Rear Spring selection

[cudazappa]

ok, my head is spinning, after looking at rear spings for my challenger.

The goal is an AutoX/Track car.  I have 1" t-bars up front, running a factory sway bar up front, none rear.  To say I'm on a budget, is no lie.  Right now I'm tying up the remainder of my money for the season up in camshaft, header$$$ and exhaust and I'm broke.  But I have rear leaf springs left on my MUST DO list.

anyways... there's a LOT of choices out there, and I'm looking for the most bang per buck option out there... I really wish I had 2g saved up for the XV level 1 setup... maybe that'll be my summer project (to save up!!)

Thanks in advance.

[dodj]

For autoX your looking to lower the rear some?

[Bullitt-]

What's wrong with your old springs?...Money for a rear sway bar may return more for the investment. 

[72bluNblu]

I'm getting ready to swap in a b body rear with a spring relocation and SS springs. When I do I'll have a set of XHDs I need to get rid of, they're only about a year old. They have a pretty good spring rate and the ride height is pretty stock ( see picture below). Make me an offer and they're yours! How soon do you need them?

[HP2]

Without knowing the weight and front/rear distribution, I'd say you need a 75-100# leaf spring. The 1" t-bars are a decent step up, but the tiny oem front sway bar really skews the percentage. That amount of rate may be simply adding a leaf to your current pack. If you step up the front sway bar to 1.125, then your rear spring rate would go up to 120-140, which is kit car to XHD range.

[cudazappa]

thanks for the info all.

HP2 - ok, you got me to bite on a bigger sway bar on ebay... 1.125" dia...

72bluNblu - sending you a PM

Bullit - I've always ascribed to buying the springs first, then the sway bar.  my rear's are pretty sagged out and I'd rather get new(er) springs.  I guess I'll start looking for deals on rear bars, too.

[cudazappa]

Ok, I'm thinking now... 

Would a 7/8" addco rear bar be a good idea now?  or will that be a waste of money or give me some oversteer?

Looks like now its 1" front t-bars, 1.125" addco front sway bar, and 72bluNblu's old xhd springs

goal: not be completely embarrased by the local 65 mustang (I'll be classed in CP with him, his isn't an all out CP car either)

[HP2]

Ok, I'm thinking now... 

Would a 7/8" addco rear bar be a good idea now?  or will that be a waste of money or give me some oversteer?

Looks like now its 1" front t-bars, 1.125" addco front sway bar, and 72bluNblu's old xhd springs

goal: not be completely embarrased by the local 65 mustang (I'll be classed in CP with him, his isn't an all out CP car either)

Great overall combo rate wise.

FWIW,  my Challenger has 120# oval track springs, .96 t-bars and 1.125 front sway bar and will have the same roll couple yours. If I add the 7/8 rear bar, I have to step up to 1.22 t-bars to maintain the balance.

Another way to alter that, is take a lot of weight off the nose, which changes the roll couple distribution and requires more rear roll rate and less front rate.

[efidart]

I'm doing a similar setup right now - 1" torsion bars, 1 1/4 front addco sway bar, stock 3/4 rear bar, Cap front strut rods, just suspension tubular uppers and weld some small braces on the LCA's.
My rear springs appear to be a stock type spring, still have some good arc so i'm wondering if I should change them?

I'm wondering if bracing your LCA's is worth it that much? and if the car will handle that bad without going to 1.22 type bars as you say HP2?

[HP2]

The jump between the stock front sway bar and a 1.25 bar is huge. Even the move from 1.125 to 1.25 is a pretty sizeable gain which will require the rear bar to balance things out. Without it, you may have rear spring rates upwards of 180-200#, which will change ride quality. So, if your springs are decent, add the rear bar and see how it all feels. You can always add rate later if necessary.

Bracing the control arms is a good idea when you get sway bar sizes over 1" in diameter. The control arm is two pieces of stamped steel riveted together. That means they can flex when those bigger sway bar rates start pulling on them. Bracing the control arms creates a boxed structure that is much less likely to twist under load.