Not that I'm planning (or even pretending to plan) on building anything like this.

How difficult would it be to lower the compression and then turbocharge a GT3 engine? It would seem that even low boost would be good for 500HP and that 8,200 RPM redline would be hoot! I'm assuming that we're talking same block diffrent heads? Does a TT exhaust manifold/turbo etc... just bolt onto a GT3?

 

Not that hard.

 

actually from what I hear... Chad has doen this... used gt3 heads on the tt mtor.

 

How is the ECU issue handled? I guess the TT ECU is missing important cam timing and/or lift parameters?

Is he using stock TT internals and spinning them to 8200?

 

You would use the GT3 ECU. There are some pitfalls that you will run into if you are not on par with the motors and difference.

 

Do the GT3s have forged internals, stock?

 

We just finished a GT3 twin turbo conversion. I will post some videos and tuning details later. This one is well over 800 HP. This engine features:

EVO Forged 9.0:1 pistons
EVO / Carrillo Custom Connecting Rods
EVO Head Studs
EVO High Pressure Head Gaskets
EVO Custom 1 7/8 Headers w/ External Tial Wastegates
EVO Modified Garrett GT Turbos w/ Exhaust Housing Wastegate Dumps
EVO Liquid to Air Intercooler System w/ Water Pump, Radiator and Custom 5 Gallon Water Tank
EVO Custom Fabricated Turbo Air Feed Pipes
EVO Custom Fabricated Turbo Y-Pipe w/ Tial Blow Off Valve
EVO Fuel System w/ Custom Fuel Lines, Pump, Filter, Fuel Rails, Injectors, FPR
EVO Modified GT3 Manifold
Stock GT3 Heads
EVO/GIAC Calibrated GT3 ECU
Electronic Boost Controller

 

Todd, is that installed in a wide body car? I'm assuming off the shelf turbo parts (exhaust manifolds, intake, etc...) don't bolt right on? Doesn't the GT3 use the same block as a turbo?

 

You need to change the pistons to bring the compression down. This will require changing the rods to rods compatible with the GT3 crank journal sizing and turbo rod length. You cannot use the regular GT3 cams as they have different pointer markers and are vario timing. The turbo ECU must be modified.

I stress this is for using a GT3 based motor in a turbo. It is easier starting with a GT3 and it's ECU or installing an GT3 ecu in a turbo. The later will be a dead giveaway and failure in a smog test.

One other item needs some thought and that is the GT3 valves which are stainless and do not lend to longevity in a turbo motor.

The above is a broad brush view and very over simplistic.

 

This car started life as an 04 GT3 narrow body car. There are no "off the shelf" parts on this engine conversion. I will post some photos of the completed car in a few days. From the outside, it looks like a totally stock GT3. Talk about the ultimate sleeper.

 

Damn I knew that car would be sick. That GT3 arrived when I was last there. Unbelievable job Todd. I can't wait to hear some numbers.

 

.... several hundred people suscribe to thread....

 

Not quite, but close. The highlights are:
1) 996 Spanish case that was shuffle pinned, boat tailed & machined for GT1 oil pump
2) GT3 RS crank, reduced journal size, oval bearings, cross drilled and nitrated.
3) Titanium rods designed for 2000 hp. (372 g each)
4) GT1 triple index pump
5) CP pistons coated for NOS with DI liners
6) Cams designed for 550 lift (both intake and exhaust have been redesigned for more lift)
7) GT3 R heads w/ Inconnel valves, intakes ported/polished, combustion chambers and exhaust ports coated for NOS. Valve stems are also a wider diameter as the valves are slightly larger than the GT3R valves.
8) GT3 cam housings
9) EVOMS intake from 90 mm TB to head ports
10) Custom light weight lifters
11) EVOMS head studs/gasket

I guess the main differences from the tt motor other than the heads, at least size and dimension wise is the crank, oil pump, rods, cam housings and intake from TB to heads.

*as for displacement motor utilizes 102 mm pistons and a slight stroke.

 

Craig

 

Todd
Very exciting project.
Will you be working on the 997 GT3 Turbo soon?