Hey guys, I'm still in the early stages of my turbo build. I am learning as I go.

I'm using truck manifolds with a flowmaster merge to make my crossover (haven't built it yet). I'm curious as to the benefits of using a t4 vs t6 turbo flange I will be doing a single turbo.

As of now it's going to be a stock ls1 with 853 heads, and aftermarket valve springs and a turbo cam. Arp studs and rod bolts etc. Just enough to get it on the road. I will be doing a forged lq4 next year, so I will definitely be looking for much more horsepower. Right now Im just hoping for 500rwhp.

Not sure on the turbo size yet either

I have a 4l80 that will be fully built and
I haven't even started with the fuel system yet, but am interested in running e85. Thanks guys!

 

Generally speaking, a T4 flange is for a smaller turbo. Again, generally speaking once you get past about 78mm it goes to a T6. If your only looking for 500hp, a T4 is fine, however if you look at say a Borg Warner turbo, a T4 will cost more than a T6. Since you should have plenty of room, I would go T6.

So is this a budget build or no? What is this going to be used for? Are you considering a Chinese turbo? With such small power expected, you won't need a turbo cam.

 

If you have the room, I would just go t6. That way you have plenty of room to grow later down the road when your build gets outta control. But in the same breath, people like stock48 have proven that you don't need a t6 flange for insane power.

 

I should add, if you have dreams of running a lumpy *** cam, just go t6 from the start. T4 based turbos generally need a milder cam to keep back pressure in check.

 

Most of the China turbos are all T4 and make power well within the limits of a T4 housing.

If you're going for big power or big cubes, I would go T6. But if you're already that far in, whoever you are having your turbo specced or built through will recommend either T4 or T6.

There are lots of people making over 1000 hp on a T4 housing. Smaller cubes can typically live with a smaller housing. If you're building a 400+", I would just go with a T6 regardless of goals.

 

I know its counter productive, but I am interested in finding a choppy turbo cam. I need to do more research on my cam selection. I actually may be changing my build direction a bit and just going with 6.0 from the start. But from research it seems like I will get the best results from a 5.3. So many decisions! Lol