What would be the requirements of a suspension built for top end? How would it differ from traditional autocross suspensions? I kow this isn't everyones cup of tea, but I would be interested in knowing any info anyone else has.

 

Aerodynamic effects will have more influence, and "flat ride" considerations will shift your front:rear spring rate selection, which in turn may affect your bar choices and shock settings. You do not want a "pitchy" ride for extended running at the speeds I think you're talking about.

Alignment settings will be a bit different from auto-x, probably not as much -camber and absolutely no toe-out. Get it corrected for bump steer.

Norm

 

For open road, stiffer springs, bump adjustable shocks, smaller sway bars, and often times not very much negative camber to help achieve higher speeds, and probably alignment is worked around avoiding tracking issues. Lots of aero work for safety at high speeds.

Road racing is middle of the road stuff, negative camber, moderate spring/shocks/sways, moderate if any aero work, certainly more aggressive for a race car versus a street car setup.

Finally lower MPH AutoX stuff will usually consist of a milder setup, although some seem to like very stiff sway bars especially on the front, Sam and others like the 35mm solid apperantly.

You will also notice aerodynamics being a bit different, the faster you want to go the more you want to avoid air under the car, not only getting there in the first place but how it will act at the rear of the car, either trying to exit, or you can actually create a small vacuum if the rear is designed properly (look at Nascar stuff). The less bumps on the race surface, the more you can lower the car and stiffen it up.

I've got a video clip of an RX7 doing "only" 215 MPH on the salt flats, and it flips over several times and slides to a stop on its roof top, so even at a lower speed wind is an evil to combat.

 

Check out silverstateclassic.com for links to some interesting set ups

 

I've been to that site several times, but thanks for the pointers.

I'm working on a rear diffuser and possibly a belly pan with a couple venturi for the car, also been comptemplating a front spoiler with a removable plastic lip that could be attatched for top end (allowing very little to no air under the car).
Mudge.....so why do you choose looser sway bars for top end, could you explain the theory behind this?
As far as wheels and tires go, would it be in my best interest to have a set of 16s? I realized that the sidewalls would be spongier maybe resulting in it absorbing some of the imperfections in the road, I'm honestly not sure how the tires would act at really high speeds.
Of course vent's towards the rear of the hood or a cowl hood would be required to release pressure, very possibbly some in the fenders as well.
I've chosen to stay with the LT1 front end as imagine it to be more aerodynamic with less frontal surface area, building some removeable fill panels for the "nostrils" in the birds front bumper.
The car is lowered, any suggestions on shocks that I could go with? Been looking at several but have made no dissisions.
Currently working heavily on the aerodynamics since I'm doing heavy work on the body at the momment.

I'm considering open road and road racing when I started this thread, there is very little info out there and I'd like to compile some more.

 

Sway bars reduce the independance of the cars suspension, and can actually lift up the other side of the car if the setup is too stiff, definately risky at high speeds.

On some cars with IRS, they remove thier rear sway bars altogether. I have a pic of an open road Camaro, with a front/side air dam and I think other than a wing no rear aero work. He's got GW coil overs, 800# front springs, I forget the rears, Koni SA in front and DA in back, and stock bars, actually pretty close to stock ride height as well.

You can also hit up Keith on the board, he's got a TA and may have some info for you, he's one of the mods of the nitrous forum.
http://www.ws6.com/events.htm

Oh, he also tapes up the front a bit. Shoot me an email if you want the pic and I can dig it up.