I have an ongoing project on my 1st gen CRX regarding suspension setup. I compete in local autocross events in SCCA F Street Prepared. I’ve been trying to find the optimum setup for the car using knowledge from RPR making changes and testing, but I realized that I didn’t know enough about what the suspension is actually doing when it’s in motion to make changes that actually helped. So I decided to model the suspension to gain a better understanding of this. This series of posts represents the sometimes rambling path I’ve taken to get to the point where I think I reasonably understand the suspension, how all the parts work together, and most importantly – if potential changes to the suspension will be helpful in terms of handling.
The car was originally an SCCA ITB car and came to me with the following setup:
August 2012
24mm front torsion bars
275# rear springs with Ground Control coilovers
16mm front ARB
22mm rear ARB
Tokico Illumina dampers
Strut bar
Roll cage
Total weight with driver 2190#
Early 2014 upgrade
Upped rear springs to 350#
Upgrades done soon after - 2014:
27mm front bars
450# springs
camber plates in place of the strut bar
Later in 2014
Upgrade rear to 500# springs
Added a 7” tall removable rear spoiler
2015
upgrade rear springs to 550# (Tokico dampers seriously over springed at this point)
2018
Removed a ton of weight from the car, about 250 lbs including roll cage, brake swaps, lightweight wheels, etc.
Upgrade dampers to Medieval Pro Teins from Heeltoe, with proper valving to match the 27mm bars and the 400# rear springs that came with them.
Also took corner weights and balanced the car for the first time.
Set the front ride height such that the lower control arm was almost parallel to the ground with the inside slightly higher than the outside, and set the rear ride height about 1/8” lower.