Need guinea pigs for 240Z rear coilover adapters

[G-E]

After a long and winding road of supply chain issues, changing priorities, and just plain forgetfulness, these adapters are back on track. An initial batch of spacer rings was made via backup channels at slightly added expense, but no biggie.

 

So where we are today: this adapter allows one to cut the rear strut, weld in the adapter, and have full S13 FRONT coilover compatible mounting, with added camber adjustment. The adapter should allow about 5-6 degrees of rotation, but the lower chapman arm length will dictate how much of that is usable. The kit consists of 1 unique part and shared parts with other platforms, as such the adapters themselves are well tested, and their performance is well known as a mac-strut conversion, but there are still questions as to how this will work on the rear.

 

The primary benefits are not having to cut the strut tower to weld in camber plates, besides drilling 1 hole or getting S30 specific tophats if available, and being able to use any low to high end S13 coilover, from ISR to FEAL. Once converted, the entire rear assembly becomes easily camber adjustable, with a convenient set screw to mark/lock the position of the retaining bolts, this means any re-assembly after taking it all apart can be done without getting a new alignment.

 

So as to geometry changes, because of the offset strut, the more static camber is dialed in, the less camber the car gains on squat, which should save some tire wear. If the arm is lengthened for a wide body application, then the adapter will allow a slight reduction of camber as well, with a slightly reduced camber curve intensity. I know many people on here fancy themselves suspension experts, so I won't bother explaining too much without specific questions. Better launches and more predictable grip in corners should be achievable.

 

So what I am looking for is 3-4 testers ideally, preferably with spare uprights and coilovers to do the swap right away. Because of the added costs for this initial run, I can't really give discounts over the final retail price of the kit, which will be approximately $200USD. I can however throw in a set of 60mm extended studs for the early adopters, to further sweeten the deal.

 

Ultimately I'm looking for feedback, not just on the kit, but relative performance to a straight sleeve-based coilover kit, and compared to quality OEM style upgrades.

 

Please send a msg via FB if you have interest in trying or want fast answers: https://www.facebook.com/responsetype/

 

Edited May 24, 2017 by G-E

[Neverdone]

How much does a typical S13 front coilover setup cost?

[rturbo 930]

Well I'm definitely not a suspension expert, so someone help me out with this. since the strut tube is now some 2-3" offset, wouldn't this result in the wheel being pushed out the same amount, as well as needing longer control arms? I'm not understanding how this is going to work, unless I'm missing something obvious.

[ZHoob2004]

Well I'm definitely not a suspension expert, so someone help me out with this. since the strut tube is now some 2-3" offset, wouldn't this result in the wheel being pushed out the same amount, as well as needing longer control arms? I'm not understanding how this is going to work, unless I'm missing something obvious.

 

The hub stays basically in the same place, since it's held in by the control arms. The adapters are pushing the strut inboard, and changing the angles a bit.

[rturbo 930]

The hub stays basically in the same place, since it's held in by the control arms. The adapters are pushing the strut inboard, and changing the angles a bit.

Right, but the strut doesn't really have much room to go inboard, which means the hub must go out.

 

I guess I need to see it on the car for it to make sense.

[jthom5147]

Aside from some static camber adjustability, what advantage is there over existing weld-in coilovers and damper inserts?

 

I don't see a cost advantage, because beyond the kit cost (which incidentally also requires cutting and welding of the strut) you also would need to buy S13 struts which are almost exclusively sold as a 4 piece set so the rear ones are trash/waste, and all except for the cheapest of the coil over sets cost more than a decent set of dampers and weld in coilovers.

 

You could add in camber plates too and still come in under the cost of this setup. With no difference significant difference in install difficulty.

[G-E]

Ok I'll respond in bullets:

 

- Yes hub stays where it is, strut is at the bottom, but as you can picture the base never goes behind the outer CV joint, thus "more vertical" would be correct

- Front S13 coilovers (even good ones) can be had used or rebuilt all over the place, check 240SX forums, I see pairs go for $300, those bastards always need money

- Maybe no cost advantage comparing a new S13 kit with a typical Stance/Megan based weld-on kit, but that wasn't the point, you have options, I'm not in the business of selling coilovers

- There are ancillary benefits like I said, the camber curve changes on squat, potentially reducing the camber gain to a point where very little traction gets lost under squad conditions, wheel hop minimized, and tire life is extended

- Best visualized as KPI adjustment, which also has an effect on dynamic camber due to the compression axis

- It is easier to replace the upright/spindle on an unmodified chassis should you ever wish to go stock, or turn it into a full restoration show car at a later date

- Being independent of chassis, they can be moved to a new car with zero work if the chassis gets totaled

 

Now I mention S13 repeatedly, but S14 fronts are basically the same, except their spindles use larger M14 retaining bolts not the M12 the S13 and adapter uses. I have reducing washers available to make that work. So really those less sought after S14 coilovers might be an option.

[seattlejester]

I'm with rturbo have you tested this on a car? The rear strut more or less sits in a pocket. You would get a little bit of room comparatively as the spring perch is a smaller diameter so you could theoretically take up some of that freed space pushing the strut more vertical, but I'm not sure there is enough space for a full offset like pictured.

 

I know buying fronts was a bigger thing when the DC2 swap was pretty popular, but even then the only company that was offering that was like megan or god speed. Are individual coilovers more readily available now?

[G-E]

"have you tested this on a car?" --- I don't wanna be a dick but did you not read the title of the thread?

 

"I'm not sure there is enough space for a full offset like pictured." --- I'm not sure there isn't, when you move a lever on a pivot, the area near the pivot barely moves.

 

"Are individual coilovers more readily available now?" --- these adapters are popular in their front applications for Z31/F31, as are the rear bushing sleeves for Z31/S12, usually without the others, meaning people are not getting full sets as a rule. We can argue about sources, whether used or rebuilt is the best way to go, but the fact is people seem to have no problem finding value with this approach.

[seattlejester]

Nice apophasis.

 

I meant in pure regards to fitment. Of course it doesn't move by much, but the strut basically touches the body at full droop. You don't get droop with this type of coilover, but is it enough say up top especially when you leave the options of top hat in the ether?

 

So you want someone to buy these, buy coilovers, remove their suspension, cut off the strut tube completely making it not usable for any other type of weld on system (gc, bc, mckinney, arizona, etc etc etc), put it on, reassemble the whole rear end, only then to find out if it even fits? What happens if it touches the body? Will you offer a refund? Will you send them the revised version? How would they go about removing and installing the revised version with it all welded in? Is there a way to index to make sure the adapter is installed straight? What about height? Will an S13 coilover be tall enough? Are you factoring in a camber top hat? 

 

I get that it is your creation, and that you had success with the Z31 chassis and such, I get that your guard is raised, but I'm genuinely curious here and all for more options.

[rturbo 930]

"have you tested this on a car?" --- I don't wanna be a dick but did you not read the title of the thread?

You don't have a chassis to check fitment? I'm really not trying to give you a hard time, but usually when people ask for guinea pigs for a new product, that means that the product fits, and now they want people to run them to work out bugs.

 

I appreciate that you're bringing a new product in here, but it sounds like you haven't checked to see if it's going to fit at all. I also have other concerns about the change in strut angle, ie, will it cause a change in handling, and if it's going to put a weird load on the top mount. Again, not a suspension expert, so those concerns may be unfounded.

 

So you want someone to buy these, buy coilovers, remove their suspension, cut off the strut tube completely making it not usable for any other type of weld on system (gc, bc, mckinney, arizona, etc etc etc), put it on, reassemble the whole rear end, only then to find out if it even fits? What happens if it touches the body? Will you offer a refund?

This too. Unless you plan to pay for all of this, you're asking a lot. Need a little more legwork from you.

[G-E]

I understand some people seem obsessed with the idea that other options are just as much work, and there are uncertainties in this route, but they are projecting personal doubts onto a lot of people who don't feel the same way. More to the point this argument happens in every single application, and nearly every product released, we're long past the point of having a guard up, it's predictable and unproductive drivel. Every damned time.

 

No, there's no 240Z shop car, though I do have access to one, one doing a 300 point resto, but there's no way I'm going to risk scratching that thing nearly finished. From all the eyeballing and measuring things should be fine, and on a lowered car, clearance would only improve. The unanswered questions aren't the obvious ones you are asking, so don't be upset or think my replies are evasive.

 

From my understanding of the geometry and behaviour of the suspension, there should be no need for a camber plate, and thus the tophat, whatever the solution or replacement is, can be more compact. If the center needs to be moved slightly for best spring/hat clearance, it can be done easily enough, and should be obvious during mockup, but given many modern coilovers are using narrower springs/bodies, again this seems to be a non-issue.

 

On a wide body car, these adapters can be aligned as straight as the coilover clearance allows on the upright, which normally goes into positive camber on the other mac-strut applications, without actually going positive camber. So you could replicate the original strut angle with the upright moved out by the 2" or so it is offset, and keep the factory camber setting.

 

I can't imagine anyone is too worried about using these with a narrowed rear end, so we can leave that an open question for the special case if it ever comes up.

Edited May 27, 2017 by G-E

[burninator]

You seem to be saying that this adapter will alter the camber change through the travel due to the offset, but the length of the arms and location of the pivots are what controls the motion of the hub/wheel through travel. Since the hub is still ridgedly attached to the strut and does not pivot the offset does nothing but create an angle on the hub/wheel giving you some positive static camber (but you have a way of adjusting that). I don't see how this would affect the camber change through the travel one way or the other. The strut angle won't otherwise matter as long as it doesn't contact the body (which I don't think it will).

 

I see the benefit as giving an option for adjusting camber (which is always nice) and perhaps a choice of coil-overs for those who don't want a weld in or sectioned struts. 

 

I also agree that it's a big ask for someone to buy this from you along with the struts to make it work if you haven't tested it yourself. I work for an aftermarket parts company and for new parts development we buy, or if possible borrow, a vehicle and do the install and check fitment, do the measurements, etc. before offering it for sale, when we're done we either return the vehicle to the previous condition, or give them the parts to keep for free. I've never heard of asking someone to buy a part just to see if it even works.

 

These arguments are not unproductive drivel, especially when you're asking someone to spend a lot of time and money on a product you've never even tried on an actual car. They are important for you to understand the specifics of our platform, and for potential customers of yours to understand what they'd be getting into.

[G-E]

The camber curve does change because of the axis of compression, think of it like the upright twisting. The top pivot of the strut isn't moving towards the pivot of the chapman arm, in the OEM setup, it overshoots causing inward rotation at the top, adding excessive camber to the lower pivot also moving outward. With this adapter, the strut is now inline or even inboard of the chapman arm pivot, depending on camber, so the camber curve is almost entirely dictated by the position of the chapman arm only.

 

I understand the sentiments around the testing regime, but I can assure you that almost every single product on offer was tested with volunteers, in many cases with the initial low volume production proofs/samples. The process is known and the results have been excellent this way, only one product to date had to be redesigned out of necessity, the rest were purely evolutions to add value, reduce weight, or offset changes due to interest.

Edited June 9, 2017 by G-E

[260DET]

G-E does some good Z31 bits, money where mouth is here. So that's my starting point.

 

What would make this product more attractive is it's suitability for lowering the rear suspension while at least retaining the original roll centre height, something that the usual strut chop does not do. Better value for money and a much bigger market. Well it should be but until modders realise that there is a need then in reality it doesn't exist, if you get my drift.  

[burninator]

OK, I take it back, I do see now how it changes the camber through travel. I also didn't think about it changing the roll center, and I don't remember seeing that on any of the threads about this. Like 260DET said, that's probly a bigger benefit than changing the camber curve.

[G-E]

OK, I take it back, I do see now how it changes the camber through travel. I also didn't think about it changing the roll center, and I don't remember seeing that on any of the threads about this. Like 260DET said, that's probly a bigger benefit than changing the camber curve.

Well look at how confusing just the camber issue is....

[G-E]

*bump*

 

Lots of inquiries on facebook, fewer ready to part with cash (to be expected), so there's several sets not earmarked for anyone...

 

Please do fire off a message there for fastest response: http://www.facebook.com/responsetype/

[tube80z]

The camber curve does change because of the axis of compression, think of it like the upright twisting. The top pivot of the strut isn't moving towards the pivot of the chapman arm, in the OEM setup, it overshoots causing inward rotation at the top, adding excessive camber to the lower pivot also moving outward. With this adapter, the strut is now inline or even inboard of the chapman arm pivot, depending on camber, so the camber curve is almost entirely dictated by the position of the chapman arm only.

 

I get the motion ratio changed but if you're using a stock arm and everything connects in the same place up top then you're not changing the geometry.  And it's the geometry that determines the camber curve.  It works the same way up front.

 

Cary