Bigchef66

iTrader: (8)

Hi,

My vortech is only boosting 6psi with 2.87 pulley!! At 3500 rpm BOV begins dumping huge amounts of air. Will simply tightening the screw on the top of the BOV be all that's required or should I be looking for something else?? (All vacuum lines are in tact and all clams are tight)

thanks in advance

deanfootlong

iTrader: (10)

time for you to make a boost leak tester. go buy a pcv pipe cap the size of your inner coupler diameter, and a tire valve(search boost leak tester if you dont get what i mean). come back if you dont find your leak. then we'll try something else.

frankie945

iTrader: (35)

The bypass valve is allways blowing till vacuum tells it to close to build boost.Make sure ur belts are tight, vortech is known for belt slip.

Bigchef66

iTrader: (8)

Thanks for your input. Just serched boost leak tester and nothing relevant came up. Do you perhaps have a link to said page???

thanks

05Z33

iTrader: (11)

Just a thought but maybe your bypass valve is malfunctioning.

frankie945

iTrader: (35)

https://my350z.com/forum/forced-indu...-test-vid.html
https://my350z.com/forum/engine-driv...-test-kit.html

Bigchef66

iTrader: (8)

That is in the thought process also. Looking for a way to test it.

Nexx

iTrader: (41)

as long as you dont hear vaccum under boost, i doubt your bypass is malfunctioning. vortech's have issues with belt slip especially with smaller pulleys like your 2.87. easiest thing to do is tighten the belt and order the gtm pulley mod.

iStan

iTrader: (29)

Could you take a picture of the BPV and post it on here? We should be able to judge if the BPV screw is too loose.

Bigchef66

iTrader: (8)

Got it, thanks, makes perfect sense...

Anybody have any views about faulty Bov, replace or repair??

iStan

iTrader: (29)

Here is one option for replacing. We're waiting to get a little more feedback and some vids

https://my350z.com/forum/forced-indu...***-valve.html

Jeremy@Altered

We have blown out a few of the bypass valves.


I would just order a Race Bypass valve and weld it on.



JT

jpc350

Providing some more info would help diagnose your problem...Is the 2.87 a new addition? Did you have problems before. What boost levels did it reach previously.. You get the drift??

Bigchef66

iTrader: (8)

I have been running 2.87 pulley for a couple of months now. The car pulled very strongly up until the monday. I took it to dyno/tune on wednesday and found there to be only 6psi boost registering at MAP and only 310WHP and 320lbsft torque. At no time whilst driving prior to monday did I feel any sudden decrease in power, no smoke anywhere, no CEL's infact nothing just power loss. and the BOV seeming dumping plenty @3500rpm. Car has the following mods.
Vortech V2, 440RC, injectors, 2.87 pulley, kinetix SSV, berk HFC's, 1 step colder plugs, APS 2.5 true dual. Non of these mods are recent additions. Still on SS box.

thanks for your input

frankie945

iTrader: (35)

The belts probably stretched. Have you checked them? You always need to check your belts when supercharged. And If you log you should see the boost level variations in the log. That's a sure sign of belt slip with a supercharger. I just noticed you have the SS box. Try picking up a utec more control over then the SSbox.

cwylie

iTrader: (1)

Do a compression test if you blew bent a valve or blew a rind you could be losing boost. Otherwise I would say cap the BOV and see if you get full boost just don't drive it that way.

Bigchef66

iTrader: (8)

I have a utec as well but no-one knows anything about them here. The tuner can work with the ss box.

350Z400rwhp

iTrader: (4)

I had a whistle sound which I thought was a boost leak for the longest time and I was only hitting 5psi. I made a boost test kit and found some leaks (my link for the homemade test kit is above here, and actually found a major one with a bolt missing in my intercooler, might explain why I only made 330 whp even on a DD). I plugged the hole and had expected the problem to be gone. Got in my car and heard the same noise and was still only boosting to 5 psi. I finally examined my supercharger pulley and found that rubber had built up in the grooves and that there was major slipping going on. I pulled the belt and cleaned every pulley with a wire brush and rubbing alochol until all pullies were super clean. I then used sand paper to make sure every groove was completely clean (the rubber builds up deep in the grooves and pushes the belt out from making contact). I then put a new belt on and tightened and wham 10 psi, problem solved.

Here is a video of what I thought was a boost leak but turned out to be belt slip http://www.youtube.com/watch?v=VC9Q_xk4mrE

Bigchef66

iTrader: (8)

Just a quick thanks to you all for your help. We changed the belt, scrubbed all the pulleys and put 1-1/2 turns on the BPV screw. All seems well again, boosting hard and running like a raped ape!!!. Will re-dyno in a couple of weeks and get some new figures.

Thanks
Chef

Mr_pharmD

iTrader: (48)

Glad to hear u are back to normal but I'm curious on your A/F ratio bc I'm surprise u aren't running lean up top with only 440cc and no fuel return line and walbro pump.