Our 6-speed Project
02-28-2013, 05:14 PM
#1
Developer
Thread Starter
Our 6-speed Project
Our project to strengthen the drive train to match our motor has left the talking stage and entered the doing stage.
After Mark Anderson and I broke 4th gear at Road America last October (I was driving at the time) we put the scraps of 4th gear in the virtual pile with the previous season's 3rd gear and spider gears and Marks' drive shaft and 5th gear. It's become quite a little collection.
Its been a long time coming, but at these torque levels, we knew this day would come. This project also comes at a good time for us as our custom polyurethane rear suspension bushings are on order, and I'm looking forward to seeing them next month.
I have spoken to a few who have already done this conversion and seen pictures of a few more. Respect goes to Benson Brothers, and Dinsdale Piranha here on the Renn.
There seem to be a lot of variables in the approach to the trans-axle swap. One team used the complete Corvette half-axles, so they also pulled the 928 rear suspension and replaced it with the Corvette IRS. That's one way to go.
Another replaced the entire clutch assembly and went Chevy right up to the engine. Custom flywheel, Chevy clutch, torque-tube, throw-out bearing, etc.
I have also seen a Tilton stack used to get the conversion done.
As usual, I am making one for myself to go into my race car, but I have an eye for making a bolt-in kit from it for my customers if I can.
My design concept is to try to:
1) keep costs down
2) make it a bolt-in kit (no welding/cutting required for the DIY'er)
3) keep the Weissach IRS in the 928
Many of my customers are driving or racing our upgraded clutches, and we know they are good to 900 lb ft of torque, no problem. Our aluminum flywheel too. I would hate to tell them they have to scrap all of that should they want to go with the 6-speed upgrade. They have a lot of $$ already invested.
So my thought is to keep the 928 bell housing, flywheel, clutch and slave cylinder - everything - and make my adapter from the Chevy Torque Tube to the 928 Bell. That's what I'm going to try to do.
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.
I'm using the LS6/M12 Z06 C5 Corvette manual trans here for the beefier guts it has over the regular T56 in the LS1/MM6 C5 Corvette. But my rear cross-member will be able to mount either one.
It's nice to see how many after-market upgrades there are for the T56. I know we wont get "stuck" or easily maxed out with this box. It should be able to grow with us and be able to be upgraded to handle whatever I throw at it.
Anyway - just an FYI. I have left the research and design stage and just entered the building stage... more to come as we proceed.
After Mark Anderson and I broke 4th gear at Road America last October (I was driving at the time) we put the scraps of 4th gear in the virtual pile with the previous season's 3rd gear and spider gears and Marks' drive shaft and 5th gear. It's become quite a little collection.
Its been a long time coming, but at these torque levels, we knew this day would come. This project also comes at a good time for us as our custom polyurethane rear suspension bushings are on order, and I'm looking forward to seeing them next month.
I have spoken to a few who have already done this conversion and seen pictures of a few more. Respect goes to Benson Brothers, and Dinsdale Piranha here on the Renn.
There seem to be a lot of variables in the approach to the trans-axle swap. One team used the complete Corvette half-axles, so they also pulled the 928 rear suspension and replaced it with the Corvette IRS. That's one way to go.
Another replaced the entire clutch assembly and went Chevy right up to the engine. Custom flywheel, Chevy clutch, torque-tube, throw-out bearing, etc.
I have also seen a Tilton stack used to get the conversion done.
As usual, I am making one for myself to go into my race car, but I have an eye for making a bolt-in kit from it for my customers if I can.
My design concept is to try to:
1) keep costs down
2) make it a bolt-in kit (no welding/cutting required for the DIY'er)
3) keep the Weissach IRS in the 928
Many of my customers are driving or racing our upgraded clutches, and we know they are good to 900 lb ft of torque, no problem. Our aluminum flywheel too. I would hate to tell them they have to scrap all of that should they want to go with the 6-speed upgrade. They have a lot of $$ already invested.
So my thought is to keep the 928 bell housing, flywheel, clutch and slave cylinder - everything - and make my adapter from the Chevy Torque Tube to the 928 Bell. That's what I'm going to try to do.
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.
I'm using the LS6/M12 Z06 C5 Corvette manual trans here for the beefier guts it has over the regular T56 in the LS1/MM6 C5 Corvette. But my rear cross-member will be able to mount either one.
It's nice to see how many after-market upgrades there are for the T56. I know we wont get "stuck" or easily maxed out with this box. It should be able to grow with us and be able to be upgraded to handle whatever I throw at it.
Anyway - just an FYI. I have left the research and design stage and just entered the building stage... more to come as we proceed.
Last edited by Carl Fausett; 03-06-2013 at 12:57 PM.
02-28-2013, 05:21 PM
#3
Archive Gatekeeper
Rennlist Member
Rennlist Member
Sounds good Carl, 'cept for that part about giving Motodyne any respect whatsoever. 
02-28-2013, 05:39 PM
#5
Nordschleife Master
02-28-2013, 05:55 PM
#6
Developer
Thread Starter
I have been very careful to not see anybody's parts, or have anybody send me their drawings or designs.
Motodyne offered to send me his CAD drawings so I could look them over, but I declined.
I want no part of the "he stole my design" thing. I don't need to do that - I'm fully capable of doing this myself. In addition, because I want to continue to use the 928 rear suspension and the 928 bell and clutch, that makes my design different from others so their designs would be no use to me.
Motodyne offered to send me his CAD drawings so I could look them over, but I declined.
I want no part of the "he stole my design" thing. I don't need to do that - I'm fully capable of doing this myself. In addition, because I want to continue to use the 928 rear suspension and the 928 bell and clutch, that makes my design different from others so their designs would be no use to me.
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02-28-2013, 06:07 PM
#8
Archive Gatekeeper
Rennlist Member
Rennlist Member
Fair is fair. Spoken to them on the phone several times, but never seen the quality of their parts, so I have no comment there. But they took a leap of faith that they could do it long before many others - and from what I understand, they did do it. So I think they deserve a nod, just like the Benson Brothers and Pirahna, Bob Mott and anybody else for their efforts. .
First, many 928 owners have your products on their cars (me included!) , you're a known quantity in the community. To my knowledge (and I've read wayyyyy too much online 928 content in the past decade), I have never heard or seen any evidence that any Motodyne product for a 928 actually exists (Yes, they re-sell a few commodity parts on their website, whoopdedoo...). Do you know anyone with a Motodyne 6-speed Getrag (or is it T56) conversion in a 928? They've been doing it since 2003, according to the website.
Anyone can post BS on the internet. But sometimes it's just BS.
Second, just Google 'Motodyne'. At least they've paid Google to come up first in the search, but it can't hide the next couple hundred hits (there are many more but that's all I wanted to skim thru), the majority of which link to threads about unhappy customers and questions about the legitimacy of the company. Maybe they're being unfairly targeted. But I'm inclined to doubt it.
02-28-2013, 08:37 PM
#10
Three Wheelin'
The 928 6 speed swap! The BIGGEST trend to hit since RMB's...
Also the Motodyne, and the ****sucker responsible for that huge scam company thing has been put to bed already. Hackstetters latest post about coming up with an RPM "adapter" module was the final nail in the coffin. He talked a bunch of copy paste bull**** and disjointed sentences that anyone with any sense/computer/DIY knowledge could see through.
Also the Motodyne, and the ****sucker responsible for that huge scam company thing has been put to bed already. Hackstetters latest post about coming up with an RPM "adapter" module was the final nail in the coffin. He talked a bunch of copy paste bull**** and disjointed sentences that anyone with any sense/computer/DIY knowledge could see through.
