MadIceV8

iTrader: (12)

Can a procharger unit be bad even if it still makes boost? Personally I would expect a unit to either work or not, seeing that it is only a set of gears.

I only ask since I've been chasing down a random problem with my Procharged LS1 for the past 2 years with zero luck. No leaks, no belt slip (sdce), no cracks, clean intercoolers, but I only see 50% of the boost I should be seeing. Also my MAF reads 6g/s without the blower... and 4.5g/s with the blower? Vacuum is really high (26) and doesn't see boost till after 4000. Ugh.

SilverSS

iTrader: (30)

Some people have mentioned on here to make sure the impeller is spinning the correct direction. Could be the wrong head unit?

MadIceV8

iTrader: (12)

Correct direction. The unit does blow a lot of air out of it. On a side note, my air temp. sensor reads at 109*. Not sure if the air coming out of the intercoolers should be that hot or not.

Monte4ever

iTrader: (2)

From what I've read 109* is not that bad.

BrianC98Z28

iTrader: (11)

109 isnt terrible, have you ever thought to send it in to Procharger and let them service it and take a look in the 2 years?

Slowhawk

iTrader: (12)

Probably the blower spinning backwards. It will boost but the boost will be alot lower. They come regular rotation and reverse rotation. Just different impellers.

BrianC98Z28

iTrader: (11)

hence why i asked to send it to ATI and have them make sure its good to go and set it up right.

KS91Z28

Post a pic of the inlet side of the blower.

white01ss

iTrader: (37)

If it's not impeller direction it's probably a bad or wrongly plum by-pass valve. To test, you could remove the by-pass altogether and plug the hole. If it makes the proper amount of boost you found the source of the problem.

The vacuum line to my by-pass was originally plum from the horn vacuum reservoir which made it stay open all the time (that black ball is fed with one-way vacuum check valve). The car made 5 psi of boost with the by-pass open, but once it was corrected boost jumped to 10 psi.

MadIceV8

iTrader: (12)

BrianC98Z28 - Thinking about sending it in just to rule out any issue. Personally I would like to borrow a unit from someone for a day but no such luck with that. See attached photo about rotation.

Slowhawk - Didn't think the unit would still make boost with the impeller set as standard rotation. I doubt that is the case but I attached photo's for you to see.

white01ss - Tired three different vacuum source's directly off the back of the manifold and at the HVAC, also made sure the check valve was removed at the one manifold source. Right now it is hooked up at the brake booster per FLP. I also have two bypass valve's that I tested. However I still plan to remove the valve and block off the port, as you mention, since I haven't tried that.

Appreciate the replies.

BrianC98Z28

iTrader: (11)

did you buy this new or used?? Heres a link to a very similar problem, thats why I say send it to procharger or call them to give them the serial and they can tell you. https://ls1tech.com/forums/forced-in...si-help-2.html

MadIceV8

iTrader: (12)

BrianC98Z28 - I've talked to them before and gave them my serial. Never specially asked about rotation. But according to the photo's in the thread and other's that I have seen, my rotation is correct. Punisher_ws7 does look like a standard rotation, reverse of mine.

Turbostive

iTrader: (3)

If it isn't leaking oil then there must be something wrong with it.

02LS1ram

iTrader: (17)

I having the same issue with my P1. But i think it may be my pulley combo. I need to call bob and ask what the right size/ combo should be. I know I have a 3.85 on the blower now and it's only makIng 4 lbs

AFASTYZFR1

iTrader: (55)

What pulleys are you running?

Are you sure SDCE is installed correctly?

Need more details on set-up

MadIceV8

iTrader: (12)

7.25" Crank/3.4" Blower spinning at 6,000rpm. Making 5-6psi. 8-Rib SDCE. SDCE is installed correct, belt is nice and tight. I upgraded to SDCE to rule out belt slip since I used to run the 6-Rib 6" crank/3.1" blower combination and only made 3.3psi.

blue00ZZleeper

iTrader: (5)

I ran the 7.25 crank with a 3.70 on my D1 combo and it made 10ish psi. I wish I had more advice on what the problem might be. I'm going to assume you checked all your piping and your manifold correct? The thing that has me confused is how the vacuum is so high. What's the rest of the combo?

MadIceV8

iTrader: (12)

I believe your psi numbers were one of the numerous members I was basing mine off of. Granted yours will be a little higher since you ran a D1SC. With a 3.85 pulley I only saw 3. But yes the piping and manifold have been checked multiple times. FLP even smoked the entire motor till it came out of the air filter. Both them and Procharger said that you have to have a large leak to make any noticeable boost drops, as I had only 2 pin hole leaks when I did the pressure test myself.

I discussed a possibility of maybe something odd with the valve-springs or if a piston ring may somehow be bad with FLP. The motor runs as it should without the blower attached.

As far what is done to the car... pretty straight forward. Long tubes headers no cats, comp pushrods, dual valve springs, level 5 4l65e with 3200 stall.

Bob@BruteSpeed

iTrader: (16)

The D-1SC seems to generally make around 3 psi more than the P-1SC with any given pulley. I'd next try removing the bypass valve and try running it briefly without it. Also, confirm the bypass valve is installed the correct direction. Bob

blue00ZZleeper

iTrader: (5)

That amount of vacuum still has me confused. Do you have any dyno sheets? That high of a vacuum and that low of a max boost pressure is weird. If you go 100% throttle at 3000rpm it should at least go to 0" I would figure (rough estimate) Try a compression test and see what it comes up with? Maybe a leak down as well?