A body spring rate with Iron Ls 5.3???

[Capown]

Im looking at buying the New QA1 Pro Adjustable Front Coil-Over Conversion Kit

They give me these options
Spring Rate Front End Weight

350 1700-1900 lb.
450 1900-2100 lb.
550 2100-2300 lb.

Ill be picking up a 5.3 w/4L60E for now later 6.0 and 4L80e probably way later, just need to know what spring rate I should go with car will be a driver no road course maybe drag strip once in awhile...

[CFster]

Doesn't matter you'll have a harsh ride and lack of supension travel with coil overs on the street anyway.

[oldgoat69]

I have found just the opposite. I have created my own rear coilover brackets and used the QA1 fronts. Car rides and drives better than I expected. I have used Hotchkis springs on on several other A-bodies with success, but the coilovers are much better. Suspension travel is a byproduct of ride height, my car is set up for minefield type New England roads so that might contribute to my success.

[UMI Tech]

We also have good success w QA1 coilovers. 450+ is a good plan. Like mentioned, low requires higher rates to keep from bottoming. The QA1 front is in stock location so wheel rate is the same as stock. 450 for 1" lowered street, 550 for 2" lowered or auto-x/road race.

Ramey

[silver69camaro]

Doesn't matter you'll have a harsh ride and lack of supension travel with coil overs on the street anyway.

That's very helpful. Is your statement coilover-conversion specific, or just in general?

[CFster]

Conversion specific. There isn't enough room to have a long enough spring to offset the stiffer spring rate that's necessary when going to a much smaller diameter coil. Meaning, you have a longer coil, then you can reduce the rate to achieve the same ride height and reduce stiffness.

[looter]

We also have good success w QA1 coilovers. 450+ is a good plan. Like mentioned, low requires higher rates to keep from bottoming. The QA1 front is in stock location so wheel rate is the same as stock. 450 for 1" lowered street, 550 for 2" lowered or auto-x/road race.

Ramey
Hi Ramey
do you offer a 550 spring rate on your a-body front coilovers?
what rate would you suggest for the rear if you're using 550 for the front?

[silver69camaro]

Conversion specific. There isn't enough room to have a long enough spring to offset the stiffer spring rate that's necessary when going to a much smaller diameter coil. Meaning, you have a longer coil, then you can reduce the rate to achieve the same ride height and reduce stiffness.

I may be misunderstanding your post, but the stiffer spring rate is necessary due to the reduced travel needed with a lowered ride height, along with a gaining a higher suspension frequency for more grip. The spring rate is not caused by the coil diameter. You are trying to acheive specific wheel rate, and that can be done no matter how tall or wide the spring is.

When calculating target spring rates, stored energy or spring length is not a factor.

[Simmo]

Get some SPC lowers (and uppers) and suitable shock for your requirements...the more you look at them, the more you realise how clever they are.

They run a lower spring pocket giving you a extra inch of shock, modular pocket for ride height tweaking and help centre the wheel in the wheel well with higher positive caster settings.

With all the true-coilovers I've come across they're to "busy" at the bottom of the shock with adjusters and perches to dont leave enough shock travel up top to have things in the sweet spot. (ie long shock body, not much rod)

[Capown]

Not sure what SPC is I googled it and it came back with gun stuff... I would like to order my fronts today so I can drive my car when my brother comes into town..

[69cutlassrkt]

Not sure what SPC is I googled it and it came back with gun stuff... I would like to order my fronts today so I can drive my car when my brother comes into town..

http://scandc.com/new/node/79
Savitske classic and custom sells spc.

[Simmo]

http://scandc.com/new/node/79
Savitske classic and custom sells spc.

Yip

Sorry my post wasnt terribly clear, SPC makes control arms (among other things) which enable ride height adjustment, you then replace the factory shock with whatever bolt-in option your wallet allows.

IMO this set-up (which I've chosen to run), hybrid or true coil-overs all have compromises of varying degrees so take some time to figure out what you'd be happy with and do it once.

[andrewb70]

I have the QA1 550lb kit and I wish I could go higher on the spring rate. I tried the 450 kit as well and it is too soft. As for the coilover conversion resulting in a harsh ride, that is BS.

If I was to do it again, I would use a conventional spring and shock, but not because of the harsh ride, but because I want to be able to run a 650 lb spring and there isn't one available in a cone style design, that I have seen.

Andrew

[Capown]

I just ordered stock height springs and bilstiens from CPP..