KE30 Air Suspension

[75RollaDeluxe]

I recently bought a 1975 KE30 Corolla-the previous owner installed a large spacing block for the rear leaf springs. The front has unidentified lowering springs as well. Has anyone explored an air suspension lift  (helper) universal kit for the rear leaf springs? And/or air suspension in the front? 
The car rides very rough and is almost slammed, I enjoy it being low but the cost of a rough ride is not fun. 

[altezzaclub]

Air suspension, no, but the first thing I would look at would be the distance from the spring to the bump stop. You should have at least 50mm there, and if not either raise the car or cut the bump stop shorter.  Naturally that might result in the shock absorber bottoming out and destroying itself, but they are crap anyway and its just the cost of a very lowered car!

Other options would be stiffer springs so the car doesn't compress so easily, and/or decent adjustable shocks so you can control how far it moves and make sure the shocks can handle the stiffer springs. A 'smooth ride' for family cars involves shocks that allow compression easily and extension with more difficulty. This sucks the car down over a couple of bumps close together, so gravel rally cars are quite the opposite. I expect your 'rough ride' is from the bumps stops being worked, and they are much stiffer than a modern car would use. You could wander around a wreckers for an hour and find softer bump stops, we used a set out of the front of a Ford Falcon for the rear of a KE70 rally car.

So, lots to learn about and sadly most people understand very little of it.

Got a picture of the car showing how low it is?

[75RollaDeluxe]

Thanks for the information-I’m a rookie when it comes to suspension but trying to learn what I can. How did you handle the rear leaf suspension (if the KE70 had leafs)?

Heres a photo of how low my KE30 sits.

[Banjo]

Thanks for the photo !   That is one very pretty Rolla.  That front angle, provides a very aggressive appearance, which I like.   Have You had the car for a while, or did You acquire it recently ?  Would love to see a couple of pictures, under the hood. It is certainly worth spending the money, & getting the suspension, & ride sorted.

I'm assuming it is a "show car"; & won't be used in competition; so You have to find that happy place, between a lowered car, & a comfortable one to drive.

Take Altezzaclub's advice, & in addition; do as much reading & research as You can. Some sort of "air bag" suspension, would probably be best, where you can dial up the suspension, at will; & find the right balance between height & comfort.  Keep the photos coming.

Cheers Banjo

[altezzaclub]

Looks good! KE70s are coil & 5-link, but the same factors apply.

Measure how long a shock is at ride height, just like it is, so jack it up and put stands under the axle & measure top to bottom of a shock. Pop one shock off at the bottom, push it up by hand until its fully compressed and measure how long it is. You want the gap between the axle and the bump stop to be slightly less or at the most, the same, as that shock compression distance, so the bump stop does the work when the car bottoms out. Otherwise the foot valve at the bottom of the shaft inside the shock smacks the bottom of the tube and breaks itself. While you're there, measure the full extension length of the shock for future reference.

I did it on a KE30 for a guy and it made a tremendous difference to the ride, we just hit the bump stop with a hacksaw and some WD40 until he could find something at the wreckers.

Same in the front if the front bangs over bumps, measure how much strut shaft is sticking out of the top of the strut and that's how much movement you have. Struts usually have a softer bump stop than the rear, and its on that shaft under the dust cover. If you're keen, you take a strut off, use spring compressors to hold the coil spring while you take the top plate off. Look at the dust line on the shock shaft to see how much it compresses,  push the shaft up and down to see how stiff the shocks still are, measure how much shaft you have at full compression and full droop. (extension). Ideally you run the shock with more compression room to soak up bumps than droop distance. Lowering the car reduces this distance before the shock bottoms out. Check the bump stop for how broken it is, replace it with a softer one if you can find one, or chop it down to half its length.

You could put an O-ring on the shaft and reassemble it. The O-ring will remain at the most compressed distance after you've driven around for a while. If it ends up at the top of the shaft then your shocks are too soft or your springs are too soft.

Look under the car from the front when its parked like the photo. If the lower control arms are pointing upwards at normal ride height from the car being lowered too much, the ratio between the steering arms and the LCAs gets upset and you get a lot of bump steer, making the car twitchy.  The arms are meant to point downwards at rest, so the chassis is higher than the wheel hub. As the springs compress the arms move through horizontal to point upwards, your camber goes from slightly positive to slightly negative, and your toe-in changes too. That affects your roll center, which is why they sell roll center adjusters to lower the outer end of the LCA and make it horizontal or downwards sloping again.

But first, just see if you can get more travel before the bump stops in the rear....  Have fun!

[75RollaDeluxe]

Hi Banjo-I just recently acquired this car about a month ago and it will hopefully one day become a “show car” I’ll attach some photos as well.

Altezza-thank you so much for the detailed response this helps immensely. I plan to start digging into the car soon and will do what you detailed to test it. I’ll definitely start in the rear as well.

[Banjo]

Thanks for the pics !  Looks like You have a pretty good car, as a starting point, to produce a "show car".  Looks very clean, & hopefully does not have any rust therein.

Looks pretty standard & very clean, under the bonnet/hood, so You seem to have a perfect starting place.  What year model is it ?  

Keep the pictures coming; as "a picture tells a thousand words"; so they say.

Cheers Banjo

[75RollaDeluxe]

Thanks! It’s a 1975-rust is minimal just some surface rust but also has a few pinholes on the hood. Got the car in good shape, runs pretty well besides a likely vacuum leak and dying at stop signs. Here’s a few more photos of it. Appreciate the advice and looking forward to scouring the forum for more fixes and suggestions.

[Banjo]

Thanks for the extra pictures, which are good hi resolutions ones.  I was able to blow the photos up, & there is the first signs of surface rust, just starting to appear, in all the usual places. Do you believe the car has been ever resprayed, during it's life ? Was the car ever located near the sea, or coast ?  I belive the car was in Alabama; & maybe near the Coosa River at one time, in it's life.  Maybe somewhere near Incaguat.

Rust is the greatest enemy of Corollas. moisture gets trapped under window rubbers & the like, & the rubbers become hard, & less protective. I'd be going over it, with, "a fine tooth comb".

Early task, would be to take out all the seats, & lift the carpet, & have a good look there.  Does it have a paint code on it, under the bonnet/hood ?

You've got a fine example of a Toyota Corolla; if You want to make a show car of it.

Enjoy !

Cheers Banjo

 

[75RollaDeluxe]

I am not sure if the car was ever resprayed-but I am doubtful it was. The color code was for silver. The car did live near the ocean before but far enough out to not affect it much. I’m at not sure where it’s home was before that. I will definitely be going over it and hopefully will repaint it in the future!