You chose GT35r or holset hx-35/40?

[dsm-onster]

They use a t3 housing for some and t4 for others. All twin scroll. So don't expect that kind of spool with a non-divided runner manifold with the stock holset turbine housing. . . The bolton housing with the hx40 has done 685whp anyway. That's the combination that I was referring to that can spool good by 4100rpms.

And not all hx40s have the same compressor. So you'll have to verify measurement of the inducer diameter.

 

[black_gst]

i think i was reading the the 6 or 7 blade compressor was better??? but which housing is better the t3 or t4. or are the differences so small that theres no real impact on performance. and will a divided mani make a large impact(is it worth the $ to get one?)

thanks for you help dsm-onster

 

[dsm-onster]

Thre's 2 6blade compressors. So if you see one, you'll have to get the inducer measurement varified before you buy it if you want the bigger wheel. One has a 60mm inducer, the other 56mm. I've not seen any small 7blade wheels, all have been 60mm. . .

T3 vs. t4 is just the difference in the flange with a holset. You can get an 28cm^2 turbien housing with a t3 or a t4 inlet flange, same outlet flange.

Yes, the spool difference will be huge running a divided runner manifold vs. an open manifold. Each volute of, for example the 18cm^2 housing is about the size of a single scroll .63 a/r garrett housing. Dividing the pulses forces them to only see one volute and spool will be similar or faster to an open .63 a/r housing around a hx40 turbine wheel. But if you run an open header, your pulses will see 1.26 a/r . With a turbine wheel the size of a P-trim, you're looking at som lag there. . .

There are other benefits to a divided runner manifold. Like isolating the pulses from the overlap times nearly removing ALL the issue of high backpressure. Imagine a turbo system with zero backpressure issues like a supercharger system. No issues with hot exhaust gases when tuning the motor. No need to run super high boost to overcome the exhuast backpressure enough to get the flow you require. As well, such a divided setup will force the exhaust gases to do all it's work on the turbine and none on the incoming aircharge. You can get away with MUCH more overlap, that incidentally helps spool a turbo AND helps a motor breath better up top. . .

. . . The divided headers are VERY expensive. And for no good reason. If you can't stomach or afford the cost, the hx40 with the .55a/r BEP housing has done 685 whp and 10s.

 

[black_gst]

thanks for the great info i think a HX40 is next on my list. with a divided mani too