i currently have a T78 on my fully ported FC w/haltech and all the necessarys. i want the car to be a very aggressive street driver.
i get 18psi at 4300rpm and 15psi at ~4k. i am dissapointed with the laggyness (big surprise) and was wondering if it is worth selling the t78 and putting the money towards a new GT35R (GT35/40) which cost about $1400. if you have had experince with both of these turbos please post your general setup, a/r's, trims, rpm at which you get full boost, etc... and comment on them both.

i have heard of 15psi at 3400rpm??? is this true??

thanks
justin

 

On my large street port I was getting 15psi at 3400 or 3500 so yes the answer to your last question is it's true

As for how the T-78 compares I wouldn't know but I drive my car on the street mainly and it's a blast to drive... many will say the 35r is too small, but that's all relative for your usage, since I drive mine on the street I wanted/needed something smaller which still has a nice kick in the ***. The 35r fit the bill for me, I love it.
-Nic

 

What the last guy said is accurate . Perhaps you are laggy due to too much overlap on the streetport. I went from a stock to a street port and its wayyyy more laggy now. At least 1000 rpm slower. For a street car the car was perfect with a gt35r/stock motor. since I have a racecar its better now.

 

does the GT35R have a T3 or T4 flange?

 

The standard 35r has a t3, but there are some now available with the t4 and the same size wheel, and I believe A-Spec is working with Garrett to get a t4 with a larger wheel. There was a thread about this a week or so ago.

 

Some good info here about the 35r:
https://www.rx7club.com/single-turbo-rx-7s-23/hks-gt3037-series-t04-bb-turbos-334158/

 

Why not just go GT40R?

Alex

 

It's all a matter of what your goals are. I like have 15 psi by 3400-3500 rpm. I don't know exactly how much slower the 40r would spool but for my use and my goals the 35r is a great choice

 

Would I be able to tell the difference between the two flanges by simply looking at them?

 

Yes the T3 will have a bolt pattern of 1.75" by 3.38" GT40R is a T4 and it's bolt pattern I believe is 2.75" by 3.5".

 

keep in mind, exhust mani design has a huge effect on lag.

I noticed faster spool when i had my motor street ported. (stock s5 turbo)

 

I wonder why we just can't merge these threads.