RCR GT40 TRANSAXLE
- Thread starter philg
- Start date
A Kennedy adapter with attachment points to the chassis is between the bell housing and the SBF style Dart block. I machined the attachment fittings teaching myself how to use a milling machine. I'm not sure how much stronger the whole arrangement is by triangulating the attachment points to sheet metal. When push comes to shove you will still end up with an hot engine next to you in the cockpit. Note the supplied exhaust had a section welded in to angle the end points down to clear the rear clip as the Porsche trans is taller than the ZF. It still fits in nicely under rear deck. I reckon I'll snap a couple of pics when I roll it out this spring, after the glaciers in my yard melt down, to send it to "the man" to wire up the fuel injection. The engine builder gave me a map good for 520HP out of the 347ci engine but the FAS harness was designed for a front engine car and will have to be cut down quite a bit. Best have someone with experience do the final thing to make this project run rather than me bone heading it as a neophyte.
Neil
Supporter
Modifying a front-engine wiring harness for a mid-engine application is not an easy task. I wonder if it would be less trouble to make your own harness?
Sounds like he’s got it handled Neil.
Neil
Supporter
I hope so.
I am gathering intel for me RCR40 that is still in Fran’s hands. I plan on going with this same setup 347 stroker, carbureted, any additional photos or tips you can give would be greatly appreciated. Thanks in advance. Jeff
You've probably already figured this out - but - scour through all the build logs and glean what you can.
For myself, I think installing an electric water pump simplified things in terms of room in the engine and passenger compartment by trading off a slightly busier boot up front behind the radiator.
Sean Starkey
Supporter
Im running an inverted Porsche G50/52. Pictures are pre shifter and nose cone shortening. I have the nose cone at the machine shop now and can share pictures when it is completed. it should end up about 4" shorter once complete.
Several other Porsche trans-axles will work and are shorter, the G50s are pretty much plug and play with the gear ratios that match well to V-8 torque. The G50/52s were standard with LSD is the reason i chose it. The older G50s have a shorter nose cone and are not quite as strong as the 03s,04,05s,and 52s. is also why I chase the 52.
I didnt do much research on other options such as Audi, etc.
Below is CMS website that has alot of Porsche specs on it. I would suggest looking at gear ratios if you use some of the other transaxles they make.
californiamotorsports.net
I also have a Excel file for a gear speed calculator if you would like it. Its handy to figure ratios to speed and RPM. Unfortunately it doesnt apper that I can upload Excel files here, so if you want it drop me a PM and I can email it to you.
Regards,
Sean
Several other Porsche trans-axles will work and are shorter, the G50s are pretty much plug and play with the gear ratios that match well to V-8 torque. The G50/52s were standard with LSD is the reason i chose it. The older G50s have a shorter nose cone and are not quite as strong as the 03s,04,05s,and 52s. is also why I chase the 52.
I didnt do much research on other options such as Audi, etc.
Below is CMS website that has alot of Porsche specs on it. I would suggest looking at gear ratios if you use some of the other transaxles they make.
PORSCHE G50 5 SPEED TRANSAXLE SPECIFICATIONS
Type: G50/00, G50/01, G50/02 Original equipment for: Porsche 911 Carrera 1987-1989 Description: H Pattern 5 speed manual transaxle with Borg Warner single cone synchromesh and synchronized reverse Limited Slip Differential: 40% LSD optional equipment Weight (approx): 146lbs Oil Capacity...
californiamotorsports.net
I also have a Excel file for a gear speed calculator if you would like it. Its handy to figure ratios to speed and RPM. Unfortunately it doesnt apper that I can upload Excel files here, so if you want it drop me a PM and I can email it to you.
Regards,
Sean
Attachments
Chet Zerlin
Supporter
Sean, I’ll be very interested in seeing pictures of your modifications to shorten the nose cone as well as any modifications to the transmission needed to make it work. Thanks for posting this information.
Chet
Chet
Howard Jones
Supporter
Chet.
CMS can supply you a G50 with the shortened rear cover, shortened bell housing, and the flipped modification as well as a variety of available gear ratios. They built mine with a Quaife TBD and added a variety of strengthening components. I also told Rodger that I wanted them to supply all the components that were required to mate it to my engine adapter plate so I would not have to figure that all out myself. So the purchase included the starter, flywheel, clutch, throwout bearing, pilot bearing adapter for my engine, and drive flanges suited to the CV;s we settled on.
IMHO this is the way to do this. Buy everything from one source and just bolt it up. CMS can do this as well as others.
Last note. If you don't have anything yet have the gearbox shop you settle on to supply the used gearbox as part of the deal. Then they will stand behind the core as suitable. It is possible to buy a used G50 from ebay for example that requires far more repair than you believed and therefore dramatically increase the final cost unnecessarily.
I have no relationship with CMS other than being a satisfied customer.
CMS can supply you a G50 with the shortened rear cover, shortened bell housing, and the flipped modification as well as a variety of available gear ratios. They built mine with a Quaife TBD and added a variety of strengthening components. I also told Rodger that I wanted them to supply all the components that were required to mate it to my engine adapter plate so I would not have to figure that all out myself. So the purchase included the starter, flywheel, clutch, throwout bearing, pilot bearing adapter for my engine, and drive flanges suited to the CV;s we settled on.
IMHO this is the way to do this. Buy everything from one source and just bolt it up. CMS can do this as well as others.
Last note. If you don't have anything yet have the gearbox shop you settle on to supply the used gearbox as part of the deal. Then they will stand behind the core as suitable. It is possible to buy a used G50 from ebay for example that requires far more repair than you believed and therefore dramatically increase the final cost unnecessarily.
I have no relationship with CMS other than being a satisfied customer.
This was the shortened g50/52 that I was going to use.
As mentioned above strong box and good v8 ratios. Plate style ZF lsd as standard (use at 40 for the road not 80 as you’ll likely understeer like a manic).
Was a full CMS build, billet shifters, side and rear plates, cryo and rem internals, side shifter modification etc. nice bit of kit.
As mentioned above strong box and good v8 ratios. Plate style ZF lsd as standard (use at 40 for the road not 80 as you’ll likely understeer like a manic).
Was a full CMS build, billet shifters, side and rear plates, cryo and rem internals, side shifter modification etc. nice bit of kit.
