zx5 /rb5 back end

[warped]

Hi all,

Am thinking of doing an inboard motor conversion on an rb5, and it looks like an easy way of doing this would be to basically graft a ZX 5 back end to an rb5 front

I'm slightly confused as to the various versions of the wishbones / rear suspension on the ZX5 though. Not having access to a zx5 to measure doesn't help.

As far as I'm aware there's a choice of the ZX5 Sp suspension or standard ZX 5 suspension, or the LA 243 mid arm, which also appears to be an option for the rb5 but possibly with different offset hubs?

So which is of the various zx5 rear suspension configurations would be closest to the standard rb5 geometry.? - Not too bothered about shocks - more roll centres / wishbone lengths etc.

Or is the geometry totally different?

I'm guessing that the inner pivots for the rear wishbones are probably slightly further apart on the zx5 than the rb5 in order to accomodate the wider transmission.- but as long as it's not too great that might be beneficial on a mid engined car.

Alternatively anybody live near Coventry / Warwick and have a ZX5 (SP) I can measure?

[RogerM]

Hi,

interesting project .... been thinking along similar lines myself!!!

I have all the various parts to hand.

Rear wishbones

Original ZX5 is the widest
LA243 was much narror, even with the 4mm extra in the hubs (same offset as RB5) the back end is a couple of mm per side narrower!
The SP and RB5 sare the same rear arm and hub geometry.

I hope that helps ..... I will try to measure the various other bits but I am crazy busy so can't make any promises!

[warped]

Roger - Thanks for the reply

Found this.

It suggests that the mid arms are 2mm longer than standard RB.

http://www.speedtechrc.com/store/ebproductdetail.asp?id=7450



The inner hinge pin mounts for the SP and the standard ZX are exactly the same, so are you saying that the SP is even narrower than the LA243 arm option?

It would seem unusual to have a 4wd offroad car significantly under the max width.

[RogerM]

Yes the SP isa fair amount under width at 4mm narrower than the LA243 "mid" rear.

It all depends on what your trying to achieve, vehical dynamics is a very deep and involved subject!!

There are very good reasons why the SPs rear is a little on the narrow side that would take a little while (longer than I have now) to explain.

[warped]

Thanks, for the info.

[moleman]

This is what the next step in my SpeedDemon project will be,
Ive been running with an old associated B2 front end up til now..
But have recently bought an RB5 in order to use its front end instead!

Check out my tread here on Oople:
http://www.oople.com/forums/showthread.php?t=8763

[warped]

well my ebay purchased Rb5 has got "lost in the post" :mad:

So Now progressing with a losi front end instead.

Have assembled the zx5 rear end, but there is quite a bit of play in the ball sockets where the rear hingepins for the wishbones insert.

This is with new parts. The holes are slightly too big for the supplied plastic balls.

Is this a standard problem with Zx5's?

Does anybody make balls, or a rear brace that's a better fit?

[Scouser]

Hi mate, you can get aluminum rear arm braces that come with removable plastic inserts which allow you to adjust track width and inboard toe-in etc. The ZX-5 rear brace is LAW36 I believe and the part for the front of the rear bulkhead is LAW37 or alternatively you could use the arm brace from the touring car which is SP13 if I remember correctly. Might be an idea to get the Delrin hingepin sleeves aswell, they make for a much snugger fit that is smoother too. Hope this helps :).
EDIT.... I got the part numbers the wrong way round. LAW36 is for the front of the rear bulkhead and LAW37 is for the rear of the rear bulkhead.