Spring Rates Needed

I'm trying to find out the stock rear spring rate for a 90 Mustang GT.

I'm slowly but surely getting my suspension together on the car and started out using Kenny Brown parts. I'm at a point now where the KB parts will no longer work due to fit problems with the exhaust system. The KB pan hard bar will only work with a select type of catback systems and once you buy it you will be stuck with that from now on. Their front K member kit will not work at all with long tube headers which is what I have.

I've decided to go with Max. Motorsports pan hard bar and UPR's front coil over and K member kit. I will be going with KB's basic formula on the starting setup. This is basically stock sway bars, stock rear springs and

650 lb front springs when using a pan hard bar and coil over/K member kit.

So far suspension/chassis changes are Tokico 5 way adj. shocks and struts, M&M camber/caster plates, KB upper & lower adj control arms, as well as KB strut tower brace and extreme sub frame connectors. I also have UPR's torque box braces installed. Any input from the suspension guru's out there would be greatly appreciated.

Reply to
Joe Cilinceon
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Sorry, dude, I don't know this one.

However...

[snip]

Goodness! 650 lb/in on a coil-over?! That's like a 585 lb/in wheel rate, or the equivalent of a 2340 lb/in spring in the stock location. That's *stiff*, dude :).

[more snip]
Reply to
Dan Talso

I know that is why I asked. The tech at KB said that is what they recommended for a spring rate using a coil over K member kit and their pan hard bar. Thanks for the input Dan.

Reply to
Joe Cilinceon

Not sure why you need the OE spring rates if you're not using OE springs but here's what you asked for...

Front coil springs: '79 V8 - 395 '79 TRX V8 - 425 '80-'81 non-TRX V8 - 370 '80-'81 TRX V8 - 390 '82 non-TRX V8 & Handling suspension - 395 '82 TRX V8 - 410 '83-early '84 non-TRX V8 & Handling suspension & TRX V8 - 410 early '84-'86 Handling suspension & V8 - 425-525 '87-'93 V8 (exc. Cobra "R") - 425-530 '93 Cobra "R" - 750-850

Rear coil springs: '79-early '84 non-TRX V8 & Handling suspension & '93 Cobra - 160 '79-early '84 TRX V8 - 175 early '84-'93 Handling suspension & V8 (exc. Cobra and Cobra "R") -

200-300 '93 Cobra "R" - 240-260 *"Handling suspension" was a package that was standard with '82-'84 V8 (exc. when TRX package was optioned) and optional with all other '82-'84 models (exc. when TRX package was optioned).
Reply to
Mick

Now *that's* more like it :). I've heard the 350 lb/in make a nice stiff street/track setup. That's a wheel rate equivalent to a 1260 lb/in spring in the stock location. Nice anti-dive, low body roll, a lot less harsh than that big spring on the stock perches.

I might have to get the 350's next year. I'm going to try out 250's first :).

Reply to
Dan Talso

I wanted to go completely Kenny Brown with the suspension but won't be using their front k member due to header clearance problems. I've looked at both D&D and UPR front k members. The UPR in my opinion is the best for the buck $645 in chrome moly. UPR is also a short drive from where I live, so no shipping charges.

I was thinking of changing the back springs from a progressive to a fixed type spring. This is another reason I asked about the rear spring rates. I've looked at several GT/S mustangs based on Fox bodies and all seem to have spring weight setups.

Thanks Dan for your input it has been helpful.

Reply to
Joe Cilinceon

The last line that says, "all seem to have spring weight setups" should read all seem to have different spring setups". Having a senior moment again. |;-)

Reply to
Joe Cilinceon

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