Compressor surge?

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95coupe

Junior Member
Did mini me swap over winter z6 head on b7 block, turbo, and threw a rod a few weeks ago. Got stock motor (D15 sohc non vtec) back out from garage, cleaned it up, so its all stock, with a t25 garret turbo, runnin 7lbs of boost, had this set up before, ran perfect, after hooking everything back up I am getting compressor surge. I have a brand new turbo xs bov, getting good vacuum. When just driving, getting into low boost like 3psi or so, the turbo flutters, but when its at 6 lbs or so it blows off, then flutters. Any ideas? What would cause the bov not to work if it is getting good vacuum and no leaks?
 
Did mini me swap over winter z6 head on b7 block, turbo, and threw a rod a few weeks ago. Got stock motor (D15 sohc non vtec) back out from garage, cleaned it up, so its all stock, with a t25 garret turbo, runnin 7lbs of boost, had this set up before, ran perfect, after hooking everything back up I am getting compressor surge. I have a brand new turbo xs bov, getting good vacuum. When just driving, getting into low boost like 3psi or so, the turbo flutters, but when its at 6 lbs or so it blows off, then flutters. Any ideas? What would cause the bov not to work if it is getting good vacuum and no leaks?

every txs bov ive ever heard surges, the fact that yours didnt at first shocks me. you need something adjustable like a hks sqv or greddy bov. i even rocked a sqv knockoff for a few months, before i got my blitz. basically anything designed with a spring softness adjustment so it fully opens at low boost. arent all txs bov's rated for cars at 10+ psi?
 
I didnt think they were, last year i did hear surge but at low boost, that doesn't surprise me, but now its after it blows off its doing it? Too low of boost you think?
 
Why does everyone buy a knock-off of a good valve? Why not for the same price, buy a bosch "diverter" valve?

This is from an Audi forum:
OE Bosch TT 710A = THE STOCK DV FOUND IN ALL (1997 AND UP) AUDI TURBO MODELS, Audi part # 034-145-710A OR 06B-145-710, $50
OE Bosch TT 710N = Basic, popular & low-budget upgrade, maintains stock look, not serviceable, Audi part# 06A-145-710-N, $50 (some dealers charge more)

You can make it work on any turbo'd car, and it works fine. It's good if you're not going for the whole "BWAAAAAPSHHHHHHHHH" noise every shift too. If you like the noise, then don't get this part. Btw: used, these valves go for about $10.

EDIT: Allow me to cite my source: http://www.audiforums.com/m_14128/tm.htm
 
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Any ideas? What would cause the bov not to work if it is getting good vacuum and no leaks?

Grease the spring/piston assembly. Try inspect the seals on the piston. Try a different swapping the port you hooked the vaccume line to on the BOV, maybe you got the wrong one (some valves have numerous vac inlets). If not, then I'm out of ideas.
 
Why does everyone buy a knock-off of a good valve? Why not for the same price, buy a bosch "diverter" valve?

This is from an Audi forum:
OE Bosch TT 710A = THE STOCK DV FOUND IN ALL (1997 AND UP) AUDI TURBO MODELS, Audi part # 034-145-710A OR 06B-145-710, $50
OE Bosch TT 710N = Basic, popular & low-budget upgrade, maintains stock look, not serviceable, Audi part# 06A-145-710-N, $50 (some dealers charge more)

You can make it work on any turbo'd car, and it works fine. It's good if you're not going for the whole "BWAAAAAPSHHHHHHHHH" noise every shift too. If you like the noise, then don't get this part. Btw: used, these valves go for about $10.

EDIT: Allow me to cite my source: BOV's, DV's and the Audi closed loop turbo system.

simple. because 99% of people that buy an aftermarket bov WANT the noise of the pressure relief--thats part of the fun. also because of the low price and their proven functionality.
 
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