GO ON...


I've heard you still get some benefit using a divided manifold and an undivided housing. Kind of like a mild tri-y header affect.

Which single scroll A/R you going to toss on?

 

we have a 0.82 housing here in T3 so we'll use that.
I'm not sure if the car will be ready for the track this weekend though, engine/gearbox needs to go in then it needs to be retuned/checked on the dyno for the single scroll housing and the reassembled engine.

I'm not going to potentially **** off ATP when we are hoping to get warranty out of them

 

Not bad at all

Will be very interested to hear findings if/when this happens

Shame he went T3, if I were going TS I'd definitely use the T4 - there's a world of options out there... though fwiw I think you can get quite good Holsets in that flange pattern.

 

I believe the larger Holset turbos are all designed for diesel applications and <850C EGTs as well...

 

Good point...

 

Correct. The HX-35, and HX-40 are both diesel apps designed for the Cummins I-6 diesel engines.

 

OEM housing

 

Wow. That's an MHI turbine housing, Charlie?

 

yup, dunno if this ones a 9.8 or 10.5, but i've actually seen a few like this

 

Answer from ATP Turbo, i put it in the first post as well

************************************
Here is the answer from ATPTurbo
"Tell your customer we are working on a stronger unit that can endure circuit racing to extended periods of time without fatiquing that way.
There is stronger material available now for turbine housings, but not in the divided (twinscroll) application that the customer is running.
There is an upcoming release of Garrett's twinscroll v-band housing that will use a stronger casting material but that is 1/2 year away.
If he has to be up and running NOW, going to the 1.06 A/R housing will give him some more strength because that unit has more wall thickness, but it's still not a 100% guarantee due to the stresses of circuit racing.
Please pass this along to your customer.
Thank you."

"Looking at the dates below, he's out of the 12 month warranty period unfortunately.
We are working on a stronger housing for the future so that he has something that will hold up forever on circuit racing though."
************************************

To sum it up, current twin scroll exhaust housings are not and were never designed for circuit racing.
beware to anyone using them.
We have had another GT30 Exhaust housing crack through the divider also. This was on a drift car.

I'm wondering if T4 Twin scroll housings would hold up any better?

 

Even the T4 stuff is still made for diesel applications.

If you can keep exhaust back pressure down though, it would help.

 

looks like we are fitting the BW EFR 7670 onto this car now, ready for racing in 2.5 weeks. Results to come.
We'll see if we can melt the stainless steel twin scroll housing lol.

 

Awesome, Mike - very interested to see how this goes. Did you ever push the GTX3076R any harder than you were? How hard are you going to lean on the EFR?

Best of luck

 

not yet.
The Subaru is still in the development phase, we are using a stock short block, so max power was set to 300kw. flick me a PM if you would like graphs, i'm happy to share.
Once we build the 2.5litre up for it over the xmas break, we'll put it on kill mode.
Carl is a big fan on larger turbo's with less boost though, so dont expect 40psi or anything crazy like that lol.
The most i've ever seen him push is 36psi on Han's SR20, and that netted 520kwatw. Not bad for a plan GT3582.

 

More info...

One of the external wastegates were jammed open.
The housing is "warped" in the direction of the open wastegate runners.

So the housing has differential pressure across the twin scroll divider in the housing, possibly causing it to push the divider over.

It's a reasonable explanation for what we have seen.