compressor surge

[hungryjoseph]

i have a fluttering sound below 2 - 3 psi when i let off the throttle, and when i shift. from the conditions that i've read, i'm assuming it's compressor surge. how can i fix this? i have a hks ssq bov, 10psi, s14 sr20 with stock t28. turbosmart manual boost controller. stock wastegate. i think that's all the information i know that would be relevent to this

[hungryjoseph]

also, on my old motor the BOV used to cause it to bog and die during high revs and hard shifts, but one this one, it doesnt do any of that, so i think the shop that did the swap tightened it too much?

[DrifterProdigy85]

Yea its compressor surge but 2-3psi wont hurt anything. I have surge up to 7psi and no problems have come up yet.

[IanS]

I had surge at 6 psi for a long time, but after I burned up the stock turbo and the used one I bought I decided to loosen it up a bit, now it only surges at 1-2 PSI, and its a freshly rebuil turbo

[hungryjoseph]

how long was it till it went bye bye? and how can u tell

[9240sx]

My Greddy RS does this at 2-4psi...Very common thing with aftermarket BOV...You can try to loosen the adjustment bolt on the bov and see if that helps...Mine is on the lowest setting and still will not open untill 5psi...But anything above that it opens perfect..Im thinking its not hurting anything,And is not a big deal..Iv had it for years..All my friends with sr's and aftermarket BOV's cant get there's to open lower then 5 or 6 psi..The Greddy RS is the best Aftermarket BOV on a stock boosted t25 sr iv used..My buddy has a Blitz on his and we could not get that damn thing to open at all...We finally hooked up a BC and set it at 12psi and got it to open..lol

[DrifterProdigy85]

Alot of the BOV adjustment is gonna depend on how much boost you run. I run 19psi most the time so i keep mine relatively tight so no leaking occurs. I use the Greddy Type R with Soft Spring. I had the hard spring but at the softest setting, it would surge at 19psi.

[IanS]

the turbo that came on the motor lasted about a year and the oil seals started to leak because the bearings were getting so bad, and the used one I got lasted about nine months and did the same thing, so I took the first turbo bead blasted and balanced the wheels and rebuilt the center section, the car is a lot faster with the fresh turbo, Im just lucky I didnt grenade either turbo, the one thats out right now, the bearing are bad enough where I can make the compressor rub on the housing.

[hungryjoseph]

would it do tht on a ball bearing turbo? aka my t28

[IanS]

Im not sure if it would make a differance, not all T28s are ball bearing though,

[180sxmonster]

so thats what caused my turbo to go bad... the compressor surge is enough to hear from the cockpit.... i thought that was normal but one day it blew clouds of crazy smoke.... i replace the oil return line and the feed line.... still smokin.... so i replaced the turbo and it went away... seems like the turbo was leaking out where the return line bolts up to the turbo.... there are two holes and one on each side that was leaking.... i guess thats where the leak is when the seals are bad......

[hungryjoseph]

when i'm cruising in like 5th gear or 4th gear, and i let it boost up to 8 psi or so, it surges, and the bov wont open. but when i go from first gear to 5th gear, letting it hit 4 to 6 psi each time, the bov opens, but i can still hear a tiny bit of surge.. and my bov isn't adjustable. what can i do?

[hungryjoseph]

lol anybody?

[goj_cloud]

maqybe u have a bad hks ssqv

[hungryjoseph]

so a new bov could be a solution?

[DrifterProdigy85]

Your fine. It all has to do with the load of the engine and RPM. When i had a Greddy RS, i found it would blow off very easy with little boost over 4krpm but if i was down around 2500rpm or so it would flutter. Your fine with it the way it is. Dont try to make a problem out of something thats not.

[hungryjoseph]

so i wont have a smoking turbo or any blown oil lines right? that happened to my friend, he said he was because of compressor surge... so it got me really scared

[IanS]

a little bit of compressor surge isnt the end of the world, as long as it is not excesive it wont harm anything, the seals and bearings, (in journal bearing turbos especialy), will wear out eventualy, and the turbos previos life in Japan will have a lot to do with it, like what kind of oil was used, was the engine warmed up befor hard driving, and was it cooled down after, all these things will effect the lifespan. and even if the seals do go, a full bearing and seal kit plus the cost of bead blasting the wheels and balancing them is only about $125, or if you dont want to rebuild it yourself it usualy costs about $450, take good care of your turbo and it will reward you with lots of boost.

[notslow]

Well this thread answers that question.

Ya I have only had my SR20 for about 300 kms and I noticed that too and wasn't sure if it was compressor surge or not but now this thread puts it to light. I am using a Greddy Type S. Yesterday my room mate and I cooked up the DIY manual boost controller (until I can afford an electronic) and I have yet to install mine. Does anyone think that will make a difference?

[hungryjoseph]

i don't think it will make a difference, or at least to my limited knowledge it SHOULDNT make a difference

[480sx]

Depending on what type of blow off valve you have and what the spring rate/ setting is it could make a difference if your going to be boosting in the range the bov is tuned for. Mostly when people think their turbo is surging its usually just the BOV doing what its sposed to do. Some valves actually make the Woosh woosh woosh sounds at low rpms and it is completely normal. Mine does. Comp. wheel surge is a very noticable sound and is not just a air 'Whoosh whoosh' sound. Kinda hard to describe but i will compare it to air surging with a train whistle in the backround. ;/ lol Hope this helps

[Silverbullet]

a little bit of surge isn't going to hurt. Running no BOV wont kill your turbo over night either. I always run my BOV adjusted fairly tight where they dont vent when driving on the street, even under a decent amount of load.

If your really concerned about surge, get a HKS SSQV. Pull types work the best. There is a new company that is coming out with a pull type BOV that is more sensitive than the HKS one. I can't remember the name but they have very good video demonstrations on youtube. They got awarded at SEMA for best new products.

if you dont want to go out buying new stuff, loosen your adjustment screw all the way. Yes, your car will stall out and run rich on shifts so recirculate if you aren't already.

[hungryjoseph]

yeah wut i have is the hks ssqv, but i think it's just old and bad, so ill try to get a new one after testing it with a vacuum pump