I have looked at the various brands of double universals. I see that some are available in two different lengths.
Xray has 50 mm and 52 mm.
RSD has wide and narrow.
Spec-r appears to have one length.
Roche appears to have one length.

According to the Xray manual, 50 MM is for foam and 52 mm is for rubber.

From what I read in this thread, If an RSD conversion is in my future, then I would need the narrow ones. Is this accurate?

I only will be racing rubber tires on carpet, if this makes a difference.

With the Xray being roughly $100.00 a set, I have not been able to find any of the others available in the US. I would like to have a set by next weekend.

Thanks.

I think the foam/rubber quote is a bit too simplistic.

You can use either length driveshaft on any surface and the RSD conversion doesn't change that.
By the way, the RSD 'thin axle' are 51mm, their 'wide axle' is 52mm

Thanks for the explanation. That will make my search for something easier.

Thanks.

Spec-r v2's are 51mm as well. I have both those and the RSD wide version on RSD RX4 and both seem to work fine. The Spec-r versions have held up very very well for me, much better than the one set of xray's that I had.

Do the different lengths make that much of a difference on handling? I currently have 50mm X-ray ones in my car, and it works well with foams on carpet. Would they work well with rubber on asphalt? Or would 52mm be better?

Basically everyone runs 52mm front (or 51mm if they choose Spec-R / RSD... I run Spec-R and like them), and kit 50mm rear. Drive shaft length is the kind of thing you mess with if you're Hagberg trying to dial in the last tenth for some obscure track / tire combination. Xray has done the testing for general use, and the answer is 52mm front / 50mm rear, which is what comes in the kit.

-Mike

back to front mike,its 52mm front and 50mm rear as standard

I always ran 50mm rear, because with narrower rear setups, the blades will bind with the gear diff. Same thing up front. I use narrower driveshafts just so it won't bind.

Everyone runs 50mm in the rear any way as this is what the T4 kits come with, 52mm's will foul on the gear diff outdrives.
The kits have come with 50mm rears ever since the kits also came with rear gear diff's.

At my last club meeting the top 3 of us were separated by 1.1s in ftd and fastest laps by 0.03s

I'll take that 0.1s!! which is why I also wonder about the performance difference.

Skiddins

Doh! I went back and fixed my original post.


But instead of asking about it in a forum, you'll probably just go try it and see what happens.

-Mike

True, but as there's never enough time between rounds I was hoping for a little insight before I'm forced to rush on a race day.

Skiddins

I am looking for a good vta setup of a xray t4 13 with full rsd conversion thank in advance.

Could anybody tell me if is possible to buy from somewhere long shock towers?

Best regards

There's a company on Facebook called Bezerk RC that does custom shock towers and just about custom anything for any car.