I have the opportunity to buy a HKS To4R kit for my FC. While I am waiting to recieve a reply from the seller, I have a few questions I thought maybe someone here could answer. 1st, the turbo has a 1.15 A/R hotside, and a .70 compressor. This is on a HKS manifold. Is the HKS manifold and/or the HKS 1.15 turbine housing divided? Also, I know the 1.15 A/R is pretty large, what would the spool time be like with my large streetport S4 engine (remember 8.5:1 CR). I know there are alot of people using a T04R, and I searched but most seem to be using the .84 hotside, or the 1.00. Is the 1.15 just too large for the street?

 

the biggest i have used is the 1.00. i have heard plenty of people in the past complain about the boost coming online pretty late with that big of a housing. if it is the cast manifold then i am pretty sure it is undivided.

 

Ok, thanks. Thats what I was thinking, with that large of a A/R, especially with an undivided manifold, it would have to have some very slow response.

 

i got the .96 ar and i think that is plenty big enough. i havent gotten it tuned yet but i would think that is as big as you need to go. if you would rather want low end spool then i would get the next size down in the undivided housings.

 

I have a 1.0 ar on my FD. It's a bridgeport and the 1.0 is divided, along with my manifold. I'm told it should make 15psi by 4100rpm.

 

and my rev limit is set for 9500rpm. I think that leaves enough room to have some fun