GT3 engine in IROC clone

Cupcar · Cupcar's Garage

I have stumbled across a GT3 short block from a crashed car. Upper fuel injection parts, wiring, headers and peripherals are history, but it looks like the rest can be salvaged.

My plan would be an IROC clone (yes, yet another one) this time with a twist in having a water cooled GT3 Metzger engine using the IROC front bumper's air inlets to duct a radiator in the trunk up out and out an opening in the top of the hood.

Engine to be stock GT3 inside with the addition of ITB's (TWM, Hargett Precision, or ?) on the stock FI's injector stumps using the stock fuel rails and lines, MOTEC M600 ECU and S-Car-Go headers using the stock 911 oil tank (or maybe a Patterson oil tank up front).

Any thoughts on this madness? Has anyone done this?

flat6pilot · flat6pilot's Garage

I'd love to see that!

DW SD · 10-12-2009, 12:46 PM

Cool idea. i think I would use hard steel plumbing to get the water fore and aft. If you tie it in well, it could be structural (maybe inside the backbone)?
Peterson is the one who makes the remote tanks.

Doug

Cupcar · Cupcar's Garage

Hard tubing, probably Stainless tubing would be my preference for the H20 transport.

Patterson is the company I like for oil tanks their home page here: Home

DW SD · 10-12-2009, 03:21 PM

these are very nice tanks too:

Peterson Fluid Systems : Dry Sump Oil Tanks

tctnd · 10-12-2009, 07:05 PM

Great idea. I would be tempted to use the standard GT3 on engine oil tank or fab up a similar one.
regards,
Phil

Cupcar · Cupcar's Garage

Interesting on Peterson and Patterson oil tanks, Peterson looks a good product as well.

Funny, we both probably thought the other had not remembered the name correctly : -)

The original oil tank was damaged in the accident- might be an idea to fab up a similar tank though- or fix the original.

My idea with a forward tank is to get the weight up front, maybe the original GT3 tank location is a good compromise- or do a 964 tank under the rear 1/4 window.

DW SD · 10-13-2009, 07:14 AM

Quote:

Originally Posted by Cupcar

Interesting on Peterson and Patterson oil tanks, Peterson looks a good product as well.

Funny, we both probably thought the other had not remembered the name correctly : -)

That is funny and correct!

Peterson has a nicer site, but that isn't a determining factor. They supply a lot of stuff to the NASCAR teams. You can actually find a lot of good used stuff on ebay as a result.

What trans will you run? I was thinking a shortened 6 speed might be great. You might have to massage the rear seat area of the tub a bit, but seems like you're not concerned about a little work.

Is the bellhousing bolt pattern different than the aircooled cars?

Doug

Cupcar · Cupcar's Garage

The crankcase is identical to the air cooled cars so bolt pattern same, the GT3 is just a water cooled version. Nikasil cylinders slip into the case with a separate water jacket that goes over it.

I may set up the crankcase so it has an oil filter on side just like 993 and use the front oil cooler and stock oil tank if I decide to go that route.

I have a relatively new factory 993 SuperCup 6 speed which has close ratios, steel syncros and motorsport LSD that I would use. I think the torsion bars would have to go for this.

petevb · 09:32 AM

It's been done- easy as pie

As you say that motor is heavy- watch weight distribution with care.
Fitting the ITBs from the RSR is more common (large ports, though)...

Kelly Moss did a GT-3R motor into a 993 chassis a few years back. Instant-G has been working on a GT-3 conversion for some time.
Because the GT-3 motor essentially takes an air-cooled motor and adds bolt-on water jackets, water pump, etc it is heavy- with the water system full you're looking at adding 100 lbs or more to the chassis, most of it in back, though this depends on the motor you're using as the RS/RSR/ DP motors are significantly lighter (and not streetable). The upside (I understand) is that water cooled motors show much lower wear vs normally aspirated air-cooled motors at sustained high power levels (~360+ hp), and obviously are capable of higher absolute numbers through to 550+ hp. I agree the torsion bars would need to go and I'd put the oil tank (and anything else you can think of) forward to offset the rear weight. I've got motor weights, etc if you're interested.