Ds1

Hey guys,

As I continue to fall in love with my 911, I do crave a bit more power. So of course, that means turbos...

The Car.

Its a ROW 1982 SC with a '84 3.2 swap. Currently its pretty stock, but just got 255/215 tires, working on adding lightness (RS carpet kit) right now, with custom exhaust and no cat.

The Background.

I recently finished a turbo build on my "fun" daily driver, a '92 Miata. This was my first time doing every turbo, including Megasquirt, myself. I learned a heck of a lot. I don't fab, and am not a millionaire yet, so it was partially bought as a used kit, with some new stuff, etc.

The outcome? One of the funnest cars I've ever driven.

The Vision.

So that brings me back to my 911. I already own my all-time favorite car, but how do I bring it from being pretty cool, to something I never want to sell? Twin turbos, of course.

But screw RWB and 935's. I don't need 750whp. I don't need the extra weight of huge flares and spoilers or huge 365 tires.

Think about this: a "lightweight" style 911SC narrow body, with 2 turbos hanging off the butt. I would like the car to be ultra-responsive (The Miata is surprisingly laggy), so two tiny turbos would be sourced, with the goal of super fast spool. That would be the entire point of the twin turbo's vs. single turbo. The power goal would be very moderate - 350WHP (but don't forget, the weight goal would be around 2400lbs). My cars are purely canyon carvers. "Fun" vehicles, and not looking for crazy top speeds, track times, or launches.

I'm also still not yet a millionaire, so the cost needs to be "effective". My goal is for the parts with the most value to them (you know, that whole cost vs. what you get thing us Americans always forget about?).

Something like this, but of course with '74 IROC front bumper, no rear bumper, etc. Of course, supporting suspension and brake mods would also be done, probably before-hand.




The Ideas.

Its really not that hard to turbo a 3.2, as the EFI is already there, plus all the 930 support (thus posting in this forum). With my last education, I'm now very ready to attack this project, er, at least the planning stage (something I learned about turboing.... you need lots of planning!).


Headers:
N/A OBX Stainless, with custom built tubes for turbo placement. This way, its cheap, yet very similar to other twin turbo headers out there. Around $500 after some fab.
http://r.ebay.com/quGyUW
To make them similar to this:




Turbos:
Mitsubishi TD04's. Very cheap to find used, yet still an OEM unit (no chinese junk), and the perfect size for twin turboing (same turbo's used on 3.0 twin turbo 3000GT's). Also available in lots of variations. Remember, I will never want more than 400hp at the crank, so I really don't need anything big at all.

Exhaust:
Zork Tubes

Wastegate:
Integrated

Intercooler:
Cheap eBay unit. Something along these lines: http://r.ebay.com/2by8nX
Could also do 2 smaller separate units.

BOV's:
eBay

Piping:
eBay

Tuning:
I've seen 3.2 guys run the BEGI FRP and stuff like that. I haven't made any final decisions, but that would probably be best unless I could find someone to flash my chip. I do NOT want to run standalone. Yes I would run AFR gauges, though.

Oiling:
Dual catch cans (or whatever you 930 guys call them). I haven't exactly figured this out yet, but apparently it works.

The big issue... Transmission:
'76-'77 short 930 4 speed. This is because a G50 is really fricken expensive and my 915 can't hold very much power at all. VERY open to input here, as I really would like to retain the 5 speed 915 if possible.

Conclusion.

So theres all the main stuff, my power goals, etc. I have been warned a few times that twins would be much more of a hassle to do, but the prestige of twin turbos is something that (I'm sure ALL car guys will agree) is a lustful thing. I'm open to a single turbo, but ONLY if it is center mount like the 934's... I can buy just these headers for $1000. http://forums.pelicanparts.com/911-9...ions-here.html




Please let me know if there are any major flaws or major issues that would need to be overcome in my plan. I can't see anything too crazy besides the transmission, given the research I've done so far.

What would you do?

The rest is up to you; what would you do if you were in my position with the same goals? I would seriously love to hear all your comments, ideas, etc. This is a fantastic forum with some really smart people with some really cool cars. I am very early in the planning stage, so I'm open to anything. Thanks!

Amber Gramps

You may want to chat with one of our site sponsors that is actually just around the corner from where I am sitting. Bisi and Julio are awesome fabricators and have no issues going turbo. I know their reputation in the JDM market is very strong and Bisi has a bunch of 911 projects in his shop. If nothing else, just check out his webpage and videos.

http://bisimoto.com/2014/

MUSSBERGER

Unless you plan on going all in (meaning lower compression ratio) you are going to be limted in boost pressure if you want any life.

Ds1

Yeah I know, but I don't need a lot. 7(ish) psi is supposed to be safe even without an intercooler, and should supply around 310 WHP. I know one guy is doing 327 to the wheels at .6 bar. Thats plenty for me still running a 915. Eventually, if I want to commit to a 930 or G50 transmission I can do the pistons too, and have a car that can safely run a lot more power than I need in a narrow-body car.

strudel

I started to go down the 3.2 n/a to turbo route. I contacted Turbo Kraft about doing the conversion. Retaining the stock p&c's meant keeping the boost low, around 6-7psi. Running efi, modifying my SSI's, gt35r turbo, i/c and extensive tuning, they figured I'd be in the 300-325 h.p. range. Since my motor had 130k miles I thought it might be a bit of a stretch to put the extra load on the long block. To me the best bang for the buck was to sell the 3.2 (46pmo carbs, crankfire ignition, ssi's) and buy a 3.0 turbo motor. I picked up the turbo motor for the same price I sold the 3.2 for. I'm freshening the motor now. The long block got bumped up to a 3.3, I will retain the 3.0 heads. The motor came with a 3.0 i/c, I picked up a set of used B&B heated headers, and will take the k27 off my 935, reground SC cams, and I'll be somewhere in the 400 h.p. range. This is going into my '68 vw crewcab. I've been running the 3.2 in there for the past 8 yrs.
As far as the trans, you can modify the 5 speed with the addition of a bearing retainer plate, and the stronger side plate. Guys are running well into the 400 h.p. with no issues, as long as you don't launch it. Someone on the Pelican turbo board suggested unless your in the 400 + h.p. range your better off with the 5 speed as far as gearing. A short bellhousing 4 speed is getting to be a rare thing, selling that would cover a modified 5 speed and leave you with some change.

Igooz

DS1, I have seen a few guys use parts, kits, and help from Protomotive with good results. (I have no personal experience nor association)
http://www.protomotive.com/home.html

Good luck.

Ds1

You're putting that in a CREWCAB?!?! My gosh, man, post pictures!

Yeah, for you it definitely made more sense for that 3.0 considering your 3.2 was already somewhat built, and the 3.0 was already turbo's. Good deal!

Thanks guys for the input. I'm talking with Chris at TurboKraft now, and have send an email to Protomotive about their tune, if they'll still do it.

Question, for you turbo guys: Chris has made me a pretty decent offer on a pair of GT28's with internal wastegates, but they are still "relatively" very expensive compared to the $400 I could spend on a pair of rebuilt TD04's. Do you think the difference in turbo technology (mainly ball bearing on the GT's) would be that different (like, worth over $1400 extra price different)?

strudel

You may want to post your build ideas/questions on the Pelican turbo board. There are a couple of twin turbo projects going on there.

Tango635

Older thread but...

Ds1, what did you end up doing? I have a 3.2 that I'm thinking about adding a turbo to.

Thanks

dariog

I wonder which gearbox have you ended with? Nowadays 4 speed gearbox from 930 is much more expensive than expensive G50 5 speed 3.2 Carrera...