Suspension upgrade, have some questions

[RamoNZ]

My question with the driveshaft question was more about the transmission end than the axle end. I have a S1 and S2 driveshaft. I was trying to confirm that the length and transmission output splines are the same for both. I didn't want to rebuild the S2 driveshaft just to find it didn't fit my transmission. I have the park brake cables as well and have already swapped to fine threads.

You'll find the driveshaft lengths and transmission splines are the same - it will be the flange that differs - sorry for the confusion - was getting confused with all the GSL-SE talk!

[mc turbo]

You want to make the watts link adjustable as this is what centres the axle and controls the lateral movement.

I have a panhard rod in my car (RX2) but the principle is the same.





I needed about 20mm movement to get mine centred again, so give your self +/- 50mm and you will have loads of adjustment. The lower you go, the more adjustment you'll need. Mines dropped about 2 inches.
Swapping the bushes won't do anything. The watts link arms are now the wrong length for the height of the car. It's basic geometry (I know, who ever thought geometry had a practical purpose lol).

Re the LSD rear, some of your terminology is a bit confusing, but I'll try to answer.
If you biought a complete rear axle for an 84-85 non SE, you have what we call a S2 rear end. Same 4x110 PCD, with solid rear disc brakes. This will bolt straight into your car. The brakes will be fine thread pitch though so you'll need an adaptor.
If you just bought an LSD diff, this will bolt straight into the SA22C rear axle. No changes required including the propshaft. The gearbox splines, length of the prop and diff flange are all the same. The driveshafts inside the axle are all 24 spline too.

TOOL

hi tool can u tell us where we can get the watts link modified ???

[Stacy]

Joe,

A few questions for you;

What binding are you referring to?

Why do you think poly bushing the Watts Link is a no-no?

Have the shocks and springs you fitted lowered the cars ride height front/rear?

All the best,

Stacy

I've read that the poly bushings in the watts causes binding in other posts on various forums. I haven't felt anything abnormal but I've only driven it on the street. I used Racing Beat springs and KYB shocks. The KYB shocks are basically stock valving. They are much better that the original ones that were on there but they will be relaced with Tokico ones once the supplier issues are resolved. The springs are supposed to lower the car about 1". The front seems lower but the rear looks higher in comparison. I didn't measure the car before and after so "looks" is relative.

Again, thank you everyone for the help.

I wouldn't worry about watts link binding. Always dangerous looking for technical knowledge on Internet forums - I've seen the rx8 owners club forum.

Binding is possible in roll but it's the short angled top links, not the watts link. The trick is just to poly bush everything apart from the inner joints on the short links. In reality though you end up just tightening the rear roll until you never get to the point of binding.

As Tool said. The watts link provides the lateral support for the axle. It's superior to the panhard rod set up because primarily the assembly marks out an almost straight line vertically through suspension travel, whereas the panhard rod naturally traces an arc. So what you need to ensure is that the arms are horizontal at your ride height. If you have altered ride height from stock substantially then that's a job at the mounting points rather than the link assembly itself. It doesn't sound like you have really.

As the Watts Link traces a largely straight line whereas a panhard rod doesn't I don't think dropping an inch will offset the axle much from stock..

If you want adjustment get some dampers with adjustable platforms - Gaz maybe.

[Joe428]

My rear end swap has been delayed due to a back injury that required surgery . All is better now. Now I'm facing working on my car in the summer. Short of having a heat stroke my plan is to get as much prep work done as I can so the swap can go as smooth as possible when it cools off a little. On to the actual question.

I going to have my spare set of watts modified but I'm trying to find how to ensure I adjust them properly. It is my understanding that it dosen't matter what angle the center link is at, only that the watts are parallel to the ground and eachother. So, with the car resting on its own weight if I adjust the watts to make that happen it will be properly adjusted, correct? If I'm off on this could someone please point me in the right direction.