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After years of troubleshooting, strengthening and otherwise prepping my '93 L.E. for dual-purpose street/track use, I've finally thrown in the towel. After my stroker FM II upgrade, I've had to fortify cooling, braking and the differential, replace broken turbo studs and address a myriad small issues. For the most part, the car is now rock solid, EXCEEEEEPT...
...the damn transmission. I've broken my Quaife gear set twice already. Best I can figure is it's heat that kills it, as it won't break on the street or even under hard autocross use. I could muck up some sort of tranny cooler that may or may not keep things together, but at this point I'd just as soon not. The T5 swap that was on the horizon is still on the horizon and I don't particularly want to lose most of our all-too-short track season. So, I bought a track-prepped MSM from a local Club member who's retiring from the scene. Like all heavily-modified cars, I got it for a good price (all the mods would likely cost me more than I paid for the entire car). Highlights:
MSM turbo replaced with an FM II (GT2560R)
FM Big Spark Kit
3" downpipe and exhaust
Xida suspension, coupled with 800 front/500 rear springs
949 Racing anti-roll bars, urethane bushings and Supermiata endlinks
Hard Dog roll bar with harness bar
Hard Dog Door Bars
5-point harness (plus a spare for the passenger side)
Aligned, corner-weighted and lowered for the track
So, how's it drive? The first thing I had to get used to was the gearing. As you know, the Quaife gearset is very long and just about perfect for a high-powered turbo. The short gearing on this thing (stock R&P) has me shifting before I'm even half-way through an intersection. Turbo response is decent but it's not, for obvious reasons, anywhere near as strong as my black car. Considering the heavy springs, it actually rides fairly well, although the ride height gives me fits over speed bumps, parking lot entrances and even undulations in the road. I've got the cringe reflex down pat whenever it inevitably bottoms out on the street. The chassis is rock-solid thought. Between the stiffer NB structure, MSM-specific upgrades and the roll bar/door bars, there is nary a squeak or shudder to be found. Very nice change from my (relatively) flexy-flier NA.
I had my first track day on Saturday and the car acquitted itself well. The suspension is very well-sorted, turn in is crisp and it's very neutral (as I found out on nearly-bald RRs in the rain). Power is adequate although I have to adapt to the gearing on our track (using 3rd and 4th instead of 2nd and 3rd). The brakes are not up to snuff though, as the pedal started getting soft by my third session (despite newly-flushed high-temp fluid). I see at least a front BBK in my future, and perhaps some ducting.
Anyway, it's nice to have a car for the track again, and even nicer to know that issues with the track car won't preclude me from enjoying my street car when the weather is balmy. I'm looking forward to getting to know the MSM over the next while.
Looks great. I like the lug nut mod. Shave weight wherever possible.
I thought about adding that to the caption. Truth is I stashed all the included bits & pieces in a different garage (that had a little more room than mine). Cleverly, I left the lugnuts there and, when putting on my track wheels, had to make do with the eight spares I had lying around. I left a note on my steering wheel to remind me to add the others (which I picked up that evening, using a different car).
Originally Posted by Savington
Was your Quaife the close-ratio or wide-ratio box?
It was the wide-ratio box. Still is, after the recent rebuild. I'm hoping I never have to do that ever again.
I thought it time to update this thread after a few track days and some inevitable teething pains:
Event 1:
The car is missing under load at high rpm. Wondering if the plugs might need to be changed. Mustang GT350 blows an oil cooler line down the main straight (especially maddening since it turns out that part is subject to a recall and he was booked in the following Monday to get it changed out). I was the next person through and found I had no braking contribution from the driver-side of the car. I spun into Turn 1, managing to avoid both the outside tire wall and inside concrete wall. Here's a very quick video showing the turn in question (no, that's not my M3 but the footage is borrowed from my brother because it shows things from a better angle):
It's a fairly short track, but speeds at the end of the straight approach 100 mph and corner entry speed is somewhere north of 70. Unfortunately, I wasn't running a camera that day. Onlookers, however, were purportedly impressed. As a bonus, I didn't have to try out my less-than-optimal restraint system (see my post in the HPDE / track day safety gear flow chart !! thread) or manage to wreck my new (to me) car.
After that event and some on-line consultations, the harness was removed and SFI padding added to all exposed steel bar. I'm also not that happy with the brakes on the car. They take a while to become effective and they're not as confidence-inspiring as the setup on my '93.
Last edited by DeerHunter; 05-26-2017 at 12:16 AM.
The engine miss is worse than ever and has become really annoying. I didn't have time to datalog before this event, but will certainly do so now. My ABS unit is leaking at one of the fittings and it makes an unholy mess of the engine bay.
I tighten it as best I can with a standard box wrench, but will redo with the proper tool at home. I also have to visit a wand wash to try and clean up the liberal application of paint stripper. It's not enough and I have to redo with a bucket and sponge.
While washing the car a couple of days later, I also notice that the front bumper cap is starting to look like the lunar surface - pock-marked with paint chips:
I think I forgot to mention that the previous owner collided with a Corvette on his last track day (in 2016), taking out the hood, bumper cap, driver-side headlight and fender. I knew that he cheaped out on the repair, using a steel hood instead of aluminum and getting the work done at the proverbial backyard shop. Well, whatever discounted price he paid was still too much, as the prep job was really, really shitty. Every time I wash it (even just using hose pressure) revealed more areas where the paint is exfoliating en masse:
Ugh! Trying not to think about it too much. After all, it's just a track car. Nope, still bugs me.
Last edited by DeerHunter; 05-26-2017 at 12:15 AM.
After the second event, I sent my Hydra map to Jeremy at FM for his feedback. He informed me that the fuel mapping bore no resemblance to anything sane and suggested that I start with a new base map. I agreed, loaded it up and then did some datalogging. The car was much smoother, feeling like a properly-set-up FM II. Also, the miss was eliminated. Jeremy agreed and I'll just let LTT (Long Term Trim) work its magic before incorporating it into the base map. Strike one issue.
To address the brakes issue, I place an order with Andrew at Trackspeed Engineering for his Gen 2 Big Brake Kit (11.75", safety-wired, Dynapro calipers) along with some brake duct hose and fittings to adapt it to the fog light openings. They won't arrive in time for the third event, so I'll have to make do.
Event 3:
The weather was perfect and things were going swimmingly. The car, with its new tune, was running happily and hiccup-free (even the ABS unit was gratifyingly leak-free). However, during my second session, I noticed that something was rubbing during hard left-hand turns (the track runs clock-wise, so left turns are in the minority). During the lunch break, I pulled the wheel off and discovered a nice circumferential groove worn into the inner sidewall:
At first I thought it was rubbing in the area of the shock tower and a little lower down:
Then I discovered that it was making contact with the spring as well:
If I crouched in front of the car, I could see that there was clearly more negative camber on the affected (passenger) side. Something slipped and my first thought was one of the eccentric bolts. Either way, my day was done.
Last edited by DeerHunter; 05-26-2017 at 12:30 AM.
I nurse the car home (tight left-hand turns reveal another level of under-fender cacophony). Still thinking the problem is with a slipped eccentric bolt, I place an order with FM for eccentric locks. I also plan to raise the car to a more sane ride height (front is currently about 3.6" measured to the bottom of the pinch weld), so I add extended lower ball joints to the order so that I can still hit my camber target.
While removing the wheels today, I discover that the passenger front has some play, so it seems that the wheel bearing is toast too. Sigh! One more thing to add to the list. Not sure if a toasted bearing could be the cause of my interference woes exclusively, or just a contributing factor. Thoughts?
Anyway, it's in to the local shop for the required parts, ride height adjustment, alignment and corner-weighting. The next track day is June 2nd, so there's not a lot of room for anything else to reveal itself.
If the bearing was that bad, would you have heard the brake rotor grinding within the brake caliper bracket?
No, I didn't hear anything over the other noise. It's still possible that the bearing is going out but that the root cause of the rubbing is the slipping eccentric bolt.
I booked my car into my local meck-ah-neek's shop on Tuesday for some work. I needed the front hubs replaced (I decided to do the driver side prophylactically, even though it wasn't showing signs of wear), I wanted the car raised to a reasonable height (about 4.5" measured to the pinch-weld, up from the current was 3.6-3.75" in front), the requisite alignment plus corner weighting. I found a local source for ARP extended studs (the GM part, which is much less expensive than the Miata-specific option), had them pressed into my replacement hubs and then dropped everything off in the morning.
By mid-afternoon, I received a call from the shop owner (who's also a Spec-Miata racer), letting me know that the minimum camber achievable on my car was about -4.5 degrees! Turns out that the previous owner had installed offset control arm bushings and neglected to tell me about it. Combined with the just-installed extended lower ball joints, and my minimums now seem to be fairly maximum. My original instructions were for them to follow 949's SuperMiata Dual Duty alignment specs. With some further tweaking, they achieved just under -4 degrees in front, so I just had them change the specs to the Race Alignment instead. I know the correct solution is to shitcan the offset bushings, since they pull the inside of the wheel to far inside (which explains the rubbing you see in my earlier pictures), but I didn't have any replacement bushings available plus it would have wasted all the shop time already used. Andrew suggested 5 mm spacers as an interim fix, so those were added to my order leaving that afternoon.
Final alignment specs:
Pretty much spot on (not sure about the front caster, which seems a little on the high side - more on that anon). Better yet, the car corner-weighted perfectly - 50/50 cross weights in both directions. Yay!
The drive home revealed no handling vices. It tracks perfectly straight, steering effort is reasonable and the increased ride height makes our pock-marked roads less cringe-worthy.
Any thoughts about how -3.9 degrees camber will affect tire life? My original plan was to drive to Miatas at MRLS on RA-1s. Not sure if they wouldn't be destroyed en route (about 1,700 miles each way) with these settings.
05-01-2017, 07:01 PM
I give up
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