Texas Mile
 

I have been to the Texas Mile a handful of times. Mostly I have been a spectator and watched many cool cars run. If you don't know what this is, it is a closed runway where you get to run wide open for a mile straight. Record is 270 in a Fort GT. https://www.texasmile.net I did do one pass in a Mercedes S63 AMG. Hit 165 and earned my class B license. I am allowed to go to 180 now, but don't think the little Miata will do it. I have been preparing for a while and here is where I am.
- Dynoed 405 to rear wheels
- LS2 with mild cam and ported heads
- T56 from 2006 Pontiac GTO
- Getrag 3.42 from a Cadillac CTS
- Tires are a 225-15
- Added a lower lip for some down force
- Reinforced front mounted oil cooler so it does not push into condenser
- Balanced all wheels and inspected suspension
- 4 point rollbar
- hard mounted the hardtop

The car is running great and I hope to get multiple runs. Unfortunately it is supposed to be bad weather, but we will see.

With that power you should be good for ~120 in the 1/4 mile. I don't think 165 would be too hard with another 3/4 mile.

With that said, I'm a little weary about the aero of a mostly stock Miata at speeds above 140-150 mph. The first few times I've had mine up in that range (yes, it was in Mexico ;) ), I had major pressure buildup under the front end. Hood vents helped quite a bit, and I imagine a front lip may help slightly too.

If it were me, I'd add some sort of under tray from the front lip, back to near the front axle to alleviate front pressure. I'd also think about either cutting the rear bumper or adding some sort of rear diffuser to reduce rear end lift.

I may be talking out of my ass or worried for nothing...but after seeing my hood bulge up 1/2"-3/4" at a mere ~140 mph, I came to the realization that a stock Miata was never designed to do more than what ours can do in just a 1/4 mile sprint.

I was a bit north of 150 a few times this past weekend. I have a aftermarket front nose and my rear bumper is trimmed. I have no hood vents or belly pan. The hood is straining at the pins and hinges at those speeds but it hasn't gotten 'too' scary. ...or I've gotten used to it... btw...that was with the soft top up.

We have the same gearing. I'm making 445 at the wheel and trapped 126 in the quarter.

I would sure love to do the TX Mile, but not in the cards yet again this year. :/

Ill take it easy for the first 2 passes as I shake it all out. I'm using aero catch pins and am pretty confident in them. No hood vents and no belly pan either. I hope to get at least 160. Gearing will be an issue for sure.

In the picture, you can see the R package front spoiler and the aluminum bars I added to the bottom of the oil cooler. I am hoping the lip will give me just enough down force and the oil cooler support will keep it from flexing and breaking off the upper support and damaging my condenser.

I have been trying to think about all the things that will happen around 140. That is a lot of wind!

https://www.v8miata.net/attachment.p...ine=1445434677

I'd be a bit concerned about not having hood latches behind the headlights. These hoods like to lift right there at speed so at least tape the gaps around the headlights.

I ran mine past 140 a couple of times with just a cheezy JDM lip and you do loose feel of the road in the steering quite a bit that way. https://www.v8miata.net/attachment.p...ine=1445434931
After I put my wing on it got down right scary so I made a splitter this year.

This is all trial and error for me but I found a $40 hunk of plywood makes a HUGE difference after 130. I ran mine back to the steering rack mounts so it's as smooth as I can make it to the oil pan. Before I lost the feel of the road past 130 but now she feels like 100 still at that speed.
https://www.v8miata.net/attachment.p...ine=1445434692

https://www.v8miata.net/attachment.p...ine=1445434692

It helps for catching frogs too...
https://www.v8miata.net/attachment.p...ine=1445434692

I can't wait to hear how it goes for you. Best of luck and be safe out there!

I agree on the headlights. I made sure my light covers were in line with the hood so air does not ram into the engine bay. I was also planning on taping those but leave hood edges open for air to escape. Originally I was going to run with no lip, but I took it off my other car last minute and installed it for the event. I also ordered a different style lip that has a more pronounced downward edge but it is not in yet. I would love a splitter with canards to keep the front end down, but have not had time to engineer that yet.

From my calculations with 5th gear at .84, rear end 3.43, 225/45/15, at 6200 RPM top speed should be about 160. Time will tell. I just hope for a dry track.

How so? Too tall?

You are on a 23" tire with 3.43s. I'm on a 25" tire with 3.55s.

Not sure if that works out to even but I'm at 135 at the top of 4th at 6500 in a 1/3rd mile run from a rolling start. And she was still pulling unnervingly hard.

Granted the difference from 135 to 170 is a heck of a lot different than from 100 to 135, but if your numbers are right I think you would be right in the sweet spot of 5th at 6200 and my hunch is the speedo would be closer to 170.

Michael what is your gut hunch on your cars speed at the top of 5th in a mile?

I feel like my car would have no trouble exceeding 160, the driver on the other hand not so much...

I don't have one. My wife claims she saw the needle at 160 Sunday when I ran the Lambo, but my eyes can't refocus from road the gauges quick enough to ever get a positive mph myself. And I don't have a good idea how long the pull was (roll from ~65 in 3rd); I was concentrating on everything else too much. Way too much going on when making those kinds of pulls on these Mexican closed courses. I was in 5th at the end of the pull.

I also use the conversion box that drives the OEM NA mechanical speedo. It is dead accurate at 65 but I never tested it above that.

And off I go
https://www.v8miata.net/attachment.p...ine=1445542820

https://www.v8miata.net/attachment.p...ine=1445542820

Wow. Their are a crap ton of cars here already. Usually you can get here Thursday and get best runs on Friday while others are just arriving. Car passed tech, and I got all the window stickers I need to run. Paddock opens at 630. First run at 830. Hopefully I can get 2 in by lunch.

They have one of those jet engine drying trucks here like NASCAR uses in case of rain. They are even gonna open the track for a night run. There are no lights on the runway, so that would be strange. Going 150+ in the dark would be a rush.

Some wicked cars here for sure. I'll post pics throughout the day. They have 1/4, 1/2, and 1 mile traps. I'll post speeds as I progress.

You have a bunch of guys living vicariously though you today! Be safe!

Got up early and drove towards staging area at 600. Their are already about 60 cars waiting for paddock to open up. SOB. This is going to be a long morning.

Track about to open and a small shower passed. Time to dry the track. You can see my little guy sitting third up on the right. Lol
https://www.v8miata.net/attachment.p...ine=1445605777

Awesome! Can't wait to hear the results!

Finally started up after brief sprinkle and track drying. I made it up to 15 cars away and the heavens opened up. Very stron head wind. Last run got a 199.8! I bet if the wind was less, he would have made 200 club.
https://www.v8miata.net/attachment.p...ine=1445620759

I know you're probably busy out there but....DETAILS PLEASE! ;)

How stable did the car feel at speed?
What gear/rpm did you finish at?

Put a camera in that thing!

Oh, and congrats on almost getting 200 :bowdown:

The way I read it, he was 15 cars away from getting in a run, so no run made yet. He's only licensed for 160 so would have to shut down and get an upgrade before another attempt. If he makes a pull anywhere near 180 he's go mucho balls and would be quite the accomplishment me thinks. :ohnoes:

Ok disregard. In my haste leaving work it seems I misread the post. Which car in the picture were you referring to as "he"?

Some clarification. I have not run yet. Last guy to run before the rain hit made 199.8, not me. I wish! Lol.

I am licensed to 199, but don't think I'll get near that due to gearing and strong head wind.

I just ran. Got the rev limiter in 5th about 50 yards shy of mile mark. I'll try to get thru 4th faster next time and use 6th gear. I took it easy thru the gears so I did not miss shifts.
https://www.v8miata.net/attachment.p...ine=1445633850

deleted as wrong years ref, reading more on ratios for various T-56s.

The way they get speed is a 2 laser trap. You cross the first laser and speed is calculated when you reach second laser. I'm pretty sure my car hit rev limiter inside the trap. I suppose my true speed was a tad bit over 150.

My T-56 is from a 2006 GTO if your looking for gearing info.

Much much better. If the wind dies down, I bet I can squeeze a bit more. Had a really good launch and running of the gears. Car is strong. Got thru the gears as fast as I could. Hit limiter in 1,2,3, shifted at 6200 in 4 and 5 ran 6th out the rest with my foot on the ground. I'll post videos later. The 2 speeds are half mile and mile by the way.
https://www.v8miata.net/attachment.p...ine=1445643244

I thought about you all day wondering how it was going. Wow that is a really epic shot there! So how does the car feel for that half mile at 150+? Really interesting to see how much more effort it takes to get those last few MPHs. I have a hunch my speedo reads fast!

Waking up this morning to some good showers. Gonna be another long day of waiting. Switching my tires out today with a set of 16in rims. Should gain me about 1.5 in in diameter.

Here is a picture of me almost to the front and some of the nice cars running
https://www.v8miata.net/attachment.p...ine=1445689999

And looking down the pipe

https://www.v8miata.net/attachment.p...ine=1445689999

More cool cars. Here is a new Z28

https://www.v8miata.net/attachment.p...ine=1445690268

And a Lamborghini
https://www.v8miata.net/attachment.p...ine=1445690268

No one wants to show up this morning.
https://www.v8miata.net/attachment.p...ine=1445694956

Day 3. Yesterday was a washout all day. Drying the track now. It's cold out and a decent tail wind. I really hope I get to run today.
https://www.v8miata.net/attachment.p...ine=1445791517

A tad bit taller tire this time. We will see what it does.
https://www.v8miata.net/attachment.p...ine=1445797388

Worth the wait. 1/2 mile trap was broken.
https://www.v8miata.net/attachment.p...ine=1445803766

Car felt really loose near the end. She did a little dance. I will need a splitter if I went any faster. I bet she has over 180 in her.

That's awesome!!

Wow buy that man a cold one!
http://i57.tinypic.com/2nbel2w.jpg

Yep, I have Ls power/speed envy!

So how'd the lit'l car feel at speed?

RR

In my first 2 runs, the car was rock solid. I think I was taking it easy as I was still trying to get a feel for how the car was setup. My 3rd run was completely different. My goal was to get thru the gears as quick as possible so that I could ride out 6th in the last part and continue to build speed.

The runway is not completely smooth, and there is a little dip in part of the transition. I really never noticed it that bad until my last run. When I finally get my GOPRO video loaded, you can see it as I shift thru 4th gear.

When I finally get settled into 6th gear, the nose starts to dance a bit and keeps me working to corral it down the track. I may get this splitter if I try it again in March Front Splitter

Over all, I was really impressed with the car. I surprised a bunch of people for sure! In fact, the first time I made it down the track to the guy who hands out the time sheet said, "That's a fast little Miata!" When I looked over next to the timing trailer, he had a yellow NC sitting there. I just smiled and said thanks as I gave him a little zoom zoom on my way back to the start line.

As soon as I can get this dang video loaded, it will be up.

Ok. Here it is. I turned on the camera early so I would not forget. 2 cars run in front of me. It gives you a sense of the time you have to mentally prepare. Skip to 3:06 for my run.

You can hear how my tires break loose in 2nd and I have to lift a bit, and then the car gets light as I hit the small dip going thru 4th. As it settles I get all the way into 6th and my hands start to move more near the end as the front starts to dance around.

Turn up the volume for sure! LOL

Here is the Youtube link:

I borrowed the type r chin spoiler off my 302 Miata to get me thru the mile. When I got home, the splitter style spoiler I ordered was waiting on me. I did a loose fit test on my 302 Miata. I think this would have really helped.

https://www.v8miata.net/attachment.p...ine=1445874504

Great thread - from the very start. I cannot imagine feeling that speed in a Miata. Seen 168 or so a few times as a passenger in a C5 Z06 at VIR and driving a stock car at Petty's 30 lap driving experience at Charlotte... but can't imagine piloting our cars at the top speeds you saw. Nice work. I tip my hat to you sir!

I was watching for the wipers to jump up and take flight for the winter, but they never did.

If I could make a suggestion to take the flex out and have it hang on at speed...

I put 5 pieces of 1/4 - 20 threaded rod hanging down from the pan under the head lights though both the upper and lower parts of the lip to support it. The center on is though the plastic bumper support and a little tricker to put in.

https://www.v8miata.net/attachment.p...ine=1445965987

You can see the one in the middle if you look close and the one inside each brake duct is easy to spot. The other 2 are at the very end of the lip and don't show at all. I put a piece of vacuum line over them to make then not look like threaded rod.

I had them in there before the splitter too and they make the lip really solid. If you put a splitter on it they make perfect attachment points.

Jim - What did you use for the ends of the rod to make connections to the splitter? I am contemplating making my own splitter using some Lexan and then making my own canards using threaded rod. I just need to find some connectors on the rod ends that allow rotation on the splitter to stabilize it to the car.

And to continue the saga - I officially have the Texas Mile fever. The next race should be in March. My car should make 180MPH with a bit better driving. I have already started the plans to build up for a 200MPH run. Just had a sit down with my tuner and here are my plans for the LS Miata:

1- Upgrade my LS2 to LS3 heads and intake. I already have a new set of heads with Yella Terra roller rockers and intake ready to go

2- V8R Long tube headers

3- Add a 50 Shot of NOS. Button push for 6th gear.

4- Front splitter

5- Rear wing

6- Switch out 15in rims and tires for a set of 16in rims with tires that are rated over 200. Current tires have a "W" code which is 168MPH rated. They check rating carefully at the mile

7- Tune the setup

I also have my 302 Miata sitting in the garage. My wife really wants to add a pool (80K) to the house and is trying to convince me to sell both cars to fund it. I will see how long I can hold out. On the flip side, she promised that after the pool is done, I can build anything I want. I have my eye on building a NC LS3 car.

LOL nothing but the finest home depot parts! The splitter is 1/2 double A plywood sanded and sealed with enough car paint you can't tell it's wood. The hardware is 1/4-20 eye to eye turn buckles. I took the right hand eye out and replaced it with threaded rod and the other is a cable clamp ubolt. I used whatever size 1/4 -20 is and used lock nuts on everything.
https://www.v8miata.net/attachment.p...ine=1445971719

Ah man.... If you keep it, you just might give me the incentive I need to keep mine. Some direct competition makes things fun!! Ever considered doing any of the airstrip racing (roll racing)?

I work at Ellington Field and have wanted to do the half mile shoot out. Other than that, interest has always been track racing. Someone told me today, if you go off the track in a corner doing 50 you survive, but if you blow a tire going 200, things get bad! Lol. I told him to shut his face. Lol. I'll know by the first week of Nov if I'm selling both cars or keeping any of them. I have 4 Miatas right now and my family has pool fever. Hard to take out a large loan when I have the assets right here.

I hear that. I'm a firm believer in toys paid in cash only.

Well done sir!!! Congratulations on the the awesome runs and thank you for the video!

Even though it was wet, I had a blast. Of the 5 Texas Miles I have been to, this is the first wet one and I still had a fantastic time talking with everyone. I am so ready for March and the next one. I think I will plan a road trip to a Colorado Mile in the future also. It's the same group of great people who put it on.

Wait you've done 5 of these? What's the fastest???

Been to 5. Driven in 2. First time I drove a Mercedes and went 164.8. This 176.6 in my Miata is the fastest I have been.