i have a hard upper IC pipe and a Type S bov as well, and dont get any compression surge. my bov is vented in to the atmosphere, 3" turbo back exhaust, and seems very similar to your setup. except i dont have a hard lower IC pipe...and i have an Injen intake as well. mine has no compression surge at all...

 

Thanks, Grifter! Do you know how to tell if there's compressor surge though?

Your Injen intake and filter (is it a K&N Cone?) fits ok? Any pics?

Fred

 

Do you know how pigeons sound like?

If you hear pigeons when you shift gears, that's compressor surge.

 

nope no pigeons in my car (other than the ones that seem to like using it as target practice...)

yeah i have a K&N in there with the Injen. the end of the filter rubs a bit on the underside of the lip of hte fender but fits in there quite well. i can break out the digital camera a snap a couple for you if you want

 

I have both the UICP and the Type-S. When I first bought my car they were already on there so I thought nothing of it but the more i researched it I realized that I was having compressor surge. It does sound just like a pigeon or a sneeze type sound. If you really want to hear it for yourself turn your Type-S to the hardest it will go and run it a little. There is no way you can not hear it on that setting. The best thing to do is to keep tweeking it until it gets just before the point where it makes that surge.

 

i have a Greddy type R, and it would surge any time i backed of the throttle below 5psi,,, and it sounded bad!! my fix was to re install a factory mitsi BOV azwell i used an evo 3 ,, the "pssshht" noise aint az loud,, but who cares i have an external wasgate anyway .. but the surge stoped ,, no idle problems(u have to absolutely thrash your car and cruise upto a stop to see if it stalls) and the plugs show no sign of over fuelling,, my plugs are a nice tan colour.. just my two cents

 

Alright maybe I read that wrong but you are saying that you have a Type R and a stock BOV? If I am not mistaken you must be running some major boost there to need the Type R and if you have the stock BOV installed also that means that you would be getting leaks under pressure am I not mistaken? The stock BOV would leak some of the air out at the higher pressures before it was even supposed to.

 

Thanks, Grifter! Do you know how to tell if there's compressor surge though?

There is no way to tell if you are getting compressor surge, other than listening for it.

 

16g-95GSX, I think what evolution was saying is that he replaced his Type R BOV with the stock one from an EVO III. I don't know what kind of BOV the EVO's used, so I can't comment. If it can hold boost as well as the Type R, then it must be pretty damn good.

This is a bit off topic, but if any of you watch the WRC rallying on speedvision, it sounds like quite a few of those cars have compressor surge. You can hear the fluttering fairly loud (such as on makkinen's EVO). Why do they run like that?

Nick

 

Red97GST, is that "chirping noise" in those WRC races compressor surge?!? I used to think that noise was cool! But it's not so cool if that's the sound of compressor surge... For the record, my car's not making that noise right now, so I think it's ok.

16G-95GSX, when you got your car with the Type-S and UICP on it, did it already have the 16G? Is that why you had compressor surge? I'm still running the factory turbo, so does that mean I shouldn't worry too much as long as I don't hear that "chirping noise"?

Another thing I've noticed in the past day or two is that when I'm in 1st gear, and I start accelerating slowly then decide to step on it a bit more, the car "lags" a bit and "sputters" a little as I gas it more... it's not a jerking kind of sputtering; it's just very subtle, but the lag is definitely there; it's like a "shortage" of power... is this due to my Type-S? Can I fix it by tightening or loosening the BOV screw? Anyone have any ideas? Please share!

Thanks for all your help, guys!

Fred

 

Btw, (for those who missed it in my 1st post in here) I also have a "3-inch" A'PEXi RS-Series cat-back, and K&N FIPK.

Fred

 

DSMs are NOT supposed to vent the BOV to the atmosphere...

...unless you've done some hardcore fuel remapping.

Another thing I've noticed in the past day or two is that when I'm in 1st gear, and I start accelerating slowly then decide to step on it a bit more, the car "lags" a bit and "sputters" a little as I gas it more... it's not a jerking kind of sputtering; it's just very subtle, but the lag is definitely there; it's like a "shortage" of power... is this due to my Type-S? Can I fix it by tightening or loosening the BOV screw? Anyone have any ideas? Please share!
[/B]

If you examine how our turbo 2G cars are set up, whatever air that goes through the air element (and through the MAF) is accounted for by the ECU. If you're BOV is venting to the atmosphere, you're going to have an unbalanced mixture of more fuel than air.

Fred, what you're experiencing is probably your engine being flooded full of fuel (thus the lag).

Running rich isn't bad; but you're going to carbon foul your plugs, have carbon buildup, etc...

How to fix it? Don't vent to the atmosphere!

BTW, you said the bottom nipple of the Type S BOV was left open. (Having not seen a TypeS BOV in person, please don't flame me.) Are you sure that nipple is not where you are supposed to plug in a vacuum line from the intake manifold? (A 'nipple' is sure small for it to be venting air...)

[Edited by 95ESi on 06-28-2001 at 07:43 PM]

 

Leon, why you little... I'm gonna flame you to h e l l and back! j/k!!! Thanks for the reply! Well, there are 2 nipples that point towards the back of the car... the upper one is connected, but the bottom one is just left open right now. I'm kinda dumb mechanically so I don't know all the terms, therefore I don't even know if this is what people call "venting to the atmosphere". In the factory set-up, there's an elbow/connector thing from the BOV back towards the air intake "hose/pipe", and that's connected to the Type-S right now... Have I confused everyone now?!?

Fred

 

any pics?

You got a scanner?
Or use your NICE digi cam and take pics of the diagram and post it!!!!!


QUICK

 

The Greedy type-R BOV is meant for race application, so it probably have a pretty stiff spring (and spring rate) to start with, that's why you get surge when letting off part throttle. Meant for drag race cars..

for a street car, use the type-S.

type S= street, R = race.

Personally I don't like greedy BOVs.

 

Here are the pics...


Before (factory 2G BOV and pipes):

After (GReddy Type-S BOV and GReddy Pipes):

Fred

 

so where's this mystery nipple?

so where's this mystery nipple?

 

Oh, it's right here...

[edit: the top nipple is attached to the factory hose (pointing upwards in the 2nd pic), and the bottom nipple is the one that's "free".]

Fred

 

Ok, i said i didnt have compression surges? i tried cranking the BOV to full hard..i did get them then..then i backed it out to where it was normally...then they went away..

also.. mine is vented to the atmosphere, i would like to try to vent it to the intake if i could, but i have an Injen hard intake w/ no inlet for that...there is a small vaccuum fitting that is plugged and not being used on it, but nothing large enough to dump the bov into.. so where would i dump it to?

i plugged the small nipple on the bottom of the bov, and that really didnt do much, but atleast its plugged. where do the rest of you have that running to?

valid information, i have a hard upper IC pipe, factory lower IC pipe, full 3" exhaust, and a profec-b. if that effects where i should route things at all...
new to the whole turbo thing so bear w/ me

 

The lower nipple on the GReddy Type-S is normally left open by DSMers. Here's my story...

When I installed my 16G, there was noticeable compressor surge at light throttle. This was "cured" by tapping the lower nipple to a positive pressure source (i.e. upper or lower intercooler pipes).

You can have a shop drill and weld a nipple on your upper I/C pipe, then run a vacuum line to the lower nipple of the Type-S BOV. Or, if you plan on upgrading to a 16G -- RRE's install kit comes with a lower I/C pipe with a nipple pre-tapped.

 

wastegate line

Here's a suggestion:

Why not tap into the turbo/wastegate line for source to plug in the bottom of the bov?

 

Jackal, you said most DSM'ers leave the bottom nipple open... so are these DSM'ers "wrecking" their cars' engines then?!?

What about just plugging up the lower nipple? (i.e. instead of trying to drill a hole in the upper I/C pipe, etc?) And what can I plug it up with?

With that "sputtering" I'd described... should I be tightening or loosening the adjustment screw on the BOV? That "sputtering" isn't the compressor surge, right?

Fred

 

teh compression surge sounds kinda like a bird flapping its wings, right after the bov vents. or kind like someone sticking their tongue out at you and making that noise that goes w/ it

you can plug the lower nipple w/ a vaccuum plug, go to your fav parts store and get one. its just a small peice of rubber with a hole in 1 end..

to get rid of the compression surge i softened mine till it went away. i started from full hard, then backed it off a turn each time till it went away

 

TSI Spy 007,

It sounds like you have everything connected correctly. As far as your K&N not fitting. Exactly what filter are you using? I have a FIPK and it came with a monting bracket that attaches the end of the filter to one of the bolt holes that was used to attach the air box. the filter does rub a little on the elbow of my greddy pipe, but not so much that i have to let it float. i can take a few pics of my set up if you like. i hope this helps.

 

It's normal to leave the bottom nipple open, you shouldn't worry about it if you're still running the stock turbo. If you're hearing a clean "whooosh" or "pshhh" then all is well. If you hear pigeons, loosen the screw a little.



[Edited by Jackal on 06-29-2001 at 01:06 PM]