Who has actually done a C4 to C2 conversion?
#1
Instructor
Thread Starter
Who has actually done a C4 to C2 conversion?
Just looking for some info on those who have actually done the conversion. This is my ‘general’ understanding so far:
- Replace transmission with a C2 5 speed or a 6 speed from 993
- Replace rear drive shafts with C2 shafts
- Replace shift linkage, tube, etc with C2 stuff
- Discard main driveshaft, front diff, and front drive shafts (Front uprights and carriers fine to leave alone? Anything else need to be done up front?)
- Do something with diff locks (plug them off in the frunk?)
- Do something with sensors and electronics (no idea what to do here)
If anyone has more insight it would be appreciated. Or if anyone knows of a company that sells a conversion kit that would be great as well.
Thanks
- Replace transmission with a C2 5 speed or a 6 speed from 993
- Replace rear drive shafts with C2 shafts
- Replace shift linkage, tube, etc with C2 stuff
- Discard main driveshaft, front diff, and front drive shafts (Front uprights and carriers fine to leave alone? Anything else need to be done up front?)
- Do something with diff locks (plug them off in the frunk?)
- Do something with sensors and electronics (no idea what to do here)
If anyone has more insight it would be appreciated. Or if anyone knows of a company that sells a conversion kit that would be great as well.
Thanks
#2
Rennlist Member
A lot of the 993 TT owners me included have discarded the front pumpkin ,axles , center
tube and shaft to go rear wheel drive only.
We all have kept the same transmission not sure you'll need to change yours either..
I know the C4 '89 was first year all wheel and was purported to be an advanced design but hey I would try it with that trans first .
We still have ABD etc and doesn't appear to make any difference.
The biggest difficulty was welding in the shift box for the linkage but once you get the parts it's no big deal really
Fister motor sports also sells a trans mount brace that adds stiffness to the trans as well..
The change to rear wheel only lightened up the turn in and front end of the vehicle made it much more Porsche like believe me! Ha ha have fun, Bert
tube and shaft to go rear wheel drive only.
We all have kept the same transmission not sure you'll need to change yours either..
I know the C4 '89 was first year all wheel and was purported to be an advanced design but hey I would try it with that trans first .
We still have ABD etc and doesn't appear to make any difference.
The biggest difficulty was welding in the shift box for the linkage but once you get the parts it's no big deal really
Fister motor sports also sells a trans mount brace that adds stiffness to the trans as well..
The change to rear wheel only lightened up the turn in and front end of the vehicle made it much more Porsche like believe me! Ha ha have fun, Bert
#3
Nordschleife Master
You can't ditch the front-wheel drive on a 964 by simply removing the forward drivetrain like you would with a 993 or newer AWD Porsche. You gotta swap the transaxle.
#5
#6
Rennlist Member
There is a lot more.
You can't just drop the center tube on the 964 the tranny needs to be converted by cutting the splined shaft and making an end cap if you go that route. This does eliminate the need for the C2 rear drive axles however the C4 tranny is considerably heavier and will add weight t the rear the C2 does not have.
You will also need stub axles for the front wheels along with the ABS gears nuts etc. There are caps that belong up front as well to keep dirt out but they were eliminated on the 993. Shift box needs to be welded in place and all the hardware including shift tube and bushings. You will need to use the shift fork and slider etc from the center drive shaft from the C4.
Then you have to deal with the extra hydraulic lines and tricking the system to believe it is no longer a C4 otherwise you will get constant fault codes.
You can't just drop the center tube on the 964 the tranny needs to be converted by cutting the splined shaft and making an end cap if you go that route. This does eliminate the need for the C2 rear drive axles however the C4 tranny is considerably heavier and will add weight t the rear the C2 does not have.
You will also need stub axles for the front wheels along with the ABS gears nuts etc. There are caps that belong up front as well to keep dirt out but they were eliminated on the 993. Shift box needs to be welded in place and all the hardware including shift tube and bushings. You will need to use the shift fork and slider etc from the center drive shaft from the C4.
Then you have to deal with the extra hydraulic lines and tricking the system to believe it is no longer a C4 otherwise you will get constant fault codes.
#7
Burning Brakes
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#10
Who has actually done a C4 to C2 conversion?
Wouldn't it be cheaper (or at least as much) and quicker just to buy a nice C2? Unless you have a bond with your particular car of course! In that case change it.
#11
^What he said.
Just seems to be way easier that route. Didn't 9m convert a C4 to a C2? But, he had a 6 speed tranny already.
IDK, I love my C4. I guess the C2 would be fun for some hooligan stuff though.
Just seems to be way easier that route. Didn't 9m convert a C4 to a C2? But, he had a 6 speed tranny already.
IDK, I love my C4. I guess the C2 would be fun for some hooligan stuff though.
#12
Rennlist Member
If our a PCA member they had an article about this a number of years back in Pano. I don't know but you might be able to find it in the archives on line.
#13
Here's the thread that Colin from 9m made about his project lightweight car. He converted a C4 to a c2 in it. It's full of good information.
https://rennlist.com/forums/964-foru...y-outcome.html
https://rennlist.com/forums/964-foru...y-outcome.html
#14
Burning Brakes
we have one car in our shop that is converted to C2 but the abs is not working. No faults stores nor abs warning light coming on
any suggestions ?