To those Venting Greddy(Studder)

[MSP #167]

Hey guys i got my greddy type s on the other day, and i'm venting, without stalling. 2 things i'm wondering about

I've noticed that there is a slight studder between 2500-3k rpm while accelerating and then the car fully takes off once it hits 3k.

Also i have been having a lot of backfire while shifting since i installed the bov.

Does anyone else have these things happen since they installed the type s?

I'm thinking that i'm going to reciruculate it to get rid of the studder.

Thanks

[TX Speed Demon]

What else in in your set up?

[ONRAILS]

I get the same studder, and I'm recirculating. But I have a forge bpv. So I don't think it's just with the greddy. Car runs real rich at that rpm range.

[Emode]

your backfiring because your running so rich from the bov. When you vent that air, the computer is used to it being there and adds the necessary fuel, but since its not it wont be fully combusted and will result in a backfire. normal.

[MSP #167]

ok yea i don't mind the backfire, its actually cool sounding.

But my mods are Hiboost fmic, injen, apex catless dp, FCD, MBC at 8.5psi, and the greddy bov.

Also i still get some turkey with this setup. I was hoping there would be none but there is a turkey followed by the blow off of the greddy.

I've messed around with the adjustment of it a lot and i have it in a spot where i get no stalling. So that's why i figured i would just recirculate.

[TX Speed Demon]

Yeah I don't think recirculating will eliminate the studder. I'm recirculating my Greddy now. My current set up is only Hiboost FMIC and Perrin SRI, stock boost (peaking at 7 and holding at 6.25)

With the greddy on the turbo>intercooler pipe (before hiboost install) I could vent perfectly, but with it on the intercooler>throttle body pipe (after hiboost install) I can not get it to not stall without any turkey. To me, preserving the life of the turbo was more important than getting the greddy sound. I do miss the sound and will probably go with a dual set up eventually.

I still have a bit of a studder under heavy acceleration as the turbo spools up under 3K RPMs. All recirculating did was fully eliminate the compressor surge and that tiny bit of bogging I sometimes got between shifts when venting.

[MSP #167]

Yeah I don't think recirculating will eliminate the studder. I'm recirculating my Greddy now. My current set up is only Hiboost FMIC and Perrin SRI, stock boost (peaking at 7 and holding at 6.25)

With the greddy on the turbo>intercooler pipe (before hiboost install) I could vent perfectly, but with it on the intercooler>throttle body pipe (after hiboost install) I can not get it to not stall without any turkey. To me, preserving the life of the turbo was more important than getting the greddy sound. I do miss the sound and will probably go with a dual set up eventually.

I still have a bit of a studder under heavy acceleration as the turbo spools up under 3K RPMs. All recirculating did was fully eliminate the compressor surge and that tiny bit of bogging I sometimes got between shifts when venting.

so do you not get any greddy whistle at all while reciruculating? If not what does it sound like?

[TX Speed Demon]

In order to completely eliminate the compressor surge I had to loosen up the Greddy as much as possible. Now the car make almost no noise at all. No real turkey, no woosh, no whistle/whine, nothing. No matter when I'm shifting or the load on the engine it is nearly completly silent.

Sometimes when shifting at very low RPMs (under 2500 RPMs), when the weather is very humid, with the radio off and the windows up I can hear what I think is a tiny woosh or maybe a bit of surge, but it's so faint I can't tell if it's really there or not.

When shifting under heavy load I get a very slight woosh sound of the air moving through the hose, but I'm sure it's not audible from outside the car. My Perrin SRI easily makes 4-5 times the amount of noise when the turbo spools up.

When I had the greddy recircing and tightened a bit I got a tiny turkey and a tiny woosh/whip sound. Loud enough to hear in the car, but probably not loud enough to hear outside of the car.

When you recirculate you may get a little noise from the greddy. I think it will depend on the length of your recirc hose. Mine is really long because of my set up. With the Perrin SRI and the Hiboost FMIC I had to have the outlet of the greddy face the right (driver's) side of the car. The recirc hose loops all the way up and around into the inlet on the Perrin (about 4 inches above the tubo inlet). This was the only way to keep the hose kink free. All together the hose is probably 2-2.5 feet long.

Due to the mounting location on the Perrin I could not turn the greddy around and use a shorter hose unless I wanted it to make a 180degree turn in the distance of 1.5 inches. There is no way to do that properly, I tried several different U and 90degree bends bought at Home Depot, all without success. The hose would always bend to sharply and form a kink.

Since you have the the Injen, you may be able to recirc with a much shorter hose and get some noise.

[TX Speed Demon]

Also you are pushing 2.5 more PSI than me and that extra volume of air may make a difference in sound too.

[MSP #167]

o damn that sucks you get no noise....I'm going to reciruculate it tomorrow.

I have the injen intake and where it is going to reciruculate into the injen from the greddy is really close maybe 2 inches away, i have to go to pep boys or somewhere and get a l shaped hose to fit inbetween it so there is no kinks.

I'm hoping i get some kind of noise from the greddy, while getting rid of the turkey.

[CasopoliS]

I am running dual valves on the HiBoost kit. I get major stutter, almost to where my head jerks. This happens as I accelerate. Its like a mis-fire or a backfire or some other shit with my engine. If I knew more I could diagnose it and fix it. Does anyone experience this? It is hard to describe. How do I fix it?

BTW the Greddy vented with a recirc valve does not stall.....and it wakes up everyone in the neighborhood. Its really a show off valve though.

[goku4658]

if i switch over to recirculating my greddy do i sacrifice any whistle at all? tx, you seem to know this bov pretty well, hehe

[MSP #167]

I am running dual valves on the HiBoost kit. I get major stutter, almost to where my head jerks. This happens as I accelerate. Its like a mis-fire or a backfire or some other shit with my engine. If I knew more I could diagnose it and fix it. Does anyone experience this? It is hard to describe. How do I fix it?

BTW the Greddy vented with a recirc valve does not stall.....and it wakes up everyone in the neighborhood. Its really a show off valve though.

i think you are hitting fuel cut, get a joe p fcd.

The studdering i am feeling is pretty subtle its not crazy.

[TX Speed Demon]

if i switch over to recirculating my greddy do i sacrifice any whistle at all? tx, you seem to know this bov pretty well, hehe

Yeah you wont get any whistle at all. Just by putting on the 19mm outlet adapter will eliminate the whistle (even when venting). and unless you want to increase the diameter of the nipple on your intake to match the stock diameter of the outlet on the greddy (I think it's like 30mm), or use silicone reducers somewhere between the BOV and the intake, you'll need the 19mm adapter to run a single size hose.
------

I turned the radio down yesterday (normally drive with it at 20-22 and have 2 12"s in the trunk) and this morning and drove it pretty hard to get a variaty of blows (hehe) out of the greddy for different sound samples. Here's what my set sounds like (sorry no clips just descriptions):

No Boost (Vac pressure is above 10): No matter what the rpm I get no sound at all. No turkey, no woosh, no whine, no nothing.

No Boost (Vac pressure between 10-0): Here I get a little woosh sound. It is a little hard to hear because this is where my perrin intake is it's loudest. At 0 vac pressure the intake is REALLY loud and I think it drowns out the most of the BOV sound. It doesn't sound like a fluttering or turkey sound, more like when a hot chick blows in your ear really softly.

Boosting: When boosting the sound seemed pretty much the same wether I set off early at 2psi or held it and set off at 6psi. I do get pretty nice wooshing sound, but it is not really loud at all. Air rushing through a rubber/silicon tube is the only way I can describe it. It's got kind of a low pitch but the overall volume is pretty low. I think people walking by on the street would be able to hear it, as would cars driving by slowly. But if you were racing someone they would not be able to hear it over the sound of their engine. And it's not goign to make anyone jump up as you pass them on the street. It's nothing compared to the level of sound my greddy made while venting.

[TX Speed Demon]

I have the injen intake and where it is going to reciruculate into the injen from the greddy is really close maybe 2 inches away, i have to go to pep boys or somewhere and get a l shaped hose to fit inbetween it so there is no kinks.

You may want to try Home Depot too. I went there and in the lawn sprinkler section were several L and U shaped plastic connectors (similar to the one that came with my Perrin intake) in 19mm (3/4in) diameter. You might be able to use something like this with a small piece fo heater hose on each end to connect everything. they were about 99 cents each.

[TX Speed Demon]

i think you are hitting fuel cut, get a joe p fcd.

I agree, this sounds like fuel cut. I get this sometimes too, but the wierd thing for me is it's never while I'm accelerating, it's when I stop accelerating. Doesn't do it all the time so I know it's not just coming off the gas. And it seems to happen more at low boost (2-4 psi) then full boost (6.25 psi). It's like if I come off the gas just a little and I go from low boost to no boost I get a pretty hefty jerk. It's happened maybe 3-4 times in the last month. I think it may be because of the Perrin SRI intake maf location. It's drawing so much air past it with the SRI filter just 2 inches away, it may freak a little when suddenly dropping out of boost (dunno). I can't be sure though, I put the intake and hiboost FMIC on within the same week.

[goku4658]

TX Speed Demon, my car threw a CEL two days ago and I haven't modded in months. It was running fine w/ my wagner fmic/sri for at least 2 months. When it threw the CEL, I checked the Greddy and the locking nut for when you adjust it was loose enough for me to move it w/ only my hand. So me and hazexban tightened it, checked the intercooler connections, and reset the ECU. CEL gone. We tightened it so much the whistle went away. So i figured we had fixed whatever went wrong and loosened it 1.5 turns. Was fine for a day or two, then it threw the CEL again.

Do you think my problems are w/ the BOV or is it just coincidence? Thanks!

[Rich24km]

my bov started stalling also, it worked fine until i went to vegas for 3 weeks. Came back and the car stalled bad. So i have it tightened alot. Now it basically sounds like the stock bypass valve. The only good thing and reason i'm keeping it on is that it will hold boost. THe stock valve on my car would only hold 3psi before leaking.

[1FASTMP5]

to all of you guys venting your bov.... i would REALLY think twice. for a lot of reasons.....1)u will loose performance every time you shift, you cant keep turbo spooled. 2) because of all the extra fuel that is being dumped you run a chance of washing out your cylinder walls(can REALLY fuck your engine up). 3) you loose your fuel econ. any car running a maf system should NEVER run a open vent bov, unless the maf meter is after the bov. some forum members have done this with a great results.

also for all of you who run open vent & tighten the adj screw to keep from stalling this is just as bad. DO NOT DO THIS!!! it will make the compressor surge & make that flutter sound some of you are talking about. the bov should be adjusted to the softest setting without leaking under idle and NO flutter.

[CasopoliS]

to all of you guys venting your bov.... i would REALLY think twice. for a lot of reasons.....1)u will loose performance every time you shift, you cant keep turbo spooled. 2) because of all the extra fuel that is being dumped you run a chance of washing out your cylinder walls(can REALLY fuck your engine up). 3) you loose your fuel econ. any car running a maf system should NEVER run a open vent bov, unless the maf meter is after the bov. some forum members have done this with a great results.

also for all of you would run open vent & tighten the adj screw to keep from stalling this is just as bad. DO NOT DO THIS!!! it will make the compressor surge & make that flutter sound some of you are talking about. the bov should be adjusted to the softest setting without leaking under idle and NO flutter.

My Greddy is tight (and venting)....I am recircing with the stock valve to eliminate stalling. Can I put the MAF right after the BOV on the IC -> TB pipe? Will it being closer to engine heat have a problem with its outer material? It seems to be a thermoplastic. Would there be a problem with it being so close to the the BOV?

Also, how would this effect the engine? When the BOV releases the air, the MAF will tell the engine that it will not be recieving air (since it is after the MAF) and give less or more fuel? Thanks. New to this stuff....

[blynzoo]

Due to the mounting location on the Perrin I could not turn the greddy around and use a shorter hose unless I wanted it to make a 180degree turn in the distance of 1.5 inches. There is no way to do that properly, I tried several different U and 90degree bends bought at Home Depot, all without success. The hose would always bend to sharply and form a kink.

Since you have the the Injen, you may be able to recirc with a much shorter hose and get some noise. YOu can buy a tight 180 radiator hose link. I dont know if Home Depot would have it, but a place that does silicone hoses certainly would.

[TX Speed Demon]

CASOPOLIS: The danger in putting the MAF after the BOV is that is is now reading pressuried air after the turbo. It's simply how long the MAF will withstand those pressures before breaking that you have to worry about. A few people have been doing this (I think BrianP5T is) with success so far. It's just that no one knows how strong the stock MAF is. If you are going to do this I would suggest picking up a second MAF sensor just in case, although I've heard these are in the $200-300 range, but am not sure.

You don't have to worry about stalling when the BOV goes off cause the MAF doesn't know the air was there in the first place, so no extra fuel was dumped. I think it would read it as if you were just sitting at idle.


goku4658:
Sounds like the problem may be the BOV. How old is it? I once drove from Dallas to New Orleans (8 hours) straight and threw a CEL cause the valve on the greddy got stuck open. Could be yours is now doing the same thing and by tightening the spring you got it to close completly, now it's stuck again. Leave the car idling and stick your hand in front of the outlet on your greddy, or your finger inside. If you feel any air movement you've got a vac leak cause the greddy isn't sealing properly.

My guess is the greddy needs to be re-oiled/greased every once and a while to maintain smooth operation. I bet with the change in temperature from the seasons changing this is necessary. I rememebr reading on the net somewhere there was a maintenace schedule for most BOVs, including the greddy, but it didn't entail what was involved. I'll do some more searching over the next weeks and see what I can find.

You could also take your car to Autozone and have them run a CEL code check. If it comes back a vac leak than the greddy is probably your problem. If it comes back something else then it will help you narrow down the source.

[TX Speed Demon]

YOu can buy a tight 180 radiator hose link. I dont know if Home Depot would have it, but a place that does silicone hoses certainly would.

Still not worth it to me. With my set up, the outlet of the greddy would be past the inlet on the Perrin. So the air would have to:
come out the greddy>make a 180degree turn>Go up into perrin inlet adpater>make another 180degree turn in the adapter to shoot down the perrin toward the turbo and not mess up the MAF reading

The way I have it now it makes a smooth arch to the side of the Perrin and makes a 90degree turn to shoot down the perrin toward the turbo.

I think having all the 180 degree bends would cause the air to back up or slow down and bring the compressor surge back.

[goku4658]

goku4658:
Sounds like the problem may be the BOV. How old is it? I once drove from Dallas to New Orleans (8 hours) straight and threw a CEL cause the valve on the greddy got stuck open. Could be yours is now doing the same thing and by tightening the spring you got it to close completly, now it's stuck again. Leave the car idling and stick your hand in front of the outlet on your greddy, or your finger inside. If you feel any air movement you've got a vac leak cause the greddy isn't sealing properly.

My guess is the greddy needs to be re-oiled/greased every once and a while to maintain smooth operation. I bet with the change in temperature from the seasons changing this is necessary. I rememebr reading on the net somewhere there was a maintenace schedule for most BOVs, including the greddy, but it didn't entail what was involved. I'll do some more searching over the next weeks and see what I can find.

You could also take your car to Autozone and have them run a CEL code check. If it comes back a vac leak than the greddy is probably your problem. If it comes back something else then it will help you narrow down the source.
you are awesome!! thanks for the help!!