Set Front HKS Adjustable Springs at Factory Height?

[i3igpete]

So I installed the kit last week and after about 6 days, the spring have just about settled - no change in height for the past 2 days, after driving everyday for at least a few minutes. I was initially bummed because it looks like the front drop was significantly larger than anticipated when I compared to the speedindustry video. In retrospect, I should have taken my own measurements from each corner before starting, since there can be non-trivial ride height variance in stock suspension. @XtremeMaC found a 0.6 inch front-to-rear diff, while @TWiTCHY found a 0.75 inch side-to-side diff.

However, I later found this thread from @bushido and @razorlab and thankfully it had additional numbers for sanity check purposes. My car was nearly dead-on with the 5" and 4.75" numbers, so here is how the car settled using my initial assumptions (5mm of thread in front, 3mm of thread in rear).

So, depending on your source of truth, its either impossible or possible to raise the HKS springs back to stock height. I will trust the data source with more reference measurements.

Final source of uncertainty: I installed verus camber plates at the same time. however, the rear is the one with the larger error, and front ended up just fine.

After doing the math and splitting the difference, my final recommendation to get back to stock is:
5mm of thread in front
12mm of thread in rear

Sponsored

 

[3TMagnetMan]

I was thinking of raising my cars height after having it lowered with HKS HAS. Thank you for posting this information. I might go up an inch higher from what I have now. How does the car ride at stock height with HKS springs??

 

[i3igpete]

How does the car ride at stock height with HKS springs??

I never ran the HKS springs in a lowered state, so i can't really compare it. in terms of rate, any of the lowering springs won't be very noticable compared to say, a coilover, where the spring stiffness can be 2x+ multiples of the factory rate.

https://www.supramkv.com/threads/stock-spring-rate.14882/post-225011

for reference, the ohlins r+t's for this platform have a default front rate of 342 lbf/in. even a set of cheapo tein coilovers have a rate of 336 lbf/in.

 

[i3igpete]

Quick update, adjusted the rear heights a bit over the weekend, and after a drive all corners are now within 0.25" of target. Not going to mess with it anymore, since the weight will continue to shift around as I adjust and I don't want to chase my tail for that last quarter inch.

 

[i3igpete]

Unsurprisingly, I couldn't just leave it alone so I adjusted the rear left and front right down. As expected, weight shifted a bit and it loaded up the other corners. I think I learned my lesson to not touch it anymore.

 

[SupraDOc]

After doing the math and splitting the difference, my final recommendation to get back to stock is:
5mm of thread in front
12mm of thread in rear

So did you install the packer and NOT cut the front bump stop to achieve your factory ride height setup?

Also, thank you so much for confirming and following up with your findings! Just started my install and also looking for factory ride height.

 

[i3igpete]

So did you install the packer and NOT cut the front bump stop to achieve your factory ride height setup?

Neither the packer, nor the bumpstop, affect ride height since they don't make contact with the spring. They only become relevant at full compression. Nevertheless, good question.

I DID install the packer because IMO, its always a good idea to spread the load during impact events. From what I can tell, the packer is just a specially shaped fender washer to prevent premature wear and puncture of the shock body by the bumpstop.

However I DID cut the front bumpstop since I installed the rear HKS bumpstop. In my opinion, you should have equal stroke range front and rear. However, you should also be able to keep both stock bumpstops if you so desire (since you're adjusting back to stock height, after all).

So both of these configurations would be valid:
Uncut front bumpstop + stock rear bumpstop
Cut front bumpstop + HKS rear bumpstop

Sponsored