69ishHoliday

I'm interested in improving my car's suspension and/by lowering it slightly.
Could someone provide any info as to why changing springs is different than cutting down the OEM springs? It seems to me that the ends of each coil are somewhat flat and if you simply cut down the spring you eliminate that aspect of the spring. This may be the difference between lowering and lowering right. Thanks for any info. - Steven

joe_padavano

Well, for starters you can't cut the rear springs. Coils at both ends are reduced diameter to fit in the spring pockets. Replacement is your only option. On the front, I have successfully cut the springs. The upper end of the front springs are a full coil and are not flattened (the bottom coils are flattened). You can cut the upper end of the springs with no problems. I've cut between 1/2 and one full coil, lowering the front of a Cutlass about 1.5". Note that cutting coils will slightly increase the spring rate of the remaining spring. Whether that gives you the ride and handling you want is up to you. The advantage of replacement springs is that you can select exactly the height and spring rate you want.

69ishHoliday

Thank you Joe, Great information!

oldcutlass

This catalog helped me a lot when choosing my springs, it can be sorted by column:


http://www.moog-suspension-parts.com...il_Springs.asp

69ishHoliday

This is a great resource Eric, Can you direct me to where I would find what was original for a 1969 Cutlass Holiday Coupe 350 engine?

oldcutlass

Rock auto lists these, you can use the dimensions and rates to choose your car stance on the moog chart based off the moog springs listed below.


http://www.rockauto.com/catalog/x,ca...,parttype,7512

Run to Rund

The spring tops are flattened to match the 68-72 frame. The bottoms are tangential but the end coil has much less "stretch" so the end of it is very close to the next coil. As you shorten the end, you get into the longer "stretch" and the spring will bow, sometimes enough to rub the shock absorber. I heat the spring about 1/2 coil from the end after cutting and reduce the stretch, if I cut a lot off the end. So, cutting and re-forming both affect the overall length and hence ride height.

RetroRanger

What do you guys cut the spring with? Torch, cut off wheel, saws all? Other?

joe_padavano

Thanks, Joe. I had it backwards. It's been more than a few years since I did one.

I've cut springs both with a cutoff wheel and with a torch. To prevent annealing the springs (and thus removing the heat treat) when using the torch, I immerse the spring in a bucket of water with the water level just below the coil being cut.

69ishHoliday

Buying a replacement spring isn't so expensive if it's a Moog brand.
Does anyone know which numbers would take 1.5 or 2 inches off of the ride height.
The Rock Auto and Summit models aren't the same and I haven't determined for certain what ride height I'm starting with. - Steven

69ishHoliday

Are drop spindles a better choice for dropping the front two inches?

Run to Rund

As you suggested, I use a grinder with cut off wheel, lightly chamfer the end, make sure not to nick the next coil. Way less messy than dealing with a tub of water

oldcutlass

The chassis manual gives you the location to measure and the measurements for stock height. You can use the Moog part #'s for the stock spring from the Rockauto list and cross them for suitable springs from the Moog catalog. Sort by end type, ID, length and load.