have a 5.0 turbo fox body car, bought it built. it has a Tial sport wastegate, it's allegedly a 38 mm unit...I'm trying to confirm, the only number I see on the unit is on the cover sn07090498 so...i think it's a real Tial unit or at least the cover.

next question...it currently is making 15 # of boost, want to make only 10 #...just change the spring?

 

using a lighter spring will let the waste gate open sooner which will result in lower boost numbers

 

What does the flange look like that it is bolted to? 2 bolt, 4 bolt or V band?

 

it's a two bolt!

 

Just put a manual boost controller on it for $50 then you can set it where you want it.

 

........ but you need to install a lighter spring first. Sounds like its a 38mm. Does boost creep, or is it steady at 15 psi?

 

boost get to 15 and it stays at 15 psi for as long as we did the dyno pull.

What supporting vendor has springs for this waste gate?

 

Brian, sent you off the pictures...let me know if you git them! thanks for all the help!

 

Isn't 1 38mm tial a little small for a 5.0 ? I have twin 38mm tials on my 4.6.

 

stangman9897 it depends on how big the turbine is, i ran a 40mm jgs gate with a 5.0 and a holset h2c and no issues keeping the boost where i wanted it but the turbine was fairly large. If the turbine is really small and it needs to wastegate a lot of exhaust to keep the boost at a certain level then it will boost creep like a holset hx35 does on a 2.3 until the wastegate hole is made larger or the scroll is cut back to exhaust both sides of the scroll.

 

I also have a 38mm tial gate w/ a 12lb spring with no boost creep what so ever on my 331.

Just swap springs, easp as pie

 

Make sure it isnt a 35mm! same body cap everything looks identical. just different diameter valve and hole in the base. I bought what I was told was a 38mm only to find out a few months later when I was rebuilding it, that it was actually a 35mm.