Hi all, would there be much of a gain in changing my GT35r T3 106 for the new GTX35r T4 106.
The reason i am asking is that the T3 seems to choke up at 7000rpm so i thought the T4 would flow better. The cars used for street use only. Thanks.

 

at the same boost level? not alot. the GTX is a billet turbo, and has the ability to run more efficiently at high pressure ratios(higher boost). and you are right, the t3 is holding you back.
search for howard coleman 's thread post on about the gtx35r. he explained the benefits in great detail.

 

Last thursday we tried to do a back to back on a few turbos including a stock gt35R, a GTX35R and our TD61( P trim GT35R). We made good power with the car running the TD61, however we ended up having a few bugs turn up and figured it wouldn't be a solid enough comparison. I believe the GTX35R will show a much greater midrange than the standard unit, but they will still probably fall off on the top end due to too small of a turbine wheel.

In your case swapping from a T3 1.06 to a T4 1.06 will do absolutely nothing, as they are the same housing. The flange is just bigger on the T4 unit. If your wastegate is not to venting to atmosphere, make it open dump. Then if you are running a 3" exhaust, or a catalytic converter, ditch those and move to a more free flowing 3.5" exhaust. Other than that I would switch to our P trim GT35R, its available in t3 or t4 housings, and will outflow that standard unit.

https://www.rx7club.com/single-turbo-rx-7s-23/just-shy-500rwhp-another-td61-dyno-942273/

 

I'd go a 500R from the site sponsor.

 

The car has very good mid range power with 334lb torque but at 6500rpm onwards it goes. It wont hardly red line.

 

400bhp is pretty shitty from a gt35r. There should be another hundred in it. From those results that setup can't be 100% sorted.