wastgate setup opinion

[mkspriggs]

hey guys i was wondering what everyones opinion was abut setup of external wastegates?

I have heard so many different things and seen them aswell.What is a better setup?On the Mani?or on the O2 housing?And does it make an actaul difference? Thanks guys

 

[T9S1i]

I just had to make this choice myself. I decided to go 38mm external off of the wastegate. The guys at FP seem to really think that this is the only way to go and i know that they know what they are talking about, so I believed them. My car holds rock solid 10psi on my 16g right now. You can read through the vendor announcement post about FP's new cast manifold to see Roberts view on external wastegate options.

Some food for thought, there is higher exhaust pressure in the turbine housing, so its easier for exhaust to go out of the o2 wastegate, rather than the #1 runner of the manifold. Also, if you need to remove more thank 25% of your exhaust gas to regulate your boost pressure, this is going to be hard to do if you go external off the manifold #1 runner, which is obviously only 25% of your exhaust gas. You can take divert more gas out of the turbine housing because 100% of your exhaust gas is going through there. The last thing that sealed the deal for my decision to run my external off the o2 housing is sound. I planned to dump my exhaust gas to atmosphere so it needed to sound good. If you search videos of externally dumped wastegates, you can tell the difference between those dumped off the manifold and those dumped off the o2 housing. The exhaust coming out of 1 runner of the manifold comes in pulses and therefore will sound like a lawnmower when you DTA. Exhaust dumped out of the o2 housing will be a smoother flow of exhaust and will thus sound better.

One last thing that i just realized about wastegates DTA is the volume of the sound of the exhaust gas dumping. Since ive put mine on (like 3 weeks ago) its kind of been a PITA at how loud the damn wastegate dump is, i was talking to my friend with a gt35 running like 28 psi, and he told me his is very quiet. The reason being that the lower the boost you run, the more exhaust has to get diverted to hold the correct boost, and the louder it will be. Once you up the boost and have to divert less exhaust gas, the sound will be barely noticable.

Hope this helps man, if you have any other questions feel free to ask.