1981 Camaro - C-Prepared Build

Yeah I fully understand the issues with panard rod setups, I used to mess around with old ford fiestas ( slightly more popular here in the UK ) which ran them, and had to deal with the issues involved when lowering them.

The setups I've seen, I guess would be watts link, but arranged like this:

Is there any benefit from fitting the propellor (I'm guessing that's what it's referred to?!) in one position or the other?

Another point I'm curious on, why the large upper link on the axle? Why not 2 link arms each side above the existing lower link arm? As again, that's the way I've seen it done over here as per the above picture. There's obviously more than one way to skin a cat, I'm just curious as the benefits of both ways.

Again, pardon the ignorance. Only rwd stuff I've ever played with have had IRS setups, so this is all fairly alien to me, but I like to learn.

I'm trying to get used to using an iPad so I'm lagging on these responses, just read your previous posts and all becomes clear! Makes perfect sense!

Stumc wrote: Another point I'm curious on, why the large upper link on the axle? Why not 2 link arms each side above the existing lower link arm? As again, that's the way I've seen it done over here as per the above picture. There's obviously more than one way to skin a cat, I'm just curious as the benefits of both ways. Again, pardon the ignorance. Only rwd stuff I've ever played with have had IRS setups, so this is all fairly alien to me, but I like to learn.

No ignorance. I'm learning all of this/making it up along the way.

As far as the rear suspension, the design is an "offset 3-link". The 3-link has more articulation and is less likely to bind when compared to a 4-link (two link arms above the existing). 4-links are great for drag cars, but for handling cars, 3-links have been proven faster for a long time now. The offset of the upper link is to counter the torque under acceleration.

The reason the mount for the upper link is so tall is all geometry. I'm shooting for certain antisquat/dive numbers to get the rear to "bend" around corners. This requires some interesting angles on the arms.

I will likely ditch the solid link for the upper and go for one of the spring mounts circle track guys like to use to ease shock to both the tires and the mounts (since it's a big lever arm).

Ok yeah most of that makes sense.

I'm just gonna throw it out there as something to look into, but researching into the geometry and methods used in setting up mk1 and mk2 ford escorts might be time well spent. I've never owned one so can't really preach too much, but they run a solid rear axle, and have been used in rallying, circuit racing and probably every other worthwhile form of Motorsport to great success in Europe, for decades. The things that people do to them clearly work as they are famously good around corners. I'm sure it'll all make more sense to you, ! Never know, could find something interesting you might want to think about applying to the camaro some day!?

Stumc wrote: Never know, could find something interesting you might want to think about applying to the camaro some day!?

I'm all for any and all ideas!

Some inspiration, probably seen them all...

My .02 cents, keep the fender flares flat like the latter cars

My first car an 80 z28,which I still have, will end up like this some day. Thanks for posting up what it takes to do it, keep at it.

Question, what's up with the wide 5 hubs, is it just to allow stiffer, bigger axle stubs and stronger bearings?

81cr450 wrote: Some inspiration, probably seen them all...

I do look good in pink...

81cr450 wrote:

That is Ron's car. He's been huge help through this whole process.

81cr450 wrote: My .02 cents, keep the fender flares flat like the latter cars

I'll have to see how things layout. I've never tried to make flairs before.

Kenny_McCormic wrote: Question, what's up with the wide 5 hubs, is it just to allow stiffer, bigger axle stubs and stronger bearings?

Some of it is "tradition." Some of it is cost. Some of it is strength.

The circle track stuff tends to be cheaper and stronger than a lot of stuff out on the market. Wide Five wheels also used to be cheaper, so it was easier to go that route.

Down the road, if I switch to the new Hoosier radials, I'll probably end up with a more conventional rear hub (those designs can get more camber).

Wide 5 is mostly about strength and cheaper wheels due to standard bolt pattern. They came about in the 70s as a way to get stronger bearings in a race car. If I remember correctly, the bearings are from a 3/4 ton rear full-floater axle. They are pretty darn big, inner bearing is 2" i.d. and 1.8" i.d. for the outer. Replacement parts are cheap too, thanks to the circle track peeps using them a bunch. Currently the wide 5 wheels are cheaper, unless you want to go larger than 16", then they get more expensive and fewer choices. Bogart seems to be the only one making a racing 17" wide 5 wheel, site says call for price. I'm afraid to make that call.

Paul, you can get cambered axle setups for wide 5 as well, at least up to 1.5 degrees camber, the 5x5 does go to about 2 degrees. When I switch to a 9", I am thinking about getting the axle setup with bolt-on snouts so I can vary the camber just by changing the ends. It will costs a bit more up front but hopefully pay off in the long run. I could also change from wide 5 to GN just by changing the ends. But that will be a bit later on.

81cpcamaro wrote: Paul, you can get cambered axle setups for wide 5 as well, at least up to 1.5 degrees camber, the 5x5 does go to about 2 degrees. When I switch to a 9", I am thinking about getting the axle setup with bolt-on snouts so I can vary the camber just by changing the ends. It will costs a bit more up front but hopefully pay off in the long run. I could also change from wide 5 to GN just by changing the ends. But that will be a bit later on.

That lines up with what I read. I'll work with what I have now and change things up down the road after the car makes a few runs.

Wow - sweet Camaro porn here

Great build, digging the pictures and theory talk.

I do love Camaros and porn!

I did make a trip up this past weekend, but not much to show. I brought my expert welder with me and we locked the rear suspension structure down. Next trip up should include some frame cutting. Look forward to that in 2015!

Keep up the good fight. I have a hard time staying motivated and my shop is in the basement. Can't imagine a 45 minute drive helps that problem.

That is going to be one trick Watts link.

SCCA rules for autox are just ridiculous. Just glancing through this thread makes that perfectly clear. You are forced to have a tube framed car with just a few structural bits of the original car left. Building a modified car would be easier?

Actually quite a bit of the cars structure has to remain, modified rules would allow more to be removed. Paul's car isn't tube framed, it just has a lot of cage in it, along with some supports for suspension stuff. Tube frame cars would suffer a 10% weight penalty in CP.

The rules are what they are to keep a good amount of separation between the prepared and modified classes. Back when the prepared rules first were done, there was only Stock, Prepared and Modified classes, not the multitude of classes we have now. It may be easier to build a mod car, but to build one competitive enough probably costs a serious amount of green.

Sky_Render wrote: That is going to be one trick Watts link.

It would be even tricker if he built it to have an adjustable roll center.

smokindav wrote: SCCA rules for autox are just ridiculous. Just glancing through this thread makes that perfectly clear. You are forced to have a tube framed car with just a few structural bits of the original car left. Building a modified car would be easier?

This is one of the more highly prepped classes in all of autox, and you're citing that as evidence that all SCCA AutoX rules are dumb? That is quite the extrapolation.

bentwrench wrote:

Sky_Render wrote: That is going to be one trick Watts link.

It would be even tricker if he built it to have an adjustable roll center.

I had considered using a screw type mount, but that was just getting silly.

DILYSI Dave wrote:

smokindav wrote: SCCA rules for autox are just ridiculous. Just glancing through this thread makes that perfectly clear. You are forced to have a tube framed car with just a few structural bits of the original car left. Building a modified car would be easier?

This is one of the more highly prepped classes in all of autox, and you're citing that as evidence that all SCCA AutoX rules are dumb? That is quite the extrapolation.

Here here. This build really isn't crazy, and there is no reason to initially go this far. That said, I want to be at the pointy end, and I don't want to be able to use my car as an excuse.

I think the newer chassis Mustangs are going to prove to more than a few people that you can be competitive in CP with what amounts to a gutted ESP car.