compression surge, wastgate flutter?

[THEEAGLEHASLANDED]

So I recently bought a 91 tsi awd talon with an upgraded turbo, intercooler, bov, exhaust and some sort of maf translater. Im sure there is more done but the dealership I bought it from were idiots and didn't know a thing about it. This is my first turbo set up. So to my question... When I first got it I noticed instead of the typical pshhhhh sound most bov's make it was what I've read to be "fluttering or the sowing machine sound " . I read that the bov was probably to tight so I loosened it up all the way and then tightened it two turns. After loosening it I took it for a drive and the bov is now venting properly. The only problem is I can still hear flutter after the bov vents and at low rpms " around 3k " its doing the same. I have read a bunch of forums about "flutter" but none seem to resemble mine. I guess im curious if I have compression surge or if I got the wrong bov or maybe its nothing at all. Thank you

 

[THEEAGLEHASLANDED]

Thank you all for the help I'm very happy with my car and I'm looking forward to learning more about it. Thanks again.

 

[brian9397gsx]

Rfls really suck my buddy had one on his car when he bought it. I have ran stock garage modded, crushed, turbonetics raptor and finally went with a synapse diverter valve best bov on the market in my opinion.

 

[THEEAGLEHASLANDED]

If my spring is to heavy can I cut it to put less pressure on the valve until I can get a better one? Im afraid im gonna ruin my turbo if I keep this one the way it is for too long.

 

[JusMX141]

If my spring is to heavy can I cut it to put less pressure on the valve until I can get a better one? Im afraid im gonna ruin my turbo if I keep this one the way it is for too long.

You will ruin the turbo eventually.

So let me get this straight- a good used 1G valve for $30 is too much to spend....you'd rather hack the spring and wait until this knockoff POS-valve destroys your turbo? Sounds logical.

 

[THEEAGLEHASLANDED]

No that's not what I meant sorry if I came off sounding cheap. I've only had the car three days and im not sure what and where to get the right stuff yet. The last thing I wanna do is ruin my turbo.

 

[NHerron]

Don't cut the spring coils. Doing that is an even more crappy way to do it. It's like lowering your car by cutting the coils Instead, decrease the diameter of the coils. This will weaken the OVERALL spring and the spring rate will stay the same

If you feel confident, you can do this until you figure what BOV to replace with

Spring Fix For Tial BOV - Miata Turbo Forum - Home to the Turbo Miata

Since yours is adjustable I would grind enough to get the BOV to open slightly at idle with the adjustment kinda close to totally loose. Trim a little at a time until you get the valve to open at idle. NOW tighten until it closes plus another full turn, to take care of high vacuum conditions such has deceleration

 

[THEEAGLEHASLANDED]

So I have softened up the spring and it blows more consistent. What is the best way to make sure its not too loose now?

 

[NHerron]

Loosen the valve all the way and once it's barely open while at idle, tighten it until it closes and give it an additional 1/2 turn. High deceleration + closed throttle plate will yield the highest vacuum readings so that's why you tighten the valve another 1/2 once it's closed at idle.

Do you have a hand vacuum pump and a boost gauge which reads vacuum?

 

[LandoAWD]

So I have softened up the spring and it blows more consistent. What is the best way to make sure its not too loose now?

Replace it. You're wearing the band-aid; schedule the surgery.

 

[NHerron]

Kris what's wrong with his BOV

Well at least I'm assuming it didn't leak during a boost leak test and if he properly sets it as outlined throughout this thread, I don't see why the OP should replace it

 

[LandoAWD]

A knockoff of a junk BOV that leaks? Hmmm...

 

[NHerron]

Oh well yeah I totally agree with ya if it is leakin

But meantime, at least save the OP from total destruction of the turbo caused by significant surge as opposed to a common boost leak

OP should really do a BLT, if you have a MBC trying to up the boost, you could be working the turbo really hard if it's just loosing boost to a major leak

 

[THEEAGLEHASLANDED]

My bov doesn't leak thank god it was just still a litte too tight. I fixed it yesterday and its working wonderfully now. Thank all you guys for the advice. Anyone have a favorite bov they wanna suggest??? Plus I have an idle issue. Should a make a new thread or you guys wanna hear about it?

 

[NHerron]

I see the Tials and Turbo XS a lot but I'm sure there is a thread on that already

Yeah start a new thread if you can't resolve the problem by searching similar problems first

And drop off the link here, I would check it out