QA1 front coilover spring rates - track days
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
The QA-1 spring choices are bad. Speed direct sold the collar adapter for their smaller diameter springs. The springs used to be $50 a pair. So I bought 600, 650, 700, and 750. I have a very light front end so I found the 650 or 700# to be the best.
On a 4 corner scale I have less than 1340 pounds on the front tires and in racing trim I was right on the 3000 lbs for my engine ci. So with 700# springs and let's hypothetically under straight line braking with slicks create over "1 G" of braking and transfer 1400 hundred pounds to the front tires. Motorcycle can use just the front brake and lift the rear tires off the ground, but not my vette!
So with 1400# and two 700# springs my front end will only dive or compress about one inch. The 500 ci GT1 historic vettes had to be 300 pounds heavier and with the big block up front were using 800 and 850 pound springs
On a 4 corner scale I have less than 1340 pounds on the front tires and in racing trim I was right on the 3000 lbs for my engine ci. So with 700# springs and let's hypothetically under straight line braking with slicks create over "1 G" of braking and transfer 1400 hundred pounds to the front tires. Motorcycle can use just the front brake and lift the rear tires off the ground, but not my vette!
So with 1400# and two 700# springs my front end will only dive or compress about one inch. The 500 ci GT1 historic vettes had to be 300 pounds heavier and with the big block up front were using 800 and 850 pound springs 
Thread Starter
Burning Brakes
Joined: Apr 2008
Posts: 825
Likes: 40
From: Glasgow, Scotland
The QA-1 spring choices are bad. Speed direct sold the collar adapter for their smaller diameter springs. The springs used to be $50 a pair. So I bought 600, 650, 700, and 750. I have a very light front end so I found the 650 or 700# to be the best.
On a 4 corner scale I have less than 1340 pounds on the front tires and in racing trim I was right on the 3000 lbs for my engine ci. So with 700# springs and let's hypothetically under straight line braking with slicks create over "1 G" of braking and transfer 1400 hundred pounds to the front tires. Motorcycle can use just the front brake and lift the rear tires off the ground, but not my vette! So with 1400# and two 700# springs my front end will only dive or compress about one inch. The 500 ci GT1 historic vettes had to be 300 pounds heavier and with the big block up front were using 800 and 850 pound springs
On a 4 corner scale I have less than 1340 pounds on the front tires and in racing trim I was right on the 3000 lbs for my engine ci. So with 700# springs and let's hypothetically under straight line braking with slicks create over "1 G" of braking and transfer 1400 hundred pounds to the front tires. Motorcycle can use just the front brake and lift the rear tires off the ground, but not my vette!
So with 1400# and two 700# springs my front end will only dive or compress about one inch. The 500 ci GT1 historic vettes had to be 300 pounds heavier and with the big block up front were using 800 and 850 pound springswill let you know, cheers
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I was able to change springs at the track between sessions. I also have a 1.125 front sway all hard poly mounts. Lessor sway can use more spring. After a few years of serious race tracking I developed a crack in the passenger side frame where the lower A-arm attaches. The local track runs counter clock wise so it really loads the outside front tire.
I welded gusseted, welded, and fish plated that area on both sides.
I welded gusseted, welded, and fish plated that area on both sides.
Thread Starter
Burning Brakes
Joined: Apr 2008
Posts: 825
Likes: 40
From: Glasgow, Scotland
I was able to change springs at the track between sessions. I also have a 1.125 front sway all hard poly mounts. Lessor sway can use more spring. After a few years of serious race tracking I developed a crack in the passenger side frame where the lower A-arm attaches. The local track runs counter clock wise so it really loads the outside front tire.
I welded gusseted, welded, and fish plated that area on both sides.
I welded gusseted, welded, and fish plated that area on both sides.
