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Rear Leaf Springs

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Old Jun 9, 2009 | 01:14 AM
  #1  
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Default Rear Leaf Springs

after months of letting the car sit in the garage, im starting to waste money on it again.

this time my goal is to get it back on the road with minimal **** to install on it.

like suspension, brakes, body panels, wiring, and a windshield and back window.

my front suspension is "good enough". with a shelby drop and cut springs. and the wilwood dynalite pro series kit. ive got to install the brakes this week and borrow the tool to check what backspacing i need.

also this week, im hoping to pull out the rear end and start to build it.

now when i put the rear back together, im wondering what leaf springs and shocks to get. i rolled the fenders, so i want the fenders to sit flush with the tires at highest. maybe a little lower. the front will eventually get coil overs and tuck the tires quite a bit. i dont give 2 ****s about ride quality. i guess i need some really good shocks to keep it from bottoming out if its lowered, right? will have 17x8's in the back. with a 265 tire. backspacing will be determined later.

should i get the standard eye or the mid-eye or reverse eye? i guess if you think about it, the standard is for stock/rake look, the mid is, well, in the middle, and the reverse is for super low, right?

im used to the air shocks so i could lower and raise the care like 1.5" whenever i wanted. i want to go with a much better shock though. so if you have non-air shocks, how would you lower or raise the car? lowering blocks? shackles?

so which spring should i go with, and whats a good, stiff shock?
Old Jun 9, 2009 | 01:32 AM
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Use reverse-eye springs. I'd recommend 4.5 leaf. Anything more is going to be very stiff for a street car. A too-stiff rear suspension can cause the rear to skip over rough roads while cornering, which is unsettling and unsafe.

Shocks don't prevent bottoming out, that's the function of the springs. Shocks are actually dampers (what they euros call them), not shock absorbers. Springs are shock absorbers. "Shock absorbers" dampen spring oscillation to keep you from bouncing up and down continuously. They have a couple other side effects depending on valving and design, but that's what they're meant for. If you want to have the rear really low and don't want to bottom out, you're SOL. You can run stiff springs, but then you'll sacrifice ride quality (which you say you don't care about, but you very well might when it gets down to it) and handling/safety on the street.

Air shocks are a no-no. The upper shock mount is unreinforced sheet metal and isn't designed to take any portion of the vehicle's weight. Running air shocks with enough pressure to affect ride height is a good way to punch your shocks through your trunk.

I usually recommend Edelbrock shocks. I've run KYB Gas-A-Justs, and while they handle well on smooth roads, they're very stiff. Ride quality is sub-par and they can cause the tires to skitter over rough pavement. The Edelbrocks I'm running now give me a better ride quality (despite going to stiffer springs) and keep the tires planted on the pavement better. They're pricey, but I think they're worth it.

Another option is Konis, but I've heard complaints from almost everyone who's run them about how stiff they are. The old saying goes, you can run over a dime with a car running Koni shocks and tell if it's heads or tails. There are a couple people here running them, but I wouldn't run them unless you only drive on really smooth roads.
Old Jun 9, 2009 | 01:47 AM
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If you want something that won't bottom and will handle well, then 5 leafs with KYB Gas A Justs. It'll be stiff and have a tendency to skitter on rough roads(like a race car suspension basically) but should get you where you want.
Old Jun 9, 2009 | 04:48 PM
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I have mid-eye 5 Leaf's on the back, and cut springs on the front, and I like the stance alot. I also have the KYB Gas A Just's on all 4 corners. The ride is just right for what I prefer (much stiffer than a stock type suspension).
Old Jun 9, 2009 | 07:05 PM
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If you plan on "17x8's in the back. with a 265 tire" be aware that it will NOT tuck in under the rear quarters. I just test fit a 16x8 Shelby 10-spoke wheel with 245/50-16 tires and its just even with the quarter. 265s would really stick out past the quarter.


Old Jun 9, 2009 | 07:30 PM
  #6  
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Originally Posted by Starfury
Shocks don't prevent bottoming out, that's the function of the springs. Shocks are actually dampers (what they euros call them), not shock absorbers. Springs are shock absorbers. "Shock absorbers" dampen spring oscillation to keep you from bouncing up and down continuously. They have a couple other side effects depending on valving and design, but that's what they're meant for. If you want to have the rear really low and don't want to bottom out, you're SOL. You can run stiff springs, but then you'll sacrifice ride quality (which you say you don't care about, but you very well might when it gets down to it) and handling/safety on the street.
Well said.

Originally Posted by Starfury
I usually recommend Edelbrock shocks. I've run KYB Gas-A-Justs, and while they handle well on smooth roads, they're very stiff. Ride quality is sub-par and they can cause the tires to skitter over rough pavement. The Edelbrocks I'm running now give me a better ride quality (despite going to stiffer springs) and keep the tires planted on the pavement better. They're pricey, but I think they're worth it.

Another option is Konis, but I've heard complaints from almost everyone who's run them about how stiff they are. The old saying goes, you can run over a dime with a car running Koni shocks and tell if it's heads or tails. There are a couple people here running them, but I wouldn't run them unless you only drive on really smooth roads.
I had Konis for years when I was in FL. Moved to PA, in a few months I was done. Pulled them off, cleaned them up, sold them at Carlisle for enough to buy a set of Gas-A-Just Kayabas. For smoother ride use their GR-2.

Originally Posted by Starfury
Use reverse-eye springs. I'd recommend 4.5 leaf. Anything more is going to be very stiff for a street car. A too-stiff rear suspension can cause the rear to skip over rough roads while cornering, which is unsettling and unsafe.

Air shocks are a no-no. The upper shock mount is unreinforced sheet metal and isn't designed to take any portion of the vehicle's weight. Running air shocks with enough pressure to affect ride height is a good way to punch your shocks through your trunk.
This 68 Shelby GT350 had the classic crossmember air shock damage and crappy repairs. It got a new shock crossmember.

Old Jun 9, 2009 | 07:39 PM
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Adrenolin, I freakin love your car. I cant wait to see it all done...
Old Jun 9, 2009 | 08:04 PM
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Originally Posted by Adrenolin
If you plan on "17x8's in the back. with a 265 tire" be aware that it will NOT tuck in under the rear quarters. I just test fit a 16x8 Shelby 10-spoke wheel with 245/50-16 tires and its just even with the quarter. 265s would really stick out past the quarter.


a 265 will fit. with the right backspacing. fenders are rolled. its got 245s right now with way more than an inch clearance to the inner fender. your 16" tire has a bigger bulge on the tire cause its not as low of a profile as a 17" tire.
Old Jun 9, 2009 | 09:50 PM
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Originally Posted by ky
a 265 will fit. with the right backspacing. fenders are rolled. its got 245s right now with way more than an inch clearance to the inner fender. your 16" tire has a bigger bulge on the tire cause its not as low of a profile as a 17" tire.
True.. but I'd still say it'll be close. The wheel wheel edge on ours is right at the inside edge of the lip with 4.5 BS. The sidewall bulge is 1" on each side.


Originally Posted by flickjo68
Adrenolin, I freakin love your car. I cant wait to see it all done...
Thanks.. I can't wait either.
Old Jun 9, 2009 | 10:56 PM
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you can easily fit a 5.25" BS wheel in the rear. thats what it was when i had 05' bullits. the BS on those wheels are actually 6.24" but i had a 1" spacer.

im almost positive a 4.75" BS will be perfect for a 265. but, like i said, ill be getting the tool to check what exact BS i need to get.

as far as the front, i think ill have to get a 17x7 wheel with a 225ish tire since i want to tuck it so much.



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