I've been searching the internet for the past few days and need some clarification. Currently I have a 351w with a Turbonetics T76 and .81 a/r undivided Q trim housing running 10 psi boost. My exhaust is killing my top end power (501 rwhp @ 4900 rpm, 597 rwtq @ 4100 rpm) and need to upgrade the housing. A .96 a/r undivided doesnt seem to be big enough, especially running on e85, and I cant find anything bigger for a Turbonetics undivided housing.

I have found lots of people saying, "A 1.0 a/r divided housing will flow similar to a .81 a/r undivided housing". But does this mean it will still choke my car switching to a 1.0 a/r divided housing or will it spool roughly as quick as my .81 a/r but not create the back pressure?

Im not looking for crazy horsepower, but i have found many other people running almost identical setups with more power and running on pump gas. I have a dual tune and only made 480 hp with 91 octane for those just in case days where I cant find a gas station selling e85.

 

what transmission you running?

 

I was using a t5 til I figured out what I wanted, but that didn't hold up very long, stripped the teeth from third gear. I'm trying to find a 4r70w right now that I can rebuild.

 

500HP at 5K and 600TQ boy I'd love that setup fro the streets!

But sure sounds like your engine has a bunch left over.

 

Turbonetics q trim... Cannot buy those housings any more

 

They have them for sale on the Turbonetics online store for $260 and a few other online places I've seen.

But the main question is still yet to be answered.

 

Q trim?

 

http://www.horsepowerfreaks.com/partdetails/turbonetics/Turbos/Turbos_Only/T-Series/3446

http://www.horsepowerfreaks.com/partdetails/Turbonetics/Turbos/Turbine_Housings//2591

still wondering about " I have found lots of people saying, "A 1.0 a/r divided housing will flow similar to a .81 a/r undivided housing". But does this mean it will still choke my car switching to a 1.0 a/r divided housing or will it spool roughly as quick as my .81 a/r but not create the back pressure?"

 

not turbonetics current stock
thats old stock from a supplier

 

got it, ok, thanks for clearing that up. But do you have any info on the flow? A size like a divided 1.15 a/r flows similar to a undivided .81? Does this mean the bigger divided housing will spool the same as an .81 but flow more exhaust, or is there more to it?

 

Using some diesel larger garrett stuff I deal with as an example.
Approx .1- to.12 smaller open equals a divided
Eg
.96= 1.08

 

That's exactly what I was looking for, thanks. Did you find that out over time or did someone tell you?

 

I think you need a turbo with a real turbine wheel in it, housing a/r will only be a minor tweak. P & Q wheels are a better match for engines 50-60 cubic inches smaller than yours.

Get an old mechanical oil pressure gauge, some 1/8" copper tubing to act as a heatsink/isolator, and measure the pre-turbine backpressure.

 

My own data

 

your own data if usual the best data. what kind of wheel ate you thinking? I'm still learning, only had a turbo car for about a year, always have been into supercharging.