69427

Just mulling over some winter projects for the car. I have a late C4 suspension under my '69, and I made all the brackets so that I could easily change the settings or geometry. Are there any noticeable upsides to reducing anti-dive that would warrant taking a few hours to change the geometry? I've got some decent rate coilovers on it, and I honestly can't say how much percentage of the "flatness" when braking is the springs or the anti-dive.

Thanks for any constructive comments.
Mike

preston

It is common for more serious race cars to pull out a lot of the anti-dive geometry. This should help free up the suspension a bit under braking loads. However the anti-dive geometry is also responsible for creating caster gain under bump and caster gain translates to camber gain especially when the wheel is turned. Based on my suspension analysis of a C5 geometry this effect is pretty significant in that suspension.

So difficult for anyone to say, would have to be tested at the race track, but I wouldn't encourage you to make any moves without modelling the suspension on the computer so you understand what is happening under roll, dive and cornering, and so you know that moving it 1/4" will have so much effect, and moving it 1/2" will have another effect.

IOW, I think it would be a real shot in the dark to just move something around in the hopes it will be better unless you plan to do back to back testing at the track with it. But hey, if its easy to change, you can't make progress without experimentation. I just wanted to point out that it may affect more than just how much anti-0dive you feel under braking.

But, I'm no expert, especially for a C4.