A great small detail is the use of rubber protective boots for the tie rod’s hiem joints. You can also see the high misalignment spacers that give room for articulation and the spacers that you can place on either side of the heim joint to control the pivot location to adjust the bump steer.
Next, we are using GKTech’s offset solid steering rack bushings. The S Chassis’s OEM bushings are super soft rubber that allows the rack to move around a lot destroying steering feel and accuracy. When the car gets older, it is not uncommon to find one of the two bushings completely missing as they have gotten old, cracked, and beaten up. The GKTech bushings are solid machined aluminum to hold the rack completely solidly with no movement.
The bushings are also machined with an offset to move the rack forward. This helps prevent an excessive build-up of Ackerman angle at high steering angles and contribution to tie rod over centering and toggling which can cause steering sticking and inner wheel wobble. When used in connection with the offset tie rod mounts, you can get up to 60 degrees of steering angle without either occurring when everything is adjusted properly.
We are using a GKTech master cylinder stopper to improve the brake feel. Master cylinders are bolted to the thin sheet metal of the firewall and when you brake hard, the firewall flexes and you feel the mush in the pedal. The brace bolts to the shock tower and butts into the end of the master cylinder positively, keeping it from moving. In our opinion, this is one of the best bang for the buck brake mods and makes a much bigger difference than things like braided steel brake lines.
7 comments
looks fanstastic! I always wondered about these arms and knuckles. Thank you for the in-depth review
“ Road racing cars need Ackerman in their front steering geometry and typically you want a gradually rising Ackerman curve that is slightly less than the geometric true Ackerman. For drifting, you want a digressive Ackerman curve. This tends to understeer in grip driving. GKTech makes 3 different knuckles. A grip driving one, a drift/grip one, and a super angle drift only one.”
^This really is ‘the secret’ to handling with rubber tires and their slip angles. In F1, I know that they even do an Anti-Ackerman setup!
https://www.f1technical.net/forum/viewtopic.php?t=8874
Until you understand these principles in theory and practice, you can’t really have a solid understanding of how to make a car handle.
It’s weird with open-wheel cars, We found that anti-Ackerman causes understeer in road racing in sedan-based cars.
I think it has everything to do with the tire. I am sure that F1 had to change up the anti-Ackerman when they switched to 18” wheel rims this year.
The ‘max lateral load’ (and associated ideal slip angles) for radial street tires is probably way different than the race rubber they run in F1. Also, downforce needs to be factored in.
My Holy Bible on tires is this book, if anyone that wants to race a car is serious about winning, or just being competitive, don’t get a HUGE REAR WING, please read the bleeping manual!
I ordered a copy and the author Paul Haney even signed it! What a guy! So happy for him to take my money!
https://www.standardsmedia.com/The-Racing-and-High-Performance-Tire-8627-book.html
I ordered the book!
they didn’t have it!
the book is out of print, considered a rare book and no one has it!