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Named Tia because it's sister car(99 ST6 build, also silver) is Mia, Tarmac starts with a "T", and this TT6 car will likely stay a street legal Time Trial car.
The car started as a rescue. Previous owner was a DIY turbo yolotard who mangled the engine bay wiring and vacuum systems, cut off the rear tow hooks and we ended up with this:
2001 base. No appearance pkg, no ABS, no Sport stuff.
72k miles.
Build theory: Do it right the first time with everything I've learned building a bunch of other Miatas while making as few budget oriented performance compromises as possible(IE: Hawk pads instead of $$$ GLoc).
Goals:
1. Regional contender in NASA TT6
2. FTD capable Buckeye Miata Club Autocross car
3. HPDE Rental
4. Regional contender in SCCA STR autocross
Stage 1: The basic mods/get it reliable.
Status as of July 2019: INCOMPLETE(car still not reliable)
Plagued with CELs and a persistent cold start misfire we found that both o2 sensors were failing/shorting on the header and ppf, respectively. This is probably from PO's turbo exhaust mods and hackjob wiring. This problem later sparked a cabin fire during the drive to my attempted first shakedown at a BMC autocross event as the front o2 sensor short smoked the lead back into the firewall and under the dash. A couple new relays, fuses and two new o2 sensors seems to have stopped this nonsense.
In addition to replacing the missing body panels, stage 1 also included a replacement soft top, second hand rollbar, and the initial round of tune up/maintenance catch-up bits. At this point it was at least a running car:
Stage 2: Chassis.
(Stage 2a: Paint the bits to match.)
Doing it right the first time means Supermiata Xida, bro. Specifically 900/500 Big Grip Kit with coaxial mounts.
I had some used Hawk DTC60s with matching bedded rotors left over from my pre-GLoc Lyfe, so they made their way onto this car.
It also got a radiator upgrade and clutch hydraulics overhaul.
This set of Kosei/RE71R is my rain TT6 setup.
I've since lowered it a bunch more searching for more front camber. It still has factory rubber bushes and a 100% stock drivetrain at this point.
Weight is 2480 with me in it on a NASA scale at two different tracks now. This COSI public scale is within 5lbs, as I weigh 190 with gear on.
Saturday I ran 2 TT sessions and the ST race. Sunday I ran TT all day so Jordan could do both ST races.
I finished 3rd in TT6 on Saturday with a 1:49.720 on the RE71Rs while working through a weird rear hub nut issue and dialing the suspension in.
On Sunday I ran the 205 R7s on my set of TiO2 949 Racing 6ULs. Sunday was much faster between the tires, setup work and getting used to driving with a stock seat/belt/steering wheel. I was able to nearly match the track record Chris set on Saturday with a 1:47.9 in session 2, which held on for P2. Chris went a bit faster, lowering his record to a 47.2.
Gingerman in-car video of Sunday P2 lap. 1:47.9
Excuse the shitty camera angle, this Bossfrog Clearview hardtop rollbar is crummy, so the camera is on a diagonal with 4 gopro extensions to get it to point straight, and its too low.
This was the lightest the car was all weekend at 2411lbs. I was running on 8" 6ULs and 2 year old 205 R7s that Sonny and I have both raced on in Socal. 119 peak whp.
20:1 peak
Probably a 22:1 AVG power car. LOL
...it’s pretty cool someone can be regionally competitive in TT6 with such a modest VVT build.
Also, I don’t know why, but the dent on the driver front fender really rubs me the wrong way. Like, really, really bothers me...
Agreed on both accounts. The fender had a stupid large bandaid sticker over that dent that I couldn't live with anymore. Also, the door grabs the fender when it opens and it echos a loud "snap" every time I get in and out. So thats fun.
The buildup continues, and gets less modest... :P
Gingerman was fun, being back in the Great Lakes fam with my old crew. Chris has gotten a lot faster in the years I was gone, so he pretty handily beat me. The video does a poor job of showing it due to the camera position, but I was two-in-dirt in three places really licking the stamp to run that 47.9. The car needs more prep, stat.
Stage 3: A few more horsepressures?
Stage 3a: A few more tire millimeters?
I snagged two NB Racing Beat headers from the classifieds here on MT, one for the ST6 car and one for this TT6 car. I also borrowed the Racing Beat exhaust from Button, my ST5 car, and cobbled together a terrible cold side intake(don't do it this way)
On the NASA dyno at Pitt Race it now makes 131(~ish, the dyno had some severe rpm signal loss), which is a bit shy of my goal. I'll probably throw a fresh set of plugs/wires, fancy oil and a better intake tube at it and re-dyno at Mid Ohio in August.
Friday morning at Pitt, I swapped in a Squaretop right before pulling on the dyno:
A nice mandrel aluminum J bend has arrived, so it will go on in place of these cast ebay 90* elbows.
The car is a heavy, full interior streetcar, so its well over 2400 with ANY fuel on board, so we get to play in the 257mm template.
I spent an afternoon on a tire machine comparing a bunch of stuff, and settled on 225 R7/9.5" The stretch is very similar to the 205 R7/9" we all love, and an NB fits the 9.5" with just a roll and camber.
This is 225/9.5" vs 205/9"
The 225 isn't that much wider than the 205. I didn't have a 10" on hand to mount the 225 too, but I don't see much reason to go there.
Last weekend was event #2 for Tia. Great Lakes/Mid Atlantic crossover event at Pittsburgh International Race Complex. "Pitt Stop Crossover powered by Hyperfest"
Pitt Race is an amazing facility. My last visit there was back in 05 or 06 when it was BeaveRun. From what I hear, VIR or the ownership group of VIR bought it, and oversaw the amazing track extension and facility upgrades. It is very VIR-like(which is a great thing) on the new South course. The Full layout is 2.78 miles.
I had never driven the new South course extension, so I watch a bunch of Spec Miata laps on youtube.
Going into the event, I set the goal of a 2:04 based on Spec Miata, HC and PTE/TTE times.
Day 1:
Session 1: My borrowed wireless transponder was dead, so my 2:12 in the rain didn’t count. Would have been 4th overall in Time Trial.
Session 2: Dry, but still learning the track, 2:08. Everybody goes faster, so I’m sitting 4th of 11 in TT6. Radiator gets punched from the back while I’m driving through paddock back to our pit. Broke a tube, evacuated the cooling system. No idea what/how got in there, but there goes a brand new radiator.
Session 3: Sat out while waiting for a replacement radiator.
Session 4: 2:06.1 was good for P2, until I DQ’d myself with an off track excursion a lap later while chasing after Chris’s 2:05.8(track record) for the win. (4 wheels off track is a DQ in TT)
Finished 4th behind the usual suspects now, Chris in p1, Boboltz p2 in his n/a Impreza hatch, and Andrew p3 in a similar NB1 ST/TT car.
The car is way faster than it was at Gingerman, and I am learning the track quickly.
Day 2:
Session 1: Chris resets his track record with a 2:04.721 while I run a 2:04.792 right behind him. This sets up a crazy battle between Chris and I.
Session 2: A TT4 car makes a pretty bozo jerk blocking move to keep Chris behind him. I get a huge run and pass them both on the back-straight. TT4 guy never returned to the track, as getting three-wide passed on a straightaway by two cars with 300 less horsepower was too large a blow to his ego.
Session 3: Chris again runs a faster time, but does the same thing I did yesterday and DQ’d himself with a 4-off mistake. I only manage a 2:05.0 due to TT5 S2K traffic. By now, we both think there’s a 2:03 out there if we could find clear track, but it’s also like 900° outside and the cars are hating it. Chris’ off track excursion bent a control arm.
Session 4: 3:00pm. Now 999° outside. Chris didn’t drive, and half the field has packed up to go home. Andrew and I have the track nearly to ourselves. He flubs T4 and falls off my tail. I have clear track finally, and really nail the three spots on track I needed to clean up a little bit. I sneak by Chris with a 2:04.613 for the win and Pitt Race TT6 track record.
Nice driving! Now that you're out in the Midwest, i'll have to keep an eye out for you at events and say hi if I see you
For sure!
I'll be running most of NASA Great Lakes' schedule with the occasional AutoInterest event thrown in, plus the Buckeye Miata Club autocrosses.
Originally Posted by Lincoln Logs
I'm liking where this is headed.
It's heading for a plane ticket and rental at the midwest track of your choice?
Awesome build. I love the simplicity. It's the same approach I've been trying to take while (slowly) building my TT6 car. Due to having WAY less Miata and track experience than you, this thread will be a great help for me to me to follow along with. I'm looking forward to more updates.
The car looks way cooler on the big wheels and lower height, but it is still very much a beater, lol.
Also, it needs a low bolster bucket seat. I have mounts already, but need a Sparco Rev/Evo, Recaro SPG etc. Out of date/expired preferably, this DE car doesn't need a current FIA tag.
07-22-2019, 11:48 AM
"Tia" the Tarmac 88 NASA TT6 car
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