matthewdesigns

iTrader: (8)

Ok, first track day coming up this Saturday for the Miata. Yes, I’ve read the track day sticky, and I typically read track-oriented threads here too so that I can absorb as much as possible. The track is Pueblo Motorsports Park. It’s a 2.2 mile course with some decent elevation changes, and the front straight also doubles as a ¼ mile drag strip. Here’s a vid and a map:





I’ve run this track before in a different car (Chumpcar race last year in a DSM), but I certainly don’t think I know all there is to know about it. Ego will be left firmly at home, and there will be plenty of folks there to beg rides from who are way better at this than me. The organization hosting the day is a driving school and plenty of their regulars will be there, including a bunch of Miatas I’m told.

Rollbar, helmet, gloves, shoes – check

Car should pass tech with flying colors based on the sample tech sheet I’ve seen.

Brake and clutch fluid flush 2 days ago with Valvoline DOT 3 / 4, which has roughly a 480* boiling point. Brake pads are EBC Green, which I know are only a hair better than OTC parts store stuff but that’s what I’m running at the moment. I’m aware that they may be totally toast after the day but that’s fine as I’ve been wanting an excuse to upgrade the fronts to 1.8’s and put some Porterfields on it anyway. I’m interested in working on momentum driving and finding the right line as opposed to going as fast as I can, so I’m pretty confident that the brake system will hold up fairly well. I will at some point have to try to beat my best lap from the Chumpcar race, though

Tires are Kumho XS, barely broken in at about 350mi total so far. Aligned last week and then flogged last weekend in the mountains for a few hours, so I know more or less what to expect regarding how the car handles.

I have not changed over to mostly water in the radiator, and I don’t know if I’ll have a chance to before Saturday.

So, I’m planning on taking tools, some fluids, some snacks/water, and very little else. From the schedule I got after registering it looks like there will be 6 half-hour car sessions between 9am and 5pm with breaks in between for the bikes.

Besides what’s mentioned in the sticky, anyone care to chime in on what they personally find to be helpful at the track in the way of stuff you bring? How about whether you like to run a hardtop or not on more “casual” days like this? I know it adds rigidity, but it’s not required and I’m on the fence as to whether I’m going to take it or not. Leaning towards not.

Thanks.

timk

You could wire the wastegate open, if the car is turbocharged.

Larimer

iTrader: (4)

I'm preparing to do the same in a few weeks. I'd bring a lot of tools in case anything happens with the turbo. Have you ducted your intercooler/radiator? I'm most worried about heatsoaking/overheating and the turbo bolts coming loose on my car. With the top, I'd bring it. Some clubs may let you run it with it down, but if you're using a headset to talk back and forth with the instructor it'll probably be too loud with the wind noise.

ScottFW

iTrader: (4)

Run with the hardtop on. On my n/a car the better aero is worth 3-5 mph at the end of a straight as long as that one.

jacob300zx

Hardtop yes. Get in there and seal that radiator up as mentioned. Also, pull the drain plug on the radiator and drain most of that coolant out. Have fun and get an instructor who drives a miata if you can. Turn the boost down.

matthewdesigns

iTrader: (8)

Thanks so far for the suggestions. I figured I would turn the boost down if the brakes were getting overworked, but perhaps just starting at wastegate pressure (6psi) is a good idea. I'll wire it open if I'm still overrunning them.

Definitely going to have plenty of tools, and will be checking the turbo bolts between sessions. I've thought about picking up a cheap set of brake pads, too, just in case mine are too fried to drive home on.

Again, I am not looking for top speed, so I don't have a need for the hardtop with respect to that. But if it's going to increase my enjoyment overall, due to comfort and/or added rigidity, I'll pop it on, though I don't have any physical fatigue issues when running around in the mountains for hours on end without it. As far as I know there will not be any instructors available, just friendly Miata owners with more track experience than me so needing to hear an instructor through a headset won't be in the cards. This is a charity event, and while organized by a racing school, is not an actual "school" day. Based on the "yes, run it" responses here I'll probably toss it on.

Radiator and IC are fully ducted and shrouded, from the bumper back, and I also have a tray between the radiator and the subframe (pics are in my build thread linked in my sig). And easy enough I guess to drain the coolant and run water...I'll get on it. Does it actually cool better than a mix, or is it for the sake of the other participants/track in case I blow a hose?

I'm about finished with a headlight duct for my air filter/box to get a little cooler air in the motor, but I've been wondering if it'll make a big difference in engine temps to pull the turn signals out of the bumper. I'll run both ways and see for myself if it makes a difference if nobody has an opinion on that.

ScottFW

iTrader: (4)

Both, but we're more concerned with the cooling aspect. Miatas aren't particularly known for blowing water hoses. Casual street/HPDE cars are often tracked with a 50/50 or 70/30 mix, but the higher % water the better it will cool. When I tracked my n/a with 50/50 it got pretty hot (210*F) so with the turbo you'll want to run more water than that. Track only cars, or cars that run a bunch of events during the summer, often run straight water with just a bottle of water wetter for a little water pump lubricity and corrosion protection. Just don't forget to replace the antifreeze before the cold weather hits.

hustler

iTrader: (6)

Run the hardtop, if you roll it you're less likely to get your arms chopped off.

Jake is right, find someone who owns a Miata to ride with you. Don't let people scare you too much, you will know what's scary and what isn't. Most importantly, take at least one session to have fun. I waste too many days at the track where I get angry because I have bad fundementals or didn't run the time I want. Sometimes you have to play cat and mouse with your buddies. Also remember that even though you're passing guys in Ferraris and Bugattis, they are going home to their supermodel wives in a mansion while you and I will go home, alone, in the cold.

matthewdesigns

iTrader: (8)

Scott, thanks for the explanation. Distilled water, I assume?

And Trey, yeah I didn't think about the lack of arms. My first thought was to keep it at home so if I did roll/have an accident I could at least recoup some of the car loss by selling the top. Not much point if I don't have arms to drive though lol.

Looks like I'll have a camera for the event, too, so I'll post up some video. No transponder, though, so I'll be making best guesses about lap times from the video and a sports fitness tracker on my phone. I know there's a lap timer thread here somewhere...maybe I'll buy one and give it a shot.

spoolin2bars

iTrader: (1)

yeah the "coolant" is actually anti-freeze and that what it's there for mainly. in hot weather it will boil at a lower temp than water. when that happens it creates "air" in your system, which, just like boiling brake fluid is not what you want. secondary issue is if for some reason you do leak fluid, you won't ruin everybody's day by dropping slippery fluid all over the track.

also, DO NOT run tap water. use distilled water. besides not having minerals and other nasty things to crud up your coolant system, the distilled water is not supposed to boil.

hornetball

iTrader: (4)

That's funny. So, what physics miracle has exempted distilled water from phase changes?

hustler

iTrader: (6)

lol @ recouping losses. You're not going to wreck it, just be cool and leave yourself a way out before you get too hot on the track. Learn where you can go off so when that time comes, you can go off safely. Every time I've gone off but a couple I've gone off straight and it was no big deal.

matthewdesigns

iTrader: (8)

Yeah, I don't have any real worries about that. I didn't go off at any point during the Chumpcar race last year, and I don't intend to run as hard as I did then. It's just the overthinking pragmatist in me lol.

spoolin2bars

iTrader: (1)

lol, i know, it'll still change to a gas i'm sure, but at a higher temp. (supposedly). that combined with a high pressure rad. cap and some water wetter or better yet the dei brand coolant stuff (the best) and you can get the temp. pretty high without boiling.

hornetball

iTrader: (4)

Actually, it's going to near 100% water plus the high pressure cap that makes all the difference.

Here's a handy reference:

http://www.engineeringtoolbox.com/bo...ter-d_926.html

matthewdesigns

iTrader: (8)

I've got a 13psi radiator cap. Should I grab one that's 15psi or higher? I don't go over 210* beating it up on WOT mountain runs, but that's a different environment than being on track and pushing it for 20+ min at a time.

hornetball

iTrader: (4)

Boiling point with a 13psi cap and 100% water is near 250°F. I think you'll be fine with that. If you exceed that, you have other problems.

matthewdesigns

iTrader: (8)

How much does elevation play in boiling point, given it's a closed system? The track is at about 5000'.

hornetball

iTrader: (4)

What you do is take the ambient pressure and add 13psi to get your boiling point.

At SL, ambient pressure in standard conditions is 14.7psi, so the system will be at 27.7psi. Use the link I gave earlier to find the boiling point (~246°F).

At 5000', ambient pressure in standard conditions is 12.2psi for a system pressure of 25.2psi and boiling point of ~240°F.

If you used the 15psi cap at 5000', you would raise that boiling point to ~244°F.

Note that actual ambient pressure is rarely the same as standard. But it won't make much difference.

matthewdesigns

iTrader: (8)

Great, thanks for the math lesson. 4* is not worth worrying about, so I'll stick with the 13psi cap. I appreciate the input on this. I get a little ---- about all this ****, and just want to make sure my day is as drama-free as possible lol.