badcoupe

I have been neglecting the poor 51 for some time now and got motivated today. For approx the 6 months I've only been able to get approx 12 psi. o I welded on my new tial wastegate. I left the dump open to atmosphere for the time being. I still only get 12 psi. I can adjust the boost controller till I hear the wastegate open lowering boost. but with it adjusted up all way even it doesn't top 12 psi. I know the wastegate isn't opening or I would hear it. There is no exhaust leak at the wastegate and I can't hear or see one at the turbo. I tightened the screw up on my BOV no difference there either. The turbo spins freely enough but maybe it is the problem?? The A/F stays good up through the range. No leaks in the intercooler pipes that I can find and they are all tight. Any suggestions??

pk951

You must have a leak some were.

Pinch the hose going to wg and check your'e boost then.

If you boost more than 12psi could be valve is stuck open a bit on wg.

badcoupe

I'm wondering about one of the rubber hoses under the intake possibly having a crack, they do tend to get hard etc over time.

eclou

You might also tell us about your vacuum routing to the wastegate and boost controller. Is it possible that the vac lines are not going the right way?

hosrom_951

You sure that the wastegate is not welded on backwards? i KNOW that the Tial and delegates or mounted the opposite way compared to the stock.

badcoupe

The waste gate works fine and does work. With it dumped to atmosphere I can hear it when it opens. I've had this same issue for quite a while, it's like hitting a wall,12 or so psi is about it. I cranked the fuel wayy up lastnight and in fourth gear I managed to see 15 but still 10 to 12 in all of the other gears. This thing used to slam 20 psi no sweat at 2500 or so.

eclou

You have a K27, so it should be able to produce whatever boost to redline. I would guess a leak somewhere on the pressurized side. Check all IC hoses and clamps (many have a tear on the bottom side that you can't see), check your TB idle screw (if it's missing), check intakle gaskets, check all vac lines. Using any coolant? Any oil leaks? Bad leaking BOV?

Eugene

badcoupe

Yanked the intake tonite out of boredom. Looks like their is oil mist all over under there didn't get time to remove the ISV etc. as I got busy. I wonder about the oil separator. Possibly cracked. or the T fitting.

badcoupe

I've also noticed some oil pudedled on the block just ahead and below the separator. I've been getting some smoke lately and the turbo and IC pipes are clean.

eclou

Mine was doing the same thing. Oil blowing out of the oil AOS seals. This is also a source for some boost loss as well. I doubt this could cause all of your loss though, unless there was a big crack

Tom M'Guinn

Leaks in the intake or exhaust are the most probably problems, or a bypass valve or turbo problem. I don't see a testpipe listed in your mods. If you have a cat, don't overlook the possibility of a clogged cat or collapsed inner pipe. This will restricted exhaust flow and keep the turbo from spinning up like it should. It is hard to detect because there are no outward visible signs, but it is known to happen on these cars.

badcoupe

cat is gutted out. Thanks for all the input