MaXpeedingRods coilovers for NA/NB Miata

MaXpeedingRods will be shipping me a replacement rear shock, and asked a few clarification questions about my description of the problem - there's a bit of a language barrier at the technical end of things. 

Meanwhile, I drove to work today on 20 miles of roads I know very well. I'll take another route home to hit a few more of my "test bumps", but I've got a pretty good idea.

I started off with the shocks at full stiff as noted, then backed them off by 5 clicks. Somewhere, I read that the recommendation is for 19 off full soft which is where I should be right now. I can't find that recommendation again, but it was from Max.

The lack of rear travel is very obvious. I'll measure it when I'm doing the shock swap, but I suspect there's no more than 1/2-1" of rear wheel travel before I'm into the bumpstop fairly hard. Lots of abrupt hits. It reminds me of putting aggressive lowering springs on an NA without touching the stock bumpstop. So it's not a very comfortable ride. Mid-corner, the car is pogoing a bit as the spring rate oscillates between spring and bumpstop - I'll see if I can manage to tune that out with shock damping. Given the hang time over a crest right now, I don't know if I'll be able to. The rear damping is already feeling a little soft.

Damping quality is a bit reminiscent of the BMW X1: both floaty and harsh at the same time. The body is moving around a fair bit - there's that soft low speed damping at work - but there's still some higher frequency "noise" coming through. 

I didn't push the handling too hard due to traffic, but on a couple of corners I did start to feel the slip angles. No surprise, it oversteers. Some of this is because of the front sway change and the way the car is set up, but the rear spring rates and short travel are both contributors. The pogoing at the rear will likely make it a little interesting on steady state corners as the tires load and unload.

Here's what the current ride height looks like. Remember that these tires are a little larger in diameter - about 3/4" larger in diameter than typical. 

Took the car to lunch with a coworker. We tried a couple of different of damper settings. The discussion came up as to whether this setup is better than stock springs with a set of blown stock shocks. It was inconclusive.

Keith Tanner said:

The discussion came up as to whether this setup is better than stock springs with a set of blown stock shocks. It was inconclusive.

LOL

Do these look like they can be taken apart for revalving if there was a way to read them?

I will try to disassemble the dead one if Max doesn't want it back. It looks like pulling off the top cap is possible with a pin wrench. I don't see any way to charge the shock with gas, which is my biggest concern and why I'm not going to do it to an undamaged one.

Note that even if you do revalve them, you're still going to have significant compression travel loss on the rear shocks, overall travel loss at both ends and you're running an oddball 2.75" spring size.

Re: spring size, is 70mm a nominal size in parts of Asia? Seems so random.

The BC racing shocks have a "self healing" rubber seal in the bottom used with a needle to charge them, maybe there is something like that on these on the bottom? It probably wouldn't be hard to add a shrader valve of some sorts to the bottom as well provided there is room between the bottom of the shock and the bottom of the adjustable height lower mount. Maybe Bilstien pistons could be fitted? Maybe thicker oil could help the dampening or will that just blow the seals out?

None of that changes the odd spring diameter or lack of travel in this application. I wonder if there will be a new revision after Keith's review?

Adam

The bottom appears to be steel. You can't put a schrader on it because then you'd lose even more travel in the rear, unfortunately. Fox uses a similar rubber pill for charging.

A new upper mount design would help these. It wouldn't solve all the problems, but it would get rid of the worst problem: the rear compression travel.

In reply to Keith Tanner :

What about welding the pogo stick stationary? Can we just "Colin Chapman" these Chinese potstickers? 

In reply to NickD :

LMFAO. Sharing this everywhere. 
 

side point- the cheap Chinese factory never design from scratch. So this is surely built on someone else's design model. If we could find who... there's potential for a half decent damping solution. (Still no solution for droop though)

Compression is more of a problem. At the same ride height as a stock 1994R package, there isn't enough compression travel to keep you off the bumpstops.

Just get some 'drop brackets' for shocks like people do when they slam the back of pickup trucks (cheaply..). 

I just got a tracking number for a replacement rear shock from Max, so it'll be here in a couple of days. I have family visiting for the next 10 days so swapping it in will not be a high priority.

But....

I've got around 100 miles on this setup now. And it's not growing on me. The constant bottoming out in the rear has transformed the car from being pleasant to drive to being a series of winces as I discover bumps I never knew were there. I was going to count the number of "bottoming events" per mile on a relatively smooth road but it should really be measured per hundred yards. At 80 mph, the car has a lack of stability that had me thinking I was dealing with serious head/side winds. The front end floats around. And of course, there's the constant rattling from the bad shock but that's a different problem.

Simply put, I don't want to drive the car anymore. I actually left it at work over the weekend because I just didn't want to deal with it on the drive home on Friday - I chose to drive an R&D car instead.

They're not damped well. You lose a considerable amount of overall travel and you lose critical rear suspension bump travel. They won't go low if that's a priority. At my very streetable ride height, I cannot lift the car off the ground without having to deal with the risk of displaced hardware. The spring rates will lead to a lot of oversteer and it's an odd size so you can't use them with other suspension or swap in something useful. Even the upper mounts have fundamental geometry problems that limit bump travel so you don't want to use them with other shocks. If you could find a way to locate the springs, the stock upper mounts might actually be a significant improvement on rear bump travel but you would lose even more droop. The car hops in corners.

I cannot recommend these, regardless of price. If you have four blown shocks, get some real shocks  from a legitimate manufacturer. A set of KYB GR2 stock replacement units for an NA cost $228 shipped from Tire Rack, and you can pair them with a set of take-off springs from another Miata if your springs are broken. If your interest is performance, you'll still get better handling out of that setup. 

In reply to Keith Tanner :

Thank you for your service.

In reply to Keith Tanner :

I think that review is what they would call "damning." Good god, did they get anything right?

In reply to Keith Tanner :

So, they aren't worth what you paid for them (which is nothing iirc).  Good to know.

NickD said:

In reply to Keith Tanner :

I think that review is what they would call "damning." Good god, did they get anything right?

The machining quality on the outside is good, no complaints there. To the point where I'd consider using them as a manufacturer for certain parts, although the packing would have to be improved to prevent damage in transit.

I didn't pay anything for these, but I did spend a good portion of my day off installing and troubleshooting them. I will have to spend more time pulling them out again although that will be considerably quicker because the old suspension will drop right back in with no fiddling around. I also have a car that is effectively out of service until I do that.

I'm "shocked" by your review.

Just kidding. Anyone who has actually driven on a properly setup suspension, knows all these brands with the generic valving and weird spring rates are garbage. 

I had been thinking it was rather brave of MaxPeedInGrods to send a set of coil-overs to Keith to review - seemed like a sure way to get a lengthy list of everything the parts had wrong if they weren't up to snuff instead of a short "These suck, don't buy them" post.

Thank you, Keith, for taking the time to do exactly that and post a detailed list of what exactly is wrong with these coil-overs.

I'm pretty disappointed but not surprised.  I was hoping they would be usable even for the 2000 challenge but I wouldn't trust them for that, even.  Like come on guys, at least get the length right so people can swap on better springs and modify your shocks to be usable!

The real test for this company comes when Keith gives them all the feedback about their suspension. If they say they will change things and make things better, then that shows some promise for improvement. But if they don't change anything, they just stay the same and will eventually go out of business

In reply to _ :

Never understimate the demand for cheap coilovers. Unfortunately for every guy on this forum that hangs on Keith's every word, there are 100 fanbois who just want to stance their whip and the cheaper they can get it done the better.    

06HHR said:

In reply to _ :

Never understimate the demand for cheap coilovers. Unfortunately for every guy on this forum that hangs on Keith's every word, there are 100 fanbois who just want to stance their whip and the cheaper they can get it done the better.    

Cutting springs is basically free and sounds like it would create a better overall result than these.

I am a little surprised they're legitimately worse than new stock parts, that's a pretty low bar to fall short of.

In reply to dps214 :

I think you're right, but then you don't get a cool sticker. I'd wager over half of ebay speed parts are worse then new stock parts.