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Its been a while since I had thought about the G50 tranny, but recent developments in the engine department made me have a second look at the conversion.
The drag slicks I now use in the 1/4 mile do give extra strain on the 915. My best 0-60ft is now 1.76 with a 2200 lbs (1000kg) car with me in it and it might get even lower with less air and more heat in the tires, which I anticipate to come next year.
Strengthening the 915 can be done with a heavy duty side plate with 930 bearing from WEVO as well as a combined bearing carrier for both shafts in the tranny, also from WEVO.
Both measures cost quite some and then it would still be no guarentee that the 915 will hold for any length of time.
The G50 will give this guarentee almost certainly, although I am not sure if my old well-used G50 is any good. Synchros for these are quite expensive as well.
It may also take a lot of time to adapt the new tranny and clutch to a type 4 and its 20-25kg heavier which is a lot.
I still think its the right way eventually as that stupid stock 2 ltr engine with a turbo gave 345 Nm and 270 hp. The new 2,2 turbo with more displacement (10% more), much better flowing heads and a dedicated turbo cam (at least another 10%) might easily have 20% more torque, so about 415 Nm could be expected at 1 bar or 14.7 psi boost.
Drag race starts and over 400Nm is not something a 915 is designed to cope with. Its as simple as that imho.
So I can wait till the 915 destroys itself or I can try to save the nice rebuild 915 and use it maybe in my daily 412 in the future. Not a difficult decision anymore when you reduce it to these simple facts.
As the engine is out now and the new 2,2 ltr parts are getting slowly ready, so now is probably the best time to remove the 915 and start investigating the G50 installation.
First of all, the shortening of the bellhousing I see as mandatory for how I want the gearbox to be positioned in the car. I.e. not cutting the torsion tubes and loose structural strength, which neccesatates new pieces of even heavier iron strcutures welded in elsewhere.
A local company wants to help me machine off the first rib of the bellhousing
Also the VW Bus 228mm flywheel seems the best solution, so i will probably order the aforementioned KEP clutch. An annual throw-out bearing still seems the best solution for that. Then I don't need to order the G50 update kit for the original G50 hydraulic relase arm bearings, which still works with a pull type TO-bearing system anyways and that doesn't supports my 228 VW flywheel and pp push TO-bearing idea.
With the conventional 228mm pp I also think I retain the option to have a double clutch plate option for future power upgrades without using a super duper costly porsche aftermarket G50 solution with double plates.
Ok, so far only ideas and words but I' ll keep you posted.Any ideas/ alternative solutions are very welcomed as nothing is in stone yet..
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