Crazy Cornering Comet

[Cyclone03]

Planning stage questions,ideas,plans. 1964 Mercury Comet.

I'm going to start with the front here but only because I know what I’m going to do.
I have experience with Open Tracker Racing roller control arms on my 68 Mustang so for the most part I’m going to set the front up first. I don’t have my notes on the Mustang but I seem to recall my front roll center at ride height was somewhere in the 4-6” range above ground.I will verify that. I’m using Street or Tracks Big Drop spindles and 13.1” brakes. I like the spindle because I can put the inner wheel barrel over the upper ball joint.
My plan is to maximize tire size and wheel width hopefully a 12” wheel front and rear with a 315 tire, same offsets front and rear as well.
That is based on the track width of the front plus 1” for the rear. No real numbers yet,planning remember.

The rear end width will be based on front track width +1”.
The rear will be an offset 3 link and here is where the questions really ramp up.
First if I base the set up on a 26” tall tire and an 18” rim is it important that the axle lower arm mount not be lower than the rim? Nominally 4” from the ground. Or is a bit higher “safer”,say 4 1/2-5 ,safe for a 17” wheel? The idea here is to not grind the mounts if I get a flat.

Next is Anti squat and horizontal CG.
With a small block Ford would I be safe using 16” from the ground for horizontal CG? Or should I go higher?
Seems the conventional rule of thumb is the camshaft- more exact numbers when I get a chance to measure my friends Comet as mine doesn’t have an engine.

With a 112” wheel base I can get to 16” with a lower rear pivot 5” off the ground and the front 6” off the ground with a 24” arm. To get to 20” would require moving the forward mount to either the inside of the frame rail or shortening the arm and mounting it on the rear of the frame rail.

Again all of the above is a WAG (wild ass guess ) based on where the front heights end up. The oil pan and bottom of the scatter shield are my hard limits. I’ve run my FE powered Mustang at 3 1/2” to the scatter shield but 4” would be safer.

My tire/wheel plan is based on a sqaure set up.
I’m planning to be “legal” in CAM with a target of 3000lbs without fat me on a 3180 total ,car driver limit.
I once heard from somebody we know if the limits are 200TW and wight run the biggest tire you can get.
Unless I missed it “everybody” makes a 315 or do I just go right to a a 335?

so this is to start the discussion so fire away please.
nothing is mounted or welded ,and only partially bought so it’s all etched in sand.
Thanks
Lance

[dontlifttoshift]

First, make sure you aren't making the car wider than everyone else's car.

Scrub line is if you pulled a string from the bottom of one inflated tire across the car to the bottom of the rim. Nothing should be below that line. I have cheated that before but it is a good general guideline.

With rear lower control arms, roll steer takes priority over anti squat. Anti squat is easily dealt with in the upper. Worth noting 100% anti squat sucks to drive.

I wouldn't build anything around a 335, you are on the right track with 315s and 12s.

[Cyclone03]

Overall width shouldn’t be a problem,the Comet stock is 3” narrower than my 68 Mustang in my avatar.
I’m using the front track width as a staring point as well as setting ride height once I get that in place the rear pick ups can be set.

For Scrub line I’ll use the bottom of the wheel above the ground to stay safe.

So for roll steer I want the lowers to point more toward the center of the front axle than strait ahead correct?
For a base line setting where do I want the lowers pointing to vertically ? Front ,theoretical CG point at axle CL? Front RC height ? Somewhere else or just what looks cool from the side?lol

For the upper I’ll say I want to keep it under the floor,the Comet has a very long kick up compared to the Mustang, but I’m not against cutting. Floor be damned do I want the upper arm the same length as the lowers? How much verticals adjustment should I build in?

Easy to tell I’m new at this, I have 3 books I’ve been,dare I say studying, but I need a been there done that guy or group to help move past theory into practice.
The anti squat is a perfect example,in reading that seems to be #1 with roll steer taking a back seat.

Thank for the reply.