Things are starting to move for my RX-7 again. The last hurdle I need to tackle design wise is lateral location. Adapting the Watts is doable but will suck, and the rear I am using already is set up for a Panhard in the right location so I want to use that.



Except it seems nobody makes Panhard kits anymore. I did the conversion myself a few years ago and it wasn't very strong so it broke, and I'm leery of trying to do it myself again. Would like to just buy something I can put in the car and call done.

 

I've always been interested in the KC Raceware trilink setup although I've never given them a call.

KC Raceware

 

I already have that bit sorted (I am NOT using that monstrosity, I just left it on because it makes a convenient place for a third jack stand) but it is the Panhard that I'm hunting.

The ONLY setup I've found available put the bracket on the left side, which is fine as long as you aren't using the stock fuel tank. If you want to keep the fuel tank the chassis arm has to be on the right side.

 

Panhard bars are easy, all you need is some angle iron and 1 inch square tubing. You can get ½ inch rod ends in a right hand and left hand set with weld bungs, get some tubing that matches the diameter of the weld bungs that you got with the rod ends and you are good to go.

 

My old Panhard bracket was 2x3 tubing and 1/8" angle iron and 1.5" square stock. I broke the hell out of it. I'm switching to a 9" because I ran out of Mazda housings to bend/break/warp, they split up the middle and the axles keep breaking, when they aren't hammering the axle bearings apart.

I think 1/2" rod ends would last one run for me Definitely a place to use rubber bushings instead of rod ends, for the give factor.

 

Try some of these peejay, offroad parts should work well in rallycross.

Ballistic Forged Poly Bushing 2.63"

 

peejay, i can't help with anything but i'm interested in your set up. I remember reading some where where you (i think) said a 3 link resulted in so much grip that you continually broke axles/housings. If this were a street/track day car, would you recommend that set up and if so, do you have any pictures of your 3 think installed/tips for designing one?

 

Pete I have a panhard bar rear suspension on my SA, I've had it on the car well over 10 years but I only go off road when I slide off the track I don't rallyx like you do. You are more than welcome to come over and take some measurements. Btw I am still using the stock fuels tank on the car.

 

Well I may be able to get my car out to a certain meet in PA on June 4th. Ohio Rotaries ? View topic - Rhinehart's Meet & Greet 2016

Or if you can make it to the next Dave meet (whenever that will be) either my car will be there, or my garage is between there and you, so you could check it out either way.

Definitely something to do. Mine is cut through the floor but there's no reason it can't be enclosed. It WILL fit under the bins with minor modification.

 

I meant that if you wanted to see how the old GForce Engineering panhard bar was made and installed you can stop over. The car is I the lift and in pieces on the floor right now.

 

Take pictures and post here

 

This is the EXACT same as mine. I bought mine off a guy that bought the patterns off Xtreme Rotaries. Who ripped off who I have no idea but it is a proven design and pretty much the whole field was running them in IPRA over here back in the day before the fancier laser cut ones.
Once you've seen it it looks very easy to do, as if there was no other way to do it! But saying that if I had tried making it from scratch without knowing what it was supposed to look like i would have f***ed it up for sure.

There's also this mob https://www.google.com.au/url?sa=t&r...Y01-rCKdygE6GA
that do some nice stuff for these cars. Their panhard looks a bit crappy maybe but the watts links look nice. The exchange rate is favorable for you guys but shipping would be exorbitant.

 

Yup built mine the same way! I'm too lazy to search but there is a massive "fb handling thread" that is a sticky somewhere. It is massively informative.

 

these guys apparently do, but are across the pond and $$$....MSF Racing Components

 

Looks like T3 is now offering one.

 

Interesting.

From their Facebook page, TTT says:" It uses the lower watts link mount and a U-bracket on the shock mount to make it a direct bolt on."

 

Sounds like a really bad idea.

Wait, isn't this the same company that sells a relocated shock mount for the rear axle so you can "make the car lower"? You can remove the springs and bumpstops and jack the axle up enough that the pinion flange hits the body. Remove the pumpkin and jack the axle up enough that the Watts linkage hits the body. The shocks will still have an inch or so of travel remaining...

I think it's cool that they sell 1st-gen parts but I can't take them seriously if they don't understand the issues involved with the chassis.

Anyway, I thought it over and I'll probably just try to adapt the 9" to the Watts setup.

 

the TTT way is pretty much how the Hatchi is setup from the factory. the gotcha is that the Hatchi isn't as beefy as an SA, so for instance they cut their strut tubes down to make them about the same length as the SA struts are...

 

So as I understand it. The watts link is not as big of an issue as the 4 link is. Since it just locates the axle side to side in the normal movement of the suspension. But, being unequal length. They do add to the binding movement of the 4 link system?

So if you just make a (like 7s only does) mount, S bracket and equal length rods you should ok.
I'm not looking at the car, nor can I remember how the rods mount. So this is all just theory.

But I would think your biggest problem is ripping out the floor with the side loads your seeing.

 

Equal length, adjustable watts link set up is all the rage these days.

 

Looks like you could replicate either setup.

 

The 4 link causes massive bind in articulation. It's crazy. If you're ever bored one day and have wrenches, remove one (1) upper control arm bolt and both springs, hold the axle up in the middle with a floor jack and articulate the suspension. It is an EYE OPENER of what the real problems with the rear suspension are when you see how MASSIVE the misalignment can be when the body tries to roll.

I have a 3 link on my car, just like my last car. No 4 link, no problem. My first RX-7 was an SA, Mazda used an 18mm rear sway bar to keep the rear suspension from trying to articulate, so it never had the "grip grip SNAP" sensation that FBs have with their small sway bars. Much more progressive and drivable.

None of this has to do with the lateral location, though. The unequal length of the Watts isn't much of a problem, it's simply a little too high for performance driving, especially if you have a soft rear suspension and/or a lower ride height. All FBs have soft rear suspension, and most lowering springs are even softer than stock.

 

i took the watts off my car and just lifting it up and down with the floor jack you could tell there was a difference. the rear end pinion angle changes as it goes up and down (didn't try to simulate a turn, but you can imagine it), so the watts has to twist, and its not very good at twisting, so it binds.

i will grant you my car has the original bushings from 1982, so they are harder than long division.

 

From my reading of threads, it seems that people don't have any problems with polyurethane bushings on the watts link, does this explain why? Forgive me if I'm mistaken, I'm learning.

 

Poly bushings will add one more thing to bind up the rear. In the watts link they will act like a bump stop because they will resist the rear axle twisting forward at the top when the suspension is compressed. More compression=more twist. There isn't much rotation in the middle of the travel range so they won't cause too much trouble.

The stock watts link is actually pretty well designed and the rear end moves almost straight up and down until the limits of travel. The only problem is the height of the roll center that it gives the rear of the car.