What would cause a Vortech 9psi kit to only make 6 indicated psi of boost?

I drove a 2002 LS1 6 speed today absolutely bone stock except for the blower. It has the aftercooler, V9G blower, etc. but only shows 5 to 6psi boost at around 6k rpms.

Might they have the psi pulley combo on there?

The owner mentioned the computer really needed reprogramming to get the kit to perform right.

Any thoughts?

 

I am working on installing my 3rd vortech kit and I have been getting a 8 # with factory pulley and stock motor the one I am putting on now will have a smaller pulley because of heads cam headers and a couple of other thing I have not heard of a vortech being so low with factory motor.

 

Someone else I talked to said there was an adjustable wastegate (or something similar) that could be set to a lower psi, does that sound right?

 

I see you have heads and cam. Right there could drop ya 2psi. Just cause its flowing more. You have the same power but you make it with less boost

 

I don't think my vortech has a wastegate btw jhelms are you running factory head gaskets and bolts I have been waiting for gaskets from are for about 6 -7 weeks now about to give up

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Cool28:
I see you have heads and cam. Right there could drop ya 2psi. Just cause its flowing more. You have the same power but you make it with less boost </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Hey guys, thanks for answering and offering your thoughts but as I stated in my first post, this blower is not on my car.

The car that I drove with the blower is not a heads and cam car. It is a totally bone stock 2002 T/A M6. Stock filter, stock exhaust, stock tires, stock clutch, stock head gaskets, etc.

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">2bseen:
I don't think my vortech has a wastegate btw jhelms are you running factory head gaskets and bolts I have been waiting for gaskets from are for about 6 -7 weeks now about to give up
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I might be calling it the wrong thing in calling it a wastegate. It makes a 'whooshing' noise similar to the muted BOV on my T5 turbo when you let off in boost or when you shift.

My other blower LT1's (the ATI and the Vortech) did not do this, but another friend of mine has a 99Z28 with a Vortech and he said his does this and it's because of the BOV or wastegate or some-other-type-of-valve that is set to let pressure off at a certain psi.

So I'm thinking that could be the case with the 2002 TA that I drove and that could be why we are only seeing 5 to 6 psi with it instead of the advertised 9psi.

Does that makes sense and seem feasible?

As far as my head gaskets go, replacement gaskets came in my H&C kit from http://www.racenet.net - I'm pretty sure they are factory replacement gaskets.

<small>[ March 22, 2002, 11:54 PM: Message edited by: jhelms ]</small>

 

I found an increase in boost when I did the "free ram air mod." I guess what I am trying to say is any restriction on the intake might cause this. I don't see 8-9 psi till approx. 6400 rpm.. Also what you are referring to is not a waste gate, it is a blowoff valve. Basically just there to prevent compressor stall between shifts. Also Vortech will tell you that "you may lose a 1-2 psi do to the aftercooler, but the increased efficiency makes up for it.." Jason

 

ATI's for LS1's have the "Anti-Surge Valve".

Mine has a "phsst!" kinda sound to it when I come off of boost.

Just another 'nasty' little noise my "Black 'Gal" makes when she's doin' her thang! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

 

It may be belt slippage also, check the belt assembly. Good luck! <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

 

jhelms, are you thinking of a bleeder valve?

Just some food for thought here...I had Vortech's V1 S-trim kit on my '91 Mustang. The kit was rated at something like 8 or 9 or 10 pounds...it was the one step above the 5 pound A-trim kit. Anyhow, the damn thing only ever made 5 psi. I could spin that SOB into the rev limiter and the boost gauge would read no more than 5 psi. It was 100% stock right down to the mass air, injectors, and throttle body. Maybe Vortech overrates their boost ratings beause they're thiking along the lines of modified motors and you'll actually see less with stock motor. But then again, like mentioned above, boost is a measurment of pressure and a more free flowing engine would accept more boost...so that may not be it.

I tightened the hell out of the belt on the Mustang. There's a little arch on the tensioner with a bolt coming through. The bolt was about in the dead middle of the arch when was reading 4 or 5 pounds so I though that was it. I tightened it so the bolt was at about 95% to the right on the "tigher" side but that was not the problem. It still only read 5 psi.

I never got a chance to look into that too much. Between the detonation, popped head gaskets, coolant loss, malfunctioning themos, dead TFI's, erratic MSD's, bad fuel pumps, and leaking FMU's the low boost was the least of my problems. I got to the point where I wasn't worried about the car running fast...I just wanted it to run in the first place! <img border="0" title="" alt="[Sad]" src="gr_sad.gif" /> POS Mustang. I had a '91 GT that ran like a raped ape for three years...then the Horespower gods screwed me. <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" />

 

No Vortech supercharger will work right just yet on the 2002 LS1's. Vortech's engineers have just now finished the computer programming for this model year as of last week. There was a lot of problems they had to work out is what I have been told.