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surge :-(

3K views 40 replies 18 participants last post by  rafal 
#1 ·
would adding another bov fix turbo surge?
i think why i have it is because i have 3inch intake pipes and the bov can not vent it fast enough. any input?
 
#3 ·
when does it surge?

bad BOVs hoot or compressor surge (that slap slap)

If it is surges on accel, then I would bet WG, if its after you get off the gas, BOV.
 
#9 ·
Is it binding wastegate or something. I did not see any benefits until we went to the bigger turbo at high revs. Looks like you are on the tdo4 maybe 18t cant see. Should be plenty what you have there. Maybe restriction on the vac signal hose or too stiff spring in the valve. Yellow max there.
 
#10 ·
ya, its a td04. i have what ever spring you sell with it, i think it is the yellow.
i have all new vacc. lines
this is the 3ed turbo on the car that does it so i do not think it is the turbo.

i thouhgt i read something back awhile ago about the TB being bad and not letting the vacc open the bov. im going to switch the line for the the oil and bov and ill see what happens i guess.

.
 
#12 ·
my little forge 001 works fine with my HX35 turbo, and it worked fine with the TD04 as well. I can tell that its probably nearing its limits with the HX35 at higher boost, high in the RPMs, but I don't think its an issue for me quite yet.

I don't think you'd need to look into a second BOV until you have a LOT more turbo and a lot more air going through it.
 
#14 ·
I bought mine from Forge before GS picked it up and you could order whatever spring you wanted at that time, so different people had different springs from when they ordered it. I am not sure if GS sells it with a standard spring in all of them.
 
#19 ·
Try swapping in a softer spring, maybe a green one, just to see what happens. You should probably leak boost, so you won't make the same level, but it would also eliminate the surge if it's a dump valve problem. For the record, the Forge valve I just got from Nick came with a green spring in it, and the blue and yellow springs in the kit.
 
#20 ·
The -007 recirc valves are supplied from me with a green spring. This is what i run in my Vig with 30psi.. ;) Holds just fine.

The -004 are supplied with a yellow spring so they stay closed at idle.

Make sure it it on its own vac port with the shortest hose possible that will not kink. < some other motivation for me moving it up to the TB. > Along this same line the t7 people can connect the valve directly to the intake manifold, bypassing the anti flutter valve that allows ecu to connect it before or after the throttle. Make sure to plug the before throttle hose though or you get a intermittent vac leak.
 
#22 ·
reworked the intake, trying to fix surge...

well i got about 8in of pipe out and moved the bov closer to the tb and cut the vacc line as short as it needs to be. i hope this means no more surge. if not i think it looks better.

before



after

 
#30 ·
psi

It still flutters at 12-17psi? Does it release all at once or are you actually getting flutter at the higher boost level?

That seems a little strange, I get a little bit with my gt3076wg when I give it light throttle and then let off, but if I am over about 5psi, its more of a pst, one time.

You can lower the tension on the spring, you can cut a little bit off or one coil or something and that would reduce spring pressure and should cut down on the flutter. Hope its not "real compressor surge"

good luck,

John
 
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