From jonh@tugmasters.freeserve.co.uk Tue Feb 9 10:40:26 1999 Date: Tue, 9 Feb 1999 08:58:30 -0000 From: Jonathan Hodgson To: 'Tom' Subject: RE: Add to your RC page? Here we go then... If you let me know the URL, I'll make a note for future reference. Cheers, and happy racing! Jonny------ =_NextPart_000_01BE5414.870BA900 Content-Type: text/plain; name="SETUPS.TXT" Content-Transfer-Encoding: 7bit Here's what I've learnt in eight years of racing, in approximate order of importance and as succinctly as I can manage. I run 4WD off road, so it's biased in that direction, but it should apply to any full-suspension car. This is just my experience, and others may disagree with some points I make. Tyres - Using an unbalanced tyre combination makes more difference than you can ever hope to fix with suspension settings. I never mix and match tyres - I buy a set of four of the same pattern and compound, and replace the whole set when they're worn out. - This doesn't apply to 2WDs! Springs - Stiffer springs generate more grip at the other end of the car. - Excessively stiff springs all round reduce overall grip. - Excessively soft springs make the car wallowy and slow to change direction in quick, twisty chicanes. Damping - Heavier damping makes that end of the car less nervous and slower to respond. - Over-heavy damping will make the car 'crash' over bumps, losing wheel contact. - Over-light damping makes the car soggy and imprecise. Ride Height / Rake - Due to the way roll centres move, lowering one end of the car makes the car lean on that end in corners (particularly on entry) so it feels like there's more grip at that end. The front should generally be a little lower. - If you're struggling for run time, make sure the car's not dragging in the grass! - Lowering the car will reduce any tendency to grip roll, but if that isn't a problem I don't necessarily run the car as low as possible. Spring Spacers - These are used to set ride height, *not* spring stiffness. The springs should never be pre-loaded at rest. Shock Position - Moving the shock outwards stiffens both springs and damping at the wheel (specifically, the straight-line distance from the shock shaft to the wishbone pivot pin is important). - Leaning the shocks in creates 'rising rate': soft springing and damping at ride height, which stiffens up as the suspension compresses. - Shock position may also affect droop (maximum downwards travel) and ride height. Anti-Roll Bars - An ARB generates more grip at the other end of the car. - A rear 'bar in particular will unsettle the chassis over small bumps. - If the car gets very sideways, the end with a 'bar will let go suddenly. This often happens throwing a car into a hairpin after a straight. - This may not apply to XX4s! They use a (deliberately?) sloppy ARB mount which seems to respond differently. Top Link Position - This is complicated since it changes the roll centre position and movement. Roughly speaking, angling the top link downwards and inwards improves lateral grip but reduces traction, and encourages the car to lean in corners. - The top link and wishbone should always be closer together at the inboard end (unlike the Bosscat Works, and a Marui Ninja I was once given). Toe-in/out - Toe-in makes the car more stable, and thus less willing to turn in. - Rear toe-out is rarely advisable unless you like huge oversteer. - Excessive values either way on the front are also not recommended. Try none on the front and a couple of degrees of toe-in (if it's fully adjustable) on the rear. Camber - Set camber so that the tyres wear flat. - If the car is 'snatch rolling' on ruts and bumps, try a little more negative camber. - Typical settings: front 0 - 1 deg, rear 1 - 2 deg negative. Caster - Less caster makes the car turn in better but increases corner exit understeer. - More caster makes the car more stable in a straight line. Power - The quickest way to find out if your car handles is to put a hotter motor in it. If it doesn't handle, it'll be travelling faster when it crashes. If it does, you won't ever want to go back to the slower motor. - You can have enough power, but never too much!