A Max-Effort Build

[Norm Peterson]

Forget the $10-$12K mod. Just buy a 2015-2016-2017 car.... which has oem adjustable rear camber.... from zero to as much as -2.7 degs. Plus IRS. The 05-10 cars are long gone obsolete in every aspect from engine to tranny to suspension, lack of irs, no rear camber adj etc. The 11-14 cars are not far behind.

You're missing the point. If nothing else, you're maximizing what the S197 could have been. Or in other words, hotrodding.

Sure you can add neg camber to the rear....for $10-$12K, but now you require deep pockets to 'fix' issues that should have been addressed earlier.

For up to about a degree - about enough to compensate for the axle's own roll - there is at least one far less expensive way. Even if you have to buy the equipment to do it with.


Norm

 

[MechE]

You're missing the point. If nothing else, you're maximizing what the S197 could have been. Or in other words, hotrodding.

 

[Sky Render]

Forget the $10-$12K mod. Just buy a 2015-2016-2017 car.... which has oem adjustable rear camber.... from zero to as much as -2.7 degs. Plus IRS. The 05-10 cars are long gone obsolete in every aspect from engine to tranny to suspension, lack of irs, no rear camber adj etc. The 11-14 cars are not far behind.

Sure you can add neg camber to the rear....for $10-$12K, but now you require deep pockets to 'fix' issues that should have been addressed earlier.

*slap*

Get out.

 

[ford20]

Forget the $10-$12K mod. Just buy a 2015-2016-2017 car.... which has oem adjustable rear camber.... from zero to as much as -2.7 degs. Plus IRS. The 05-10 cars are long gone obsolete in every aspect from engine to tranny to suspension, lack of irs, no rear camber adj etc. The 11-14 cars are not far behind.

Sure you can add neg camber to the rear....for $10-$12K, but now you require deep pockets to 'fix' issues that should have been addressed earlier.

10-12k to have fun with your car or 30k for a new car and start all over again ... hmmmmm

 

[Boaisy]

10-12k to have fun with your car or 30k for a new car and start all over again ... hmmmmm

...and that's just a motor.

 

[Vorshlag-Fair]

Admittedly, this is the most dramatic pic I could find of my whip. Slow right hander, power on so torque is twisting the axle, and downhill.

I have tons of pics of our S197 with "positive rear camber"... or what appears to be so. Its actually not - the solid axle isn't bending, the entire body is rolling relative to the axle.

That said, sure, a cambered rear axle would be better for handling. The problem is the EXTREME costs and high wear items involved. Its also usually banned in most racing classes.

 

[barbaro]

Perfectly good three link? Bull! Thats a max race build. They know what they are doing. As does Griggs, as does Cortex. Btw Filip is chief engineer for Rehagen and now Rousch Performance at Pirelli World Challenge. There's an entire racing series at Sonoma spec to his equipment. I think their credentials trump Vorschlags by a large margin. These guys had a choice as to which philosophy to go with and they make exotic racing machines I have to assume they know what they're doing because it's consistent with what I know to be true. Torque arms are vastly superior to 3rd links . https://youtu.be/UhjQXJ6Yegs

 

[Norm Peterson]

↑↑↑ Have you ever researched the use of 3-link suspensions in the Trans-Am series?

I'll give you a hint . . . all three longitudinal links ended up being much longer than they are in the S197, especially the upper.

Where am I going with this? Let's just say that the devil is in the details for both of these rear suspension configurations, and that from there you can end up with a range from really good to horrible with either kind of suspension. Google 'Track-link' sometime if you still think that torque arms are always superior.

It would be necessary to know the details of the rules for the class this car runs in, in order to know whether use of the torque arm was driven by limitations preventing a proper long 3-link arrangement (such as the extent of allowed floorboard cutting).


Have you ever stopped to consider that a torque arm is little more than a virtual 3-link with a couple of the pieces turned ~90° in side view? (should I put "pieces" in "" . . . . naaah)


Norm

 

[ford20]

...and that's just a motor.

I'm not talking to you. You gave me bad juju and caused me to have to wait another month or so.

 

[Pentalab]

10-12k to have fun with your car or 30k for a new car and start all over again ... hmmmmm

For under $40k, you can now buy a 727 crank hp 2016 stang, complete with Roush blower, adj rear camber and IRS. Ok, start there, then mod it.

It gets to the point where you are throwing $$ at old technology. Why mess with a 05-10 3v....when the 11+ engs are way better, right out of the box.

 

[Norm Peterson]

It gets to the point where you are throwing $$ at old technology. Why mess with a 05-10 3v....

I realize that it's "only HPDE", but it's pretty satisfying when something like this happens for any reason (I'd been not all that far off his tail for several laps).


Norm

 

[SoundGuyDave]

Yeah, you're right. We should all throw away our well-developed race cars in favor of starting over again. FWIW, I have well in excess of $40K in on TOP of the purchase price of the car. For the S550, you could make many of the same arguments about the engine architecture (no direct injection?!?), transmission (where's the DSG sequential?), differential (computer-driven torque-splitting??) suspension (still has struts up front, and the IRS is HARDLY "optimized."), dampers (gas-charged monotubes??? Unless it's computer-controlled magneto-hydrodynamic, it's essentially tech from two centuries ago), brakes (no carbon-ceramics???), at infinitum. If you want to go hardcore, the chassis itself is probably one of the LEAST costly parts of a race car build. "Pro" racing Mustangs can easily top $100K by the time you're done fitting them out to be competitive.

Are the days of the S197 as the leading-edge of pony-car technology numbered? You bet they are. But, I would still take a fully-developed, well-sorted "last generation" racer than a fresh-built, untried "next generation" car any day of the week. Drop the green, wait 12 hours, and see who's still moving under their own power at the checker... FWIW, I've never, not once, had a mechanical DNF (excepting wrecks) in my S197.

All that said, I'm also not planning on tossing a bunch of $$ into the chassis either. Next move is indeed a new car, but it won't be one that was ever in a showroom or dealer lot, either. If you want zero-compromise, the ONLY solution is a purpose-built tube-frame silhouette car.

 

[Boone]

For under $40k, you can now buy a 727 crank hp 2016 stang, complete with Roush blower, adj rear camber and IRS. Ok, start there, then mod it.

It gets to the point where you are throwing $$ at old technology. Why mess with a 05-10 3v....when the 11+ engs are way better, right out of the box.

I don't want a fast car... I want my car to be fast!!!

I should put that in my signature, if I knew how to make a signature. Have a great Memorial Day weekend y'all.

 

[MechE]

I realize that it's "only HPDE", but it's pretty satisfying when something like this happens for any reason (I'd been not all that far off his tail for several laps).


Norm

ATTA BOY NORM!!!

 

[El_Tortuga]

I have tons of pics of our S197 with "positive rear camber"... or what appears to be so. Its actually not - the solid axle isn't bending, the entire body is rolling relative to the axle.

That said, sure, a cambered rear axle would be better for handling. The problem is the EXTREME costs and high wear items involved. Its also usually banned in most racing classes.

Of course the axle isn't bending. But is it planted evenly on the ground? Heck no. It's going with the body, worst on slow right handlers when torque is also lifting the passenger side rear wheel.

 

[El_Tortuga]

Cost prohibitive in my book of course. Worked for Harry Gant. 4 in a row!

 

[Norm Peterson]

I have tons of pics of our S197 with "positive rear camber"... or what appears to be so. Its actually not - the solid axle isn't bending, the entire body is rolling relative to the axle.

Terry, I'm not looking at the body at all, or even its roll relative to the axle. Hell, all that red and white sheetmetal and all the sprung weight bolted to it could be invisible for all I care. There is no way that axle isn't "rolling" and putting a little +camber on the outside and a little -camber on the inside. Near-zero inside tire load and a couple thousand vertical lbs on the outside is somewhere around a 1" difference in vertical tire deflection, spread out over 62" or so. First cut approximation, I make that a little less than 1°, + on the outside, - on the inside. It's not an optical illusion.

You know as well as I do that the axle is not infinitely rigid, so it has to be bending some very tiny amount. But I'm willing to say that effect is negligible noise in the bigger matter here if you are.


Norm

 

[kcbrown]

Fortunately for us, it's easy to draw the lines showing the relative angle of the wheels. To draw the lines, I located the uppermost and lowermost points of each wheel, and drew the lines to intersect those points. When you do that, it becomes clear that the rear has positive camber relative to the front (click on the image to see the lines better):




Now, that could be because the car was going over an irregularity of some kind, but that doesn't appear to be the case here.

And assuming that the front's camber is optimized, it seems unlikely that the rear's would also be, based on the above.

 

[barbaro]

All that work, sequential trans, and they slap a torque arm on there...

Yes, yet another adherent. They must be stupid. You are the smart one.

 

[barbaro]

Cortex sells one purpose-built for the S197 chassis. After you fit it with a diff and brakes, you're out $10-$12 kilobux.

They also sell a torque arm. ;-)