Could it be a boost leak?

[Trizon]

Well, once i try setting it to 17 psi, and try boosting, itll hold the boost for a few sec, then boost will drop to 10 and hold steady at 10. If it is my BOV (Greddy S) -- Is it possible to fix this one rather than buying a new one?

 

[Trizon]

.

 

[project94tsi]

if your on the t25 i heard that they fall on their face in upper rpms, just a thought.

 

[95tsiawd_86]

the t-25 isnt really worth a $hit above 15 or 16 psi. If u are still on the crap t-25 thats your problem. And u are prolly wearing the turbo out pretty quick trying to push 17psi with that little crap turbo

 

[Trizon]

Ironically, no its not that small, I'm running the 18g

 

[95tsiawd_86]

it could be the BOV. try tightening the screw thing on the BOV if u havent already. i dont really know much about that BOV but u might need a stiffer spring if one is available for it, u could look into that also.

 

[project94tsi]

Originally posted by Trizon
Ironically, no its not that small, I'm running the 18g

yeah but the efficiency range is horrible, it was made for people who drive around town at low rpms but want the torque and power of a turbo. I only flows some thing like 250cfm at 15psi and your 18g probably is in the range of 580cfm at 15psi, im not sure on the exact #'s but even the 14b is a big upgrade from the t25

 

[Trizon]

hmf, would a 16g be running more efficiant than my 18g? ifso why exactly? and by how much? -- atm its ported and clipped, doesnt take too long to spool, but if so ill just do the swap to the 16g and do the same.

 

[Trizon]

anyway, i believe its called "recirculated" when you have the BOV fixed? and ive read that the Greddy type s could be recirculated, ifnot could someone give me the correct definition? -- Anyway I rather avoid spending another 250 on a BOV if i can just have this one recirculated.

 

[1990CherryTSI]

recirculating? Recirculating is not "fixing" the BOV as those BOV's dont have to be recirculated. My gf has one on her 96 and she has the hole plugged on her intake and the car runs fine. Take a pic if you're not sure and post it. On those BOV's there should be about a 1/2 in diameter hole (not sure of that measurement) and if you're not recirculating then no hose will be attached there and your intake hole of the same size will be plugged. If there isn't one, you can just connect a hose that fits and see how that works (will have to find a way to remove the plug on your intake hole. It'll make the BOV quieter but may help resolve the problem.

 

[1990CherryTSI]

She is not recirculating - 1. not connected to 2.

 

[Trizon]

thanks!! -- going to go check right now. If its connected, then could my problem be my BoV? -- keep in mind, my boost would hit 17 then drop immidiately to 10 / 11. and ifso, would i have to buy a new one? is that the only option?

 

[Trizon]

yep its recirculating, hm any ideas why my boost could be dropping?

 

[1990CherryTSI]

What are you using to "set" your boost to 17? Have you tried adjusting the screw? If so I'd try adjusting it more - check what it tops at then what it settles at, and a bit more. Is it always around a 7 lb drop from high to low?

 

[Trizon]

where would i be setting that? and i have an HKS EVEC IV

 

[project94tsi]

Originally posted by Trizon
hmf, would a 16g be running more efficiant than my 18g? ifso why exactly? and by how much? -- atm its ported and clipped, doesnt take too long to spool, but if so ill just do the swap to the 16g and do the same.

no your 18g will be running more efficiant then even a 16g evoIII turbo, i would just keep the 18g unless you are upgrading to a 50 trim or something but its not worth it to downgrade IMO.

 

[Cirus_93TSI]

unless you have an hks vpc or a blow through MAF set up, leave your BOV reciruclated into your intake. if it doesnt dump the air back into your intake your intake then you lose air that has already been metered every time you let off the gas, and suck in unmetered air at idle and when cruising at a steady rpm. all it does is make your car run like crap, sometimes to lean, sometimes to rich, all for the bov to be a tiny bit louder.

running a bov that is not recirulated is what causes problems, not the other way around

 

[Trizon]

well the question i have is what could be casuing my boost to drop from 17 to 10/11? -- I have an HKS EVEC iV, i was thinking maybe my BOV was leaking? if thats the case, is my only option a new BOV?

 

[1gGSXboostin]

I got the same prob. I have my MBC set at 14psi. When i get on the gas it will hit 14 then drop down to 9-10psi and hold there. It is worst in 1st and 2nd gear. Takes a little longer to drop in 3-5 gears!! I think its a boost leak but I haven't tested it yet. I have heard it's ad to hook a pressure tester to the turbo inlet....that you can blow a seal or something;;is this TRUE???

 

[ArticNemesis]

As stated above, trying tightening the screw on the BOV to make it hold more boost (not too tight, or you will get compressor surge.) You should also check for boost leaks..