for those running a greddy kit on a sohc w/out BOV: do you hear a fluttering type sound when you get off the gas or shift while you're in boost? i just put in my kit and im getting this sound a little. just wanna kno if its normal or ok. i'll be getting a BOV soon tho. thanks

-alan

 

depends on the BOV...for most BOV's, this is a sign of compressor surge (compressed air bouncing back and forth off the throttle plate and the compressor blades)...which is bad. Short term affects are major turbo lag, and it can ultimately cause the turbo to fail. Solution is to losen up the BOV a bit until the flutter is minimal or gone.

however, I think if you are using one of the Greddy BOV (I forget which one) it may be just the characteristics of that particular BOV..

any other inputs on this?

 

he does not have a bov at all

 

could it be the turbo spooling down at a rapid rate?

since there is no where to vent the charge it will slow down the turbo, so maybe thats it?
get that BOV soon, its really not good for it not to have one

Rob

 

I had the same problem on my DOHC before I put my BOV on a stronger vacuum source (it wasn't opening properly). Yes, I know that you don't have a BOV, but it produced the same fluttering sound you're describing since the BOV wasn't functioning properly. It's mild compressor surge.

 

You have compressor surge. Go to the junkyard and pick yourself up a BOV off a Eclipse GSX or GS-t... it works fine and sounds good too when its not recirculated as it is on a stock DSM. For that matter, you can make any BOV work pretty much, so if you have a friend who, say has a stock boosted car and put a aftermarket bov on, you should be able to use their stock one with a little work.

 

yea i was plannin on running a dsm bov cuz i can get one pretty easy. so the greddy kit for the sohc has compressor surge? i thought greddy didnt include a bov flange cuz the kit would be safe on 5psi? o well, i guess i'll get that bov like planned anyway. should i just let the shop both drill the hold and weld the flange?

oh yea, if i drive around like this for like just another week and try to stay outta boost, it shouldnt damage too bad rite? thanks

i would appreciate if another sohc greddy owner could tell me they're experience with this. thanks alot guys

-alan

 

Yes, it is compressor surge...sounds like a horse. I had to wait a month after I installed my kit because my BOV was on backorder. It will be fine, just work on getting the BOV on soon though, I know you'll like it.

 

guys Bosch generic BOV is around 25 dollars and it works wonders.
stan

 

yea i heard about those. where can i find one and how does it sound?
thanks

 

anoth sohc turbo awesome

mine is about to get the rebuild done gl with yours

 

its not that any certain kits has compressor surge more than the other, its the fact that the turbo is still spooling for a fraction of a second when you close the throttle so where does the boost go, it hits the throttle plate and comes back hits the turbo and keeps doing those trips back and forth till it runs out of energy.

BOV is good

 

i'm running a sohc with a homemade kit, and i'm running the dsm bov and it works great...and it's pretty loud

 

Ebay. From what I've read, they're pretty quiet. I love my DSM. :D

 

any car using bosch ECM/turbo will have the BOV, Saab, Audi, and some Nissan. get it at the dealership.
quiet and stealthy.
stan

 

i do'nt want to be an *** but i think he's talking about the fluttering noise of the internal wastegate.. i't sounds like an laughing jakhal...

 

the best thing to do now is just dont let go of your throttle all of a sudden. just ease off of it.

 

hey hardcore, you had this sound too with yours from the wastegate? or you're just guessing that that's it? i dont kno what compressor surge sounds like, but my sound is like if you closed you lips lightly and blew out some air. how's your setup doing? got it in the car already?