AE86 ride height adjustment

[GZE_RA21]

What's up C4AG?

So I'm trying to get my build wrapped up and I've got most of the last few things sorted so I can actually drive the car (9 month process ) and now I'm trying to undo the ridiculous ride height (slammed) my car was set at by the previous owner via the Megan racing EZ street coilovers. I understand the process by which they are adjusted with the threaded rod into the strut body and 3 lock ring system, but I can't seem to get the ride height to match.

I've done lots of research and tried setting everything back to zero and adjusting from there but I'm still having a hard time with it. It seems when i have both front coilovers set exactly the same I'm still getting a different ride height on both sides, I'm measuring from ground to fender, length between lock rings, top of tire to fender, just to make sure I'm getting an accurate amount of unequal ride height, and sure enough its the same amount off at all points. So you'd think, okay just adjust to compensate. But, for an example, say its an inch higher on one side, so I adjust an inch to equal it out, now it's half an inch lower on one side and 3/4 inch higher on the other side. And it seems to have no repeatable pattern to this weird inconsistency which has me just guessing at an adjustment to get it close.

This has me really confused and kinda frustrated. Just to be clear, tire pressures are all identical at 32psi and the rear adjustable perches and shocks are adjusted to be identical also, 100% all new suspension components and bushings all around, car is in a level garage, spring preload is always set to zero before each check, front struts aren't blown, no unequal weight on the interior of the car. I tried to take out as many variables as possible.

Any assistance would be greatly appreciated! Thanks ladies and gents.

[Deuce Cam]

Its because each corner of the car is a different weight. More weight compresses the spring more so the ride height is lower, and the opposite for less weight.

Measure the distance between the hub and fenderr at each corner, then adjust the height to compensate. Will take some trial/error.

[Jayrdee]

Unfortunately I've found there's no way around this other than getting down and dirty. I'm super anal about my ride height being equal all around so you have no clue how many hours I've spent jacking the car up, fiddling with the rings, setting the car down, measuring, etc.

Ran into this issue when adjusting my fronts. Regardless of what I did, the front right was always about 1/4 inch lower than the left. I finally got it within a 1/16th of an inch even yesterday Lol.

Although be sure and remember it takes a few days for the suspension to settle after being fully decompressed. Measuring as soon as you let the car down doesn't always provide an accurate reading. So when you get the adjustment as satisfactory as you want it, take it for a drive and/or let it sit for a few days and then measure it. 100% guarantee you, the measurement will be lower than when you first let the car down.

[CloudStrife]

I would just have it corner weighted at a proper shop.. Also you should check for frame straightness.

[totta crolla]

Changing the height on one side also changes the height (in the same direction) on the other side.
Measure from the centre of the track control arm inner pivot bolt to the ground as per the factory service manual.
Don't assume the spring rates are exactly the same each side.
Make sure that the springs are pre-loaded by the same amount and ensure tyre pressures are the same.

[Deuce Cam]

Its because each corner of the car is a different weight. More weight compresses the spring more so the ride height is lower, and the opposite for less weight.

Measure the distance between the hub and fenderr at each corner, then adjust the height to compensate. Will take a lot of trial/error.

Cornerb weighting will help. A pro can do it for u if needed.

[SgtRauksauff]

I'd say get to an alignment place that can do corner-weighting, and set it up with you in the car. Especially if you plan on actually driving the car in any timed events. That's the point of adjustable spring height, to perfect the balance of the car for racing applications. "stance, yo" is just a cool side effect.

[CloudStrife]

Also, I would take all the shocks out and test if they are in working condition, and not "blown". Even BC Racing has had blown shocks from the factory. Basically just push down on the rod and make sure it goes down and returns full stroke in a reasonable time.

You can also just push on each corner of the chassis, but that's less specific.

[davew7]

For the setting up, ride height you need locate the car on four level pads. Your typical garage floor can easily be off by a 1/4" [cross-car] plus the floor will slope towards the doors. You need four pads, with the appropriate pad shims leveled to within a 1/16" or better. Mark the floor and pad so you also put the leveling pads back in the same location. As mentioned you need to check your height at the C/A pivot bolt, the fender lip is not accurate. Compare RH side to LH side front and rear and then recorded each. If the Suspension is low on the corner turn up the spring and if high reduce the spring pressure on the shock. The difficult part is that raising or lower a single spring perch not only changes the wt on that wheel but will also affect the weight on the opposite diagonal wheel besides the opposite wheel. It will probably take several tries to get each corner reasonable close to even. If you are set up with only the driver you will probably have to settle for a diagonal balance only Vs a side to side balance. [front is more important then the rear relative to balance] Then drive the car around the block and verify that it has not settled. [Good chance it has] After you have finished adjusting the spring perches for the "10th time" go back and verify that the rear axel is centered. Once the task is completed, wrap tape around the threads of each shock to prevent road damage that would make it difficult to adjust the springs at some later date. Dave W7

[GZE_RA21]

Unfortunately I've found there's no way around this other than getting down and dirty. I'm super anal about my ride height being equal all around so you have no clue how many hours I've spent jacking the car up, fiddling with the rings, setting the car down, measuring, etc.

Ran into this issue when adjusting my fronts. Regardless of what I did, the front right was always about 1/4 inch lower than the left. I finally got it within a 1/16th of an inch even yesterday Lol.

Although be sure and remember it takes a few days for the suspension to settle after being fully decompressed. Measuring as soon as you let the car down doesn't always provide an accurate reading. So when you get the adjustment as satisfactory as you want it, take it for a drive and/or let it sit for a few days and then measure it. 100% guarantee you, the measurement will be lower than when you first let the car down.

Dang, solid advice man. Good to know I'm doing it right and not just crazy. I did notice the car settled quite a bit after I got it dialed in for the most part.

I would just have it corner weighted at a proper shop.. Also you should check for frame straightness.

Also, I would take all the shocks out and test if they are in working condition, and not "blown". Even BC Racing has had blown shocks from the factory. Basically just push down on the rod and make sure it goes down and returns full stroke in a reasonable time.

You can also just push on each corner of the chassis, but that's less specific.

The shocks are not blown I can promise you that, it was about the first thing I checked when I thought I had it adjusted properly and realized it was totally out of whack.

I'm in the home stretch of a 9 month long corolla project, funds are a little tight to be taking the car to get corner balanced unfortunately lol and also the frame is in fact straight, the car was in a minor accident but no frame damage.

I'd say get to an alignment place that can do corner-weighting, and set it up with you in the car. Especially if you plan on actually driving the car in any timed events. That's the point of adjustable spring height, to perfect the balance of the car for racing applications. "stance, yo" is just a cool side effect.

Roger that, honestly I could care less about any sort of ' stance' I was really only going for like an inch or so drop over stock, and in reality I'd be cool with the stock suspension and lowering springs BUT my car came with coilovers when I bought it. Not that I'm complaining by any means, I just want to get it setup somewhat decent. Oh and no competitions for this cars foreseeable future, I got it to be a fun daily. Yes, that was a bad idea.

Changing the height on one side also changes the height (in the same direction) on the other side.
Measure from the centre of the track control arm inner pivot bolt to the ground as per the factory service manual.
Don't assume the spring rates are exactly the same each side.
Make sure that the springs are pre-loaded by the same amount and ensure tyre pressures are the same.

Will do, tire pressures are all identical.

Its because each corner of the car is a different weight. More weight compresses the spring more so the ride height is lower, and the opposite for less weight.

Measure the distance between the hub and fenderr at each corner, then adjust the height to compensate. Will take a lot of trial/error.

Cornerb weighting will help. A pro can do it for u if needed.

Good to know, glad I'm not crazy or have a terribly twisted corolla.


Thanks for all the replies! Your assistance is greatly appreciated, I have new motivation to tackle this challenge

[Deuce Cam]

Its prob a little twisted haha. All are. Theyre tin cans and 30 years old.

[CloudStrife]

Yeah.. Just being an old car causes the chassis to lose rigidity. Tsuchiya's 86 had a huge crack on the front shock tower, Pretty sure it was just hard driving, not collision.

I would really check the frame, I guarantee it is off. You should be corner balancing anyway

[totta crolla]

Adding height and spring rate adjustable dampers without corner weighting them is like building a race engine without tuning it on a dyno.
Getting the correct ride height front to rear is also very important, take care to get the roll centres somewhere close to stock as this is a good starting point.
Unless you have a height adjustable panhard rod the rear roll centre is not adjustable so work the front around that, if the front R/C is too low in relation to the rear (lowered front without R/C adjustment) weight will be pitched over the outside wheel when turning and can cause understeer and a lack of response.
Try to get the target height you want before corner weighting, this usually requires some trial and error to suit your driving style.

[GZE_RA21]

Okay, you guys are probably right. Let me re phrase what I said, the chassis has not been damaged from a collision causing it to be visibly bent, it may in fact be not as true as it was from the factory due to external forces and age. Lemme just list a couple facts real quick

I did not install the coilovers

I do not care about having coilovers

I do not have the stock suspension parts

I do have front RCAs

I do have an adjustable panhard bar

I have no interest in having it corner balanced due to fundage

I will not be racing this car in the foreseeable future

I would like the height to be close to even all around

I will attempt to do this myself through trial and error

Despite having racing capable parts, I did not make the decision to install them, the previous owner did. I just need them to function similar to stock parts for now.

If I decide to take full advantage of the front coilovers I would start by ditching the current 8K front and 6K rear spring rates and get some quality 6K front and 4K rear springs and really put some legitimate effort into getting it dialed in perfectly for spirited canyon driving, perhaps a corner balance at that time. For now, I'm trying to get the damn thing rolling in a decently straight line and to turn corners, all without bottoming out or scraping on small bumps and dips, that is all.

I'd like to thank you all for your opinions and advice, C4AG to the rescue once again, you guys are the shizz!

[totta crolla]

Fully understand the fundage thing !
For now then you may be best to set the ride height as a percentage of stock height. The factory service manual shows where and how to measure heights front and rear, it also gives you the measurement. If you set yours as a percentage you will at least be in the ball park of having a balanced car.
Again the rear height will dictate what happens at the front unless you can adjust rear spring platform height ?
There are many length adjustable panhard rods but very few are height adjustable, probably because to do that requires fairly major work to mountings etc.
Actual height adjustment requires that both sides are adjusted, usually one side raised and the other lowered and personally I wouldn't worry about a difference in height at the actual damper.

[Deuce Cam]

Totta corolla is an asset to the community. What he said is why i wont lower my car much over 1". The rear geometry doesnt respond well to a moderate/agressive lower ride height.

[totta crolla]

Well thank you Mr Deuce Cam !
My car is restricted power wise by regulation, basically needing to use a stock engine which means to be competitive I have to get the very most out of the handling and grip.
My next legal modification will be to lower the rear roll centre by lowereing the Panhard rod on its mountings although I remain mindful of reducing ground clearance, it's just another compromise.
My preference is to keep the suspension travel as long as possible so short stroke suspension and RCA's won't work for me.
One thing I have learned over the Years is that the Corolla chassis is very sensitive to ride height adjustment, especially front to rear.

[GZE_RA21]

I'm not discounting anyone's advice, quite the opposite in fact, just trying to explain my present situation and what I am trying to accomplish given the present circumstance. I guess I did forget to mention the car also came with adjustable rear spring perches, so the rear height is adjustable as well. I thank everyone for their input from the bottom of my heart and will make a point to utilize every bit of info given to me when I'm at a point where I have the cash to really get into dialing in the suspension for superior handling, thank you again!!