Ryan23silverado

iTrader: (1)

Okay, I am not admitting defeat to a Radix

I need some help though with my Whipple. It is a single belt setup, and I am running an '02 LS6 cam in a 5.3L. You can see my setup for the intercooler in my signature. Here is my problem, with the 4.25" pulley we saw 3psi. I am now running a 3.5" pulley (which stock should be somewhere around 13-14psi) well, I am seeing 4psi of boost

I knew it was not pulling as much air as it should be because on an AutoTap run I registered only 37.8 lb/min. on the MAF. Other engines with this 3.5" pulley see around 50lb/min. going through the MAF.

There are No vacuum leaks, so there should be no boost leaks (I have looked and tighten and retightened everything) So, today a friend and I took off the blower to make sure the bypass valve was okay. We pulled vacuum through it and it stayed open for as long as we had vacuum on it. So this means no tears in the bypass valve diaphram, therefore cant be leaking boost through that. The belt does not slip at all since I made it really tight. There are no signs of belt dust. I know the bypass valve is not being blown open by the amount of boost being pushed against it because many others have gone this high without popping that butterfly valve open.

Whipple superchargers cannot go bad can they? This is my last resort that I can think of since there are no vacuum/boost leaks, the bypass valve functions like it should, and the rotors in the supercharger turn very smoothly with not even a hint of grinding noise. So can it just be that the supercharger is not putting out 13-14psi of boost in the first place and that is why I am not seeing this on the boost gauge? I need some good advice.

Thanks.
Ryan

EDIT: with other testing, the intercooler drops a hair less than 0.5psi. With the 4.25" pulley it measured 3.5psi right after the blower (reading taken by teeing off a bypass valve line) and 3.0psi after the intercooler (reading taken by teeing off the fuel pressure regulator line)

454SuperSport

check the bypass again. that has to be it, is there any way to hold it closed? are you still using any of the whipple computer stuff?

Ryan23silverado

iTrader: (1)

I took off all of the Whipple computer stuff, including the solenoid that loops into the bypass valve (thought that solenoid may be causing the bypass to be opened, but I guess not)
The bypass checked out though I would think that is the only thing also to be venting upwards of at least 6-8psi. The rest of the drop may be due to cam and headers and half pound to intercooler.

Ryan23silverado

iTrader: (1)

Okay, inbetween studying for finals today, I will clamp the bypass shut on the outside. Maybe the bypass valve is getting popped open with the pressure built up inside...

BigTex

iTrader: (16)

I agree, look at the bypass valve first. Obviously, the MAF numbers are low, so it can't be a boost leak otherwise the MAF would show larger numbers.

SPRAYEDSIERRA

iTrader: (2)

My truck will show 7 lbs of boost on the boost gauge, i can unhook the whipple computer and it will only show 4 lbs, i dont know if that helps any, but i tried it to see if the computer had any affect and on my truck it did.

Ryan23silverado

iTrader: (1)

I don't know why the computer would improve anything? The boost making process is all mechanical. Who knows though, I will try almost anything at this point.
I will hook up the computer sometime today and see if it helps.
Thanks for the advice guys. Keep it coming.

ranwalk

iTrader: (1)

I would hook up the Whipple computer also. Isn't some of the boost bypass saftey system electronic?? I'm not sure, but it's worth a try.

Ryan23silverado

iTrader: (1)

AWESOME!!! The computer actually does do something on these kits. Thank you guys sooooo much for the advice!
I guess that bypass valve can be blown into the open position if it does not have that electronic solenoid hooked up to it...let that be a lesson to all -don't take off the computer.
My truck is scary fast now! I need to retune for less timing as it pings at 3/4 throttle with this pulley.
I will have to hit the track soon. I think low 13s-high12s are close.
Thanks once again guys, you rock!
Ryan

454SuperSport

does this mean we have to keep the computer?? damnit! thats the sole purpose i wanted bigger injectors!