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hey guys,

i know this topic has been covered to death in the past but my querie is a little different, i did a search and got the same old answers.

my problem is:

I have an r33 s1 and the car came with 2 bovs a stock and a blitz bov. the blitz is all the way down on one of the pipes that go to the intercooler.

i decided to take the stock off as it was defeating the purpose of an aftermarket. i put a plate where the stock was and blocked off the plumback with a turbosmart blocking cap (orwhat ever you call it). The after market bov goes off on heavy accleration but on lite exceleration i get that flutter noise (which i dont want ) i set the bov to go off pretty easy and it used to with two bos but now its not and i have set it to almost the weakest spring rate .

what have i done wrong ?? or is it normal to get a flutter at low RPM with an aftermarkt pod and front mount ??

i dont know if im parenoid but i can swear its increased lagging between shifts, my mates reckon that its the same so i could be wrong.

any help would be appreciated

thanks

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the turbo doesnt spin the other way

and yes the flutter is normal. Obviously its just air hitting the closed throttle creating the phenomenon of reversion lol

Yes, the air is going back into the turbo but the pressure from a stock turbo isnt going to cause too much trouble for a metal blade spinning at 100 000rpm

its not the blitz bov noise that i hate, its the flutter that you get when you block off your std bov and dont use a aftermarket. ( pressure building up and forcing turbo to spin the other way)

The BOV's have a screw for adjusting, this works like a tensioner.

When the screw is wound one direction, say in, then the spring inside becomes harder, therefore needing more pressure to open, so then it will open only on high rev's.

When wound out, the spring is softer, then it will open on low revs, which means less pressure to open a softer spring.

Just find the BOV, and screw the adjustment screw out a few turns, you should be fine.

If you want it to open on low revs = undo the screw

If you want it to open on high revs = tigthen the screw

If you open it to much you may get stallng issues when rev's drop, and I think thats also the case with it being too tight maybe?

Your getting the flutter because the BOV is set to firm or harder, =high rev's. Its not opening on low rev's so your getting flutter.

Found this on a site which talks about how to set your bov:

Most BOVs have a screw or nut to adjust the tension. You can turn the screw/nut to the right and increase the tension. Do this several times with a test drive in between. If your BOV stops letting out the pressure, you have adjusted it too tight. You will then need to start adjusting soft again. You must keep playing with this adjustment until you get it just right. A good adjustment will allow the BOV to release pressure after slight boost, and not stall afterwards. It is not necessary for the BOV to release pressure when you rev the car.

Hope that helps. :P

Thanks,

Abu

Edited by abu

Forgot to tell you where the screw is lol

Usually on the top of the BOV, or on some model BOV's the whole top section of it turns to make it fimer or softer.

Below is a little diagram of a BOV and how it works. If you look to the far right of the picture, at the top there is a screw, that is the adjustment screw your looking for.

2.jpg

Good luck! :P

Thanks,

Abu

thanks Abu,

yeah i know all about the screw to tighten or losen. I played around with it and made it so it went off alot earlier, unfortunantly though there is not much adjustment left and loosning it up any more causes it to stall.

its makin the flutter at very low rpm on light exceleration before it even hits boost so i doubt if it will set to that low without stalling

thanks Abu,

yeah i know all about the screw to tighten or losen. I played around with it and made it so it went off alot earlier, unfortunantly though there is not much adjustment left and loosning it up any more causes it to stall.

its makin the flutter at very low rpm on light exceleration before it even hits boost so i doubt if it will set to that low without stalling

ey dude, my car had the same setup on it wen i bought it, blitz pipe and valve down to stock cooler. try opening the valve up and cutting the spring inside down a bit. do little bits at a time till your screw will make it chatter all the time screwed in and release when screwed out. keep in mind with future plans on your car that more boost will make the valve release easiier!

hope that makes sence and helps!

brett

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