troubles with compressor surge

[blckkat]

okay so I got my car up and running finally and I'm running the IAP stage 1 kit. seems no matter how I adjust my BOV I'm still getting the fluttering surge even if I barely see boost. I've read on here different situations of running vac lines but I'm confused on the best way to run it.I'm currently running a recirculated BOV with the vac source tee'd into the FPR line and the wastegate runs a line from the side of it to the hot pipe just after the turbo. and I left the bottom hole open. the only other T i have is a 2nd one in the FPR line for a boost sensor. any thoughts?
Modified by blckkat at 1:01 PM 3/22/2006

[Ligouri Rd]

What blow off/diverter valve? I had a turboxs H34 diverter valve and it would not open unless the boost was more than 6 pounds or so. I changed to a forge diverter valve for an EVO-8 which comes with four different spings to change the opening characteristics. With the lightest spring I have no sign of surge. As a side benefit the diverter opens a little by the vacumme drawn at idle allowing the engine to pull directly from the maf instead of through the slowly spinning compressor. Since then I have not had to have any decel-air correction and the idle is rock solid.

[blckkat]

I'm pretty sure its a Greddy RS that's included with the IAP kit. I loosened the thing to the point that the adjustment screw fell out and I just partially threaded it back in....but then the BOV just bounced the whole way down the rpms when it actuated. and it seemed like it still was getting some fluttering before it opened.
Modified by blckkat at 4:47 AM 4/5/2006

[blckkat]

bumpity bump...still having troubles. I took one of the springs out of the BOV just to make it ridiculously soft to the point it sits open at idle and it still surges when i see any kind of boost? I'm kind of running out of ideas. new vacuum source maybe?

[Florida240sx]

Think it is the bov itself. I was told it's releasing the pressure.So no compressure surge.Just the pressure of it makes it open close open close open close. Not just open and close. 1st 30miles I drove it worked perfect. Now it's been doing the fluttering. As much as I've been boosting if it was surge my turbo would of been dead by now. Call Marc up and ask him.

[C-Kwik]

Surge will not be heard at the blow-off valve. If anything, the BOV is doing it's job. There was an article in turbo magazine a while back that tested a lot of BOV's. They showed it graphically and every BOV had a rapid open close cycle to it. The frequency and severity varied, but it was definitely there in every one.

[nissanfanatic]

Is it a Greddy Type S? Sounds exactly like typical Type S-hit.

I fought with that BOV for over a year trying to stop the surging... I never could. Now that I run a TurboXS RFL, I never get surge... I run no spacers and the BOV still stays closed at idle keeping my idle nice. And I run my BOV non-recirculated with a SAFC. Idle is rock solid.

[blckkat]

well I asked Marc a while ago and he's the one that told me it was compressor surge, he told me I should never hear any kind of fluttering and that the car should "never sound like a turbo car" he also suggested that the BOV be set to the lightest setting. honestly I think Marc is tired of dealing with me he no longer answers my calls and hasn't replied to my emails in over a month so...guess since the car is up and running he's done with me.is there a good way to tell if its just the BOV and I'm being paranoid? this is just killing me because I feel like I have to drive this thing like a little old lady.

[DammitBobby]

It seems like there are a few people with this same issue. It is a PITA when you buy something that is suppose to be a reliable part only to give you problems. I replaced a TurboSX knockoff bov POS open atmosphere a few months ago because it leaked. When I took it to someone who work on many different turbo setups to fab up a new hot side ic piping and install a bov, he recommended me to us HKS Type 1 bypass valve. I really like the design of this bov. It has 2 ports one is used for boost signal the other if needed assists in daily driving. Also you can buy it with 3 different springs. Since I replace the old defective bov and recirculated the new one the car idles, no backfire and runs smooth. I never had to adjust it.

[WDRacing]

Actual compressor surge is air making it all the way back to the turbo and coming out of the turbo inlet itself, or the air filter. If this isn't happening then drive it like you stole it man.

HEy blckkat, are you a MFFO...lol.

[blckkat]

Actual compressor surge is air making it all the way back to the turbo and coming out of the turbo inlet itself, or the air filter. If this isn't happening then drive it like you stole it man.

HEy blckkat, are you a MFFO...lol.

not to keep asking stupid questions, but how would I know if its doing that? could I be hearing air coming out of the air filter from too much blowoff being recirculated?MFFO?<--sorry not familiar with that one.

[nissanfanatic]

To support another arguement (BOV on hotpipe or coldpipe..???), having your BOV on the coldpipe will make it much easier to recognize surge. If you here little sputters of air from the driver's side of the car, you have compressor surge.

And just so you don't freak out, its normal to have slight compressor surge under normal driving conditions. Especially on larger compressors (T04E+). Just as long as you only here like one or two sputters of air under hard acceleration followed by the BOV opening, you are gravy.