|
Actually, as I think about it, the rear suspension is probably one of the more liberal areas for modifications in IT, but it's still somewhat restrictive.
The axle housing, axles, and brakes must be stock, but you can use any differential (limited slip, locked, etc) with any rear end ratio.
All spring and shock mounting points must be in the stock location. Springs and shocks of any origin, provided they are the same type as original (e.g. no coil springs in place of leaf, no external reservoir shocks). Maximum of 2 external adjustments on shocks.
Adjustable spring spacers, including threaded coilover types, may be used. Any rear sway bar, panhard rod, traction bar, or Watts linkage may be added or substituted. Bushing material is free, heim rod ends may be used.
I suspect my car is probably a pretty typical ITB 140, with respect to rear suspension. IMO, any further mods would probably be throwing money down a rat hole... very little bang for the buck. Anyway, it has the following modifications from stock:
- 225, 250 and 275 lb springs with shim sets for tuning
- Carrera racing shocks, custom valved (no external adjusment)
- Adjustable (rotating blade) anti-roll bar with heim rod ends
- Adjustable height panhard rod with heim rod ends
- Metal bushings everywhere
Incidentally, the allowance for threaded coilovers is a fairly recent rules change that came into being after my car was built. I will probably look into this mod at some point in the future, as it is obviously much more desirable than my current setup (spring shims) when tuning ride height and corner weights.
Speaking of ride heights, there is a limit.... minimum of 5 inches at the lowest part of the rocker panel, not to include pinchweld seams or fasteners. If you want to know what a "5 inch car" looks like, see my pictures in the 140 gallery... my car is exactly at that minimum ride height.
FWIW, I wish your friends all the luck in the world, but I know of no ITB 240 that has consistently beaten a decently prepared and driven 140. For starters, the minimum weight for the 240 is nearly 150 lbs more than the 140, while the 240 has very little (if any) additional horsepower. Plus, much of the extra weight is in the form of heavier bumpers that add significantly to polar moment, and there's nothing you can do about it... stock bumpers must be retained. Also on the subject of weight, if I remember correctly, the front-rear weight distribution on the 140 is significantly better than the 240. Finally, I'm of the opinion that in ITB context, the strut suspension at the front of the 240 may not be as desirable as the double a-arm setup of the 140.
|
