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Nov. 5, 2008 3:17 p.m. measure twice None

I'm going to pick up a Miata in the new year after moving to Atlanta from LA. I'm trying to budget the upgrades, but I have a few questions. I'd like a track car that I can drive to events, hauling DOT-R tires and other goodies on a small trailer.

I'm not sure how far to go with the suspension - I'd like adjustable coilovers for corner weighting, but as I price the options it seems silly not to get the spec miata items. For track days, what sort of performance advantage is there between the spec miata suspension setup version something like Koni sports with stiffer springs, etc?

Any info or links appreciated.

Thanks!
Nov. 5, 2008 3:48 p.m. billy3esq Dork

I'm having similar thoughts for my new (to me) Miata track car. My current thinking is the GC coilovers with the 375/250 or so springs (see, e.g., good-win-racing.com) and Koni Sports. However, I'm open to suggestions from the peanut gallery.

My thoughts on the Spec Miata suspension (rates something like 700/350) are that while it is a known quantity, it may be too much for driving to/from the track, which is a minimum of 60 miles for me.
Nov. 5, 2008 3:59 p.m. Keith UltraDork
Spec Miata racers run the SM suspension because they have to, not necessarily because they want to. I'm not a Spec racer, but I believe the biggest complaints center around the damping quality. They also run a lot more front spring than is typical - I like to keep my front springs about 1.5x my rears at stiffest. For the Targa car, I had 375/300 and while I needed more spring overall for the race, the car had the perfect balance.

I'd probably stay away from the Konis with stiff spring rates myself, as I think they work at their best with stock rates. My personal "do everything" Miata is fitted with (no surprise) the FM suspension parts, including the Tokico Illuminas. I don't have Ground Controls on there as I don't feel the need to cornerweight that particular car, but that's a good combination that's made a lot of people happy.

My recipe for a great little HPDE Miata on a budget that you can drive to the track:
- FM suspension kit (I have to say that, but since I helped develop it I'd be lying if I didn't think it worked well!), possibly with GCs
- Roll bar - my favorites are the Hard Dog Sport or Hard Core, depending on local regulations and ratio of track/street use
- Harnesses or a CG Lock
- Decent 15" wheels (the upcoming TRMotorsport C1 looks good for $99) with 205/50-15 Toyo RA1s
- Good brake pads
(sorry about the formatting of the list, I cannot make anything else work)

That'll give you a good little giant-killer that you can drive every day if you want. If you want to add more power later, you'll have the platform to handle it.
Nov. 5, 2008 4:11 p.m. Type Q HalfDork

I am running 500/350 in my Miata with a set of "R" package Bilstiens. While stiff, it isn't unbearable for 60 miles or more. You can run some some surprizingly high rates in Miatas without breaking your back. The trick seems to be getting dampers that valved correctly. I have been a passenger in a car that runs higher spring rates than mine and ride better. It has OEM Bilsteins that were revalved by Fat Cat Motorsports, a Miata suspension tuning business here in the bay area.
Nov. 5, 2008 7:39 p.m. measure twice New Reader

Thanks for the comments - it becomes so easy to start spending too much money and have nothing left for event fees!
Nov. 5, 2008 8:52 p.m. Woody Dork

I've actually done 100 mile round trips with the Spec Miata suspension and a thinly padded race bucket. It's tolerable as long as you know what you're getting into.

I am between track Miata builds at the moment. I still have the Spec springs and his would be the perfect time to switch to something lighter, but I'll probably just stick with what I've got.
Nov. 6, 2008 6:40 a.m. wreckerboy SuperDork

My Spec Miata spent a fair amount of time on the street while in SM trim. I drove it from NJ to Boston on several occasions. Unless you are a masochist, don't do it. Besides, as noted above, there are far better options out there. The SM suspension couples absurd spring rates with Bilstein shocks that are not well matched to the task.

Someplace in the dark ages of 1998 or so when the class was hatched this is what the "founding fathers" came up with, even though Miatas in other race classes were running set ups in the 500/250 range at that time. A friend ran one in the Motorola Cup series at the time on 350/200's (with really good Penske shocks) and said it was the best set up in a race car he'd ever driven. Usually absurdly high spring rates are a crutch used to keep the suspension from working in cases where suspension travel results in undersirable camber or toe changes. Just ask any Honda or Fox chassis Mustang racer why they run 900 lb. + rate springs in the rear / front. The NA and NB Miata do not suffer from these problems. (I have no idea about the NC.)

The FM kit(s) are a great compromise set up , and what will be going on the street Miata in the future. In addition to what Keith listed above I would add the so-called "99 shock hats" to the earlier cars to increase rear travel, which is limited on a good day. It makes a huge difference in the way the car rides and handles.
Nov. 6, 2008 7:04 a.m. Dashpot New Reader

billy3esq wrote:

I'm having similar thoughts for my new (to me) Miata track car. My current thinking is the GC coilovers with the 375/250 or so springs (see, e.g., good-win-racing.com) and Koni Sports. However, I'm open to suggestions from the peanut gallery.

My thoughts on the Spec Miata suspension (rates something like 700/350) are that while it is a known quantity, it may be too much for driving to/from the track, which is a minimum of 60 miles for me.

I'm doing a 75 mi. each way track commute in an SM suspended '95. This is subjective, but in my opinion it's tolerable unless there are potholes or big dips on your route. In that case the short travel and crappy bump stops add up to harsh bottoming at both ends despite the high spring rates. It can be a rim bending experience.

I don't have a lot of track time on this car yet, but initial impressions are that the SM package sort of does the job despite being under damped. My biggest related complaint is chassis flex, because that feels like half the suspension package. In my opinion there's no point to running high spring rates without a full cage, the steering accuracy turns to mush as soon as you start to load the thing up.

Some chassis bracing like the FM butterfly brace is tops on the list for me.
Nov. 6, 2008 10:30 a.m. Keith UltraDork

wreckerboy wrote: The FM kit(s) are a great compromise set up , and what will be going on the street Miata in the future. In addition to what Keith listed above I would add the so-called "99 shock hats" to the earlier cars to increase rear travel, which is limited on a good day. It makes a huge difference in the way the car rides and handles.

Keep in mind that those NB upper shock mounts will also lower the car. If you install them on a set of non-adjustable springs, you may drop the car to the point of unstreetability. That's not an issue with coilovers. FM does have an option that increases the rear travel without affecting ride height if that's the way you want to go.

Interestingly, at the same time those NB upper mounts have become a popular mod, I've seen a shift in what people consider to be a good handling car. They're being biased more towards understeer now. I don't know if it's a coincidence or not, but the sway bar sets that we've been selling for 15 years or so are now getting complaints about being too tailhappy.