Boost issues

Tsi · 01-06-2005

I really don't know whats going on with the boost controller, but I've had the knob in all the way and out all the way, and the boost just climbs everytime to 20+ psi. (I usually let off when it gets that high) Could it be boost creep, I just have downpipe and a cat hooked up right now and the downpipe isn't all the way bolted on. The boost controller can't be bad already its a month old, and it worked fine holding 18psi before, which way do u turn the knob for less and which way for more?? I have been hand tightening it, does it have to be wrench tightened in order for it to work right?? Maybe someone could enlightin me

95tsi · 01-06-2005

Generally speaking, turning the knob out will lower boost. However, if it is turned all the way out there is obviously another problem. Are positive you have it hooked up proper with no other vacuum leaks on the car? Thats where I would check first. Otherwise, were you having any problems with the stock boost control priort to installing the mbc? Few things to think about.

**1ViciousGSX** · 01-06-2005

Moved to correct forum.

What boost controller are you using?
Chances are your exhaust is flowing more without the rest of your exhaust attached (what ever it is you are running). That could cause some higher boost levels/creep. Are you running a stock O2 housing? What wastegate are you using?

Alpine TSi · 01-06-2005

This may sound stupid but is the boost controller installed correctly? If it is installed backwards, the wastegate will never open and it will just keep building boost. If it is installed correctly it could be creep, but creep would be that the boost settles at where the controller is set and then goes up after a few thousand RPM. Also if you have the knob turned too tight the spring is too hard and will never open, so your wastegate will never open either. Just crank it almost all the way out and make sure it won't fall out, then give it a shot.

CarPsyco84 · 01-06-2005

I'm having the same problem with my tsi, It goes to what you have it set at, then around 4500rpm, it starts going up again. Only thing I changed was I made some 2.75" turbo back exhaust. I guess 2.5" down pipes don't usually have issues, but those with 3" ones have lots of issues, so if your boost issue is identical to that, and your making sure its not just somthing simple, your gonna probly need some evo3 exhaust parts, less someone has any bright ideas,
btw, i took a grinder to the waste gate opening to make it bigger, and it helps, but not nearly enough

Tsi · 01-07-2005

I'm using the SLS boost controller, quality boost controller. I believe it is installed right, I don't know if its creep I guess, because it just climbs right up to 20+ psi. stock wastegate, stock o2 housing, 14b with 16G compressor wheel and the exhaust is stock downpipe and stock cat, and thats it. I"m posting a pic of the controller tell me if its hooked up right, the bottom goes to the nipple on the elbow and the side part goes to the wastegate nipple.

carltalon · 01-07-2005

Your install looks right. The knob should be screwed all the way out for low boost. you could also check your vac. lines for restrictions. I got a small pice of something caught in mine once and It would boost out of controle.

Tsi · 01-07-2005

screwed the knob all the way out today.....still boostin right on up to 20+psi. I still don't think its a bad BC because it is brand new, would a leak in a line somewhere cause this

TheBlizzard · 01-07-2005

List your mods; if I were to just guess I would say you are having boost creep issues. Did it do the same thing when it was warmer out? I know my 3" turbo back with the O2 eliminator boost creeps like crazy now that its cold out. But in the summer it was rock solid. Tell us a little more about your car and your problem will be easily solved im sure.

CRAIG

Tsi · 01-07-2005

Well Its only been running in cold weather so far, just got the car running not too long ago, so I wouldn't know. Mods are built 6 bolt bottom end, 3"intake w/2g mass w/k&n, 14b w/ 16G compressor wheel, stock o2 housing, stock wastegate, Walbro 255lph fuel pump, super AFC, Greddy Type S, MBC. The car didn't come with exhaust when I got the car, soo for now I just have a downpipe and cat hooked up.

john · 01-07-2005

A pinch in a vaccum line or a small hole will have the same effect. Pull off your intake and take a look at the nipple coming off the wastegate actuator. I have seen a lot of times that a 3" intake will rub and pinch the line. Over time, it can also give you a little hole. Boost will be uncontrollable. Look that over. The ghetto intakes do that all the time and yours may also.

Tsi · 01-07-2005

Well figured the problem out...took the MBC off and found that the spring inside the boost controller was pinched, soo pushed the spring out and tadaa...boostin at 12psi

Shotgun! · 01-08-2005

Quote:

Originally Posted by Tsi

Well figured the problem out...took the MBC off and found that the spring inside the boost controller was pinched, soo pushed the spring out and tadaa...boostin at 12psi

LOL! Simple and stupid, no one would have guessed that! I love the K.I.S.S. problem solving.