Good to see it fixed

 

I have the divided 1.06, wonder if I could have went bigger, if that is even an option with the 35r?

 

i wonder if this would fix my buddies civic last night on the dyno they could only make like 350whp at like 13psi on a fully built laskey motor, but he has a divided .90a/r housing (T4/T67) and a twin scroll full race topmount, i wonder if he is getting ridiculous back pressure causing similar issues?

 

This is strange I just had this conversation at my shop yesterday as we were discussing whether or not to go twinscroll/divided manifold or just traditional.

He found that with the divided exhaust housing there is indeed quicker spool but it is divided all the way through the snail and doesnt allow exhaust gases to spool the turbo up top the way a non divided snail would.

He said your sacrificing top end power for spool which is quite evident from your findings!

 

Very nice!

I wonder if this is the same problem that my buddy is having with his Skyline

RB26 with a Full Race divided mani and divided 1.06 GT35R making only 460 on Evan's dyno - so probably 400 rwhp +/- elsewhere

 

so would a divided gt40 be a better bet if u wanted to use a divided house turbo?

 

hmm this is very interesting

 

IF you go with a divided manifold and housing, it HAS to be big to work properly. The 35R is not suited to a divided setup, the wheel is small and there aren't any turbine housings big enough to comfortably flow what the compressor will.

With the GT40 stuff, if you go divided, do the 1.19 housing or it's not worth the time. GT42 and bigger, we run 1.44 housings and that's with a much bigger turbine wheel than the 35r.

The thing is, engines with cams that have a lot of overlap are very sensitive to exhaust backpressure. To make matters worse, in that situation, high backpressure and big cams, lowering compression is one of the worst things you can do.

So this setup was about worst case. Big cams, low compression, high backpressure. Either way, clearly, don't waste your time with a divided T4 setup on a turbo below a GT40.

 

Exactly. I'm glad guys are doing thse comparisons. It saves gus like me and the rest of us time and money down the road.

 

I've said this for a long time. Divided housing arent at all what they are praised to be unless you go with a HUGE turbo and turbine housing. They may help with a little quicker spool, but the top end will be compromised. Regular open housing FTW.

Glad you got it figured out.