:. Prosport Setup Info .:
Last Updated: 2007.07.19
Successful / Continuing Setups
While I've found Radical owners to be tremendously helpful, getting a 100% complete picture of a car's setup
has turned out to be a bit tough. Here are some of the setups I've run/am running.
Remember, these are on my Clubsport, rear swaybar chassis, so Prosport setups may differ fairly significantly in necessary rear springrate and shock valving. As well, if you're not running bias Hoosiers or Goodyears, these may need tweaking for different tire construction and grip levels.
| Setup: Jake Latham Current |
| Measure |
Front |
Rear |
| Springs |
450# |
650# |
| Preload |
0, but zero drooped |
-- |
| Swaybars |
3/4" (Medium) Nik Bar |
3/4" (Medium) Swaybar, Middle hole. |
| Ride Height |
2 3/8" |
2.75" |
| Camber |
~1.1* |
~0.4* |
| Toe |
1/16 (out, total) |
1/16 (in, total) |
| Wheels |
8" |
10" |
| Tires |
20x7.0x13 Hoosier R35 |
22x9.0x13 Hoosier R35 |
| Pressures (C) |
~16 |
~16 |
| Pressures (H) |
~20 |
~20 |
| Front Aero |
High DF Dive Planes, Std. Splitter. |
| Rear Aero |
Standard Prosport Wing, Std Diffuser |
| Shocks |
Penske 8100, A/B (Front), A+/B+ (rear, hi-flow piston) |
| Canister Pressure |
80psi |
80psi |
NOTES:
My current standard baseline. Still searching for a bit more front grip, but pretty good for now.
No splitter rub. Braking is fine, seems good over a long stint. Soaks up
bumpy tracks excellently.
|
Failed Setups
Sometimes, it's useful to know what does NOT work, as well as what does. Here are some of the things I've tried this year while playing around and having fun. Remember, what doesn't work on my Clubsport chassis may work pretty well for a Prosport!
| Failed Setup Attempts |
| Setup Attempt |
Notes |
| |
2005 |
| 250#/300# springs |
good grip, poor response. Aero pushed rear body down onto wheels - not stiff enough. very mismatched with original stiff shock valving
|
| 250#/350# springs |
good grip, poor response. stiffer rear exposed how mushy the front was.
|
| 250#/400# springs |
Actual reasonably balanced, but soft felt very strange. Moved around a lot, slow to respond. Excess movement at front caused difficulty with power down out of tight corners. Odd tire wear. Could really feel the mismatch of spring and shock, the car would move almost 2-phased when you turned - on to the shock (stiff), then off the shock, onto the spring (mush)
|
| 300#/350# springs |
Wanted to see if stock Prosport setup might be a good baseline. It wasn't. Front-end responded better than with 250's, but car had big understeer bias. Plus, still ground a lot of splitter away...
|
| 300#/400# springs |
More of the same, albeit slightly better
|
| 350#/400# springs |
Tried this briefly at season start to see how it would go. Big understeer.
|
| 350#/450# springs |
Car's original setup. Better than 350/400, but with initial shock valving, I blamed poor bump handling on the springs. When I tried it again after doing everything I could to soften the shocks it wasn't sooo bad. This is what I had on the weekend of the Denver tour T&T that went pretty well.
|
| 400#/350# springs |
Tried this to see if the Radical had the same issue as the Corvette, i.e. needing a lot more front-end roll control to keep camber angles in check. Maybe true, but with the soft rear springs, understeer was of biblical proportions. Negative!
|
| 400#/550# springs |
This one could actually go in the successful column. After feeling like the car could still go stiffer and still be "biting" well, went to 400/550 from 350/450. Even better balance-wise, and front-end response, even before 0-droop. However, even with 20x7.5 fronts, we still went to nearly 3/4" of rake for Steve at the club National to dial out some understeer.
|
Starting Point
For reference, here is the starting point of the car when I got it, November 2004
| November 2004 Starting Point |
| Measure |
LF |
RF |
LR |
RR |
| |
Alignment |
| Camber |
~2.0* |
~2.0* |
~1.5* |
~0.25* |
| Toe |
3/32 (out) |
6/32 (out) |
2/32 (out) |
2/32 (in) |
| |
Handling Balance |
| Swaybars |
3/4" Nik Bar |
3/4" Swaybar, Hard. |
| Springs |
350#, 8" |
450#, 8" |
| Preload |
-- |
-- |
-- |
-- |
| Ride Height |
2.75" |
2.75" |
3.25" |
3.25" |
| Corner Weights |
-- |
-- |
-- |
-- |
| |
Running Gear |
| Wheels |
6x13 (8x13) |
8x13 (10x13) |
| Tires |
20x7.0x13 Hoosier |
22x9.0x13 Hoosier |
| Pressures (C) |
-- |
-- |
-- |
-- |
| Pressures (H) |
-- |
-- |
-- |
-- |
| |
Aero |
| Dive Planes |
Std, w/ Gurney |
-- |
| Splitter |
Std, w/o Gurney |
-- |
| Wing |
-- |
Std, 2/4 of max |
| |
Shocks (Penske 8100) |
| Bump |
1 |
1 |
| Canister Pressure |
200/110psi |
170/140psi |
| Rebound |
-10/-0 flats from stiff |
-0/-14 flats from stiff |
| Valving |
B-/C |
B/C+ |
NOTES:
understeer everywhere, awful over bumps. Long springs prevent low enough ride height, etc etc etc.
|
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