ok new turbo setup for the winter time.

[b00stinbmx]

OK so this is going to be a little mini build thread i guess. more so just a turbo set up thread.

quick background. s13 hatch, this past year i swapped in a s2 rb25det, ran it stock all year. motor runs amazing, very happy with it. it made 289whp and 241lb/tq on 12psi. seriosuly the only thing that went wrong when i just pulled the motor out was the valve cover gasket has a leak... whatever.

recently purchased a garrett gt3582r. and some detschworks 740cc injectors. im going to be going with a tial 44mm wastegate. my horsepower goals for next year to START are 400-425whp. im not going to push the crap out of the bottom end but i may try to squeeze more out depending on how it runs initially. planning on going with a haltech system, not sure if im going to use the sport model, or the plug and play one. Heres where im running into some questions.

first: exhaust manifold.
my options so far. back when i boguht the motor i friend had a brand new egay manifold. never been used to i grabbed it off him for pennies. i already did the research and saw that they fit like crap. and it can be confirmed. i bolted it out and i can already tell theres going to be some valve cover to turbo compressor clearance issues but honestly its not a big deal. I have a full shop, access to pretty much any tool to modify it and do it the right way. the wastegate placement is directly underneath and has a older style tial 38mm 2 bolt flange welded on. i was planning on going with the new tial v-band 44mm... now is it just the flange that is that size? or do you think the piping is too small for a 44mm wastegate to be effective. if so i will have to cut it out and bend in a new pipe to replace that.
i guess what i am really asking is does this manifold (with modification) have a decent enough design that its not going to HURT me performance wise over running the stock cast manifold?

my other option is to do what a lot of people i see doing lately and drill out the top of the cast manifold, fabricate a pipe in there and run a wastegate right off the top. i know the gt35r will fit if i run a spacer in there which i will also just weld in. i guess my questions about this manifold set up is is it any more beneficial compared to that aftermarket one? and where would i be looking at for power levels or spool time for when it becomes inefficient ?


i understand nobody may be able to answer these questions for me but i figured it was worth a try. either way like i said i will keep posting in this thread to document the turbo set up so opinions are welcome and anything else you guys want to post, thanks for reading!

[l0nestar]

The 35r is a pretty healthy sized turbo for the 25. Knowing that, I would dump the fleabay manifold and use a stock (CAST) manifold and just modify it. Unless you want to spend some serious coin to get a 'proper' tubular manifold.. but since this is a 'street' motor, I wouldn't be concerned with it.

Additionally, you will be able to run whatever flange wastegate you wish.