i'm wanting to install an external wastegate and was wondering what size do i need, i don't want to go to small and then have to upgrade. is a 38mm or 40mm too small or do i need a 60mm. right now i'm only trying to wastegate it to 35psi, but here in the future i want to be able to use it for 70psi. where are you guys putting it, do you just drill a hole in the midde of your exhaust manifold or do you put it on the one side or the other.

 

I would think a 40mm would be okay...joefarmer has a 38mm on his workbench to use on his new turbos. I'm not sure how far he will be wastegating, though!

Chris

 

A 38mm is more than enough to keep a single slowed down. You might want to go a little larger if you're using one in a set of twins, but it depends on how large your twins are. Search up some posts by "rjohnson"... he put an external on with his single and had good results with it.

 

Like "banshee", I am also running a "Tial 38mm External Exhaust Wastegate" on my 96' Dodge CTD. I have had good luck with mine with the exception of the gaskets blowing out. If you order one of these, get the better metal gaskets from Tial which are much stronger. One place that has GREAT prices on the Tial 38mm wastegates is "Extreme PSI Racing." Here is there website if you are interested: www.extremepsi.com. I think they are selling this model for about $220.00.

Good luck!

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John_P

 

More pics in my gallery. 38mm Tial worked well on my B-1 reducing boost from 53 psi to 40 psi. Played with it as low as 25 psi...comparing EGT's. No surging and no flapping (problem if you go too big). Have seen a 38mm work well on several twins running 60 psi.

Agree with JohnP...Gaskets, and I would say SS bolts, need replacing for best long term results.
My total cost for all parts (flanges, hoses, regulator, clamps, etc), including the 21 psi spring combination was $388.00. $230.00 for wastegate. Tial WG's are not the cheapest...but they are excellent quality, IMO.
http://www.tialsport.com/
RJ

 

check out ebay. i paid 209 for the tial 38 and 2 flanges.

 

i checked banshees and rjohnsons old post and have a pretty good idea what i need i found a bunch of 38mm on ebay for under $200. right now i can get 60psi out of the stock turbo( i don't do this often it just happens) so i'm trying to get it down around 33-35 psi

 

The 38mm TiAl worked well to limit the 68mm charger to 38psi. The only problem was getting the boost controller set right. That took about a half a tank of fuel and 2 hours of SMOKE.

brnadon.

 

"rjohnson" is giving you guys very good advice on using stainless steel bolts for the manifold! We got some real high quality SS case hardened bolts from "Fastenal." Here is the size and part number for you guys:

Description: M10X35 HCS A-2
Part Number: M82600035A2000

I bought twenty-five (25) of them and paid about $25.00 for them. They will NEVER rust on you. "banshee" and I are running them on all our trucks.

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John_P

 

John, I was actually suggesting members stay away from Stainless. Didn't you guys have problems with siezing from SS? I know one other member that took the threads out with the flange when removing the Tial SS bolts after brief use!
I went with black oxide/carbon steel bolts...I thought, on advise from you and Banshee??

 

rjohnson,

The stainless bolts for the flanges of the wastegate itself are where the problems were occuring. On those bolts we went to carbon steel bolts (oxide or zinc coated) after we pulled two sets of threads out. The number listed above is for the bolts that bolt the entire manifold to the head. I don't think they get hot enough to become a problem like the wastegate flange bolts, and they look much better after the miles pile on. I also run two thick SS bellville washerrs to help keep bolt tension constant as the metal expands during heating. So far I haven't found a manifold bolt loose!

John

 

Got you....I mis understood what J.P. was saying.
RJ