wheelsmithy
wheelsmithy SuperDork
12/26/19 7:48 a.m.

Background.

I have built a coilover setup once, using an excellent Techno Toy Tuning kit. We're talking basically weld a washer on the strut body, add a threaded pipe, a collar, a cap, and Bob's My Uncle.

So, on the cheap, I can use something like these:

$46.99 on Amazon, make my own appropriately sized "washer" hold the barrel in the right place (of course, removing the strut insert to weld it on!), and be most of the way there. The problem is the "Hats". Where do I get them cheap, but not homicidal?

 

Struts in question are for an '86 MR2. Challenge car, cheapskate, blah, blah.

Thank You in advance.

Knurled.
Knurled. MegaDork
12/26/19 7:57 a.m.

I made my own out of plate and some appropriately sized washers.

 

 

Large washer on the bottom locates the spring by ID, two smaller washers on top spigot the bearing plate.  The strut tops I use hold the strut shaft stationary.

 

I've been running this setup since 2009 or so.

 

I also don't bother with welding a ring, which is also kind of dangerous if you can't disassemble your strut tube.  I just let the spring mount float on the upright bracket.  You need longer threaded sleeves for this that the amazon kit has, though, depending on the lengths of springs you want to run.

DeadSkunk  (Warren)
DeadSkunk (Warren) PowerDork
12/26/19 8:16 a.m.

I ran some $40 Ebay coilovers on my Challenge Miata and was able to use the stock tophats. No experience with MR2s though.

adam525i
adam525i Reader
12/26/19 8:23 a.m.

Those $46 amazon ones do come up with aluminum top hats that fit to 2.5" springs, you can see them at the bottom of your picture (you probably noticed that), between those and the stock top hats and maybe some spacers (washers) you can probably make that work.

wheelsmithy
wheelsmithy SuperDork
12/26/19 9:07 a.m.

Responses appreciated, and I may be overcomplicating things.

Don't the tophats need bearings?

This is a strut type situation, and maybe could abide solid mounts in the rear, but I'm pretty sure bearings are needed in front. 

Like so,

for steering.

I do have a lathe, and may have just answered my own question, but any easy-won (for me) knowledge the hive is able to share is greatly appreciated.

SkinnyG
SkinnyG UltraDork
12/26/19 10:01 a.m.

I bought some cheapie eBay coilovers years ago, they came with plastic top hats - I made new ones out of steel...

Knurled.
Knurled. MegaDork
12/26/19 10:04 a.m.

In reply to wheelsmithy :

Is the bearing on the spring seat (like my Protege/Escort/ZX2 mounts) or are they part of the top mount?

 

If it's on the top mount, like 90% of strut cars, you just need to make sure the spring seat rides on the mount properly.  Easiest way is to use the OE spring seat, with maybe some bits here and there to keep the spring from walking.

_
_ Dork
12/26/19 10:36 a.m.

As a former owner of a Mac strut celica, and having done a diy coilovers setup on that, I would get the eBay coilovers for the sleeves. Ditch the "top hats"- mine were plastic and broke as soon as I left the garage. Ditch the dubious springs for some hypercoils that will match your shock's valving. Don't forget, when you lower, you lose travel, and that puts the shock in a weird place. Shock needs to be ok with being lowered. You don't need those bearings, but it's nice to have them. Springs twist when compressed. The less movement in your suspension while cornering, the better. It's an mr2, so you really want compliant, predictable suspension setup. 

Keith Tanner
Keith Tanner MegaDork
12/26/19 11:14 a.m.

Shock should be fine for any position throughout its travel unless you’re dealing with something that’s been sitting unmoving long enough to rust the shaft. The problems you may have with a lowered car is hammering on the bumpstops incessantly. If your shock cannot bottom out internally without damage and your geometry lets it, it will take damage. 

Anyone got a picture of a stock MR2 assembly? I’m in the “use the stock top hat” camp. All you’re doing is making the lower perch adjustable. 

wheelsmithy
wheelsmithy SuperDork
12/26/19 6:31 p.m.

In reply to Keith Tanner :

This is for a challenge car. '80 model X1/9, PT Cruiser engine and transmission, and MR2 suspension (struts, brakes, uprights, outer axles).

My thought was to do something like this:

at all 4 corners (much more barnyard, minus the sweet adjustable struts) 

I don't mean to argue when I'm asking questions/favors of others, but really? I don't need some kind of bearing/bushing on the steer wheels? 

I would like to drive this on the street post-Challenge, and prefer to build it as much to that end as I can the first time around, For What It's Worth.

All discourse appreciated.

Edit: Full disclosure, I've barely looked at the strut assemblies in my shed, and both pictures are pilfered off the interwebs.

Knurled.
Knurled. MegaDork
12/26/19 7:19 p.m.

Those mounts look like the bearing that accommodates rotation is part of the mount, not the spring seat, so the craptanium ones that come with the springs may be just fine if they mate up to it reasonably well.

 

You will always need some form of bushing to accommodate the strut gyrating side to side, even in the rear, because the strut will change its angle relative to the body as the suspension moves.

Keith Tanner
Keith Tanner MegaDork
12/26/19 8:45 p.m.

If I were building a Challenge car (which I have never done, so keep that in mind) - I'd use a cheap sleeve to give me an adjustable mount for the lower perch and leave everything at the top the same. It's got all the bushings and bearings you need. If you need more camber, look at crash bolts to see if there's an option that means you don't have to mess with the upper mount.

Brotus7
Brotus7 HalfDork
12/26/19 8:52 p.m.

I did this very thing in my AW11 way back. Memory is kinda fuzzy, but I don't remember it being too hard. I want to say I retained the stock upper mount, and maybe made a metal washer/plate that took the spot of the stock spring and had centering tabs for the spring.  In hindsight, a piece of exhaust tube, welded to a plate would probably work just as well.

DeadSkunk  (Warren)
DeadSkunk (Warren) PowerDork
12/26/19 9:13 p.m.

In reply to wheelsmithy :

Unless the strut mounting points in the X1-9 chassis are exactly  the same center-to-center distance as the MR2 you're going to be introducing a camber change. I'll ASSume the X1-9 is narrower to begin with. You may not need camber plates at all, or you may even need them to reduce the camber. Without measurements I wouldn't jump to the conclusion that camber plates are a necessity yet.

Stampie
Stampie UltimaDork
12/26/19 9:35 p.m.

Really cheap bastards like me ditched the sleeve totally. I did a lot of measuring and some math to calculate the drop under weight of the car. Then I cut steel pipe to the height I had calculated to get ~ 1/4 inch of where I wanted to be. That saved me the $45 in sleeves. We ran speedway clearance springs. It helps to know your current spring rate and weight at each corner to calculate all this. 

wheelsmithy
wheelsmithy SuperDork
12/27/19 7:29 a.m.

Again, guys, The discussion is greatly appreciated. To further it, One of the reasons I want to do coilovers is space. The idea of going down from 5" o.d. to 2.5" is enticing. Crash bolts or slotting the struts is great advice. 

I plan to build new control arms to mate the MR2 parts to the X1/9 body, so to an extent, I can put the camber/caster where I want it. The camber plates (though they take up some of that space i was after) would be added bling, and a fine tuning tool. You know, get everything as close as I can in the center of adjustment using the Stampie method above, then be able to fine tune with camber plates. They would also be an excellent project for the mini mill I have recently acquired.

It sounds like basically replicating the Techno Toy Tuning kit is the way forward.

I'll keep all this most welcome advice in mind, and things will become clearer once I have my hands on all the stuff, as well as a better idea of budget. Thank You, one and all

wheelsmithy
wheelsmithy SuperDork
12/27/19 7:39 a.m.

So, something like this would have the rotational part covered, as well as the camber change a strut goes through as the wheel cycles.

Into a much, much cruder version of something like this, with snap rings, of course.

 

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