Ron Sutton Offset 3-Link install

[Vince@Meanstreets]

You don't have to add more tire just getting rid of unecassary fluff and making room for the unknowns. Exhaust, fuel system and I know it's always nice to have the just in case space.

Just saying it's easy to do now and why not push that tub out to the new frame rail.


Don't worry, these guys know what they are doing and should have it buttoned up sooner than you think.

[Sieg]

Originally Posted by Vince@MSperfab

Don't worry, these guys know what they are doing and should have it buttoned up sooner than you think.

You know he's not happy unless his hair is on fire.

[SteveN69]

Looks good. Was there a reason you didn't fully remove the old "frame rails", and push the new ones out the the edge of the wheel tubs? It looks like the rail bends would have fit nicely with the floor if they were a few inches out. For Ron S., what sort of effect would having the top bar offset on the rearend, but angled toward the center of the car have on handling? Weird roll steer? I'm trying to think of packaging in a 2nd gen Camaro, with a rear seat, maybe split bottoms like a 4th gen Camaro uses.

[Blake Foster]

IMO that 2x4 cross member under the drive shaft is going to hit the ground it will also limit your droop on the rear end. it is so far ahead of the wheel and 4" below the rocker. just saying

[Ron Sutton]

Originally Posted by SteveN69

Looks good. Was there a reason you didn't fully remove the old "frame rails", and push the new ones out the the edge of the wheel tubs? It looks like the rail bends would have fit nicely with the floor if they were a few inches out. For Ron S., what sort of effect would having the top bar offset on the rearend, but angled toward the center of the car have on handling? Weird roll steer? I'm trying to think of packaging in a 2nd gen Camaro, with a rear seat, maybe split bottoms like a 4th gen Camaro uses.

Hi Steve, I'll answer both of these ...

We made the frame rail placement decisions based on performance, not looks. In the end, when Mike Tolle does the sheet metal work, it will look sweet. But the frame rail location is optimum for the 3-link & shock mounts.

I'd better clarify three things ...
1. The shocks are more responsive (more grip) the farther out we place them. The ultimate location for the lower rear shock mounts is inside the rear wheel. I've done that many times, but you have to run a separate shock mount from the trailing arm mount.

2. The lighter the rear end assembly ... specifically out at the ends near the wheels ... the more responsive (more grip) the rear suspension is. For optimum grip, we want to pay attention to weight out at the wheel, including of course, the tire & wheel, brake system & any extra mounts.

3. When we mount the shock on the back of the trailing arm mounts ... and place the shock, trailing arm mounts & trailing arms ... outside the frame rails & next to the tire ... we can get dang close to ideal shock placement ... without having to weld a separate shock mount on the rear end. I have found this to be the optimum set-up.

Some simple math for sake of conversation ... if we put ...
A. 1" of clearance from tire to frame
B. 2" frame rail
C. 1" of clearance from frame to trailing arm
D. 3/4" to the center of the lower shock mount
... we have the lower shock mounted 4.75" away from the tire.

For Ron Myer's Camaro that would have put the:
* Frame width at 38"
* Shock Mounting width at 30.5"

On the other hand ... if we put ...
A. 1" of clearance from tire to trailing arm
B. 1/2" to the center of the lower shock mount
C. 1.75" of center of the shock mount/TA to frame
D. 2" frame rail
... we have the lower shock mounted 1.5" away from the tire.

For Ron Myer's Camaro that puts the:
* Frame width at 33.5"
* Shock Mounting width at 37"

Summary:
Whether the frame rails are 33.5" or 38" wide ... will have basically no effect on the handling of the car. But the lower shock mounts being 37" wide or 30.5" is a very big deal with a significant handling & grip gain to the wider option. So in other words, shock mounting width trumps frame width for performance.

-----------------------------

Your question: What sort of effect would having the top bar offset on the rearend, but angled toward the center of the car have on handling? Weird roll steer?

Not roll steer, but definitely torque steer. Which way you offset the top link ... with it angled back to the chassis centerline ... would determine which rear tire is loaded more, causing the car to drive harder off of one tire. Not suggested.

[Ron Sutton]

Originally Posted by Blake Foster

IMO that 2x4 cross member under the drive shaft is going to hit the ground it will also limit your droop on the rear end. it is so far ahead of the wheel and 4" below the rocker. just saying

Good eye Blake. With the car at ride height the crossmember "as it sits" would only have 2" of ground clearance. But Mike Tolle already planned to "trim" it down & re-box it.

[Ron Sutton]

Originally Posted by SteveN69

Looks good. Was there a reason you didn't fully remove the old "frame rails", and push the new ones out the the edge of the wheel tubs? It looks like the rail bends would have fit nicely with the floor if they were a few inches out. For Ron S., what sort of effect would having the top bar offset on the rearend, but angled toward the center of the car have on handling? Weird roll steer? I'm trying to think of packaging in a 2nd gen Camaro, with a rear seat, maybe split bottoms like a 4th gen Camaro uses.

P.S. The old frame rails are fully removed ... now ... just not in the earlier photos.

[SteveN69]

Ron S. , Thanks so much for the informative reply. I realize this car is being built for serious track oriented use, and now I'm aware of how important shock/spring placement on the rearend is.
I really enjoy reading your forum posts, they are incredibly detailed, yet easily understandable for us non engineer types ( sometimes I do read them over 2 or 3 times though) Thanks for taking the time and sharing your wealth of knowledge, it's really appreciated.
Looking forward to the rest of this build.

[Ron in SoCal]

Originally Posted by Blake Foster

IMO that 2x4 cross member under the drive shaft is going to hit the ground it will also limit your droop on the rear end. it is so far ahead of the wheel and 4" below the rocker. just saying

Originally Posted by Ron Sutton

Good eye Blake. With the car at ride height the crossmember "as it sits" would only have 2" of ground clearance. But Mike Tolle already planned to "trim" it down & re-box it.

Agreed and thanks for chiming in Blake. I've not yet seen the crossmember mod; Ron is measuring and building ground clearance at each fab step. Latest pics and a good example of ground clearance, Ron and Mike set up the subfr to connect and align with the work going on in the rear.

Trimmed down. I think Dave and Payton have run into this as well:


Which also had to trim the core support bushing:


And then we connected the sub with bolts and crush sleeves:


There's more progress, but I'm on the road and will speak with Mike by Friday.

[Ron in SoCal]

Lots and lots of pics of the watts and three links installed: