hacker-pschorr

It's to install a transmission that can take the amount of HP many of us are pushing through our drive-train.

docmirror

In aviation circles this is called the sacrificial component. Most would not consider the diff/gearbox to be a sacrificial piece, but I could be wrong.

docmirror

So, we're changing the CVs, axles, hubs, stub axles?

Jon B.

Those sound like questions to ask Carl. These transmissions are flat BETTER than the stuff in the car now. If you want, just substitute the word "stronger" for "better" if that floats your boat.

Aspkiller

...and then some!

xschop

Tell your enginerds it should look a little something like this and be within + /- 0.0005

Pics are Dinsdale approved.....

hacker-pschorr

Some are, this is one of 4 known variations on the C5 rear in a 928. I cannot comment on what everyone is doing.

So far Todd has yet to break the CV's, axles, hubs etc.. with over 800rwhp in a street car with DOT drag slicks installed. He's trying!!!!!!

With the frequency of CV joint replacments we experience at the track with C5's and C6 race cars, I'm wondering if using those from the Chevy is the best idea...... These are on ST2 NASA class race cars with less than 400rwhp.
One of them ended up national champion so it's not like we go easy on them

Carl Fausett

From Post #1 on this thread:

So in broad-brushstrokes our kit would be the:
Custom Torque Tube and drive-shaft
Custom half-shafts in the rear, (Chevy on the inside and Porsche at the outside)
Custom Trans-axle support with mounts.
...and the customer is free to get his own LS6/M12 or LS1/MM6 6-speed trans and diff.

Carl Fausett

Good information, Hacker. I'll look into an upgraded CV joint while i"m in the process of having the axles made.

Mongo

Hey Carl, with regard to the custom torque tube, will it be 'rebuildable' in a sense that we can source bearings later on? Also, will the tube be significantly more robust than the current one in 928s now?

Aspkiller

I believe Driveshaft Shop will make almost any axle you want with Porsche (and/or Porsche style) cages. I'm using them without issues, so far. At to hubs, stock C6Z hubs need to be upgraded to ZR1 hubs, if you want to last more than a weekend on a road course with HP and sticky tires. The Porsche hub with a replaceable bearing is much more economic.

Carl Fausett

It will be as rebuild-able as the stock C5 torque tube is at present, because we will start with the stock Torque tube and be shortening it and relocating the shifter box into the correct position for the 928. No plans to change the pillow block or bearings at this time. I have not heard that they are a problem.

It will be significantly stronger than the current 928 driveshaft. That is one of the breakage points we are deliberately addressing. I have several driveshaft options to select from, all of them upgrades relative to the 928 shaft. Porsche made the 928 driveshaft from 1144 alloy steel and the stub shaft from 4140. Really good materials, followed up with a well-engineered design. The greatest gains in strength of the new driveshaft will be as a result of its larger diameter, nothing else. If needed, we can also shot-peen the driveshaft to add additional toughness, but that is not in the plan at this time.

whatudrivin

How is this upgrade going to change the weight balance of the car? May be too early to tell but haven't seen this come up in the questions yet.

James Bailey

It should IMPROVE the weight distribution by moving it back.....50/50 is NOT ideal. Just better than the 60/40 of many front engine cars !

Mongo

Carl - whatever it takes to make the torque tube service less costly. I have a rebuilt and the bearings are growling in it after about 60,000 miles.

It'd be real nice to go manual and get rid of an ATF leaking transmission (not the unit itself, but the reservoir bottle). I have missed driving a stick since I sold my 944 track car.