How low is too low?

[flat6_musik]

I cut one coil on my Corsa, but I could swear it did nothing! Then I cut another coil.....PERFECT! For me, that is. Since there's no weight up front, I don't feel there's a lot of crazy bouncing inertia (like 600 lbs. of engine) that's going to go on a bounce-a-thon and bang up and down off the bump stops. Seriously, I haven't found the ride to be ridiculous or unstreetable whatsoever!

I say chop 2!!

[Motornoggin]

Yeah. Cutting two coils. One thing though is I'm not finding any bump stops that dampen on the compression end of things. Only one I can find is on the underside of the upper control arm. This dampens the unloaded end of things. Just making sure I'm not missing anything.

[azdave]

Yeah. Cutting two coils. One thing though is I'm not finding any bump stops that dampen on the compression end of things. Only one I can find is on the underside of the upper control arm. This dampens the unloaded end of things. Just making sure I'm not missing anything.

Bump stop on the down motion is handled by a rubber stopper that slides over the top of the shock shaft. Many people take them out or cut them in half when they ride really low to try to get some suspension travel back.

[Motornoggin]

Ok, that's what I was thinking, no bump stops present any longer. The shocks look like factory GM shocks, maybe they have been out sometime in the past.

Thanks for the info!

I promised pics when it's done. If the weather improves, I'll try to get some this afternoon.

[rjonec]

I do not want infringe on the forum policies. However, I am a suspension guy by trade so if anyone wants help with springs I have a wealth of knowledge on the subject. I have been in the high performance suspension industry for 23+ years. I know pretty much zero about Corvair suspensions though. I just recently acquired my first vair so I will be doing my own research, but why reinvent the wheel. If you guys know of spring rates that are a good starting point let me know. If you can provide front and rear motion ratios and if you have data for the stock springs that would be helpful. With most of us running on modern radials the spring rate can be adjusted to take advantage of modern tire technology. I also have great contacts with several shock and sway bar manufacturers so if there is an interest on that front let me know.

My 2 cents on stock suspensions being too low is a problem especially when it comes to reducing the usable suspension travel. Also the suspension geometry can be negatively affected when set too low. A good rule of thumb is to make sure the lower ball joint centerline should not be higher than the centerline of the lower inner pickup point. This will usually keep from having the roll center go below the ground level. Most double arm suspensions in a road going vehicle will experience adverse affects if the roll center is below ground level. The typical result is excessive understeer. Most people then try and take was the traction at the rear to compensate for the poor traction at the front. The same rulesapply for the rear suspensions as well. Make sure that your axle shafts are parallel with the ground. If the outer u-joint is higher than the inner you will experience adverse effects regarding to u-joint wear and unwanted friction. Most suspensions of this variety also suffer from adverse toe steer characteristics when working outside a narrow range. Although I am sure GM did their home work on the kinematic behavior of the 65 and later rear suspension having to overcome the deficiencies of the swing axle rear of the first generation Corvair and all the other associate political BS they had to deal with during that era.

If you guys want to pm me on this topic that is fine or post on this thread. Or direct me to previous threads.

Just here to learn and provide input if I can.

Richard Jonec

[4carbcorvair]

Coil spring specialties has all of the stock specifications. I'm not sure if anyone else does?

[rjonec]

Our Company has a good relationship with them I'll inquire with them and see what data they have available.

I'll be dropping the suspension this weekend. Do the rebuild process and gathering data at that time.

Richard

[cad-kid]

Sounds like an interesting project Richard. Keep us posted.

[rjonec]

I wanted to give you guys an update on my project. It has been going a little slower than anticipated. However, the spring package I came up with has been ready for a couple of months. I have not had the chance to get it installed as I have decided to completely rebuild the suspension and drive line after conducted the initial tear down.

My initial research on the stock suspension is the front springs are 250 lb./in and the rear are 200 lb./in. These are stock 1966 Turbo springs. The spring tags are 3875088HJ front and 3875090HL Rear.

The motion ratio near static ride height is about 1.6:1 front and 1.25:1 in the rear . After reviewing ride frequency and calculating the wheel rates I arrived at a revised spring selection of 325 lb./in front and 315 lb./in rear. The targeted drop is about 1" lower than stock ride height. I am looking at achieving a slight rake about 1/4" higher in the rear than the front. I have chosen to increase the rear rate more than the front rate as I plan to run a staggered tire set up and looking for more neutral handling characteristics as I plan to do some autocross events with the car.

I am also planning on increasing the front sway bar diameter to increase the roll rate hence the disproportionate rear rate increase relative to the front. I have not selected a front diameter yet, but most likely it will be less than 1” in diameter. I expect to have the suspension in the next few weeks and will provide an update and some pics at that time.

I will publish more details in the coming weeks. If you have any questions let me know.

Richard

[freedo]

saw this on instagram today,

[Scott H]

THAT"S LOW!!! looks so cool

[bbodie52]

Yeah, but the camber looks real bad even in the picture! I'll bet the handling isn't too good, the tire wear is terrible, and watch out for those speed bumps!

[freedo]

Yeah, but the camber looks real bad even in the picture! I'll bet the handling isn't too good, the tire wear is terrible, and watch out for those speed bumps!

Cars probably rarely driven and only on smooth roads

[Am-Iron]

I cut two coils out of the front of mine and will adjust once I have my tires and I am sure the front is settled in. I plan on 245 50 16 in the rear and 225 50 15 in the front. I also have to get some center caps and lug nuts when I get the wheels refinished.

[UNSAFE]

Too high --
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original.jpg (64.4 KiB) Viewed 1187 times

Too low ---
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Just right
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[Am-Iron]

Kevin what did you do to yours for the just right stance? You probably have HD springs correct?