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Mazdaspeed Archive => Suspension => Topic started by: Chrisbee on August 13, 2015, 10:32:45 AM



Title: Fox suspension option from FM
Post by: Chrisbee on August 13, 2015, 10:32:45 AM
Has anyone seen this Fox suspension setup from FM for our cars yet? I heard about them working with Fox back in April, and was waiting for these to be released so I could get some stats on 'em before I decided to pull the trigger on suspension.

I know it's still a pre-order deal, so no one has actually tried them yet (other than FM). I just wanted to get some first impressions, and opinions before I reserve a set. To me they look like they have some nice potential!


Title: Re: Fox suspension option from FM
Post by: magnus on August 13, 2015, 06:54:11 PM
Link:
https://www.flyinmiata.com/fox-suspension-for-nb-chassis.html


Title: Re: Fox suspension option from FM
Post by: '95MSM on August 14, 2015, 01:16:40 AM
If I was looking for suspension, I'd jump on that offer. Fox has an excellent reputation in road racing. Not quite Penske or Ohlins, but close.


Title: Re: Fox suspension option from FM
Post by: Chrisbee on August 14, 2015, 01:25:38 AM
Thanks for the link magnus.

It's really tempting. It doesn't look like they're offering it in a kit with sway bars though. And it doesn't say what sway bars they used while doing their tests. I'm assuming they used their bars.
I think I'm going to give them a call within the next couple of days and pick their brain on this a bit. Hopefully I can get a few more details!


Title: Re: Fox suspension option from FM
Post by: rotorglow on August 14, 2015, 04:50:26 AM


It's really tempting. It doesn't look like they're offering it in a kit with sway bars though.

The early-bird discount on the Fox setup means you can get the swaybars almost for free.


Title: Re: Fox suspension option from FM
Post by: pepegas187 on August 14, 2015, 11:03:49 AM
I'm already in. I had a 1980 KTM 175 enduro and it had the most evil set of shocks. After going through a few pair of aftermarket units, I finally installed a pair of Fox Shox. It transformed the bike. Every bike I bought after that sported a set of these excellent dampeners. Add to the fact that everything I've bought from FM has been of excellent fit and finish. Sure i used a set of Ohlins on a Husky enduro I had. They were comfortable. But comfort wasn't what I was looking for. Those early Fox units provided a level of precision and control that I've never experienced with other shocks. So yeah, I'm in.


Title: Re: Fox suspension option from FM
Post by: Jeff Goji on August 21, 2015, 10:31:09 PM
Haven't tried them, but Emilio at 949 Racing over on Miata.net gave a pretty nice write-up on his comparison to their Xida system:

Quote from: emilio700;7634875
No numbers published for either but it appears the fronts have the same stroke (125mm) and probably length. Fox rear is about 20mm more stroke (125 vs 103mm) than Xida if I'm reading it correctly. All else being roughly equal, that gives the Fox more rear droop but less available bump travel. Looking at the Fox hardware, it appears the rear bump travel limit of the Fox is roughly that of the stock NB, which is very good. Better than almost all aftermarket coilovers we have seen.  The Xida rear allows significantly greater than OEM rear bump travel, thus the slightly shorter stroke. We designed them that way because the front likes to work at a certain height and the car is sensitive to rake. That dictated where the working rear travel needed to be for autocross or track use. The Fox kit takes a different approach, optimizing stroke for taller ride heights and softer springs, sacrificing a bit of bump travel at low rear ride heights with stiffer springs.

Where I would expect the Fox to shine is with medium grip tires like say 205 Star Spec on 15x8's at tall ride heights, say  5" front pinch weld on bumpy, cambered back roads. I'd venture to guess they would be difficult to distinguish from Xidas in that environment. Run with something much stickier say, 225/45 Rival-S on 15x9 at 4.25" front pinch weld on a racetrack and I think they would start to be out of their envelope a bit. Probably still work really well, but past their optimization point. That opinion, based on their published dyno plot shown below.

You'll also notice the Fox appears to be single digressive and only adjusts rebound. Xida are double digressive (digression on both compression and rebound stroke) and the single adjuster effects both compression and rebound at the same time. This is key for us as our stiffest damping settings utilize that steep compression nose that would be unusable (or ride horrible) without the digressive piston.

For street driving, we find compression values close to 50lbs at 3 in/sec give the best overall compromise between grip, body control and ride quality. Both the Fox and the Xida hit that sweet spot. Up the grip/aggression level with autocross or track driving and that "nose" of low speed compression needs to come up by about 100%. The Fox is non adjustable there. The Xidas offer that adjustment range.

On the rebound side one can see the Fox have a more conservative "knee" point, again aimed more at ride quality than body control with high grip tires. We experimented with this extensively and found that, particularly with high grip tires, getting those high rebound values at the very lowest piston speeds increased responsiveness and stability at high speeds tremendously. For reference, look at the stiffest setting on both plots at 1 in/sec. 125lbs vs 450lbs. That part of the dyno plot only matters to autocross and track rats running high grip tires in the 1.3G+ range. That would be 225/45 Rival-S on 15x9 or 100tw and softer race tires.

Overall, I think the Fox hit that target street, casual autocross/track customer quite well being a few hundred dollars less than the Xida. For the focused driver looking to optimize for high grip while retaining the same level of street cush as the Fox, the Xida go to 11 :)


SuperMiata Xida front
(http://949racing.com/supermiata/SuperMiata_Xida_F_FVS.jpg)
FM Fox front
(http://949racing.com/supermiata/fox_20miata_20na_20nb_20front2_1_1024.jpg)

Having driven on a number of Xida systems and loved them since my first first drive, I would be more inclined to buy a set of those over the FOX kit as I haven't driven on anything suspension wise from FM that I liked.


Title: Re: Fox suspension option from FM
Post by: Chrisbee on August 22, 2015, 07:00:30 AM
That Xida setup has always peaked my interest. But because the closest track for me is about 3 hrs. away, and I don't have a tow rig, I think that the Fox setup will work pretty well for me. I do agree though, if you're really into tracking your car, on paper the Xida looks like the better way to go.


Title: Re: Fox suspension option from FM
Post by: Chrisbee on September 15, 2015, 12:13:17 PM
Just a FYI for anyone interested in the Fox setup. Sense it's not posted in the Fox suspension page on the FM site, they DO recommend their front and rear sway bars with this suspension.


Title: Re: Fox suspension option from FM
Post by: Woody on December 14, 2015, 09:36:05 PM
Has anyone installed the fox setup yet?  Looking for feedback.


Title: Re: Fox suspension option from FM
Post by: Chrisbee on December 18, 2015, 02:11:42 AM
I know a few people have received their suspension (including myself), but haven't heard anything yet either.
I plan on doing mine over the winter. And having it ready to go by Spring.


Title: Re: Fox suspension option from FM
Post by: timely on May 19, 2016, 08:25:05 PM
So it's been 5 months... anyone here install the suspension that can chime in on how it is?  I'm thinking of getting it for my DD but am trying to decide if it's overkill or not.


Title: Re: Fox suspension option from FM
Post by: Chrisbee on May 20, 2016, 08:42:42 AM
Yeah, mine's in! It depends on how you drive it if it'll be overkill or not. If it's just a commuter, it probably would be excessive/costly option that wouldn't get used to it's potential. I have access to some great twisty mountain roads, and it performs awesome! I wish I knew an alignment shop that does corner balancing too. Can't find anyone who owns the scales to do it.


Title: Re: Fox suspension option from FM
Post by: timely on May 20, 2016, 11:26:33 AM
How is the ride comfort?  I'd get good use out of it and do eventually want to do autox.  I'm more concerned about breaking my back on the crumby philadelphia roads


Title: Re: Fox suspension option from FM
Post by: '95MSM on May 23, 2016, 06:46:46 AM
... Can't find anyone who owns the scales to do it.
2,500 mile round trip from Williams to Newport, WA.

Now you'll have to say you can't find anyone close enough.


Title: Re: Fox suspension option from FM
Post by: Chrisbee on May 24, 2016, 06:26:32 AM
How is the ride comfort?  I'd get good use out of it and do eventually want to do autox.  I'm more concerned about breaking my back on the crumby philadelphia roads

It definitely rides better then stock! The roads suck pretty bad in my town too. I'm not sure how comfortable of a ride you're expecting out of these cars though. There is still a lot of jouncing over rough roads, but being what it is I expect it. There is a adjustment for the dampers on the top, but I just set it up a bit on the aggressive side and left it, as I don't DD mine. I think it just depends on what your wallet says.  ;D
I've already spent so damn much money on this car with the FM 2 kit, I figured why stop there!


Title: Re: Fox suspension option from FM
Post by: Chrisbee on May 24, 2016, 06:28:55 AM
... Can't find anyone who owns the scales to do it.
2,500 mile round trip from Williams to Newport, WA.

Now you'll have to say you can't find anyone close enough.

Yes, I guess I should've elaborated on that.  :)