i am in the process of getting custom lowering springs made, because i want a 150% increase in suspension stiffness, (road/track car) and i need the dimensions and spring rates front and rear, plus the inches of suspension travel. Anybody know anything?

 

Hi Calvin,
I think going 150% up in spring rate is going to be too stiff for a road car, (ok for a track ONLY car) I know a couple of the Targa XJS race cars here in Aus are 50% stiffer, any stiffer than this on the road and they have issues with wheel hop over bumps. Inother words on an uneven surface the tyres do not stay in contact with the road very well reducing grip and steering.

I am a firm believer in spring the car enough to keep it from bottoming out then control the weight transfer with swaybars. This has a number of benefits as I see it:-
1. Keeps the suspension soft enough to keep all 4 tyres on the ground better drive out of corners.
2. Allows enough squat and dive for weight transfer for traction at each end. ie the car will squat as it accelerates increasing weight transfer rear and hence traction. Stiffening the rear will allow the car to break traction easier.

I would be inclined to go 50% stiffer in rate and add very large adjustable ant-roll bars front and rear, these would need to be custom made as well. Using the rotating blade or rod end bar with sliding clamp ends will allow easy adjustment.

blade anti roll bar Racers Monthly

or this type with sliding clamps

 

by 150% i ment an increase of 50% over stock.

 

i was thinking of using one of these kinds of sway bars Redirect Notice