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240Z camber adj. rear coilover adapters (bolt-on)

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Ok let's start a list of who's interested, consider this a pre-buy since they are going to be produced anyway...

 

Intro price will be $260+ship

 

Installation:

1. cutting strut tube

2. drill a hole in the bottom

3. clean everything thoroughly with acetone or other potent solvent

4. installing the adapter oriented correctly with panelbond or equivalent glue

5. torque bolt with stainless spacer underneath to 150ft-lbs, locktite recommended

 

Requires:

1. almost any front s13 coilover or other coilover with s13 lower bracket

2. suitable 240Z top hat for coilover (or universal)

*** I will be producing a batch of stepped washers to use s14 brackets on s13 spindles or this adapter for extra cost...

 

 

Benefits:

1. will allow up to 9 degrees of camber adjustment depending on coilover bracket

2. doesn't require camber plates

3. has set screw on adapter to mark camber locations for disassembly

4. pre-set screws can be made for quick road or track alignments

5. lightweight aluminum body, stainless lower plate, oversized retaining bolt, approx. 700grams total

6. adds up to 1.5" of backspacing depending on wheel used

7. allows really wide wheels

 

 

s30asm-rear1.jpg

s30asm-rear2.jpg

 

Let's make a list...

1......

2......

3......

Edited by G-E

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The adapter is slotted to allow rotation of the bracket, or to put it another way, to rotate the whole hub assembly relative to the car...

 

The glue is only there help keep everything tight and improve rigidity from twisting forces, there's no risk of the assembly falling apart once torqued and locktited.

 

The panelbond or panel weld (whatever product used) will also prevent galvanic corrosion between the steel strut and aluminum adapter.

Edited by G-E

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By moving the bottom of the strut inwards, won't that change the shock travel direction, as in camber gain?

 

To get 1.5" of extra wheel clearance won't the lower mounting point have to move in even more than 1.5" since the wheel is a foot or so higher?

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The adapter can go slightly positive, assuming your control arm is lengthened or the use of camber plates is set to restore the camber, you actually do...  of course there's much more backspace increase down at the bracket, but that's not relevant unless you run go-kart wheels :)

 

This would be at max negative:

 

post-43768-0-88018400-1410737843_thumb.jpg

 

The difference in angle on a real hub:

 

post-43768-0-02113300-1410738705_thumb.jpg

post-43768-0-35116500-1410738723_thumb.jpg

Edited by G-E

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An adjustment screw at the top (through the upper portion of the adapter toward the shock) would be nice as a back-stop to the camber adjustment. Screw in, less camber; screw out, more, provided only the upper bolt holes are slotted. The corner weight will always ensure the screw stops prevent any slippage if the two bolts fail hold properly, and adjustment screw's threads will provide some degree of vernier adjustment.

 

I like the idea. A question I have is how much additional shear will this add to the strut (shock) rod with the lateral displacement from a more ideal "in-line" compression/rebound force? In other words, the further the shock centerline is moved toward the housing pivot point (spindle pin centerline), the more rotational force that is introduced to the assembly when viewed from a fore/aft viewpoint. Ideally, the shock centerline should be where the compression/rebound forces are perfectly aligned (which is not even achieved with the OEM housing). Moving the strut centerline inboard decreases the balance of the rotational forces of the wheel "pushing" up on the outboard end of the housing, and the weight of the car pushing down in the outboard end of the housing, all of which are centered around the spindle pin (whose location relative to these two forces can be very important). With both forces on the same side or relatively close to each other compared to the spindle pin, this is somewhat aligned. The further they are separated, especially with the pin in close vicinity, the more rotational force (or lack of force alignment) that is introduced. Is it insignificant? Is it significant? Would this impact the wear-rate of the shock? I don't know, but this is one reason why manufacturers push the limit of clearance between the shock (or strut), and the wheel (or tire) to the very minimum.

Edited by blueovalz

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The forces aren't significantly different to the front of the s13 (less in fact, unless you have monster sized tires with serious mexi-poke), and we know those aren't falling apart like tea biscuits when people go racing...

 

The other question about the slots, they oppose the twisting force on the bracket, like you say it wants to rotate, and there's always one slot that's perpendicular to that angular force. Also there is in fact a boss on top for a set screw, but it's for quick alignments more than anything...

 

You could have a street alignment of -1 degree out back, then you decide to go racing, once you're in the pits, loosen the retaining bolts, pull out the -3 degree setscrew you made, insert it into the top boss, push or pull the top of the wheel to slide everything to the setscrew stop point (the car will need to be on a jack taking most of the weight off the wheel for this part), and finally re-torque the retaining bolts.

Edited by G-E

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The adapter can go slightly positive, assuming your control arm is lengthened or the use of camber plates is set to restore the camber, you actually do...  of course there's much more backspace increase down at the bracket, but that's not relevant unless you run go-kart wheels :)

 

This would be at max negative:

 

attachicon.gifmax-neg.jpg

 

 

 

 

Looking at this pic, the piece you are making shows the original strut angle(and therefore strut path) while the s13 strut shows the new strut path. With the s13 version, won't the tire be gaining much less neg camber than the original version as it compresses?

Edited by logr

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Looking at this pic, the piece you are making shows the original strut angle(and therefore strut path) while the s13 strut shows the new strut path. With the s13 version, won't the tire be gaining much less neg camber than the original version as it compresses?

 

Yes, the more static camber you add with the adapter, the slower the gain on compression, or vice versa. How much depends on ride height and other factors.

 

To quantify why this is a good thing: the ford gt was modeled after the ferrari 360 suspension, and while it obviously uses wishbones, the camber curve is relevant; for every degree of roll, the compressed wheel gains .7 degree of camber...

 

With the "normal" 240z strut axis being past the pivot, the increase is over 1:1, and increases for lowered cars; it can creep towards double the ferrari's, not exactly ideal is it?

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Well after a long hiatus from this project, too many things happened, and too many other innovative parts took precedence... it's back on the table :)

 

The adapters themselves are done, the only thing left is to machine some spacer rings since the strut tubes are so much deeper on the 240z upright than the other applications.

 

If anyone wants to be a guinea pig for this, all you'd need is front s13 coilovers, and either drill the top hat or the strut tower to make the hat work....

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OK, so the current plan is to make a weld-on version only, and I should have spacers sometime at the end of next week or early the week after.

 

The adapters I had made were for another application of very similar diameter, and may require a tiny bit of dremel work on the strut tube inside if it isn't perfectly round, or alternately some sanding of the adapter. In most cases we're talking about a difference of 0.1mm or about 3-5 thou.

 

I'm doing my best to keep the price below the magic $200 mark, which is similar to what weld-on sleeves cost, but with tons of added benefits, including not having to cut up the strut tower for camber plates.

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