Moton Street Sport Review

rldzhao wrote

well, it is christmas, and europeans love to take vacations... haha

according to my conversation with moton, the replacement parts are going be made in the netherlands, so it will be at least a few weeks.

Any more news?

STALKER wrote

Any more news?

They have built a whole assembly (with springs) on their shock dyno and were able to replicate the problem and determine the exact cause of the noise.

I for one am not rushing them since I want it done right this time. This will be my 4th set of shocks and I will freak out if my next set makes even a peep.
I volunteer rldzhao to be the 1st to try out the new shocks when they're ready.

I did some driving in the hills today to get some baseline settings with the new springs. There is no way I'll have any bottoming problems now.

RickyBobby wrote

They have built a whole assembly (with springs) on their shock dyno and were able to replicate the problem and determine the exact cause of the noise.

I for one am not rushing them since I want it done right this time. This will be my 4th set of shocks and I will freak out if my next set makes even a peep.
I volunteer rldzhao to be the 1st to try out the new shocks when they're ready.

I did some driving in the hills today to get some baseline settings with the new springs. There is no way I'll have any bottoming problems now.

When were you bottoming out with the Motons? Thats not a good thing to hear.

I was bottoming out on all of my local tracks under full compression. I could get it to happen with stock rubber and larger sized r-comps. I was only lowered .8" and I'm not sure why no one else was experiencing this. Maybe it's a coupe vs sedan thing. Who knows. I'm a bit baffled as to how they chose the rates for this kit. I would think that anyone dropping this kind of money would be serious about track driving and would want something a bit more aggressive, but I understand that they wanted to make something for the masses. Lex from Moton told me that some people might actually want to take their wives and mothers in the car so the spring rates were chosen accordingly . Perhaps some people like to keep their cars stiff so their wives won't want to drive them.


At any rate, the fronts were rubbing away at my fender liners and the rears were rubbing at the gas filler tank. Early adopter syndrome again..
Pics attached of my wounded car.

Im disappointed that Moton did not take their time with this kit to work out all the bugs. I still think its the best kit out there because of their shocks, but it still needs some work.

STALKER wrote

Im disappointed that Moton did not take their time with this kit to work out all the bugs. I still think its the best kit out there because of their shocks, but it still needs some work.

Moton bumpstops are way too short. This is why Ricky experienced "hard" bottoming, i.e. tires rubbing.

The OE bumpstops, which also act as addtional springs, are at least 3x longer vs. Motons. This is how the OE suspension prevents bottoming out.

Moton has always been a racing damper manufacturer, and they only got into the so-called street sport dampers in the past few years. Hence, they have limited experience when catering to the needs of those who drive street cars, i.e. plug and play, minimal noise, durability, etc.

One needs to understand that for a racing suspension, every application is highly customized: spring, dampers, mounts, etc. are all specified by the customer. And this of course, includes the bumpstops, if they are needed at all.

In many race car applications, because the springs are so stiff, the suspension deflects very little. Therefore, a suspension would almost never reach full compression and need bumpstops to help absorbing the impact. This is probably why Moton did not spend a lot of time designing the bumpstop for the E92. Rather, they probably threw on some generic bumpstops from other applications.

Therefore, with these things in mind, the Moton kit is NOT your average plug and play kit. It is a kit for those who have some technical know-how and are willing to spend time and effort, and the result should be quite rewarding.

I do, however, think that in a few years, Moton kit will become much more user friendly. It just takes time for a manufacturer to mature.

Possibly the difference here is that their ClubSport models had internal limiters that acted as bumpstops at extreme limits of travel. Perhaps the streetsorts don't have that cricuit. In general, the more travel the better for a given ride height, outside of causing damage.

rldzhao wrote

Moton bumpstops are way too short. This is why Ricky experienced "hard" bottoming, i.e. tires rubbing.

The OE bumpstops, which also act as addtional springs, are at least 3x longer vs. Motons. This is how the OE suspension prevents bottoming out.

.

When I initially discovered the rubbing, my first call to bw was to get longer bumpstops. In the pictures above you'll notice that there is a zip tie pushed way up on the front bumpstop indicating that the bumpstops are not long enough. In the rear, the car bottoms about an inch before the bumpstop even is reached!

There are many different opinions on tuning with bumpstops. I have always used them in my applications to ramp up spring rate under the very last bit of travel, but moton and James are on the other end of the spectrum and think the bumpstops should never be touched. If you run out of travel, add more spring.

I'm going with James and Moton on this since they know a thing or two about suspension. From my limited testing, it looks like the stiffer springs have given me more than enough platform support to stay far far away from my bumpstops.

RickyBobby wrote

When I initially discovered the rubbing, my first call to bw was to get longer bumpstops. In the pictures above you'll notice that there is a zip tie pushed way up on the front bumpstop indicating that the bumpstops are not long enough. In the rear, the car bottoms about an inch before the bumpstop even is reached!

There are many different opinions on tuning with bumpstops. I have always used them in my applications to ramp up spring rate under the very last bit of travel, but moton and James are on the other end of the spectrum and think the bumpstops should never be touched. If you run out of travel, add more spring.

I'm going with James and Moton on this since they know a thing or two about suspension. From my limited testing, it looks like the stiffer springs have given me more than enough platform support to stay far far away from my bumpstops.

Sure for an ideal race car suspension what they are saying makes sense.

But for the spring rates that have been chosen for the street sport kit, if it is still bottoming out, obviously something should be done to address the issue.

Hey Ricky, for the rear shock, did the Moton bumpstop ever reach the top? Or is the picture showing how high it will go?

I am inclined to just use the E36 M3 bumpstop (0.25" shorter vs. E92) for the front and the E92 bumpstop for the rear.

Do you guys think slightly stiffer springs is a good idea?

rldzhao wrote

Hey Ricky, for the rear shock, did the Moton bumpstop ever reach the top? Or is the picture showing how high it will go?

I am inclined to just use the E36 M3 bumpstop (0.25" shorter vs. E92) for the front and the E92 bumpstop for the rear.

The rear picture is showing how high it will go. You can add about an inch more of bumpstop if you want to protect from bottoming.

rlzhao, did you ever experience bottoming? I know that barryc didn't experience any rubbing even after track driving. Maybe it's just a sedan thing.

stalker wrote  

Do you guys think slightly stiffer springs is a good idea?

I'm the wrong person to ask (said the man with the higher spring rates)

RickyBobby wrote

The rear picture is showing how high it will go. You can add about an inch more of bumpstop if you want to protect from bottoming.

And this is with what kind of ride height?

I haven't taken the car to the track yet, but I just want to play it safe

UPDATE - the problem is solved and is now a solution that will fit in the production assembly. No final date, but hoping in a month or so. I will drive for 1 week on our car to prove and then we will retrofit existing dampers.

JamesC wrote

UPDATE - the problem is solved and is now a solution that will fit in the production assembly. No final date, but hoping in a month or so. I will drive for 1 week on our car to prove and then we will retrofit existing dampers.

Sounds good. Thanks for the update.
Are they making any other changes to the kit, spring rates, bump stops, sway bar link attachment points??

There will be a tweak to sway attachments, but it is pretty typical to need shorter links when you lower a car or put on a more aggressive suspension. No change in spring rates planned and as noted here bump stops aren't necessarily what we want to rely on. The car can be lowered on par with lowering springs and still not bottom for track use - although the Laguna situation is certainly a test and that might require a closer to stock height.

I have done the work (with a little help) to make changing spring rates painless so for those who do want a more aggressive setup, the dampers will fully support it and we can double the spring rates or more if desired.

jamesc wrote  

UPDATE - the problem is solved and is now a solution that will fit in the production assembly. No final date, but hoping in a month or so. I will drive for 1 week on our car to prove and then we will retrofit existing dampers.

Great news James! I'm assuming the changes will not affect the current performance or durability, correct?

STALKER wrote

Sounds good. Thanks for the update.
Are they making any other changes to the kit, spring rates, bump stops, sway bar link attachment points??

I hope that you don't think that the kit needs new springs based off of my review. The supplied springs are perfect for the intended target audience. They're pretty much the same as what comes with other kits like the bilstein pss and KW V3's, except the superior shocks do a better job with body control. Camber plates aren't really that necessary either. Rickybobby wants to go fast so he went with stiffer springs and plates In a couple of weeks, I'll be at the track to see if we chose wisely on the spring rates. Based off of my street driving I think we (James) did.

While I understand Moton's stance on the bumpstops, I still think that they could be longer to provide a safety measure against rubbing. I'm an anal retentive car owner and it kills me that I rubbed through the fender liners and took off some sheet metal. Laguna was pretty much undriveable at .75" drop and I couldn't take T15 flat out at Thunderhill without smelling buring rubber. For my last event, I raised the car back to near stock height and didn't get any rubbing at thunderhill but I was not pushing it as hard since the rubbing was always in the back of my head.

I'll post a full report in a couple weeks with after a (hopefully dry) track day.

RickyBobby wrote

While I understand Moton's stance on the bumpstops, I still think that they could be longer to provide a safety measure against rubbing. I'm an anal retentive car owner and it kills me that I rubbed through the fender liners and took off some sheet metal. Laguna was pretty much undriveable at .75" drop and I couldn't take T15 flat out at Thunderhill without smelling buring rubber. For my last event, I raised the car back to near stock height and didn't get any rubbing at thunderhill but I was not pushing it as hard since the rubbing was always in the back of my head.

I completely agree with RickyBobby. 1 Moton bump stop at each corner (0.8" uncompressed length) is obviously NOT enough to prevent bottoming.

From my calculations, testing, and measurements, in the front, one needs a bump stop that will compress to about 1.0" (at this point the bump stop stiffness should shoot up) to prevent bottoming.

The front is an issue because the Moton front strut body are about 1" shorter vs. factory. This means that the wheel/tire is actually mounted 1" higher vs. stock, so it is more prone to rubbing the fenders.

The rear is less of an issue due to larger wheel well clearance.

I understand that Moton wants to utilize the springs and only the springs for predictable, consistent weight transfer and handling, but IMO this is not a race kit for a race car, so safety, compatibility to OE, and 'plug and play' should also be considered. Further, having a properly designed bump stop with a progressive rate is not going to kill handling.

The shaft is not going to bottom which is usually the concern. Tire rub can be addressed by raising the car. Even a very long bump stop won't stop tire rub. A progressive rate is not the performance option - makes dialing in a damper fairly impossible.

This kit is a higher end kit with adjustment and a lot of options to tailor it to your use. As-is I ran ours on the track about 1/2" lower than stock with 275 tires all the way around and no rubbing. Some tracks are more demanding (Laguna is a shining example), so you may need to raise the car some from the lowered height. Or if you are a track guy, you probably aren't too upset with a stiffer spring as long as it doesn't add harshness and you can upgrade easily.

There is rarely a one-size fits all solution when you get to higher-end niche products. This kit has the capability to cover a lot, the components available to make it suit your needs, and the adjustment to work for almost every application with the included parts.

The Moton spring is shorter, but the rates are higher and the perches are adjustable and stock ride height can be achieved. Stop calculating and get some laps on them!

James, I understand where you are coming from. I just wanted to voice my opinion as a user for the benefit of Moton... most people buy this kit for their DDs, so it is supposed to be a compromise between practicality, street-driveability and sportiness. And I believe that for the more serious racers, they would opt for the Clubsport or Motorsport line of products.

Perhaps a middle ground would be for Moton to provide some instructions and let users know, for example, how to set up the ride height to avoid unintended damages to their cars.

Yes I am going to the track in two weeks. I just got my kit back from Moton and installed so that I can get some laps on them -- even though they are not yet updated. I will just need to give the noise some more tolerance.

Your presence on the forum and the knowledge you bring is very much appreciated

RickyBobby,
Just curious but am I reading it correctly from the post above, that even with the stiffer springs you are still experiencing rubbing at a 0.75" drop but not at a stock ride height. I guess I'm curious if the stiffer springs helped with the bottoming out or not at the lowered ride height (0.75").

Thanks,
Royce M