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Motion Control Suspension (MCS) for NSX

I didn’t even think about the extra fluid volume. Would 1/2” of less body make a significant difference? I did basically need to pry the lower control arm down to get the bottom bolt in. So maybe these are a similar length.

Good to know on the cups. Your cups are like 20-25mm compressed? with a 25mm cup and 6” springs it’d be in the same perch position as my 7” spring. Though I wonder if I could have the spring directly up against the cups instead of the spring hats that are on there now adding 1/2” of height

The curse, already thinking about changing stuff and I have 20 miles on them lol. They do feel good!
1/2" of fluid volume probably makes no noticeable difference but it makes me feel better and I can brag on the socials lol

yes, my cups take up about is about 20mm or so of spring travel so to speak, but you'll notice I machined my cups to mate flat with my monoball top hats. I wanted zero compliance there. NVH has been neglible. I really should get shorter helper springs but after all these years they have been problem free so it didn't occur to me to do so until just now.

I'm sure your new dampers feel great! Love to try them one day.
 
What spring length are you running? That may need to be factored into the final number.

Unfortunately my car is in the shop having the StopTech calipers swapped out or I would get you my number as well.
 
What spring length are you running? That may need to be factored into the final number.

Unfortunately my car is in the shop having the StopTech calipers swapped out or I would get you my number as well.
6" front
7" rear
 
What spring length are you running? That may need to be factored into the final number.

Unfortunately my car is in the shop having the StopTech calipers swapped out or I would get you my number as well.
It looks like somewhere between 1-2”. This is at rideheight:
Something is wrong, then. At the MAX height on the rear shocks (using the 7" springs), I'm at 165 mm or 6.5" measured to the factory point on the rear toe control arm! That's a drop of 48 mm or 1.88"! Slammed! Is it even safe to drive at this amount of drop? :mad:

@MexiRicer @RYU

Even with an 8" spring, the highest I can go is 190 mm, where the minimum specified NSX-R height is 203 mm. Should I order 9" springs, so I can at least adjust the height within the factory specs? Or stick with 8"? Grrrr....

20230127_172746.jpg
 
Paul, you should contact Martin at AR and see what he says. You didn't indicate what length your damper bodies are. I know MCS manufactures them in a variety of lengths.

I have my car back and can measure my springs and dampers tomorrow.
 
Man that’s too bad. Is the car on the ground? Does it look way slammed? Fwiw my rideheight is pretty high as far as hotbois go and there is def plenty of extra room with the 7” rear springs

I’m on 18s in the rear. Measured on the ground after driving, tape pulled from the lowest point of the wheel’s lip (outer of the lip) to the top of the rear fender opening is 23 1/2”. It’s an easy 2 finger gap with chonky 275/35/18 RT660s. That’s 26 1/8” from the ground to the top of the fender opening.
 
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Paul, you should contact Martin at AR and see what he says. You didn't indicate what length your damper bodies are. I know MCS manufactures them in a variety of lengths.

I have my car back and can measure my springs and dampers tomorrow.
OK - here are my numbers:

Rear wheel diameter = 17"
Distance from bottom of wheel rim to bottom of fender opening = 22 7/8"
Damper length = 11"
Spring length = 7"
Distance from top threads of damper to top of top rear perch = 2"

Hope this helps
 
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What’s up Paul! Saw your beautiful Imola on the gram just yesterday. You should post that photo here as well! The ride height looks fine to me definitely not slammed. Looking much more on the highly functional spectrum. Is the issue that you are keen on achieving identical NSX-R ride height settings?
 
What’s up Paul! Saw your beautiful Imola on the gram just yesterday. You should post that photo here as well! The ride height looks fine to me definitely not slammed. Looking much more on the highly functional spectrum. Is the issue that you are keen on achieving identical NSX-R ride height settings?
Thanks Mexi- The IG photo is of the car on NSX-R suspension (cuz, you know, I just happened to have a full R suspension sitting in a box in my garage LOL). Go check my build thread- there are a lot more pics! :) I'm going to do another post here explaining the issue with the MCS.
 
Ok here we go. There are two key problems with this setup. First, the rear shock is several inches too short. Second, the front shock perch is too close to the control arm (thought the front shock may achieve the correct height setting...maybe). I'll explain with pictures.

Let's start with the stated spec. I asked for shocks that would allow me to set the car to the NSX-R specified height range of 165-175 mm Front and 203-213 mm Rear, as measured to the control bolts specified in the workshop manual. Here's a visual from the 1997 FSM:

fsm height.jpg

Why that height? Well, I know that's about as low as I can go to clear the gutter curb to my driveway and the ramp to the parking garage at work. Those are hard limits. In my mind, this meant that, when set to the highest perch setting, the front shocks would sit at 175 mm and the rear shocks would sit at 213 mm. I asked for approximately 10 mm of "safe" adjustment down from that top setting, to account for corner balancing, load differences, etc.

After setting the MCS shocks to the highest perch, here is where I ended up. Note that the fronts are on 6" springs instead of the 7" that came with the setup.

Ride Height.jpg

You don't have to measure to see the the car is sagging badly in the rear- (reverse rake). As noted above, the rear shocks are 48 mm too short (213 - 165 = 48). Looking at the MCS rear dampers next to a genuine NSX-R damper, we can see why. Please ignore the brake line holder and 8 kg spring- we tried this setup on the front side to see if it helped by using the shorter shock body- it didn't.

Rear Shock.jpg

Even without the helper spring fully compressed, the lower mount is drastically too short. Compressing the helper spring, like when the car is sitting on its own weight, only makes things worse (denoted by red arrows). The good news is that the adjuster perch does not seem to interfere with anything, so really all we need is to add 48 mm to the suspension height. I'm not a suspension design expert, but maybe that means either lengthening the shock body by 48 mm, or splitting the difference between more shock threads and a longer spring? You would have to be careful to not make it too long so as it cannot be installed. You can see that on the genuine R shocks, Honda used a really long spring, but it's not the only solution. These dampers will have to go back to MCS for revisions.

Next, attempting to adjust the front shocks to lower them to at least get a proper rake with this too-low rear height setting revealed the second problem: the adjusting perches are too low and hit the upper control arm. Let's take a look.

Front perch.jpg

Here it's not so bad of a problem, but still, it won't work. You can see the difference on the perches. Honda set the perch far away from the control arms and used a very short spring. Even with the helper spring fully compressed (green dotted line) the perch is still too low. I didn't measure, but I think this setup might be better without the helper- the key is to get those adjusting perches far away from the control arm at ride height. However, even with the 7" spring, deleting the helper might make the suspension sit too low.

Looking at the R shock, you clearly don't need all of that droop. It may be better to go with a longer shock body (more threads) and a 4" or 5" spring to more closely match the Honda design, which as shown below, keeps the perch well clear of the control arm.

Front Arm.jpg

I was so furious on Saturday that I was ready to just throw the MCS in the bin and say f$@k it and just run the Type R (which is the perfect height and rides so nicely). But, they are a really, really good shock and I would like to try and make them work. I'll reach out to Martin at AR and see what they can do.
 
Oh my what a PAIN!!! Looks like this damper manufacture still has lots of R&D to do, and you are single-handedly helping them with that. Sorry to sound ignorant but I had never heard of MCS until reading this thread. Those rear shock bodies need an extension of sorts.
 
So I was reviewing a video I made long ago on my JRZs. Just eyeballing it, it doesn't seem like the rear JRZs are that much shorter than yours. Of course, every centimeter matters as you have come to find out unfortunately. I think, per your instructions to the MCS distributor; they didn't measure correctly.

Here's some photos. Notice the shock body on the rears of the KWs are really quite long but overall shock travel seems shorter. Anyway, the suspension guys that sold you the MCS setup ought to know how best to maximize your shock body size taking into account your ride optimal ride height. Your current setup looks even too low for a slammed guys. Again, hard to say without me being there to measure.

JRZ RS (couldn't find a decent pic of the RS Pros). I assume the rears shown below are on a 7" spring so that's also about a 7" exposed shaft lenght (i.e. approx 7" of travel)
img_9633-jpg.135459


47417592751_4f259f5b68_b.jpg


KW V3
037ab246a2a3a03074462c838f1ef92c.jpg


uploadfromtaptalk1362983090361-jpg.98429
 
Oh my what a PAIN!!! Looks like this damper manufacture still has lots of R&D to do, and you are single-handedly helping them with that. Sorry to sound ignorant but I had never heard of MCS until reading this thread. Those rear shock bodies need an extension of sorts.
I am going to strongly disagree with that statement regarding development. MCS does not release a product unless it is thoroughly vetted. I have MCS on my NSX and they are nothing but gold. Hundreds of track miles without an issue. Thousands of road miles - NO ISSUES.

Paul needs to contact AR Motorsports and discuss the issue with Martin. I believe a solution can be found. May be as simple as longer damper body in the rear.

As far as the front goes, the helper spring needs to be under the main spring. That is the way it is on my car and I have NO ISSUES with front control arm clearance.

Here are my front and rear damper specs:

FRONT
:
Wheel diameter = 17"
Distance from bottom of wheel rim to bottom of fender opening = 22"
Damper length (body only - does not include bottom mounting eye) = 12.5"
Spring length = 6"
Swift spring part number = Z60-152-080
Distance from top threads of damper to top of top rear perch = 2"

REAR:
Wheel diameter = 17"
Distance from bottom of wheel rim to bottom of fender opening = 22 7/8"
Damper length = (body only - does not include bottom mounting eye) = 11"
Spring length = 7"
Swift spring part number = Z60-178-060
Distance from top threads of damper to top of top rear perch = 2"

Paul (@Honcho ), please compare these numbers with what you have. While my goal was not Type-S ride height (a little to high for my taste), I did want spring rates equal to the 1993 NSX-R. I am not sure why AR settled on the spring lengths they did for my car, but the whole package works.

Paul, I know you can get to your end goal and hopefully it is just a simple spring length change. Let me know if you need pictures or any other information.

Mark
 
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@mwagner10702 Mark I am in contact with Martin. I've calmed down and I think we can make it work. The rear shock bodies need to be lengthened by 48-50 mm and we can use the existing 7" spring. This will make the rear of the car sit right at 213 mm with the perch at the highest level. For the fronts, it's more about keeping the perch away from the arm than the height- it's not the spring that contacts it, it's the adjusters themselves. Using the 6" spring totally solved this, but it cannot be lowered enough to get to the right height. Either I can try a 5" or add about 10-20 mm to the front shock body. I'm going to discuss with Martin to figure out the best way. Basically, I need the car to sit at 175 mm with the perch at the highest setting.
 
While I'm sure you were disappointed about this obstacle right at the last minute when you're close to driving the car after a few years, these custom fitments typically take some iterations to work out. After Mark, are you only the second person running these? MCS is high quality and the OR shop has a good reputation so I'm sure you'll get this straightened out soon.

I went through the same thing working out customized fitments for my desired goals and the unique restraints with the NSX suspension design. Just takes some patience and iterating. Since I wasn't local on my build, I think we mailed a few dummy setups across the country about 5-6 times! Sucked at the time but it was ultimately worth it!
 
. . . For the fronts, it's more about keeping the perch away from the arm than the height- it's not the spring that contacts it, it's the adjusters themselves.

OK - here is where I am confused. I don't see how it is possible for the lower perch (adjusting rings) to contact the upper control arm. They move in tandem. Here is mine along with a video. This is with a 6" front spring. Damper body is 12.5" long.

EDIT:
After thinking about it and staring at the pictures I can totally see that if your damper body is less than 12 inches long I can see where you could have a clearance problem.

I think extending your front damper length should accomplish what you need. I'd worry a 5" spring might be too short and you might get coil bind under extreme compression.

Also looks like I need to re-do my undercoating . . .

IMG_1451.jpg


IMG_1449.jpg
View attachment NSX Front Suspension.mp4[/USER][/QUOTE]
 
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