Reducing scrub radius vs. track width

[Salt Racer]

Yeah, better stay away from Katz guy. He's been known to sweet-talk people into some fancy suspension schemes that cause massive delay of projects. He's a trouble.

I don't know exactly what (who) Tsubai is. I'm thinking he's more of a wanna-be-racer, closet street rodder. He probably enjoys polishing chromed brake rotors and never takes his car out on tracks, even though he says otherwise. I know the type.

OK, I think I bad-mouthed about myself enough.

So, for someone like myself that has OEM C5 rims with allot of offset, it would be advantageous to work towards a longer upper and lower A-arms instead of spacing the rim out with an adaptor. I would need to confirm that I can fit the knuckle inside the rim without interference. But the scrub radius and side scrub would be reduced.

I believe that my adaptor is 1.75" thick, so my other question would be if I moved the knuckle out that amount would this significantly affect the motion ratio of my spring and shocks if they remain in the stock location?

Generally yes. But better check where you're at right now as David suggested. If I'm not mistaken, UCA/UBJ interference is the limiting factor on A-body. You'll need some sort of drop knuckles.

IIRC, A-body swallows 9.5" rims w/ 6" BS up front - I think that's what Jeff Smith had on his '65 Velle for a while. Anyway that's +0.75" offset. OE Z06 front rim has +56mm (+2.205") offset. So everything else being equal, Z06 rims will reduce scrub radius by 1.455". This actually might work out pretty good.



Motion ratio will be affected by fair amount. Let's say your LCA measures 15", and spring/shock are located 8" from inner pivots (my wild-azz guess), and you lengthen the arm by 2". Motion ratio will be 78% of what you currently have, assuming track width remains the same.

I wouldn't worry about springs - all you need to do is increase rate(make sure LCAs can handle the added stress). The downside is increased mass from heavier springs and heavier LCAs.

I'd try to move shocks outboard however. Might be easier to notch the frame rails and mount coil overs.

Shock shaft speed will be much faster if the shocks are left in OE location. Revalving may be necessary. One benefit of leaving shocks in OE location, though, is the difference of shaft speed between high speed mode (hitting bumps) and low speed mode (body roll, pitch) will be greater. So it might be easier to fine-tune valving. This is just my guess, however.