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View Full Version : front coil rates


kiwi1955
09-03-2016, 03:24 PM
I race a late model in New Zealand, they're are called super saloons here. We have to run steel block engines 6" forward, the #1 plug has to be in line with the centre of the front spindles. To compensate for this and to gain more rear % we run our radiators mounted over the rear end. We have a sliding scale for total car weight versus engine capacity. My car runs a 358ci so has to weigh 2390lbs with me in it, we normally run around 2450lbs to allow for fuel burn off, alcohol in our case. The car has 54-55% rear, what front coil rates would you advise? I should mention our engines have ally heads. Our tracks are mainly stop and go, flat, narrow 1/4 miles. Thanks.
billetbirdcage
09-03-2016, 04:29 PM
I race a late model in New Zealand, they're are called super saloons here. We have to run steel block engines 6" forward, the #1 plug has to be in line with the centre of the front spindles. To compensate for this and to gain more rear % we run our radiators mounted over the rear end. We have a sliding scale for total car weight versus engine capacity. My car runs a 358ci so has to weigh 2390lbs with me in it, we normally run around 2450lbs to allow for fuel burn off, alcohol in our case. The car has 54-55% rear, what front coil rates would you advise? I should mention our engines have ally heads. Our tracks are mainly stop and go, flat, narrow 1/4 miles. Thanks.

The actual spring rate is going to depend on the control arm/spring leverage point to get an actual wheel rate. Meaning a spring that mounts more towards the center of the lower arm vs a coil over type set up that is really close to the ball joint will be totally different spring rates to get the same wheel rate. Could be like 500# spring for the spring in middle of arm vs 350# spring close to the ball joint = the same wheel rate.

So hard to say without knowing the motion ratio of the front suspension, COG, momentum arm, ETC your using. For the most part there isn't a right or wrong answer to some of these things, just different ways of doing things.