BBC big block coilover spring rate
Thread Starter
Racer
Joined: Sep 2016
Posts: 307
Likes: 66
From: Louisville, KY
BBC big block coilover spring rate
I'm leaning towards QA1 coilovers on the front and curious on spring rate feedback from those who have installed and logged some miles. I'm talking with QA1 as well but want to hear your thoughts.
Iron head big block (may switch to aluminum in the future...)
Aluminum radiator
No A/C
I'm fine with a bit harsher ride but are 650# spring too much for the street? 98% street driven cruiser which I would like to get on a track at some point; purely recreational.
Iron head big block (may switch to aluminum in the future...)
Aluminum radiator
No A/C
I'm fine with a bit harsher ride but are 650# spring too much for the street? 98% street driven cruiser which I would like to get on a track at some point; purely recreational.
Race Director
Joined: Jan 2000
Posts: 13,015
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From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
C2 of Year Winner (performance mods) 2019
2017 C2 of Year Finalist
The regular 550 lb springs lots of folks use worked very well for me when I had iron heads on big block. They lower the front a little also. I have a buddy with some 750's on his and it handles very well. I've got Viking coil overs on the front of mine now...but they are only a 350# rate. I'm more of a drag race/street cruiser guy...not a corner burner....so they are probably light for cornering...but they don't bottom out or anything bad.
JIM
JIM
Team Owner
Joined: Apr 1999
Posts: 21,953
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I have a light front end SBC with qa-1 dual adjustable. I drove around for 20 years with 550 front springs. I have modern low profile tires and better brakes. I felt like I had too much front end dive under braking. So after talking to those worthless QA-1 tech support guys that go by some weight formula and tried to tell me that some dual rate 350/450 is what I needed, when I already explained that 550 wasn't enough. So anyway Speed direct used to sell collars and springs in 50# increments. So I just bought 600, 650, and 700# to try. I find the 600 or 650 great for street driving and 700 for weekends. You could also try the shot gun effect.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I was going to add that changing out semi coil over springs is a simple job. Maybe 5 minutes a side. I bought nice spanner wrenches the 180 degree and 90. So without weight the up and down adjustment is also fast.
Thread Starter
Racer
Joined: Sep 2016
Posts: 307
Likes: 66
From: Louisville, KY
Thanks for the input! I'm thinking 550 may be too light for my tastes. That's the hard thing, ride quality is entirely subjective!
The regular 550 lb springs lots of folks use worked very well for me when I had iron heads on big block. They lower the front a little also. I have a buddy with some 750's on his and it handles very well. I've got Viking coil overs on the front of mine now...but they are only a 350# rate. I'm more of a drag race/street cruiser guy...not a corner burner....so they are probably light for cornering...but they don't bottom out or anything bad.
JIM
JIM
Thread Starter
Racer
Joined: Sep 2016
Posts: 307
Likes: 66
From: Louisville, KY
The QA1 tech I spoke to today also seemed to err on the side of soft when talking about spring rates. I assume because most people want a firm ride on the bench but can't handle it on the actual street. So I didn't get the warm and fuzzy 550lbs was the way to go for me.
However, I'm now struggling with the 2" max drop on these semi-coilovers; I don't think it will be enough. Especially if I go to the 650lb spring...
However, I'm now struggling with the 2" max drop on these semi-coilovers; I don't think it will be enough. Especially if I go to the 650lb spring...
I have a light front end SBC with qa-1 dual adjustable. I drove around for 20 years with 550 front springs. I have modern low profile tires and better brakes. I felt like I had too much front end dive under braking. So after talking to those worthless QA-1 tech support guys that go by some weight formula and tried to tell me that some dual rate 350/450 is what I needed, when I already explained that 550 wasn't enough. So anyway Speed direct used to sell collars and springs in 50# increments. So I just bought 600, 650, and 700# to try. I find the 600 or 650 great for street driving and 700 for weekends. You could also try the shot gun effect.
Race Director
Joined: Jan 2000
Posts: 13,015
Likes: 2,260
From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
C2 of Year Winner (performance mods) 2019
2017 C2 of Year Finalist
This is all a balancing act. There's multiple ways to get around corners. Relatively softer springs and larger swaybars can work also....
JIM
JIM
Safety Car
Joined: Nov 2005
Posts: 3,961
Likes: 573
From: Lompoc, CA. Santa Barbara County
I have a light front end SBC with qa-1 dual adjustable. I drove around for 20 years with 550 front springs. I have modern low profile tires and better brakes. I felt like I had too much front end dive under braking. So after talking to those worthless QA-1 tech support guys that go by some weight formula and tried to tell me that some dual rate 350/450 is what I needed, when I already explained that 550 wasn't enough. So anyway Speed direct used to sell collars and springs in 50# increments. So I just bought 600, 650, and 700# to try. I find the 600 or 650 great for street driving and 700 for weekends. You could also try the shot gun effect.
I'm about to go to front coil overs, and this thread came up in search. Like you, I care less for ride quality, and more for handling. As you know, I'm running a 427 aluminum LS up front, and my car is down to 3000 lbs. I also want to keep the car low. So do you think this QA1 kit from summit will make me happy?
QA1 GS507-09650D QA1 Pro Coilover Systems | Summit Racing
PS, I got a C8 about two years ago. You have got to drive this thing. I mean really drive it, like you and I would drive it. Dang thing, Z51 with magnetic shocks comes with a Track setting. You have to manually put it there every time you start, but it is well worth it.
PSS Are you going to be at Lagun Seca August 19th?
Bee Jay
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