Max Diameter for Wastegate Hole???

[Jwest]

What is the maximum diameter the the turbine exhaust wastegate hole can be ported out to when using a Terry Houston 3" downpipe? If I remember right, the TH wastergate puck is 1.375" in diameter. Is this correct? Would a 1-1/4" diameter wastegate hole be too large?

Why I'm asking is that I'm looking at buying a newly rebuilt John Craig TE-60 turbo that has the wastegate hole ported to 1-1/4" in diameter.

Thanks,

James West
Omaha, NE.

 

[Joe Lubrant]

Originally posted by Jwest
What is the maximum diameter the the turbine exhaust wastegate hole can be ported out to when using a Terry Houston 3" downpipe? If I remember right, the TH wastergate puck is 1.375" in diameter. Is this correct? Would a 1-1/4" diameter wastegate hole be too large?

Why I'm asking is that I'm looking at buying a newly rebuilt John Craig TE-60 turbo that has the wastegate hole ported to 1-1/4" in diameter.

Thanks,

James West
Omaha, NE.

James,

I would think that 1/8" (.125) seal all away around the wastegate hole would be OK. But???????????? How are you going to determine if the Hole Location is going to be exactly lined up with your specific THDP Puck??

I personally remember when PTE HP Turbo Turbine Housings WG holes were enlarged to 1.125 or 1.250 for aftermarket DP's.
Problem calls started rolling in about slow spooling, which later was identified as WG Pucks not sealing over the holes because ATR, TH, BGC, M...SE, etc. varied in actual puck location and tolerance. Just to verify I had ATR, & TH send me their flange with
puck installed to use as template, and there was a definite difference in their locations.
To try and solve issues we started asking what DP the customer was using, and used the appropriate template. This resolved issues for those customers, but would cause a problem if that turbo was later sold by the customer to someone else with a different DP. I also remember a poor guy that bought a used hp turbo from someone and used the stock elbow/puck I guess you know what happen?? yep the puck was to small and got stuck in the hole... ouch!!

PTE no longer opens up the WG holes to the maximum size of the pucks out there for the reasons stated above. PTE or any other turbo mfr. should not have to chase the location of DP suppliers, it should be the responsiblity of the DP suppliers to maintain there puck location centerline to the turbo's.

Also remember that the holes in the DP Flanges are larger than the Bolts, and that in itself can allow slight rotation of the pipe, hence.. puck alignment to the hole.

I personnally would rather have the hole size approx. 1.00" and determine my actual puck engagement or carbon track. Then I would enlarge the hole using the appropriate centerline.

Believe me there are lots of TR owners out there experiencing slow spool that may be blaming it on chips, converters, turbo etc etc......when its really puck seal.

 

[GNVYUS 1]

You would not need a larger hole for a TE60.

If you have a huge turbo and need it to run low boost, you need a big hole. The more boost you run, the hole does not need to be maxed out. A TE60 does not need a huge hole as yours is fine just the way it is.

IF you were to port it, you would need to drive it around so that the carbon can build up around the hole on the housing. Then smooth out the inside and open it up only where there is more meat on the housing compared to the rest of the pucks carbon centerline like Joe said.

If the car started spooling slower you would have to make up for that by turning in the rod and going to a manual boost controller.

 

[turbojimmy]

I have a THDP and when I first got my PT-51 it wouldn't seal. It was because of the problems mentioned above - they sent me a "big hole" but it didn't match the THDP. They replaced the housing and informed me of their decision to just sell turbos with the standard 1" hole.

So, I had substantial creep with that PT-51 and had to port the wastegate hole. I simply used the carbon track as a guide and ground out to about 1/8" of an inch of the edge. It solved the creep problem.

My PT-61 is creeping now. It looks like the hole has been worked on (bought it used) but it's not big enough. I'm going to put a few miles on it and do with it what I did with the PT-51.

Jim