Hey, could somebody with a Tial 44mm wastegate please help me out. I need you to apply pressure about 20psi to the lower vac port to see if the air is coming out through the dump tube. On my re-build w/g when doing boost leak test I have air coming out of the dump tube is that normal. ?? thanks

The only reason for it to come out of the dump tube is if it is opening. What spring do you have in it?

I have the 20psi spring combo, even at 10psi it comes out the lower port..

Paul, what happened to your other thread? Still having the same issues, huh?

You do realize the wastegate is set to START opening at a certain PSI and be fully open at a designated rate. 20psi in your case.

Air is easily passing by the shaft of the wastegate and out the dumptube while sitting on the workbench ..... like there is no seal between the shaft and the wastegate housing. It's not coming through an open wastegate valve.

I have send the w/g to tial and they replaced the valve(just got it back today), as Staytuned said the air is leaking by the shaft and that has nothing to do with spring rate. What bugs me the most is the fact that ALL weird problems always happen to my car..

Any details about the cause?

No not yet, still trying to get other people that have one to try it on their set up to see if it also does leak..I have noticed that after my car wouldn't build boost(only 6-7psi max) afer I hit the rev limiter at 7950rpm(clutch slip in 2nd) drag racing. Did comp test and it was OK. When doing boost leak test air comes out of the dump tube, when you by pass w/g it holds fine?.

DSMunknown said:

Any details about the cause?

Click to expand...

The WG is fresh back from Tial after an inspection and rebuild .... the biggest question here is how much air is supposed to get by shaft and out through the dump pipe.

My guess is this is a clearance issue on a cold wastegate, after the shaft heats up and expands clearances should be tighter right? thus less air can get by right? who boosts on a cold engine right?

Tial says it's good to go ....put it in your car and go Paul ..... once you get the right Fidanza flywheel surface pieces of course.

OK, after the new clutch install I took the car out and it makes a very slow 10psi max even with the w/g unplugged i get very low boost. The turbo is new and has no shaft play and spins freely. I did a boost leak test and its OK. Comp is at 162psi on each cylinder. could it be??. Vac is at 13inches at 900rpm.

BOV sticking open just a tad? I had this happen to me twice with an Apexi BOV i had. IT would stick just enough to not seat and i would be driving wondering why the ehll i couln't make 13psi on a 57 trim. Both times the BOV passed a BLT because sometimes it would seal and sometimes it would hang open. I found out from watching the BOV shaft/plunger moving while i free revved the car by hand