NZ951

Thanks Duke, yes thats what I am talkin about. Hey did you win the poll? I owe you a pipe if you did! I think it must be about up right?

J Chen

Hi Dukse,
Internal dimensions would end up somewhere
between the .48 & .63 AR

Duke

You set the end date to the 17th, but last time I checked things were looking good for me

Do I get something to smoke with the pipe as well!?!

Andrew Wojteczko

Hi,

Going to order our new race turbo today, any reason I should chose a 3037S over the 3071R? I have done our compressor plots on the 3071R and it seems the perfect match, I guess the 4" inlet would work best with that nice ventury built in. I would like the port shrouded inlet but that doesn't seem available on the 3071R.
On the turbine side there are three options, 1.06A/R, .82, and .63. All at 84 trim and 60 mm. This is where I really need help still, without the exhaust manifold pressure values I can not use the compressor maps, which A/R do I need for our built 2.5L race motor? (Race Cam, 3" exhaust, mild head work, balance and blueprint, aluminum flywheel, pressure plate, knifed crank, TEC3R, 83lb/hr. injectors, Looking for around 400 at the wheels.

Thanks again,

Andrew Wojteczko

Corleone

No reason to have bigger than .63! I have a HKS hotside house with .61 and the same wheels and trim. I have not anytime yet had moore than 800 degrees C (1472 F) in exhaust temp and that whats decide how big you need. I run 20 psi up to 7000 rpm. (I have logged my exhaust temp).

Even if the .61-63 is similar in area to KKK8 it will flow a lot moore at the same time it will spool sooner/faster.

mrfixit951

Andrew,

I am in the process of ordering a GT3071R turbo from precision turbo (I gave in ;~) ). Both Precsion Turbo and Edman951 recommended the 0.63 A/R for the T3 (65 mm bolt spacing) based turbine housing. Precision indicated that the smallest A/R of the GT (100mm bolt spacing) flanged turbine housing is 0.82 which seems a little big.

If I may ask where are you sourcing your turbo from? Several vendors that I contacted have the GT3071 on backorder.

Edman951 in another recent thread posted an informative video of his car spooling with the GT3076 with a 0.63 A/R.

Ben

Corleone

Thats why you need a HKS house with T25 flange and .61 A/R. Se the HKS list in my previous post in this thread.

J Chen

Hi Corleone,
How come HKS have the .61 housing ?
Is it specific to HKS only ? Also you mentioned
T25 flange but is it base on the T3 housing ?
Oh going HKS will mean big dollars.

J Chen

mrfixit,
So you've decided to go BB ? That turbo looks
& sounds like yummy to me. Wish that it was
available before I went GT25. Looks like a
good compromise between my turbo & Edman's.
Are you getting it cheaper than ATP's price ?

Andrew Wojteczko

I am ordering from a local parts distributor in ontario canada called JRP, no doubt the turbo is coming from the US, not sure where. They said a week delivery, but until I have it in hand we all know how that works. Has anyone else done the plots on Edman's cold side? Are you not crossing the surge around 4000?

Thanks,

Andrew Wojteczko

Pauerman

Ben,

I just spoke with ATP Turbo and they told me that the GT3071R uses a standard GT hot housing w/ a T3 inlet flange and 4 bolt exit (65mm stud spacing) - not a complete T3 based hot side. They have this turbo in stock.

I don't know if I'm reading your post correctly, but are you saying that the smallest GT based hot housing is a .82 A/R and that is has a 4 bolt exhaust flange w/ 100mm spacing?

Please let me know if I've been misinformed.

Andrew Wojteczko

Thanks Corleone,

Your comment about EGT's determining turbine requirements makes sense, too small a turbine housing will increase back pressure, and increase EGT's indicating too small a turbine housing. 1478F sounds safe and seems to indicate that the 61 is a good A/R. I am going to order the GT3071R with the 4" inlet and the .63 A/R hot side.

Thanks again,

Andrew Wojteczko

Corleone

Yes I think so. Only HKS has the .61 with that wheels and trim. Its for sure a T25 flange because i have a T3 flange in my garage and its much bigger.

Works great on my car and it seems that this turbo, GT 3071 with my HKS hotside can produce up to estimated 450 hp. I have now done a short run at second and third gear with 22 psi and 6800 rpm and it showed a injector dutycycle of 85% with a AFR at 12,7. 450 hp is close!

I think that 3071 is the very best choise for most of us!

J Chen

Hi Pauerman,
It's correct standard GT series hot housing
without build in wastegate is huge but
according to my data there is a 0.63 AR
available. It comes with 0.63, 0.82 & 1.06 AR.
on standard BB series. Am I missing something
or it's not available in the US.

Duke

This thread has some great info!

But I think Andrew's engine will have trouble reaching 400rwhp with the .6X hotside at reasonable boost (less than 20psi).

Corleone your spool-up seems very good! A lot better than my current setup with a K27/8. Although I'm still on the crappy stock WG and a MBC.
I wonder how much extra lag the 0.82 will add. I feel no need for better spool-up than today. Boost below 3500rpm really isn't necessary for me.