HKS spring height

[drave199]

Looking for advice on Installing HKS springs. The actual installation I think I’ll figure out but any pointers are cool. The main question and thing that’s making my head spin is the height. I’m not sure if I should just throw them on out of the box or go lower. I’m not looking to slam it so I don’t want to just max them out. I’ve looked at a ton of photos but it’s tough to gauge as every photo is different lol. Some where they are “out of the box” height look great while others seem to tall. If I go 1/2” lower, photos showing that is the same, some look great and others look to low. Any advice and photos (preferably on stock wheel/tires) are appreciated. Just want to get it right hopefully the first time since it seems it’s a pita to adjust once their on the car, especially the rears.

Stupid question, in order to go 1/2” lower, do you guys just measure the threaded section and just loosen a 1/2”? Seems straight forward but want to make sure I’m not missing something lol. I’m pissed cause I didn’t take any measurements of the height before I put it up on jack stands so I’ll never know the actual drop.

Thanks

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[Baldmonkey22]

No a half inch adjustment wont result in an equal change in ride height, as the spring rate also changes at the same time.

best thing to do is measure all 4 corners stock, install springs and make adjustment until all 4 corners are equal to where u want to be height wise. also after adjusting you gotta drive it around the block to let the springs settle in before taking your measurements

 

[drave199]

No a half inch adjustment wont result in an equal change in ride height, as the spring rate also changes at the same time.

best thing to do is measure all 4 corners stock, install springs and make adjustment until all 4 corners are equal to where u want to be height wise. also after adjusting you gotta drive it around the block to let the springs settle in before taking your measurements

well shit, I have no idea what tf your talking about lol. You think it’s a problem that I didn’t measure before? It’s on jack stands right now and kind of a pita to do it so I’d rather not drop it to have to lift it back up again. Also, I likely won’t be able to drive it for several weeks (maybe months) as it’s winter right now and about a foot of snow outside.

 

[Baldmonkey22]

oh in that case the best you could do is match your measurement or visable threads below the collars to what somebody else set them too if you like how their car sits.

worst case set them all equally if they arent already and re adjust them once you can drive it.

 

[suicidaleggroll]

I installed them as-is, drove around for about 2 weeks to let them settle, made some qualitative observations (I like the back left, front right is too low, etc.), made ground-to-fender measurements to pair with the qualitative observations to make sure I wasn't crazy, and then adjusted them accordingly.

When I adjusted them, I just measured from the spring seat to some fixed part of the assembly and adjusted the seat up/down by the amount I wanted to change the height. The earlier post about that not being exact due to non-linear spring rate is correct (I think?), but for small adjustments the error won't be enough to matter, you'll have just as much error on your eyeballed measurements anyway.

End result was I left both springs on the driver's side alone, raised the front right about 1/4", and lowered the rear right about 1/4".

 

[drave199]

I installed them as-is, drove around for about 2 weeks to let them settle, made some qualitative observations (I like the back left, front right is too low, etc.), made ground-to-fender measurements to pair with the qualitative observations to make sure I wasn't crazy, and then adjusted them accordingly.

When I adjusted them, I just measured from the spring seat to some fixed part of the assembly and adjusted the seat up/down by the amount I wanted to change the height. The earlier post about that not being exact due to non-linear spring rate is correct (I think?), but for small adjustments the error won't be enough to matter, you'll have just as much error on your eyeballed measurements anyway.

End result was I left both springs on the driver's side alone, raised the front right about 1/4", and lowered the rear right about 1/4".

Did you need to remove the rears in order to adjust like I’ve read?

Out of the box, should the height adjustment and number of threads be the same front and rear? Just so I can make sure they are the same before I install. Likely, in order to do this right, I’m probably going to put it back on the ground and take some measurements. Then just install as is and see what I think. Then adjust if in need to.
Stupid question, it’s been on jack stands for over a week. If I put it back on the ground, do the stock springs need to settle before I take measurements?

 

[suicidaleggroll]

Did you need to remove the rears in order to adjust like I’ve read?

Yes. I was able to adjust the front on the car (I still needed a spring compressor and a hammer though). The rear I had to remove and stick in a vice to loosen the seat. Luckily removing the rear from the car is pretty quick and easy.

Out of the box, should the height adjustment and number of threads be the same front and rear? Just so I can make sure they are the same before I install. Likely, in order to do this right, I’m probably going to put it back on the ground and take some measurements. Then just install as is and see what I think. Then adjust if in need to.

I think so, I didn't measure though. When I first installed them and drove around the block, they measured perfect left to right (both fronts measured exactly the same, both rears measured exactly the same). It was only after that initial 2 week settling time that the discrepancy on the right side showed up that I ended up having to correct.

Stupid question, it’s been on jack stands for over a week. If I put it back on the ground, do the stock springs need to settle before I take measurements?

Probably? But not for long, maybe a day I'd think to let the seats squish back down to their normal thickness. You at least need to drive it around the block though, if you just lower it and then try to measure it'll be way off because the tires will be holding the car up (When you jack the car up, the wheels swing inward to free-hang. When you lower it back down they have to swing outward as they compress, friction with the ground will prevent the tires from swinging outward as far as they need to, so they'll still be pushing inward slightly, which will prop the car up higher than it would sit normally.

 

[drave199]

Yes. I was able to adjust the front on the car (I still needed a spring compressor and a hammer though). The rear I had to remove and stick in a vice to loosen the seat. Luckily removing the rear from the car is pretty quick and easy.


I think so, I didn't measure though. When I first installed them and drove around the block, they measured perfect left to right (both fronts measured exactly the same, both rears measured exactly the same). It was only after that initial 2 week settling time that the discrepancy on the right side showed up that I ended up having to correct.


Probably? But not for long, maybe a day I'd think to let the seats squish back down to their normal thickness. You at least need to drive it around the block though, if you just lower it and then try to measure it'll be way off because the tires will be holding the car up (When you jack the car up, the wheels swing inward to free-hang. When you lower it back down they have to swing outward as they compress, friction with the ground will prevent the tires from swinging outward as far as they need to, so they'll still be pushing inward slightly, which will prop the car up higher than it would sit normally.

Yeah that’s what I figured. If I decide to put it back on the ground first, it could be weeks before I can drive it due to the weather. Not sure if it’s really necessary to get a pre measurement or not though?

 

[suicidaleggroll]

I didn’t, it’s really more of a curiosity thing…it doesn’t affect the process or your results in any way. If it would be that painful to get before measurements, I’d just skip it.

 

[drave199]

I didn’t, it’s really more of a curiosity thing…it doesn’t affect the process or your results in any way. If it would be that painful to get before measurements, I’d just skip it.

Last question. After lowering the car, are people usually looking for a level car or same drop all the way around. I know certain springs offer more drop for the rear vs the front so I’m guessing the car must have a slight rake to it. I suppose in the end, all I’ll be looking for is equal “flushness” Between the tire and fender. And to make sure front and rear (left and right side) are equal. The rear shouldn’t have to drop as far as the front to achieve this since the rear tires are slightly taller. I may have just answered my own question. I seriously hate the way I am, I always overthink everything lol

 

[suicidaleggroll]

I suppose in the end, all I’ll be looking for is equal “flushness” Between the tire and fender. And to make sure front and rear (left and right side) are equal.

That’s all I did

 

[Thill444]

Last question. After lowering the car, are people usually looking for a level car or same drop all the way around. I know certain springs offer more drop for the rear vs the front so I’m guessing the car must have a slight rake to it. I suppose in the end, all I’ll be looking for is equal “flushness” Between the tire and fender. And to make sure front and rear (left and right side) are equal. The rear shouldn’t have to drop as far as the front to achieve this since the rear tires are slightly taller. I may have just answered my own question. I seriously hate the way I am, I always overthink everything lol

Well Toyota designed the car to have a slight rake. I think it might be good to start with the front being slightly lower than the rear and you can always adjust it. I personally like the look of a car with a small rake to it but all of us are different.

 

[METAL]

I am OCD about this as well. The reason you see some images that seem good to you and then some too tall vary on the wheel and tire setup. Out of box height is perfect for 275/35 and 305/35 tires. If your tires are smaller I would suggest a 1/8" drop for every tire size smaller.

 

[dzeleski]

Just installed mine this weekend. If you read the manual there is a ratio for the front and rear suspension geometry that will tell you exactly how much to move the adjuster to get x amount of ride height change.

 

[METAL]

Just installed mine this weekend. If you read the manual there is a ratio for the front and rear suspension geometry that will tell you exactly how much to move the adjuster to get x amount of ride height change.

That is very interesting I don’t recall where my manual is but can you post the geometry ratio?

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