Set Front HKS Adjustable Springs at Factory Height?

[Twundy]

Ordered the HKS Hipermax Touring Adjustable Springs, and I'm wondering if they are able to be set to factory height in the front, or a mild drop like 10-15mm which I'd prefer. I think it's possible, which is why I ordered them, but I'd love confirmation.

Here's my (lengthy) reasoning and guessing, please correct me if I'm wrong:

At first glance, the product description says:
Front Height Range: -25 to -45mm (cannot set fronts to 0mm apparently)
Rear Height Range: 0 to -50mm

However, there's a note that "Fixing the provided Packer in the spring is needed when the height adjusts more than 24 mm." and "Packers are used when setting the front height to 21mm or more." Does "more than" mean a higher height than -25mm, or a larger drop than -25mm?

I think this lack of clarity could be due to some confusingly worded instructions from the manual to be done ONLY for certain height ranges: adding the Packer on top of the front spring perch, and cutting the OEM Front Bump Stop.

Here's the language in the manual, plus my interpretation notes in red (take em with a grain of salt):
*Note: Fixing the provided packer in the spring is needed when the height adjusts more than 24 mm [add the packer when it's higher than a 24mm/0.9" drop]. (Diagram. 2-2)
*When it adjusts the height under 24 mm, remove the provided packer from the spring [remove the packer when it's lower than a 24mm/0.9" drop]. (Diagram 2-2)
*When it adjusts the height less than 17 mm, cut an excess height portion of the front spring bumper [cut the factory front bump stop when it's lower than a 17mm/0.7" drop].

By this logic, for a -12mm/0.5" mild drop in the front for example, I would then ADD the packer, and NOT cut the bump stop. Common sense would reason that the bump stop should be longer (uncut), and that a spring packer should be added at the highest height (to insulate against large jarring bumps with the longer shock travel), and the notes I've made above reflect that. If this is true, then the Front Height Range is more accurately 0 to -45mm.

This could all be wrong if I don't have enough threads in the first place to go above -25mm, but when I see people on YouTube and elsewhere post their installs with a 1"/-25mm front drop (the upper limit of the listed front height range), there's a LOT of upward thread left for a height increase (even more thread than is left for lowering the car to the -45mm limit).

In most of the YouTube installs I've seen, people are almost always cutting the front bump stop and adding the packer regardless of the height they are setting it to, which could be part of some people's complaints about ride or clunking that I've seen.

Would love if others can chime in who have installed this and have experimented with different heights, before I undertake installing these.

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[dzeleski]

I installed the packer and also cut the bump stop. Largely because I dont fully understand the point of the packer. It does not change the installed spring height it only effects where the bump stop touches.

The packer is less then 1/8 inch thick and sits flat on the top of the coil adapter. I raised the car from the hks default about 1/4 inch of threads which is roughly 1/2 inch higher then the default. I have no cluncking, knocking, or noise of any kind but I was very particular in where I put the coil isolators, holding the spring exactly like it is shown in the manual and putting them exactly where they are shown.

I have a ton of threads left at this setting.... BUT I would start to get concerns about going higher (aka closer to stock height) because the lever arm the spring would put on the coil adapter is too close to the top of the strut. Which probably isnt strong enough which is why they limit the max height even though there are threads left.

 

[dzeleski]

Couple photos of what that setting looks like. Rear is slightly higher then I want but Im going to let the springs settle for a bit before I adjust it. Keep in mind im running 275 35 in the front and 295 35 in the rear which means my tire diameter is about 1/4 larger then stock.

 

[Phantom Menace]

I installed the packer and also cut the bump stop. Largely because I dont fully understand the point of the packer. It does not change the installed spring height it only effects where the bump stop touches.

The packer is less then 1/8 inch thick and sits flat on the top of the coil adapter. I raised the car from the hks default about 1/4 inch of threads which is roughly 1/2 inch higher then the default. I have no cluncking, knocking, or noise of any kind but I was very particular in where I put the coil isolators, holding the spring exactly like it is shown in the manual and putting them exactly where they are shown.

I have a ton of threads left at this setting.... BUT I would start to get concerns about going higher (aka closer to stock height) because the lever arm the spring would put on the coil adapter is too close to the top of the strut. Which probably isnt strong enough which is why they limit the max height even though there are threads left.

Did you ever determine the minimum drop you could go on your HKS adjustable springs? I am considering buying a set but I also don't want to go as low in the front as the factory minimum of -25mm. Any feedback you can give me would be appreciated.

 

[Phantom Menace]

Ordered the HKS Hipermax Touring Adjustable Springs, and I'm wondering if they are able to be set to factory height in the front, or a mild drop like 10-15mm which I'd prefer. I think it's possible, which is why I ordered them, but I'd love confirmation.

Here's my (lengthy) reasoning and guessing, please correct me if I'm wrong:

At first glance, the product description says:
Front Height Range: -25 to -45mm (cannot set fronts to 0mm apparently)
Rear Height Range: 0 to -50mm

However, there's a note that "Fixing the provided Packer in the spring is needed when the height adjusts more than 24 mm." and "Packers are used when setting the front height to 21mm or more." Does "more than" mean a higher height than -25mm, or a larger drop than -25mm?

I think this lack of clarity could be due to some confusingly worded instructions from the manual to be done ONLY for certain height ranges: adding the Packer on top of the front spring perch, and cutting the OEM Front Bump Stop.

Here's the language in the manual, plus my interpretation notes in red (take em with a grain of salt):
*Note: Fixing the provided packer in the spring is needed when the height adjusts more than 24 mm [add the packer when it's higher than a 24mm/0.9" drop]. (Diagram. 2-2)
*When it adjusts the height under 24 mm, remove the provided packer from the spring [remove the packer when it's lower than a 24mm/0.9" drop]. (Diagram 2-2)
*When it adjusts the height less than 17 mm, cut an excess height portion of the front spring bumper [cut the factory front bump stop when it's lower than a 17mm/0.7" drop].

By this logic, for a -12mm/0.5" mild drop in the front for example, I would then ADD the packer, and NOT cut the bump stop. Common sense would reason that the bump stop should be longer (uncut), and that a spring packer should be added at the highest height (to insulate against large jarring bumps with the longer shock travel), and the notes I've made above reflect that. If this is true, then the Front Height Range is more accurately 0 to -45mm.

This could all be wrong if I don't have enough threads in the first place to go above -25mm, but when I see people on YouTube and elsewhere post their installs with a 1"/-25mm front drop (the upper limit of the listed front height range), there's a LOT of upward thread left for a height increase (even more thread than is left for lowering the car to the -45mm limit).

In most of the YouTube installs I've seen, people are almost always cutting the front bump stop and adding the packer regardless of the height they are setting it to, which could be part of some people's complaints about ride or clunking that I've seen.

Would love if others can chime in who have installed this and have experimented with different heights, before I undertake installing these.

Did you ever determine the minimum drop you could go on your HKS adjustable springs? I am considering buying a set but I also don't want to go as low in the front as the factory minimum of -25mm. Any feedback you can give me would be appreciated.

 

[Twundy]

Did you ever determine the minimum drop you could go on your HKS adjustable springs? I am considering buying a set but I also don't want to go as low in the front as the factory minimum of -25mm. Any feedback you can give me would be appreciated.

Yeah, had the shop set it to a minimal drop, it's at about -15mm front and rear.

 

[Phantom Menace]

Yeah, had the shop set it to a minimal drop, it's at about -15mm front and rear.

And no issues? Do you think it would be possible to go even less of a drop or is what you did about the most you can go outside of the factory minimum?

 

[Twundy]

And no issues? Do you think it would be possible to go even less of a drop or is what you did about the most you can go outside of the factory minimum?

Yep, no issues at all. I actually love the ride height, it looks low but it is very maneuverable to pretty much never scrape. There is someone in the Facebook group who has it set to -10mm or something very mild, so I'm pretty sure you can even set it at factory height if you wanted. Experiment with adding the packer and/or not cutting the bump stop and see how that is.

The ST and MSS adjustable springs are also able to be set at 0mm drop if you're interested in those.

 

[Phantom Menace]

Yep, no issues at all. I actually love the ride height, it looks low but it is very maneuverable to pretty much never scrape. There is someone in the Facebook group who has it set to -10mm or something very mild, so I'm pretty sure you can even set it at factory height if you wanted. Experiment with adding the packer and/or not cutting the bump stop and see how that is.

The ST and MSS adjustable springs are also able to be set at 0mm drop if you're interested in those.

Thanks for the feedback Twundy.
I'm looking for the narrower diameter spring to be able to run wider wheels and tires on track.

 

[SupraNews]

Yep, no issues at all. I actually love the ride height, it looks low but it is very maneuverable to pretty much never scrape. There is someone in the Facebook group who has it set to -10mm or something very mild, so I'm pretty sure you can even set it at factory height if you wanted. Experiment with adding the packer and/or not cutting the bump stop and see how that is.

The ST and MSS adjustable springs are also able to be set at 0mm drop if you're interested in those.

What shops do you recommend for catted dp, springs and intake install? Looking to possibly get work done all at once but not go to the wrong shop just because the price is great

 

[Twundy]

What shops do you recommend for catted dp, springs and intake install? Looking to possibly get work done all at once but not go to the wrong shop just because the price is great

I've installed everything at Texas Track Works in Fort Worth. They'll be pricy though, but their alignment and suspension work is top notch. You can also check out PRT Performance in Lewisville, they're the most popular Supra tuner out here in DFW.

 

[SupraDOc]

Thanks for the feedback Twundy.
I'm looking for the narrower diameter spring to be able to run wider wheels and tires on track.

Any updates on your install? Also looking to run wider wheels with no drop or minimal drop with the HKS HAS. Curious if anyone has tried -10mm or less.

 

[i3igpete]

Based on this speed industry video, the HKS kit ships with (post-settling) drops of front = 1.375 inch and rear = 1.125 inch

According to this facebook post, there is 34 mm of visible thread for the front, 20mm of visible thread in the rear. The lever ratio is 1.18 front and 1.69 rear.

So if I'm doing the math correctly, to cancel all drop back to stock height:

To cancel front drop:
1.375 in / 1.18 = Reduce top thread by -1.16 in = -29mm
Front ships with 34mm of available thread on top, so adjust the collars up so there is 5mm of thread showing

To cancel rear drop:
1.125 in / 1.69 = Reduce top thread by 0.67 in = -17mm
Rear ships with 20 mm of available thread on top, so adjust the collars up so there is 3 mm of thread showing

Can someone check my math?

screenshot for traceability, red lines show dependency for front suspension

The part that makes me unsure is that the facebook post has a shipped heights of -25 and -20 along the left margin. I've traced these down to the HKS product page for the DB42 (2-port engine variant), but I'm guessing this is the unsettled height?

Edit: sketches to show the reference measurements:

 

[CafeRacerQueen]

Fuck that, just get MSS height adjustable if you want zero drop to be possible. This sounds like a headache.

 

[i3igpete]

MSS height adjustable

according to this reply, MSS coils use the factory spring perch, which would not provide additional clearance needed to run a 18x11 square setup.

https://www.supramkv.com/threads/pics-vids-of-supra-with-aftermarket-wheels.2022/post-323208

Regardless, the same procedure would need to be followed with the MSS kit to zero out drop as well.

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