Who's using a GT35R B.B Turbo?
 

Just curious, who's using a GT35R on their 930 here?

Just wondering how well they perform on the 930 headers and how well they live? Are these B.B units all that they are made out to be in terms of "ultimate spool-up"?

I've read conflicting information about their reliability on an air cooled engine. I mean, if it's lubricated sufficiently via a -3AN or -4AN feed, oil is kept fresh and clean and proper precautions are taken for cool-down, then I can't see why they won't last like any other KKK unit.

I also notice they use a T60-1 compressor housing, so these should be capable of high 500-600HP, right?

Discuss please?

Yep, they are definitely capable of 600+rwhp. They have a 65#/min compressor wheel (the 82mm Gt40r wheel). Plenty of significantly smaller displacement imports have used these and pushed over 600rwhp. I can't speak from personal experience on a 930, though they are most definitely capable of those power levels. On a 3.3l they should be fairly responsive too, though I hope someone can chime in here with some personal experience so it's not just heresay from me. ;)

If you should decide to go with a gt35r, I'd highly recommend getting one of the larger exhaust housings (.82 or larger, I wouldn't go smaller), and possibly even a gt35r with a compressor surge housing (this would be custom but there are shops that do it). The reason I mention this is it should be very responsive on a 3.3l, let alone one with the low-end VE like air cooled f6's tend to have. You could run into compressor surge issues if it ends up spooling too low in the rpm. Just to give you an idea, I have multiple acquaintences with 2.2-2.6l i4's and different Gt35r variants that are seeing positive boost pressure anywhere from 3.5-3.8k rpm and they generate full boost very quickly in the 4-4.5k range. This is an apples to oranges comparison of course, but regardless it will still be very responsive on a 3.3l or larger motor.

Protocab, what type of fuel injection setup are you using? CIS, aftermarket, etc? I was figuring it's tuned Bosch Motronic by Protomotive or Protosport because of your screen name. Tuning will have a HUGE effect on response as well.

Carrera base engine with 930 P&C's, GT2 EVO CAMs, ARP fasteners, titanium retainers, turbo racing valve springs, turbo guides, C2Turbo head gaskets, 964 piston squirters, full bay intercooler, factory Motronics with Protomotive CHIP & FPR.

I'm either considering the GT35R or a T60-1.

I have one on my car. It has a T4 flange and a .82 or .84 hot side. You can not compare this to other hot sides, as I had a turbonetics T60 with a .69 AR and they are about the same.

If you are using CIS, I wouldn't waste the extra money, although mine only cost $1200. The cartridge is meant to be water cooled, but I left the ports open and have no problems with cooling so far. I also have the hot side wrapped and covered in a stainless shield.

You can lightly blow on the turbine blades and it turns. That being said, I am not sure a CIS car can take advantage of the BB. As stated above, flexibility in tuning (EFI) can really light these up. On an engine dyno, my motor put out 530hp and 470ftlbs torque.

Thanks Don. My car is EFI and I'm really tempted to go down the GT35R route. Anyone wanna buy a low mileage K27HF? ;)

At what boost level did you develop 530HP? That's awesome!

Also, did you get the GT35R with the anti-surge compressor cover? Do you have any surging with your setup?

I'm interested in your K27HF if you want to sell. :)

-Rod

HP kept building through 6200rpm which is where I stopped - we were also breaking the engine in. There are two opportunities for additional HP - lower IAT temps (the runs were at 50C) and take it to red line, 6800rpm. However, I have no interest in any more HP - I want torque, which I got. One bar of boost was around 3600 rpm, .4 at 3000.

No, mine is a straight GT35r. I have a TIAL wastegate and BOV, but that's it.

Thanks for the info DonE! Wow, I knew my 60-1 was excessively laggy for it's size, but the spool you are getting with your gt35r proves it. So were you just running 14psi @ 530 flywheel hp?

Protocab, I actually have a similar setup to yours minus the head mods (I just have 964 cams). Mine is a 3.4l with a 7.5:1 CR. I also have Protomotive tuned chips & FPR, 37# 951 injectors, and the Protomotive dual fuel pump setup. I have a Turbonetics 60-1 T4 with a .81 exhaust housing. Unfortunately my setup runs dangerously lean on the top-end as 37# injectors are just way too small for this power level.

Todd does an excellent job with the constraints of such an old engine management. Though, considerable gains of engine/throttle response, torque, power and spool can be had with a more modern aftermarket ems. With my 60-1 it doesn't start to build boost until ~3.3k rpm, it reaches ~5-7lbs of boost between 3.5-3.7k rpm and doesn't reach 14psi until 4.5k rpm. My headers have 1 5/8" primaries, which from my understanding is large enough that it shifts the powerband up several hundred rpm. Still, I've seen smaller motors making ~14psi with the same turbo at nearly 1000rpm less. From what I understand in talking with Todd @ Protomotive, the full throttle maps on my chips have the max amount of timing retard possible for safety reasons.

DonE, I forget but aren't you using Autronic or a similar ems?

Garrett Gt37 w/ a t4 hot side

Made 490 rwhp @ 16 psi

Call Martin @ AMSperformance.com

Yes - 1 bar. I use Link Electronic for EMS.

Also, you will have a difficult time comparing turbos on this (or any other) list because of cams, headwork, header constructions, timing, injectors and so on. Not to mention comparing HP from one dyno to another is a waste of time and money. Each modified engine is different and sometimes very different depending how its tuned and configured. For example, I have 8.0:1 CR with very advanced (timing) cams. In addition, I am using up to 36 degrees of timing early to get the turbo spinning. Good luck with your decision.

Timing is what's killing me right now. I'm planning on switching to an AEM setup from Turbokraft a little bit later in the year.

What about the GT30R BB unit? Anyone here using that?

It's rate as a 500HP Turbo, which I'd think would be a good match for an EFI'd 3.3 running ~1.0bar, if someone was after ultimate spool-up and streetability and willing to sacrifice a bit of top-end power.

~1bar @ low 3K rpm's would be very nice on the street ;)

The 60-1 is a relic from the 20th century that does not deserve to occupy even the same sentence as the GT35R - nevermind any sort of comparison.

Can't argue with that! The 60-1 uses old technology. The GT series is a more efficient beasty in every respect. I'll be going with a GT35R when I'm ready.

I'm planning to use a T4 style turbine housing though. Has anyone used one of those TiAL T3 -> T4 flange adaptors, so I can use a T4 style turbine on the 930 headers?

i have just had my engine rebuilt with a whole heap of things including a GT35R BB turbo. it will be fed by a set of schnell extractors. i hope it does what i hope it is supposed to. i have added a water cooling circuit, which comprises of a suzuki 250cc motor cycle radiator, thermo fan, custom made cowling and davis craig water pump mounted in the left hand rear wheel arch. if any on is interested i can send some pictures.
Alex...