are and if the proper press fit and/or the bolt isnt tightened enough it will shear the keyway right off.

Either way check it as soon as you can, it can still be something else but the balancer slipping is something that can cost you a lot of $$.