Cal Club Autocross Forums

During the last event my car was totally undrivable.
The first and obvious reason for that was the lack of my beloved Hoosiers A6… but when I drove the car back to Thousand Oaks I felt that something was different. You see, since I put my new PRO PARTS/KONI 3012 and the Kevlar body kit back in November I was driving the car with the coilovers set at the highest level. I did that to protect the Kevlar front end from rubbing on speedbumps/driveways etc.
When I came to Fontana this Sunday I set the car to a normal/low height for the event and when I left I decided to leave it there (so I can figure out if the car would scrape anywhere).

Here is a picture of the ride height:


My Fwy drive was almost scary with the car hitting hard every time I was passing over the fwy connections – to the point that my seat belt was holding me from hitting my head on the roof (I'm serious on this ).
That made me think that the shocks are probably touching the bumpstops but I would never imagine how bad the situation really was.
Today I removed the front bumper and I looked at the suspension travel… what I saw was terrifying.
The bump stops were squished to almost 5% of their size and there was ZERO travel at the front.





The situation was equally bad at the rear where the shocks were fully compressed.



I’m currently trying to think what I can do and how I can improve this condition.
One thought would be to reverse the two piece shock mounts but if I do I’ll need to weld the two mounts together – otherwise the load will go on the four little bolts that connect the two mounts together. Still I’m not sure if gaining that much height would make any huge difference and if the weld mounts will be able to hold the car's weight.





The other option would be to get other mounts and get rid of the floating perches. I wanted to get these ones but they are discontinued



What do you think?

Just get the shock bodies shortened 2". Or more if you want to run bumpstops.

Jason Rhoades wrote:Just get the shock bodies shortened 2". Or more if you want to run bumpstops.

They are already shortened

Those shocks are seriously too long. I'm sure the shock re-builder will not forget that you also need the piston shortened by an equal amount when they shorten the body. Get some measurements of the Koni Sport and Race shocks to get a range of how much shorter your shocks should be.

I think George runs these front and rear with his Koni's....

http://www.flyinmiata.com/index.php?dep ... %20%2010MM" onclick="window.open(this.href);return false;

I have a pair to fit 12mm shock shafts I'll sell for $150.

Christos Adam wrote:

Jason Rhoades wrote:Just get the shock bodies shortened 2". Or more if you want to run bumpstops.

They are already shortened

Shorten them more. Unless you need 11" of droop travel from your present ride height.

I'd do some asking around before getting rid of the floating spring perches.

In your pictures: see that gap between the top of the spring and the bottom of the mount? You need to shorten the shock bodies by at least that much.

Jason Rhoades wrote:

Christos Adam wrote:

Jason Rhoades wrote:Just get the shock bodies shortened 2". Or more if you want to run bumpstops.

They are already shortened

Shorten them more. Unless you need 11" of droop travel from your present ride height.

Guys these are supposedly shortened shocks tailored to the miata needs. I'm not sure how they did it when they made them but I just checked this morning and the front fender - wheel gap at full drop was 3,25-3,5" (so we are talking about 2,5"-3" drop). At the rear fender to wheel gap was ~6" so the drop was probably 5" (since there is already a 1" gap the way the car sits anyways).



(Maybe not clear in the picture but the wheel is not touching the ground)


This is with the wheel on the air - you can see the spring to perch gap but still the suspension travel is very limited


Match better at the rear (drop ~5") but still not able to go low enough.



Is it possible that the shock shaft is shorted but the shock bodies are not shortened?

Christos Adam wrote:

Is it possible that the shock shaft is shorted but the shock bodies are not shortened?

If someone misunderstood what you wanted, sure.

When you ordered the shocks, did you tell them you were going to use those top mounts and intermediate spring retainers?
Those shocks look like they are sized for a setup with stock-style mounts.

Bill had the same problem when he bought his Koni 28s—they were too long.

Steve Lepper wrote:When you ordered the shocks, did you tell them you were going to use those top mounts and intermediate spring retainers?
Those shocks look like they are sized for a setup with stock-style mounts.

even with stock style mounts... i think i would have shortened the shocks a bit as well. Temporary fix, raise it like a bro....bro

Christo,

The shock mount is the issue. When I had seen their picture I had assumed that there was room for the shock to slide into them and that the shock body was even shorter than mine. These mounts will not work properly for an SP/SM Miata with 3012s.

I am not sure that flipping them will work well enough or even at all(bearing support...). Jeff should be able to swap these out for FMs(these need some machining too but I know what to do).

Another possible "stop gap" measure could be this:A stock NA mount would work better with some modification and there is a chance that NB mounts can be modfied to work and these place the shock mount even higher.

George

George Doganis wrote:Christo,

The shock mount is the issue. When I had seen their picture I had assumed that there was room for the shock to slide into them and that the shock body was even shorter than mine. These mounts will not work properly for an SP/SM Miata with 3012s.

I am not sure that flipping them will work well enough or even at all(bearing support...). Jeff should be able to swap these out for FMs(these need some machining too but I know what to do).

Another possible "stop gap" measure could be this:A stock NA mount would work better with some modification and there is a chance that NB mounts can be modfied to work and these place the shock mount even higher.

George

Hi George
I though that I couldn't do that with the current two piece design and that I needed the old FM mounts which where solid...is that correct?
What about shortening the shock body?
I need to call Jeff and see what he thinks...

OMG!

Okay, Christos remember when I showed you on my civic and explained to you how to find out what bottoms out first????

1. Put it on jack stands.
2. Take off the Spring
3. Take off the Bumpstop
4. Assemble it and put on your race wheels while it is on the jack stands.
5. Compress your suspension till something bottoms out and find out what it is.
6. Email me the pics and info at jeffw at propartsusa dot com

I told you the bumpstop might have to be shortened based on what you gathered from this. That bumpstop is 1.5" which equates to about 2.14" of wheel travel. If the shock is TOO LONG, I will take care of it...

Christos, does this help?
http://www.cardomain.com/ride/2343497

It seems to give the shock an extra 1.5-2" of space.

We used these to get Philip's ITA car really low: http://iscracing.net/miatasuspension.html" onclick="window.open(this.href);return false;

Michael Smith wrote:Christos, does this help?
http://www.cardomain.com/ride/2343497

It seems to give the shock an extra 1.5-2" of space.

Going with an upper mount that does not have a floating spring perch that is pivoted properly on the bearing, he will be creating bind period.

The bind occurs when the strut rod presses against the upper shock bushing during suspension compression?

Michael Smith wrote:The bind occurs when the strut rod presses against the upper shock bushing during suspension compression?

Yes and also when the spring is resting on the upper mount only.

Isn't that top mount upside down? BTW, the weight of the car will not be on the four little bolts.

Walter Wong wrote:Isn't that top mount upside down? BTW, the weight of the car will not be on the four little bolts.

Why not?
Please explain If I put the mount upside down what will hold the two pieces of the mount together?

Unless if you mean that the whole weight of the car will be in 16 little bolt since four will suspend roughly a quarter of the weight... but I guess it's still the same issue...

The spring holds the weight of the car at each corner. The bolts will only see any significant weight if the shock bottoms out before the spring does. I'm not saying that the mounts are upside down, they just look like it because aftermarket Miata mounts tend to have a recessed design to gain compression travel, especially in the rear. The ones on your car seem to lose that precious compression travel, so much so that your car may sit fully on the bumpstops at 'race' height which is a bad thing. I'm sorry if it seems like I'm making inaccurate statements. I actually don't know the year of your car as I don't race in your region.

Walter Wong wrote:The spring holds the weight of the car at each corner. The bolts will only see any significant weight if the shock bottoms out before the spring does. I'm not saying that the mounts are upside down, they just look like it because aftermarket Miata mounts tend to have a recessed design to gain compression travel, especially in the rear. The ones on your car seem to lose that precious compression travel, so much so that your car may sit fully on the bumpstops at 'race' height which is a bad thing. I'm sorry if it seems like I'm making inaccurate statements. I actually don't know the year of your car as I don't race in your region.

Jeff Wong wrote:Going with an upper mount that does not have a floating spring perch that is pivoted properly on the bearing, he will be creating bind period.

Jeff Wong wrote:

Michael Smith wrote:The bind occurs when the strut rod presses against the upper shock bushing during suspension compression?

Yes and also when the spring is resting on the upper mount only.

He could possibly invert the mount however, I'm not sure if the angle of the spring perch would bind or not against the upper mount. Only he can be able to tell that by installing it upside down and going through the range of motion.

It is a 5/8's bearing so it has a lot of range.