Ok, I have a question that someone here may be able to answer. I just installed a Greddy Type S blowoff valve tonight, and now when I shift gears, the engine briefly revs up before falling back down. I will do this in any gear once boost has built up. I took out the inner spring like SILVER SURFER sugested in his article on testing the blow off valves, and it is set to recirculate. At this time the little nipple on the bottom of the chamber is left open with nothing going to it at all. The adjustment on the end of the Type S is set about half-way in, and before this I had it nearly all of the way out, but I think that the boost was leaking at 20 psi. What now? Does the little screw need to be adjust in to make it tighter, or out to loosen the clamping pressure? Do I need to put both springs back in? On a side note, the CEL came on shortly after I installed the Type S. I have had issues with the CEL before when I first installed a 3" turbo back with a cat, but it dissapeared after I had the ECU reflashed, it reset itself after the car had run about 30 miles. I am going to have the code pulled tomorrow and see if it is the 0420 code that says that the cat is not operating efficiently, or if it is something else. I would think that the engine has to be seeing a pretty lean condition when the trottle is closed and it revs up. Anyway, if someone else has dealt with this then please lead me in the correct direction. Thanks

 

We don't recomend the Greddy type S

There are some who get away with it but generally there are many who have ideling issues, stalling and other problems

In fact I dont feel you need a BOV at all unless you are going for a much bigger turbo

The stock bov works fine and you have great driveability - I tuned a car to 340 whp on one with zero boost leak - its a wonderful unit and will serve your needs with no problems

IF you really MUST get a BOV the one we recomend is the Forge re-circulating

 

Forge flutters like mad under light throttle liftoff. Its very annoying and dangerous when going around a roadcourse, but then again if you're not into courses you might never know.

 

A lot of people install te forge unit backwards !

Make sure its the right way around !

 

see, now why bother with a BOV, when people like Al and Shiv are saying that the stock turbo works just fine without it?

Lookin for more trouble than is necessary

 

Has anyone had the same problem and fixed it? I have now tried both springs (too much even with the screw all of the way out, the car would stall and did not run evenly at idel), I have tried the large spring only going from screw in, to mid, to out, and I have tried small spring only screw in, to mid, to out (it would not hold boost when set loose). I had a MBC spliced in to the blow-off valve line but took it out and used a different vacuum/pressure line from the manifold and ran the blow-off line directly to where it went stock and it still revs when shifting although not as bad with the pressure set light. I have the small spring in with the screw a little over half way in and the car drives great with no stumbling or hesitation, but it still revs some when shifting. Do other peoples cars who are running the Type S have this problem? The tube built on to the Type S is going to the intake track before the turbo, and the side with the flange and adapter is going to the intake tract after the intercooler attaching to the aluminum pipe that then goes into the throttle body. This is correct isn't it?

 

Joey,

When your adjustment screw is in to far, it limits valve opening which can cause surge. I would not go more than a 1/4 in, mine is adjusted almost all the way out. If everything is working properly the single large spring should be more than enough to keep from leaking under WOT even with the adjustable tension screw all the way out.

I believe you live in my area? I would be happy to take a look at it with you, PM me.

The Greddy can and does work really well if properly set up, this has been tested and confirmed by myself and many others.
Do you really need this mod? Hell no, it really is a minor upgrade, there are certainly many other mods for the money that will give you significantly more power. If you don't have it setup correctly it can signifcantly hose your drivability. When setup correctly it can give a slight improvement in drivability and power, but it's hardly worth all the time and effort we have spent discussing it on this board.
I really enjoy sharing information, ideas, and helping out when I can, but man I almost regret posting about these bloody DV valves.

 

does any1 have a pic of the forge valve installed in the CORRECT position?

 

I will pm you once I know what my schedule is next week. Two jobs and school can kind of cramp up a schedule. After looking at the length of the blow-off valve testing thread, I can sympothize with what you are saying. During the meantime I will put the single large spring back in so it is set up similar to what you are running succesfully right now. I have a day run with the Maverick Region Porsche club this Sat., that is why I have been pressing so hard to get this done. I have a couple of more ideas that I may run by you if we get a chance to meet up.

 

You can always get the tried and true 1G dsm bov. Can probably get one at a junkyard for cheap0.

Although I to dont have any boost leaks with the stock bov. Even though it is fugly and plastic...

 

I beleive Buschur installs it on his fmic pipe kits for this very reason

 

I get the same rpm rev during shifts also with a forged DV. Personaly I think it sucks, and it flutters like hell. It makes my car jerk and can hear the turbo flutter like no other. Personaly I didn't want to have to deal with changing springs, and shims but I suffered because I wanted to have a nice polished piece in there. But for drivability... it's a no go for me. It definitly won't be there next spring. Actually it's for sale if you want to purchase it. $60. Looks brand new.

 

Hey EVOlunchbox, make sure that it is in the correct way. I know that this sounds stupid, but the fluttering sounds like you have it in backwards, very easy to do especially with the Forge. Make sure the piston side is going to the upper intercooler pipe and not to the inlet hose before the turbo.

 

I tried both ways and it seems to work better in backwards?? I'll try it again today and post results when I'm finished. Thanks for the insight joeycoates I'll give it a try again.

 

Hi,

Here is my Forge installed:



I get almost no surging/fluttering, except slight in 4th or 5th at partial throttle. Very rarely though. I'm very happy with it. Make sure your hoses are routed cleanly, I had some fluttering originally, but after trimming the vac line on top it pratically eliminated it. I have the original spring (Blue?) and no shims.

Take care

FB