i am contemplating welding the internal wastegate on the td-04 and going with an external wastegate. i am wondering what size would be best for low boost (8-14 psi), 38mm, 40mm, 46mm, 50mm? What are the pros and cons of internal and external wastegates? Thanks, jake
External wastegates give you better boost control. I would say the only con is the added cost. A 38mm wastegate would be fine for what your doing. Depends on what your doing in the future. If I was doing one on mine I would do a 44mm due to the fact that I will probably do a bigger turbo in the future.
All I know is that it will make your turbo breathe better and is also loud as hell. I love it I have a 38mm.
An external wastegate does not change the flow characteristics of your turbo. It may spool a hair quicker due to less turbulence within the exhaust housing, but you do not majically have a larger turbo when you intall an external wategate. Also, external wastegates do not have to be "loud as hell." If you have the capability to add one yourself, you are also capable of plumbing the outlet back into your exhaust. Done correctly, this detracts very little from the EWG's functionality.
96' impreza with: EJ18 block, 22T heads, delta cams, sti injectors, wrx fuel pump, custom headers up-pipe and turboback, FAT topmount, td-04 with rotated compressor housing, and some other goodies.
Yeah man, it's probably not worth it. You won't gain much (if any) power, torque, or drivability if you're just running low boost through the TD04. EGW's are usually best on larger turbos, or if you are desperately attempting to get every little PSI out of the top of the RPM range. You're best spending your cash elsewhere.
My main reason for getting an EWG is when i rotated my compressor housing it screwed up the internal wastegate actuator mounting spot. I either have to make a bracket to mount it as close to the original location, or go EWG and weld the flap.
Before you go and damage the turbo by welding it closed,the company i work for, GrimmSpeed, (located in st paul) manufactures a bracket that hold the waste gate closed for this exact reason. Mike
How far did you clock the compressor housing? I has one clocked about 45 degrees up from stock, and one clocked so the out let points straight up (basically 90degrees from stock) and I used the stock wastegate for both. I can get pics if you need/want them.
i clocked mine close to 90* and if you could post pics that would be great. The bracket will not work for my specific application, the compressor housing is clocked.
I would not go EWG in your case. I would look at making a new mouting bracket for the stock wastegate. It shouldnt be too difficult to do with just some scrap steel or aluminium.
