My ultimate favorite is the Porsche GT2 with a GT3R mainshaft.
Details:
-6 gears.
-Cable side shift, no rod or end linkage.
-Uses G50 style clutch components and drive flanges.
-Use of the GT3R mainshaft gives a 3.1 1st gear ratio and allows a removeable 2nd of any ratio to be fitted.
-Nice 0.75 ratio 6th gear.
-Handles well up to 700 + hp and more as proven by many Ultima builds.
-Stock Porsche motorsport LSD.
-Integral mechanical driven oil pump.
Price => $13500, with inversion procedures and oil pump modifications to allow braided oil lines for cooler fitment or direct oiling manifold.
Downside => Length is a bit long for most of the direct GT40 replicas. It is about 4" longer than your standard G50-52 unit. However no shifter on the back of the gearbox so it is a possibility!!!
It is not bad at all, but...
in the 911 GT3 RS of ART Engineering, driven by Babbini, with the gearboxes tuned by GearFox TC, many modifications were necessary in order to shift faster, whithout burning the synchro rings and for lubricate adeguatly the LSD.
In state you are an expert of those boxes, tell me if I did correctly or not.
1) Synchro spring load doubled.
2) Synthered rings added with 3x3mm holes.
3) Gear cones for synchro rings with a double machining U shaped for lubrication increasment.
4) Exchange of the watercooler with an air cooler.
5) Closure of the pinion, in the diff side with a threaded tap with a 2mm hole for spraying into the LSD.
6) Machining at 6 mm all the lubrication channels in the case.
7) Preload of the pressure valve in order to open at 6 BARS.
8) Piping increasement at 10 mm diameter.
9) 5 mm by pass shortcutting the cooler.
10)Oil spray on the pinion in the exit side.
11)Superior gear oil in use.
Results:
1) Up and down shifting to the rev cutter in 60ms without synchro burning.
2) Perfect lubrication of the LSD internals
3) Operation oil temperature 84-86°C
N.B. A Sachs Race synthered clutch was used but with a spring system pushing the floter away from the flywheel and the pressure plate from the floater in order to minimise the clutch drag.
Tell me your opinion....
Regards
Wanni