350zDCalb

iTrader: (21)

So, I'm helping out Barzten1 put on a UTEC and tune his car..only, his Vortec supercharger is not making any boost....

A few weeks ago, we installed a rear cooling mod..to do this we had to remove the upper and lower plenum (he has the kinetix crazy looking plenum )... Barzten told me that his car had been bogging down for a few weeks (I interpreted this as not building boost, and the car was very rich under load)
Barzten told me that after we instaled the cooling mod, that the bogging down was stil there, and then it has progressively become more noticeable.

I installed a UTEC on the car today, disconnected the vortec fuel pump (switching to a different fuel system very soon here)..and went to go for a test drive..the car made a max of 0.7 psi....so I did the following trying to rule out blow off valve issues and boost leaks...

checked line going to BOV: has vacuum under idle, upon revving, can feel pressure coming out- boost...

disconnected vacuum line to BOV to see if we could build boost (suspected BOV was leaking out al the boost)---did not make a difference...

routed a different manifold source to the BOV- to no avail

-----------------
My ?:

Has anyone ever had a vortec failure where it stopped producing boost? The only reason I suspect a supercharger problem at this point is: we cannot find any boost leaks and the BOV did not change the scenario when altered

I am extremely familiar with the greddy tt kit and aps tt kit... and have always been able to resolve any issues quickly...I'm wondering if I am missing something with the supercharger setup

If anyone has any advice, I'm al ears, I plan to pul the upper and lower plenum off on Friday (next day I'm going to take a look at it)..and see if this sheds any light.

Thanks guys!
-TODD

Barzten1

iTrader: (18)

Thanks for helping me out with this Todd. I'm hope Sentry or Booger can loan us a hand

tig488

iTrader: (18)

is the pulley locked down tight, i remember reading about how on someones vortech, that the key that held the pulley to the shaft was broken, maybe the key is broken and the pulley isnt turning the shaft. it will stay on the shaft but not turn, when you rev the motor, does the turbine spin? and does it make that whine noise?

Julian@MRC

iTrader: (28)

We had a similar issue a while back..The problem was the mating surface on that Piece OF Sh iT Kinetix manifold was not properly machined and was causing a leak under boost, not under idle..We replaced it with a stock manifold and the car made boost fine.. Another issue we have seen besides the obvious belt slippage issue which Im sure you checked..Is the bypass valve in the lower front of the motor was filled up with all road crud and would not properly seat, causing it not to seal, thus, not holding boost..We had to remove it, dissasemble it partially and clean it very good and lube it up..Try these fixes first..

Barzten1

iTrader: (18)

Yeah thats all in order. I dont think its the blower. The blower itself still sounds and spins in normal fashion.
Remember the bolt we stripped on the lower plenum? Maybe there is a boostleak there under load.

booger

iTrader: (6)

Todd
the only thing I can think of is to preasurize the whole system . Make a capped off pipe the same aize as the IC pipe . Put a air connector at the end of the pipe . Break the IC pipe right before the BOV and hook up the pipe there . Then cap off the exhaust . Set you air compessor to around 40psi . Plug into the pipe you made and wait to see if you hear a leak .
I'll try to post a pic tomorrow of the pipe I made to do this . Im going out the door right now

booger

iTrader: (6)

This is what I found when I used my home made pipe . Mine was the Crawford though . I added more gaskets and I was fine afterwards

baileyrx

iTrader: (16)

the bov is "always" open, unless there is boost! Then it will (should) snap shut

thats how the bov my old ati procharger worked I assume the vortech is the same.

its opposite of a turbo setup.

the bov probably isn't closing properly! which means boost cant build up

DMK

iTrader: (6)

Well, for some reason the Vortech doesn't make any boost in neutral. I tested mine out and rev'd it to redline and it made near zero boost. Under load, it makes boost and act's normally.

Try connecting the engine to a smoke machine. That way, you can actually see a leak.

deanG35c6

The BOV remains open because you can't get the hg/mm low enough to close it. The SC is probably sending boost through the IC, but in never reaches the engine in neutral because it never makes it past the BOV. You'll have to trick the BOV into thinking its seeing 10 hg/mm or less to get to to allow air into the engine.

Barzten1

iTrader: (18)

Thanks for your help and ideas

booger

iTrader: (6)

There is no load on the motor when in neutral . Thats why no boost . The only real way to test the BOV to see it is closing properly and not leaking , is to do it on a dyno or the way I described in my earlier post

350zDCalb

iTrader: (21)

Yes, I realize that, we had puled the BOV off before and inspected it, when I alpied pressure to the BOV nipple (with my mouth blowing) , the valve closed, the action was smooth...no cause for alarm here

-TODD

Julian@MRC

iTrader: (28)

No way should you be able to close the valve with pressure from your mouth..I would check the spring and diaphram inside it..You would never be able to blow or suck hardenough on a vacume line to make that bypass valve close..Unless your VERY talented..

jpc350z

Another possibility is the S.S Box is not operating properly...cam signal, crank signal Maf signal, ground lost ???

DMK

iTrader: (6)

Doesn't SS Box only control fuel? Even if it wasn't working, shouldn't he still be getting boost?

jpc350z

Negative.. The S.S. box does a lot more than fuel...It takes the MAF signal modifies it and provides it to the ECU in addition to providing the RPM signal, timing, and fuel maps under boost..Look at the instructions manual and see the signals from the engine and thru the S.S. box and on to the ECU...maf, crank, and cam 1, cam 2, ground and battery... No rpm signal no boost for instance..

Julian@MRC

iTrader: (28)

This would not affect making boost on a SC car..A supercharger is purely mechanical and as long as the engine spins the belt, the blower compresses air.The only thing it could be is the Bypas valve is not operating properly,there is a vacume/boost leak, the belt is slipping, or the blower itself is not making boost..The function of the unit is purely mechanical.The SS box only has to do with tunning A/F and timing..Your information is incorrect.

deanG35c6

it is possible to use the SS for just fuel. You still have to use the MAF wire, but that's it. THis was when I used the J&S for timing. The J&S hooks straight up to the coils, so the crank position sensor, and cam sensors on the SS box were disconnected or bypass to allow the stock ECU control them. The J&S can pull timing based on RPM or Boost.

Julian@MRC

iTrader: (28)

Guys, this has nothing to do with the issue he is experiencing..His situation is purely mechanical,IE boost leak or belt slippage..There are no electronics involved in the operation of the Supercharger itself.