Greddy Type RS flutter or surge?

[ishnish]

Hey guys. So I recently installed my Greddy Type RS in my car with the help of my friend. We then tested it out trying to fix any issues with flutter. The adjustment screw was pretty tight cause all together, I probably loosened it with 7 full turns or so. Anyways, typically it would flutter at 4k even 5k rpm. I got the fluttering to stop but today when I drove it, I noticed that it flutters a bit at 2.5k rpm. Should I loosen up the adjustment screw a bit more? I don't know how much more I can loosen it but I really don't want that flutter to be there because I don't know if it's surge or not. From what I know, you shouldn't have any flutter but I've read many threads where people say it's normal when reflecting how much you're boosting at the time. I have a fairly new 16g turbo in there so it gets me worried. Also, I don't have a boost gauge installed yet so I'm sure this would just make everything a lot harder. Any help would be appreciated.

Thanks

 

[GSXbooster]

There are 2 springs in the BOV itself. Remove the top housing and take out the smaller spring. Fine tune the adjustment screw afterwards. This should solve your fluttering issues.

I did the same thing with my type-S. Save the smaller spring for when you run more boost down the road.

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[JusMX141]

It can either be Blow Off Valve flutter from the valve being too stiff, or Compressor surge from the valve not opening at all. One occurs at the turbo, one occurs at the valve.

Start by setting the adjustment screw softer and see if the problem clears up. If not, you may need to remove a spring from the valve. When I first bought my GSX it came with a knockoff Greddy Type S and both springs were still in it...the valve was stiffer than a crushed 1G BOV; I'm surprised the previous owner didn't murder the turbo.

 

[ishnish]

Thanks for the info guys. I have to go to work in an hour so I don't know if I would be able to accomplish this in that amount of time. For now I guess I will try to loosen the adjustment screw and see what that does.

Is it pretty easy to tell which one the smaller spring is GSXbooster?

jusMX141, I'm guessing Blow Off Valve flutter, just like compressor surge, is not a good thing as well. So even if I have one or the other, they're both still a problem correct?

I've been reading a bit more on other forums or threads by searching on Google and some people say that if you're at low boost and shifting in the lower RPMs, then the flutter or surge is normal. Idk if this is true. Either way, I don't think any surge should be "normal". If that's the case, then it would mean that I should just be shifting much later since the flutter or surge at lower RPMs is apparently inevitable.

 

[GSXbooster]

Yes, it's pretty easy to tell. The smaller spring sits inside the larger one. If you can, check out the diagram I posted.

 

[JusMX141]

Any surge at all if definitely not "normal"....it means the blow off valve is not doing it's job. It may be normal if you're running 35psi and have the valve adjusted super-tight, but the general consensus is that you can have a soft valve and no flutter/surge or a hard valve for high boost and a little flutter/surge in the lower boost levels is accepted.

The only turbos that will not suffer from compressor surge are ball-bearing turbos as the shaft is always supported by the bearing. A surging journal bearing turbo will force the shaft to contact the bearings, or the bearings to contact the housing instead of floating in oil.

 

[ishnish]

Yes, it's pretty easy to tell. The smaller spring sits inside the larger one. If you can, check out the diagram I posted.

I did look at the diagram sorry about that I guess I just didn't notice at first because it all looked like one spring. I can see it now though after you described it. Thanks

Any surge at all if definitely not "normal"....it means the blow off valve is not doing it's job. It may be normal if you're running 35psi and have the valve adjusted super-tight, but the general consensus is that you can have a soft valve and no flutter/surge or a hard valve for high boost and a little flutter/surge in the lower boost levels is accepted.

The only turbos that will not suffer from compressor surge are ball-bearing turbos as the shaft is always supported by the bearing. A surging journal bearing turbo will force the shaft to contact the bearings, or the bearings to contact the housing instead of floating in oil.

Yeah I'm definitely not running 35 psi. I'm only at stock boost anyway. So I guess I will first try loosening the adjustment bolt and see how that goes. If that doesn't work, I will then just take out the smaller spring like both of you suggested. I'll report back tomorrow on how everything went. I'm guessing my valve should be very soft btw then. Since I'm not at high boost at all?

 

[FIBA M - EC17PSE]

Mine does the same but only at around 2k if I'm just on acell then i let off! But when i drive normally it don't do it. I've read that lower down the rev range you are it will most likely happen. As I said mine does the same flutter at 2k, mines the type s on the medium setting so around half way on the adjuster screw.

Is yours doing this even at 4k + revs? Even after you've now adjusted it?

 

[ishnish]

No mine actually is like how you described. If I let off the gas at around 2 to 2.5k, it'll flutter. It won't flutter at 3k though. I just thought that any flutter whatsoever is bad so I'm trying to get rid of any.

 

[FIBA M - EC17PSE]

No mine actually is like how you described. If I let off the gas at around 2 to 2.5k, it'll flutter. It won't flutter at 3k though. I just thought that any flutter whatsoever is bad so I'm trying to get rid of any.

im pretty sure its ok mines been like this for a few years now and i've read others saying it happens to them aswell! just keep an eye on it but to be honest i wouldn't worry. as long as its not in the upper rev range then your fine.

 

[ishnish]

Thank you that's good to know. Like I said, I've read many other threads about others going through the same thing saying that it's fine. I think just to stay on the safe side, I might loosen up the screw a bit more just to adjust and see if it goes away. If not, I might try the spring removal suggestion. My only problem with the adjustment screw is that it's a little long because there's a very small dent on my hood from my BOV . New knew what it was until now haha.

 

[FIBA M - EC17PSE]

Thank you that's good to know. Like I said, I've read many other threads about others going through the same thing saying that it's fine. I think just to stay on the safe side, I might loosen up the screw a bit more just to adjust and see if it goes away. If not, I might try the spring removal suggestion. My only problem with the adjustment screw is that it's a little long because there's a very small dent on my hood from my BOV . New knew what it was until now haha.

haha thats kinda funny. if you loosen it too much it wont allow you to build enough pressure up and might leak past so be careful.

it took me about 11-14 drives before i got the right setting and its been good ever since. try it like mine and have it around half way or a little more.

and i know what you mean ive read the flutter issue aswell but ive also read its fine so i guess its up to the person really. im happy with how mine is so its up to you now and how you feel happy.

 

[ishnish]

Lol yeah my friend and my bro looked at it and were like "Bro I don't know if you have enough clearance for the hood with that thing" haha. Yeah my main concern is loosening it too much also. I don't want it to basically leak. But if this were to happen, wouldn't I have a rough idle or something?

Idk what you mean by halfway. I honestly can't tell what's halfway on the adjustment screw. I'm pretty sure I'm way more than halfway only cause it's hitting the hood now. I can easily turn it with my finger.

 

[romeen]

If you eventually decide to replace your Greddy then I would suggest looking into the stock BOV from an EVO9 MR or EVO X. You want the metal ones, not the plastic 2G looking units used on earlier EVO's. They can be found pretty cheap on the EVO forums. No flutter regardless of how little boost you run. They react very fast and hold pressure better than a 1G. The only difference between the EVO9 MR and EVOX valves is how the vacuum nipples are "clocked" so they point in different directions. Otherwise, they appear to be identical.

But hopefully you'll be able to get that Greddy working properly.

 

[Talondvr]

This guide does a very good job at explaining things. I followed his guide to adjusting it and also took the smaller spring out on mine. Best I've got it to work so far but still flutters at low rpms. Hope it helps! http://www.dsmtuners.com/forums/bolt-tech/96185-wobbles-guide-setting-up-your-bov-properly.html

 

[ishnish]

UPDATE: Alright well I adjusted the screw a bit more but now it's really loose I'm pretty sure any further and it'll come off . The fluttering around 2-2.5k hasn't gone away. So I think I'm gonna remove the spring now. Can anyone explain HOW the spring suggestion will work? Not that I doubt it or anything but I would just like some enlightenment on the subject =). So basically, I would just like to know how it would help because if this is the case, wouldn't it make it kind of useless for Greddy to use another spring in their BOVs?

Thanks for the suggestions guys! Romeen, Idk if I will be investing into another BOV just yet only because I just got this one plus I have a 1g BOV also. I planned to use the Greddy until it can't hold anymore boost and maybe modify the 1g BOV later on if boosting higher.

Talondvr, you're awesome man I'm gonna actually read up right now. Do you have the same BOV as me?

 

[Talondvr]

I have a type-S. The flutter is unstoppable on mine. Only under high boost (8psi+) does it not flutter.

Basically the bov will open your manifold sees vacuum. Pull the dump tube so you can see the valve then (with the dump tubed blocked for a steady idle) adjust the screw so the valve is just barley open under idle vacuum. This is whats worked best for me.

 

[chadkassinger]

Mine does this around the 2-2.5k range also but it actually sounds as if it is coming out of the air filter. I think its just the excess pressure in the IC piping after the throttle plate closes it just pushes out of the intake pipe

 

[Boosted98gsx]

Mine does this around the 2-2.5k range also but it actually sounds as if it is coming out of the air filter. I think its just the excess pressure in the IC piping after the throttle plate closes it just pushes out of the intake pipe

That's called compressor surge, and it can kill your turbo's bearings.