Open T3 vs Twin-Scroll T4

[ceedawg]

Here is an interesting thread http://www.dsmtuners.com/threads/is...true-twin-scroll-setup.488300/#post-153483591

 

[Seamus]

When the then new gt35r turbo firrst hit the market it was only available in open t3. It took a while for the divided t4 and other housings to come out. I was looking at some old dynos from around that time, because there was a rush to try the new t4 housings we were used to using. Its widely known that the divided housings flow less, than equvilent housings, but I noticed that everything was still in the 400-430 range at around 14-15 psisi on pump gas regardless of housing. E85 hadn't hit yet either. you guys are thinking that boost isn't going to show much gain in the bigger housings, but these are on rotary engines that ate producing significantly more exhaust energy and flow. A open t3 has always been considered an undersized housing and open o t4 of at least .8x or ..9x and up divided is pretty much standard on a pump gas car. A funny note on e85, remember how many believed u should avoid the 10% ethanol blends if possible?

 

[mercaholik]

Great real world info in here, this will help me make a more informed decision. I just read a mag article about this guy Austin Oakes sweet evo 8. It was built by English racing with wiseco hd 10.5:1 pistons, r&r rods, gsc s3 cams and using a ets t-4 twin scroll manifold. It made 1,053 awhp @ 7,800 and 722 lb-ft at 54 psi from a precision 7285. Says 42r style frame 1.28 a/r twin scroll. I wonder if this is a good combo of parts or if an open scroll would make more power but I've heard only good things about English racing and ets. Any thoughts, I've only run open scroll and was seriously thinking of going t/s, until this thread.