A couple of Miata questions...

So I've been tearing into the recently purchased '95 NA, basically ticking off the list of well-known Miata issues going 'yuuuup', then fixing them as the parts made their way across the continent. Once I fixed all the usual issues like leaking slave cylinders, electric antennas permanently stuck at half mast, torn shifter boots etc etc, it's time for some actual improvements on the car and I figured I can do with a GRM reality check on those.

Overall plan for the car is to have a fun DD with some HPDE use and probably the odd Auto-X (never took part in the latter so I don't know if I'd like it). As such, a completely stripped car with racing seats bolted to the floor and window nets isn't quite on the agenda, but I'm planning to attend the local SCCA HPDEs and probably go to Thunderhill/Infineon occasionally. And if Miatas at Mazda Raceway Laguna Seca is happening this year I'm probably in, too.

Once the servicing is concluded, I was thinking of addressing the various issues in the following order:

• Brakes. There isn't much live left in the pads anyway (we're talking them being down almost to the wear indicators), but the disks look OK-ish. No big wear lip or anything. That said, the car hasn't got braided brake hoses either so I'm toying with the idea of doing hoses/disks/pads at the same time. As to pads, what's the current consensus for mostly street use? I used to run one with Hawk HP+ but that was more of a track car and I can't remember how well they worked cold.
• (Snow) tires - the tires on the car need chucking anyway so I'm thinking about putting some snows on the 14s and get a second set of 15" wheels for the summer
• Suspension. The one on the car is the original one and it's done 125k. 'nuff said. The above mentioned Miata that I had in the UK was running GAZ coilovers and that was a pretty good setup, but I'm not planning to import a set from the UK. Plus I'm not sure I actually need coilovers - I need better (well, decent working) dampers and probably a 1" drop in ride height, plus some sway bars. Any recommendations? I was considering this kit from FM, but are there others I should consider?
• Rollbar. I've got a hardtop already and the local SCCA tech guys would let me run like (they've confirmed that) that once I've put the side striker plates in, but I'm still thinking that a rollbar is more or less a necessity.
• A set of 15" wheels (15x7 preferably) with decent high performance summer rubber that's trackable. I don't really want a set of track-only wheels due to transport issues, but summer wheels with something like 205/50/15 RS3s on should probably do the job.
• Chassis stiffening. I was thinking Boss Frog arms and some sort of underbody bracing.
• Seats. Not sure that I'll put that this late. I'm currently trying to figure out what I want to do seat wise - foamectomy, if so how much would that affect the long-distance comfort, a set of decent race seats (might be an expense probably as I don't really want to buy knock offs, so I'd be looking at ~$1500 for seats and sliders) or a set of Elise seats. I might do this earlier as I know just how much of a difference a good seat makes in a Miata on the track. OTOH, there isn't much of a track season going on at the moment.

Anything I'm missing? I've left out the obvious maintenance work and some of the smaller "fun" bits, but other than that this is the "grand plan" atm.

Seems like a well thought out plan. The only change I'd really make is to get some wider wheels. 7.5-8" wheels should fit easily. I'd get some 6UL's if for no other reason than because they don't seem to depreciate. People sell used ones for only slightly less than the cost of new ones minus shipping.

Look at the Flyin' Miata VMaxx coilovers, that's why I bought for mine (but haven't installed them yet). $700 for quality coilovers with mounts is pretty good. Also planning on poly bushings, FM sways and adj links.

Mine is going to be an HPDE, nice weather toy. And my plan is similar.

I'm going with 15x8s, but have a set of 205/50 R888s in the spare bedroom. Like the Konig Flatouts since they are same weight and nearly $200 cheaper a set than the 6ULs.

Going with the Hard Dog Core and FM butterfly brace.

As for brakes, I picked up a set of NB Sport brackets/calipers. And I'll order a set of new rotors/pads/lines, likely Carbotech XP8 on the pads.

Also discovered a nice puddle of hydraulic fluid on the garage floor when moving the Miata after not being driven for a few weeks, so I too am about to do the slave. And probably rebuild the shifter.

Two things.

Yes, Miatas at Mazda Raceway Laguna Seca will happen in 2012. Announcement next week. Mazda gets twisty if we just call it Laguna Seca, and since they're instrumental in us getting the track, it's Miatas at Mazda Raceway Laguna Seca!

Second, give me a call. We'll talk through your options.

Keith wrote: Two things. Yes, Miatas at Mazda Raceway Laguna Seca will happen in 2012. Announcement next week. Mazda gets twisty if we just call it Laguna Seca, and since they're instrumental in us getting the track, it's Miatas at Mazda Raceway Laguna Seca!

Fixed.

Keith wrote: Second, give me a call. We'll talk through your options.

Ok. Just call FM and ask for you?

Tim,

You've got mail

BoxheadTim wrote:

Keith wrote: Two things. Yes, Miatas at Mazda Raceway Laguna Seca will happen in 2012. Announcement next week. Mazda gets twisty if we just call it Laguna Seca, and since they're instrumental in us getting the track, it's Miatas at Mazda Raceway Laguna Seca!

Fixed.

I have no idea what you fixed...

BoxheadTim wrote:

Keith wrote: Second, give me a call. We'll talk through your options.

Ok. Just call FM and ask for you?

Could be anyone here, actually - Bill, Jeremy or Brandon would be just as good.

Since we are on Miata questions, Keith, '90 adding NB sport brakes............which master cylinder would you recommend?

change out the Tranny fluids and the diff fluid if you havent already. the chassis stiffening can be done with the front subframe brace, the cannon brace, the rear subframe brace and the Boss Frog side arms. Flying Miata makes a Butterfly Brace that looks beautiful. a strut tower brace really doesnt do much seeing as Mazda incorperated a double wishbone, fully indy suspension in the Miata from the get go.Also, check check out your bumpstops. that should give you a good start on it. also, if you plan on keeping the factory airbox, drop a Green filter in there. best aftermarket filter out there. I know. I have one and i love it. waaaayyy better than a K&N filter.

Fluid are all on the list of items that need to be changed out (that's the maintenance part I was referring to above).

If your changing the transmission fluid and replacing the shifter boots, Mazdaspeed sells a cheap little aluminum bushing that replaces the plastic one at the bottom of the shifter. It's a drop-in replacement that upgrades an already great shifter to bolt-action rifle precision.

From their site:

Part number: 0000-02-9402

C

BUSHING, SHIFTER (1/2")

1

RX7 TT, Miata

ALL

1993-95 1990-03

$9.35

Replaces the stock plastic bushing which can wear quickly under racing conditions. A worn shifter bushing causes increased wear to synchro rings which can result in serious damage to other trans components. Aluminum bushings are not available for 1981-86 RX-7's. Fits 3rd gen RX-7 and all Miatas.

Notes: MIATA, RX7 TT

I am also interested in brake options and opinions ..

Installed the FM gas pedal extension and discovered that the brake pedal needs to be higher, I think the old stock pads might have a lot to do with that.

As far as suspension, I am quite happy with my (possibly spendy) setup. Ground control coilovers with Koni SA yellows, RB adjustable front bar.

Wheels, you could get what I have been drooling over. http://949racing.com/15x75-6UL--wheels.aspx

Right now I have Konig Foils on mine http://www.1010tires.com/images/wheels/konig_foil_slvr_lg.jpg

If you leave the Boss Frog stuff off and dont have a torsen, you have a good STS autocross car. If you do have a torsen, you have a decent STR ride. The Boss Frog stuff will bump your class (if you care about that).

z31maniac wrote: Since we are on Miata questions, Keith, '90 adding NB sport brakes............which master cylinder would you recommend?

If possible, I'd put in the entire system: master, booster (those two have to go together), all calipers, all rotors, etc. I'm considering putting the Sport master and booster in one of my cars that doesn't have any of the other Sport bits, as it's a larger diameter.

You can adjust the height of the brake pedal somewhat. Just make sure you don't take out too much free play, or you might cover up the return hole in the master. The result is brakes that apply themselves as the fluid gets hot.

^Thanks for the suggestion, I've got all 4 calipers/rotors, brakes feel fine now but I get all ancy and start replacing stuff, so I might as well make it a matched system.

Say I wanted to be lazy, would the stock '90 master/booster OK for now, so I can direct that money toward chassis stiffening/safety, or would you go and do it?

It'll probably be okay. The downside is the potential for a softer pedal, as the pistons are larger in both the front and rear Sport calipers. The main reasons I'm thinking of installing the later master/booster on my car is that 1) mine just started leaking and 2) there's a Mazdaspeed being torn apart on the lift right now. I have the Sport booster/master on the Targa Miata as well.

mguar wrote: OK you seem to have a plan and a priority list. What I suggest is that you assign some sort of cost benefit ratio.. Example the improved shocks might save you say a second a lap. (stiffer springs will save you several seconds a lap, do not mistake the need for stiffer springs for a need for adjustable shocks..)

Part of the problem is that as I mentioned, I'm still running the original shocks and they're shot, period. The state of them is noticeable even during spirited road driving so I think it's fair to say that they need replacing . Which leaves me with the choice of either replacing just the shocks or going for a package that's designed to work well together. Part of the reason of me asking for recommendations was because I'm not that familiar with what's available in the US suspension-wise as the previous Miatas/MX5s I owned were all in the UK. Over there I know what to buy.

mguar wrote: Seat? Well it will help you stay in place during high speed cornering. at a cost of comfort.

It's also a helmet clearance issue - on the stock seat I barely clear the hardtop with a helmet on my bonce. Going for something like Elise seats would fix that, as would swapping in a race-ish seat for track excursions, if I get one that is low enough.

mguar wrote: Chassis stiffeners? Only if a lot more power and stickier rubber is added will an improvement in lap times be seen..remember in the end you are adding weight.

Fair enough, OTOH with the cars I've driven that had frame rails put on, it did make a noticeable difference to the feel of the car. I haven't had a chance to drive one with the Boss Frog arms so I can't comment on their effectiveness.

Don't forget that the car is not a stripper - it's a fully loaded Miata and it's going to stay that way so the weight penalty is not as high as if I'd started with, say, an R spec.

mguar wrote: Wheels and tires.. Boy more money is wasted on that subject than you can believe.. First find out what the stock wheels weigh.. then no matter what keep the weight at or below that.. Otherwise you will need to re-engineer the suspension in order to get better performance..

Yes and no. The choice of performance rubber is much better in 15" than in the OEM 14". I've run Miatas on the track with both 14" and 15" wheels with almost equivalent rubber and I'd go 205/50/15 any time. Which means I need a second set of wheels . That said, I'm planning to get some fairly lightweight wheels, it's just a matter of how much the wallet can bear.

mguar wrote: Then adding power to an underpowered car is a improvement but there too you need to balance cost benefit.. Realize that much of the stuff advertized won't make anywhere near the power they talk about.. As far as camshafts go, yes they make more peak power but at a cost of bottom end power.. The average power may actually go down.

TBH I'm not planning to add much power to the car as the additional cost isn't worth it. If/when the time comes that I've wrung out the Miata completely, I'm probably going to get something with a little more poke instead - either another 911 or I'll get a friend in the UK source me a Caterham or Westfield that's old enough for importation.

That said, I have owned a mildly turbo'd Miata before that was about as quick as the Elise S1 I bought afterwards. I might consider that route, but at the moment the idea is to optimize what's there and learn how to make the most of it.

In reply to Woody:

That might be a good idea. I've just swapped in new shifter boots, but I'm pretty sure that the whole mechanism could do with an overhaul.

In reply to Apexcarver:

Given an almost unlimited budget I'd get a set of TE37s in bronze, but I am having thoughts about the 6ULs. Still prefer the looks of the TE37s, though .

If you like the GAZ setup, I can only promise that you will love almost any suspension you put in the car We tested it and, well, let's just say it didn't get into our catalog. You'll LOVE the Stage 2.5 by comparison.

mgar, I'm going to disagree with a number of your points. Springs will make a difference to a suspension, but the shocks are what make it or break it. And it's not just lap times, either. Allowing the suspension to follow the road surface will improve both handling and ride quality, and it's the shocks that make all the difference. A Miata with 125k on the chassis no longer has properly functioning shocks anyhow.

Chassis stiffness is always good. A stiffer chassis effectively isolates the suspension, freeing it up to do its job without the platform flexing around. The end result is more effective damping - which means better roadholding and a better ride. The Frog Arms from Boss Frog are useful, but not as effective as the FM frame rails or (even better) the butterfly brace. The reason is because of the area they address.

Light wheels are good (and especially when the car is light), but if you're forced to run poor rubber on narrow wheels as a result then you'll pay a penalty in performance. Luckily, Spec Miatas run a 15x7 wheel with a 13 lb minimum weight, which means there are a lot of strong, cheap 15x7 wheels on the market right around 13 lbs.

Keith wrote: If you like the GAZ setup, I can only promise that you will love almost any suspension you put in the car We tested it and, well, let's just say it didn't get into our catalog. You'll LOVE the Stage 2.5 by comparison.

Heh . The ones I had were not the ones direct from GAZ, but a tweaked version (I think they had different spring rates) by one of the Miata specialists in the UK, but I guess that was still a sow's ear/silk purse problem.

Keith wrote: Chassis stiffness is always good. A stiffer chassis effectively isolates the suspension, freeing it up to do its job without the platform flexing around. The end result is more effective damping - which means better roadholding and a better ride. The Frog Arms from Boss Frog are useful, but not as effective as the FM frame rails or (even better) the butterfly brace. The reason is because of the area they address.

The plan was to fit the frame rails and possibly the butterfly brace first, then maybe add the Boss Frog arms at a later stage.

I assume that a proper rollbar (most likely a Hard Dog) will also stiffen up the rear of the chassis?

With the mention of shocks and springs, dont forget to include the sway bars. Also, as I mentioned earlier, check out your bump stops. In a straight line, there isnt much resting on a Miata's bumpstops, but start cornering and alot goes on to the bumpstops. Flying Miata sells em for $50 or so. I'm gonna look into getting the metal shifter bushing for my 91 NA even though I've already dropped a new plastic one in. A roll bar could stiffen up the rear end of the car. Have you thought about advancing the timing on the engine from 10 degrees BTDC to 14 degrees BTDC? That can help free up some power at the expense of MPGs.

The roll bar will certainly add some stiffness in the rear of the car, but it's also probably the stiffest area to start with. So don't get too excited about that. Luckily, that's not their primary purpose

The 2.5 kit that Tim mentioned earlier includes bumpstops as well as sway bars. My priorities when upgrading the moving part of NA/NB suspensions is:

1. replace what's broken (ie, worn out stock shocks)
2. sway bars
3. springs/shocks/bumpstops (together)

Also, upgrading the part of the clutch line that is rubber and that goes down to the coils then goes into the slave cylinder to one that is stainless steel and goes straight down into the slave cylinder should help too. Better clutch disengagement with better pedal feel. couldnt hurt to do it at the same time as the slave cylinder if you havent already done that. 5XRacing.com has em pretty cheap and they have pretty fast shipping. Thats where I get the majority of my part orders at.

I assume that a proper rollbar (most likely a Hard Dog) will also stiffen up the rear of the chassis?

Yep, most definitely. I installed a Hard Dog Hard Core DD a few weeks ago. The car isn't insured right now, but I did drive it up and down the road and tossed it back and forth a little. An immediately noticeable improvement in chassis stiffness. You can also tell that you've picked up substantial weight up high though. For what you're planning, its not really "optional" though.

miataman86 wrote: Also, upgrading the part of the clutch line that is rubber and that goes down to the coils then goes into the slave cylinder to one that is stainless steel and goes straight down into the slave cylinder should help too. Better clutch disengagement with better pedal feel. couldnt hurt to do it at the same time as the slave cylinder if you havent already done that. 5XRacing.com has em pretty cheap and they have pretty fast shipping. Thats where I get the majority of my part orders at.

There's a stainless steel line in the same parcel as the slave cylinder that's creeping across the state over from FM...