boost on a 14b

[freebmx444]

last weekend i put an aftermarket bov on my car and the boost went up to 17 psi. i thought to my self how is this possible, so i went out muscle car hunting and found a 02 transam raced it and i had 1-1.5 car lenghts on it in the end. at this point im really confused, on my way home the turbo seemed like it was hesitating to spool so i put the stock bov back on and no it only has 10psi when it use to have 12. i was wondering if it was possible to run 17 on a 14b and did i mess up my turbo from that? ( it still does the hesatation thing when jumping on the gas)

 

[kenamond]

Race at the track, please.

First of all, your profile indicates you have a stock 2g. The stock turbo is a T25. Is your profile out of date, or are you actually talking about a T25, not a 14b?

The stock BOV can't hold more than 12 or so psi, so you're not going to be able to run higher boost than that. Basically, fixing the BOV has probably unmasked another problem with your boost control system somewhere. Here's my list of possible culprits:

1) Broken, cracked, or disconnected vaccuum line to your wastegate solenoid or compressor housing
2) Bad boost control solenoid (BCS). The stocker limits boost to around 11-12psi.
3) Bad wastegate actuator solenoid
4) Boost creep (I doubt this, as you have stock turbo/mani/O2/exhaust)

You can test these in order. Others should add to this if I've missed anything.

If you want this level of boost, fix the problem and install an MBC.

 

[fourreGsixty3]

14b's have run up near 20lbs, and they are fine, thats not your problem. Do you have a stock boost gauge or aftermarket if its stock then its probably accurate to with in 2 or 3lbs. As for it "jumping" up to 17lbs that sounds like boost creep but unlikely because you are straight stock. Something else may have gone and its just a coicidnce(sp?) that it occured soon after you put the new BOV on or like ^^^ said it uncovered another problem. Mack I think he is going off of the stock gauge and saying 12lbs because it looks like its right below the 14lbs mark. Also i cant say how important this is...race at the track not on the street. Its sh!t like that that makes us all profiled, and marked by cops. By the way your problem is probably with one of the things ^^^ listed.

 

[freebmx444]

i bought the car about a month ago and to my knowlege the car is stock besides a cone filter. the guage i was going by was a faze boost guage, and the bov was a greddy type-s the only thing tht worries me is the car use to boost up to 12 and now it can only raach 10 and when i floor it, the car boost for a sec then it stops then boost again and stops again then it spools up to 10 the rest of the way through the gear. could this be my turbo starting to go?

 

[-DSM2NR-]

You should only run 15psi max on your stock fuel system. With a 190fuel pump you can run 18psi. With a 255fuel pump you can run 18+psi
Did you harm the turbo? Probably not.
But get a mbc and adjust the boost accordingly. If you keep running the car at 18psi you'll eventually blow either the turbo or the engine.

My boost went up from 16psi to 21psi when i put my Greddy Type-RS. That's because unlike the stock 2g bov the Greddy doesn't leak.
The boost increase caused my car to hesitate whenever I would hit boost. That's because not enough fuel is being processed for that much boost.
So like I said before, get a mbc and turn boost down or up a little bit and everything should work fine again.

 

[kenamond]

It doesn't sound like it's necessarily your turbo, but here's how you can check the turbo.

You can check the turbo to some extent by checking for leaking oil and shaft play:

1) Pull the intake pipe off the turbo compressor housing with the car cool and reach in and grab the nut on the center of the compressor wheel. Try wiggling it side/side and in/out. You should have a very small amount of side/side play, and no in/out play. If you have excess shaft play, your turbo is going.

2) Pull the lower intercooler pipe (LICP) off the compressor housing (the lower tube coming off the compressor). Clean up the oil that's probably in there (both the LICP and the compressor outlet) due to recirculated oily air from the valve cover which is normal. Reinstall the intake pipe and LICP. Disconnect the valve cover breather hose from your intake pipe and cap the nipple on the intake pipe (to keep new oil from getting in there and confusing the issue). Go for a hard short drive (hit full boost for a bit). Pull the LICP again and see if there's new oil in there. If there is new oil, your turbo is going. If this is the case, your car will typically be blowing blue-white smoke out the exhaust especially at high revs.

 

[freebmx444]

ok ill have to try all of this after school thanks

 

[TSIMonsteR]

Get an MBC and at least rewire your stock FP. I think you should be fine at 16-17psi on the T2small. I run 16psi on my 16g with no knock

 

[kenamond]

Should he reset his ECU? If he was knocking badly with the new BOV, would the ECU still pull timing with the lower boost after swapping back the 2g BOV?

 

[-DSM2NR-]

would the ECU still pull timing with the lower boost after swapping back the 2g BOV?

I doubt it. But reseting your ECU is always a good idea after changing something.

 

[TSIMonsteR]

Yeah, I think an ECU reset is always good after changing anything.