JWERION

Ed, Do you know what a new GT3 crate motor costs? The answer may make my decision for me.

mooty

i found this number on my database: GT3 - $26531.50

Ed Newman

My understanding was about $28k, but $26,5 could be it. A M96 crate is half that.

karlooz

TRG has a low hour cup motor for 22K... if you don't mind used.

JWERION

Thanks guys, I have checked the rules for the GT2 class I run in SCCA and if the latest CRB proposed rules package passes it will allow me to change to a water cooled 4 valve motor.
The potential problem is that the GT general rules (GTCS page 1 "Intent")state that a specific make and model of a car must have 3,000 units produced with in a 12 month period.
Does any one know how many GT3 road cars are produced each year and how many GT3 Cup cars are produced each year? If it is over 3,000 units then I am definitely going to make the switch to the best motor possible.

M758

I believe the GT3 cup is legal in SCCA GT2. It was allowed by rule I believe in the past year or two.

JWERION

The GT3 Cup is legal as a whole if run in the legal CUP specifications. It runs in GT2 as a spec car like the Panoz. If Porsche builds 3,000 plus GT3 street cars then I belive the motor would be legal to use in the class if built to SCCA GT 2 rules regarding motors.(no titanium rods)

Greg Fishman

Kelly Moss did such a conversion. Think the whole shooting match was over $300k. I think Excellence did an article on it.

Adam@Autometrics

We have never installed or even seen accusump on any Porsche in GAC.
Almost every team has had engines blow up. The 3.4 (especially the '99) was much more prone to putting holes in the case than the 3.6 engines, but they will do it too. We lost 2 997 engines at the VIR race this season (we are working with Marcus this season), but that was the exception, not the rule. It seems like the engines that blow are the ones where you're getting the maximum power. Tune it a little more conservatively, leave about 5 HP on the table, and the engines last MUCH longer.

38D

Is there a specific thing that fails, and have you been able to solve the weak links?

Ed Newman

Adam, do the engines that you have seen fail have aftermarket ECU software? Is that what you mean by tuning? What has been the point of failure?

penguinking

bump for a good thread.

Adam@Autometrics

Sorry, I kinda lost track of this thread.
It is difficult to say what exactly failed, but the end result is a hole in the engine case for sure and broken rods and even a broken cam cover where the chain jumped presumably due to the cam stopping. when these engine go, it is catastrophic.
It is not really cost-effective to attempt a repair, so as far as I know, no one has investigated further to see what was the initial failure.

By tuning I refer to reprogramming the stock ECU, using custom maps ultimately created by GIAC (through AWE or EVO).

The 6-hour GAC race at VIR last weekend should relieve any concern about these engines being problematic. Many Porsches in the field, both 996s and 997s, and I heard about only one engine blowing (997). In fact, it seems the transmission might be a weaker link than the engine. We lost 4th about 4 hours in and 3rd with an hour to go. Lally ran on 2nd and 5th for an hour, so you can imagine what kind of revs that poor engine saw.

Larry Herman

That must make for some interesting driving at VIR.

Adam@Autometrics

Fortunately, it was wet, and our car was great on rains. He was loosing less than a second a lap average to Boris in the Turner M3. We told him his pace was still good, and he thought we were joking. It took a few laps to convince him we were doing well.
I'm confident we had a shot at the win if the box had held on to 3rd.