Its been done it was rubbish on our car Derek the guy with the twin dump pipes out off his hood .Just waiting for him to retune with a different housing and gain 150whp from his mistake.Search for Booztins

 

Losing is a relative term. Two turbine housings would need to be directly compared, as well as projected boost levels. The GT40R turbos are used in diesels, hence the reason they only use divided turbine housings.

The GTX is a decent spooling turbo. I would personally use the GTX3071R for quicker spool, no matter what turbine housing is used. The divided housings dont cause a power loss. By dividing the exhaust pulses, overall turbine efficiency increases meaning quicker spool and better power at low RPMs. The advantage that a large turbine a/r has is the path of the exhaust, which will flow more direct into the turbine wheel. When you look at a turbine map for a GTX30R you will see the relative efficiency between the 3 a/r choices. Compare the difference between the 1.06 and the .82, which is more substantial than the difference between the .82 and .63. Efficiency goes up at an exponential rate the larger the turbine housing gets (to a certain point, obviously).

Were the target boost levels identical and was the comparison back to back? I can say I am 100% sure they were not. With a direct comparison between those two turbos I can say the GTX35R would absolutely make more power than the GTX30R, all other things being equal.


I would almost say the opposite. For autocross and street courses the GTX30R would be a better choice. The lower compression will give increase spool time, and therefore you would want a smaller turbo. The lower compression would also allow for slightly higher boost levels, and with the smaller GTX compressor producing higher temperature the head room would be good. When comparing two turbos at the same boost level, a higher static compression works better with a larger and more efficient turbo.

The GTX3076R would be capable of ~650whp at the ragged edge.


I think the choice of a GTX30R is a good one. If you are running pump fuel only, it will work just fine. If you are going to run a higher octane fuel or use an additive, you should consider waiting for the new GTX28R that will be out very soon. They are a huge improvement over the standard GT series and will be more than capable of making 400-450whp.

Divided housings are not power robbers by any means. Sure, an improperly chosen divided housing can work less well than a properly chosen divided housing, so it all depends on the application and ideal use.

 

https://www.s2ki.com/...ld/page__st__50 430whp 12psi on pump twin gtx3582r



http://nissansilvia....howtopic=497486 gt3076r against gtx3076 TRUE comparison.

 

Great posts guy im just going to throw this in. I think the key is the 3mm headgasket.
http://dynos.evans-tuning.com/2010/1...425tq-aem-ems/

 

My understanding of the issues with the twinscroll housings on the smaller turbo is that ATP, the company that makes them, used a regular T3 housing and then added material to the mold to get the two paths into the exuder. This causes an increase in back pressure and hurts a high CFM motor like the f2*C1. Larger sized turbos, like the GT40, with bigger housings don't have that problem. GL!

 

Here is the answer to what you wrote:
https://www.s2ki.com/...s-dyno-pricing/

The Ptuning kit with a GT3076R spools crazy fast (pretty much instantaneously) and pulls hard all the way to redline. IIRC, it hit full spool at 3,700rpm. Go with a GTX3076R if you want more power.

There have been a few folks in this forum who tried twin scroll, and they seem to have discovered that with the manifolds and turbos they chose, on these motors, they needed a bigger turbo (especially the turbine housing) in order to make the power they expected.

I believe twin scroll is a great way to go, but there doesn't seem to be as much experience among the S2000 community with twin scroll as with single scroll. So, help us out by buying a twin scroll setup and posting dyno charts please!

 

Great info! What about a t4 divided turbine on a gtx3586r 1.06ar?