930 turbo into 911 chassis

voitureltd · 09:24 AM

In a previous thread I was faced with the 930 engine & trans being to long for the 911 chassis mounting. The way to solve it, if you need the strength of a 930 trans, ( rated to 700+ HP), is to either use a short bell housing pre 1978 930 trans ( as the factory did ) but now in short supply = very pricey, or use the 915 ( factory says not strong enough ). Patrick Motorsports of Phoenix re machined and reinforced my 1980s 930 bell housing and input shaft, to early 934-935 spec. also I now can use the 935 competetion clutch system. Some on this thread thought it would be really pricey however the invoice was just under $1000.

onboost · 10-20-2008, 07:01 AM

Did that include disassembly and re-assembly of the trans itself, or was this just for machine work on empty case & shaft sent to them?

Thanks,

Paul

voitureltd · 09:27 AM

That was for the machine work to the input shaft and the bell housing and additional welding in of reinforcements to areas weakened by the material removed and to create clearance for the 935 clutch pack. I ds-assembled / re-assembled the rear trans but sent the front bell housing containing the ring & pinion that they had to dis-asemble and re-assemble to remove the main shaft . The other alternative to use the later trans axle would have been to move the motor mounts back ( more tail happy car as 78 and later 930 ) along with relocating all the other stuff to hook it up. Lots of jerry rigging to puts with at the track in case of necessary support if repair of something would be needed. Moving the motor / trans toward the front of the car ( as some had suggested ), is not a option, as then the trans axle output shafts will not align to the factory wheel base

NathanUK · NathanUK's Garage

Thanks for posting the details.

Can you be more specific to why the assy couldn't go forward?

TIA

voitureltd · 06:44 PM

If you move the Motor & trans axle toward the center of the car the half shafts will not be in a 90 degree alignment with the rear wheel hubs. You would have to accommodate by lengthening the half shafts that would result by being out of the production 90 degree alignment.. Not to mention moving or cutting the Torsion tube and shortening up all the other stuff the corresponding amount you have removed . That is not as much a issue if going to coil overs however doing it as the factory did with the correct trans axle length for the chassis being used is the cleanest, best solution. No need to re-engineer what Porsche did back then. I just had to return it to the original bell housing specification, then everything aligns & fits.

NathanUK · NathanUK's Garage

Thanks. You threw me on the 90degrees for the axles, there is no way they are 90degrees on my stock 3.2 carrera that has a 915. I do agree though that moving the assy forward would need longer axles though. I presume my G50'd 930 axles are also not at 90 degrees, but I'm not actually certain.
I think they lost being 90 degrees when the 911 went LWB around 1969 (B) series. This was done for better weight distribution. I know race cars are built so that when you accelerate the axles are ideally straight but the 911 benefited from the weight distribution more.
Porsche rewrote the rules once again

voitureltd · 06:03 PM

Yeh, they had a way of doing that. It was a evolving work in progressive development back then.I just want to have my car close to the specification they ended up to race with at that point .That way I will have less grey area to sort out.

onboost · 10-23-2008, 07:34 AM

voitureltd...

Did you recently buy that on or were you selling it sometime back? I saw it advertised and either way it looked like a pretty good deal.

I'm working on a "track whore" myself though non-turbo and not quite as radical as that one.

Funny, I have that exact wing sitting in my garage.. same color.. well let me check. :-0

P-

voitureltd · 04:59 PM

I do not have a Vintage license to use it with so I wanted to sell it and use the running gear in a Porsche DE car. No takers @ around $13K ( chassis only ) so now am putting 935 rear suspension in ( it originally ran with around 400hp so it was ok without it) but will need that after putting in the 600+ HP twin turbo freshly redone ( about $35K worth ) motor. Add another + or - $10 k or so for the other stuff to get it updated to current vintage specks, as it was last run many years ago. Then next year I'll put it on the track ( lots of offers to get it sorted for me by other Porsche race drivers ) to run with the big dollar ( 800K to over 1 mil ) Porsche factory or Porsche/ Kremer built ones. Then maybe I will get some big bucks offers. Or maybe I will get the nerve to drive it myself and keep it for awhile. Still will sell all or just the chassis as this race season is over now in WI.. Otherwise it will be a work in progress till next summer and the price will be adjusted up wards as it is being completed in case anyone gets the bug to jump in.

onboost · 10-23-2008, 09:04 AM

Was just curious.. figured maybe you had been bitten by the track bug! Fun stuff anyway.

NathanUK · NathanUK's Garage

Looks great fun! Sounds as though it will be too

voitureltd · 10-23-2008, 04:49 PM

Oh well, someone has to do it , so mabe it will be me. To neat to just let it sit in parts, when it can be put together and driven.

Miguel Antonett · 10-24-2008, 03:52 AM

Voitureltd, that's an impressive tail!! what benefit do you get from it?

voitureltd · 09:51 AM

This is a rear wing as used on some early 935s. It should work good as the car was developed and tested in its day by some with this aerodynamically designed tail. I have seen and talked to some type 934 &935 owner/drivers that still run with it in the vintage race classes and it works for them. Maybe a newer version would be aerodynamically better , but then it may have to run in a different class

Reaper930 · 10-26-2008, 10:32 PM

That tail is pure sex...and I of course really dig the slant fenders