Check out my little baby turbine housing
 

Heeding Braineack's advice I picked up the smallest A/R housing I could find for this GT30 turbo I snagged last winter. It's a T25 HKS housing made specifically for Garrett's 60mm, 84 trim, UHP turbine, but dang this thing is small.


HKS 0.61 A/R and Garrett 1.06A/R GT30 housings side-by-side
https://www.miataturbo.net/gallery/f...1/p1010028.jpg

Its hard to believe these housings are for the same turbo.
https://www.miataturbo.net/gallery/f...1/p1010031.jpg

...and here it is sitting daintily atop my GT3071R
https://www.miataturbo.net/gallery/f...1/p1010032.jpg

Looks sick!

holy shit, thats a large turbo.....is it really beneficial to run such small hotside on such a large turbo?

Yea, I'm kinda wondering why myself

I didn't know it was going to be so farking small. To be fair I am comparing the largest Garrett to the smallest HKS GT30 housing.

Maybe some of the mturbo.net gurus will weigh in later today and school me on my latest acquisition.

Oh lol. That makes sence, I probably missed the thread where you explained what your goals were, can you give a brief explaination of what you're shooting for?

it is amazing to see that much of an extreme for largest to smallest :eek5:

I'm assuming a usable torque band :) Interesting in seeing how it responds!

Exactly!

I'm not too concerned about the small turbine housing since the internally wastegated version of the GT3071R that most Miata folks run is a T25 0.64 A/R housing. (60mm turbine clipped down to 56.5mm) FM recommends it for 2.0L engines and those wanting to run higher pressure ratios than the GT2560R supports. This housing lets me run the full size turbine in a similar A/R with an external wastegate.

Garrett specs the GT3071R for 1.8-3.0L engines and the compressor flows enough air for 300-450 hp with very high efficiency.

Initially I will run it in the 250-300 range on a stock 99 engine while I build up a forged short block. After that I'll bump it up to 300-350 and see where the power bug takes me.

I was, however, shocked by just how small the housing was when I opened the box. HKS actually uses this turbine housing to drive the next size bigger compressor, their GT3076R equivalent.

Keep it coming guys! All feedback appreciated.

If all else fails, there's the .86 housing. that would be like the .63 T3 housing.

But considering the size and shape of the turbine it should perform well, you might not make as much up top comparatively, but it should still suffice. when you decide +300 is not enough, strap the .86 in place.

+1.....you will get some better spool with that tiny hotside, and massive amounts of torque once it does spool, but up top it will choke.....id say its ok to use this no the stock engine, but on the built one id go bigger hotside no matter what

that size turbine housing hasn't choked out all the others here running 2560, 2860, 2871, 2876s.......while the top-end might suffer compared to a T2 .86, the torque should hold flat in the least.

That's what I want, massive spoolage, with a nice flat torque curve out to redline. No doubt the spool will be good, but I am a little concerned the VE party may end too early for my taste.

HKS offers this housing in 0.61, 0.73, 0.87, 1.01, & 1.12 A/Rs so I have a good upgrade path. Discount retail pricing on the HKS housings is the similar to wholesale pricing on the Garrett housings too.

BTW, I thought I was buying a housing just a smidge smaller than the Garrett T3 0.63. Teh internets says teh mad tyte JDM HKS howsing has teh full T3 scrollz, jus wif teh T25 flange. This is obviously not the case, but I could believe it at the time peering into the 1.06 I currently have. The volute on that massive beast necks down quite noticeably right after the T3 flange. I imagined the 0.63 A/R T3 must look like a trumpet. :)

I have the .86 ar on my DP...if that shit doesn't spool early enough, I plan on sticking a .63 on there.


horrer

I assume when you change housings like this, there's an extreme change?