Slo_crx1

iTrader: (9)

I'm running a Tial 38mm wastegate on my HE351CW Holset to regulate it to 28psi...when it wants to. Lately I've been having an issue where it seems as if the valve seat in the wastegate is not sitting flat against the fire ring. I'll get one solid gear of quick spooling and 28psi to redline and shift, and then the next gear it will lag horribly all the way up and only hit a max of 22psi until the wastegate barely cracks open, and then I shift to the next gear and I'm back to quick spool response and 28psi. I've tried 2 different fire rings so far as well as new gaskets between my manifold and the wastegate and nothing is leaking there. I even upgraded the spring sets in the wastegate to an 18psi spring combo (big blue and little red springs), but it still keeps doing it. Is there any way to order a replacement valve itself and only change that to see if it works? I've had this wastegate apart at least a dozen times so far and it's getting really aggravating...any ideas?

P.S. the wastegate diaphragm is still new and no holes or rips in it and I'm using a ball and spring type MBC that I built and has worked flawlessly for the past 3 years at 28psi.

TiALSport

take the boost controler off and run spring only and see if it still does it

1NastyMR

iTrader: (102)

I had the same issue with the 38mm wastegate on the AMS Turbo Kit. Would start in 2nd gear hit 33lbs shift 3rd it would only do 20lbs then when getting closer to redline it would start to spool up the rest of the boost shift 4th and have 33lbs right away... I ended up changing the spring in the wastegate and had no issues after that so if you already tried that maybe like you said the valve has gone bad.

Slo_crx1

iTrader: (9)

It does, sorry I forgot to mention that before. It still hits 18psi no matter what, it just takes longer to get there (i.e. more lag) on the next shift. I did notice a little bit of side to side play on the valve when I had it out so I guess the shaft is worn down a little too much or the guide is worn (hope that's not the case). I found replacement valves, think that would fix it? I really don't want to have to spend another large chunk of money on another wastegate if I can repair the one I already have.

Wickedwhite8

iTrader: (9)

Email Jake at tial. He is a great Guy and tial customer service is awesome. My valve was an old style with a cracked weld. I sent it to him and he replaced it with the new one piece valve no questions asked.

TiALSport

the play is normal, what is the SN on the top

Slo_crx1

iTrader: (9)

From what I can see the SN is 8N09080817. It's in a tight place to see since I have a top mount off to the side, so the wastegate sits about 3" away from the driver's side frame rail. I'm pretty sure that's all the numbers though.

Slo_crx1

iTrader: (9)

Well I had an interesting time today trying to find out more with this problem. I pulled the wastegate back off today and checked it with my air compressor to see if anything is binding or sticking, but so far everything looked normal with the valve movement. It does leak the air pressure out through the stem of the valve and into the exhaust chamber area, although I don't know if that's normal either. I ended up putting the valve back on the car and trying a different reference port besides the one off the turbo. I hooked just the lower port for the normal 18psi spring pressure to the line that runs to my blow off valve, and for some reason it worked much better than previous attempts. It actually spooled normally without any major amounts of lag, however I'm still at least 10psi off my target boost. I decided to try a regulator T'd in to the top port to see if it would increase my boost pressure, what I got instead was a setup that didn't want to spool at all but probably because there was still a vacuum source at the top of the wastegate helping to pull it open as well. Either way it didn't work. Tomorrow I'm going to try running the vacuum line to the lower port like before, but T'ing in my MBC as a bleed off valve instead while using the ball and spring effect to prevent any vacuum leaks while in vacuum. I figure once I hit a set psi the spring will pop open and vent out extra pressure that would normally go to the wastegate, so maybe I can keep the quicker than usual spool and still be able to hit my 28psi target.

Other than my weird ways of trying to figure out how to keep this pile of junk working right, does anyone have any good ideas? I'm about 2 steps away from tossing this POS Tial in the garbage and ordering a Synapses valve.

Slo_crx1

iTrader: (9)

I retract from my previous post, using the other line for reference boost only lasted about 2 or 3 gears and then I was back to the constant lag again. Just for the heck of it, last night I pulled the line completely off the wastegate to see what would happen, and what do ya know...2nd gear hit 36psi before I let off quick, 3rd only lagged to a max of 23psi, 4th only lagged to a max of 23, and 5th didn't want to spool at all. If that's not a sign about what a piece of garbage this wastegate is then I don't know what is.

yellowevo82

iTrader: (100)

If you bought it used , you never know how many miles this wastegate has seen buddy, do what the one kid said n see if tial will help ya out if not i would look into a new one. I have really never heard of issues with Tial at all..

buchnerj

iTrader: (19)

This. Tial makes a quality product and they stand behind it. Call them up and see if they can help you out. I know your frustrated with things, but that is a tried and true WG, something is just wrong with your individual unit.

TiALSport

yep that is normal....if the valve is actuating normal i doubt it's the gate, what boost pressure is the spring set and what was it cracking at when it was on the regulator

does it hold pressure if you are applying it to the top?

also big blue and small red is a 20psi combo, if you are only getting 18 i'm thinking there might be a backpressure issue...what A/R is on the turbo?