and that, ladies and gentlemen, is what's called DOING IT RIGHT
:D

So with my silly Catfish body on Exocet, I'm going to have a slightly different flat bottom than most factory miatas.

Where most miata flat bottoms step up at the frame rail, my car is going to step down (about ~1") as the edge of the body is lower than the floor pan. This will create a "channel" under the body from front to back, is this good or bad?

I can take a picture next time it's on the lift if this doesn't make sense.

It's good.


Ryan,
Your car looks sticky.

Or maybe it's just my screen.

Ryan... i'm jelly

It looks great,but I am going to be "that guy" and point out that your tires are backwards

Haha, I knew someone would ;) those are just rollers for pushing the car around.

Ryan, how do deal with heat?

From that picture, it looks like transmission won't get any airflow. Same for the diff.

Ryan's diff has a NACA duct inlet.

Yes, hard to see in that pic but there's a big (over 12" long) NACA that feeds air to the diff. The transmission is a bit of an experiment. With an entire flat bottom, the transmission tunnel becomes an air duct - passing air from the higher pressure region in the engine bay to the lower pressure zone above/behind the diffuser, which sounds good enough on paper to pass air over the transmission continually, and hopefully it can move enough air to keep the heat from the exhaust that is running right alongside it in that same enclosed space from severely affecting the transmission. It's rather uncharted water with the Miata though, so the only way to find out if it's adequate or not has been to run it for several years. I haven't seen transmission lifespan dramatically affected, so I'd say unscientifically that it's working.

I'm actually having more trouble with boiling the fuel in the tank than with overheating the tranny or diff :party:

One goal, at least on paper right now, with the new engine config going in will be to move the exhaust out of the transmission tunnel so that heat source is no longer by the drivetrain above the flat floor.

Is there any way to test if they're getting too hot? Maybe if surface temps are xx*? I tried to get baseline surface temps of the diff and trans, never got insanely high readings, but it was a bone stock 1.6L I was testing with. I've had the diff covered for the most part and still didn't run too hot on 95* days at BW.

Sure you can test it - fluid temps are what you want to look at, not housing temps. Super easy to do in the diff by just replacing the drain plug with a threaded adapter and a temp sender for a standard oil temperature gauge.

Transmission could be done similarly but because the drain plug is pointing straight down you'd need to get a bit more creative, or just drill and tap the transmission case for a sender. I just haven't gotten around to doing it. After seeing that I still wasn't prematurely blowing diffs or transmissions with the flat bottom, monitoring their temperature just moved lower on the priority list.

I'll very likely set up the MV7 and Getrag with sensors before they go in, particularly with the trans as it is a $1200 unit, so I'd be less excited to lose one of those compared to a $250 Miata 5 speed.

With your new setup it'd def make sense to monitor the fluid temps. I think it'll be safe to assume if your old setup was fine, than it shouldn't be an issue w/ lower hp levels.

I'm sure Ryan has completely sleeved his exhaust to keep the heat out of the transmission. Look at all of the other work he has done.

You would think so.. I would think that too. But I haven't.. mostly because with a new drivetrain config on the horizon I stopped worrying about it. Most of the work has been on shielding the tunnel to keep heat out of the cabin. IF the new exhaust ends up running down the transmission tunnel, it will definitely be shielded.

I recently discovered this but forgot to post it here. It's the nicest product I've seen for quick and easy exhaust shielding. They have other sizes too.

https://www.pegasusautoracing.com/pr...paign=201509-1

Easy install when new, a bit harder to remove when you take the header out again (since header->right Foot is where you use it).
I have a schredded one somewhere, and this summer I got a burn blister on my ankle...
So it works, when installed :)

Shilds with spacers and air running between the layers work.

For Ryans LFX project, sidepipes or bust (you still lack the side parts + skirts for the floor build anyway). :D

I have nothing on Ryan's awesome build, but I still am very happy with my first foray into aero mods.

Dollars spent: 800-900
Hours spent: 20+
How effective: 3
0=slower, 1, no improvement, 2 =slightly better,3= big improvement
Materials used:
1/2" Birch Plywood
CoT wing with Singular end plates
URL, brand name, material type
Size/thickness of materials:
.060", 3/16" etc
Bracket location:
Splitter mounts near the tow hook location, sub frame to in front of the tires, and at the rear stock undertray bolt holes.
Tracks tested on: Hallett - clockwise
Race/TT class built for: HPDE

Everyone's favorite plywood splitter. Extends 5-6" from the bumper.
https://www.miataturbo.net/attachmen...ine=1443063558


NASCAR CoT wing
https://www.miataturbo.net/attachmen...ine=1443063558

Used at one event so far. Took 2 seconds off Hallet clockwise on my first session with a wet track. Another 2 seconds off my second session. Before adding the wing I have only run clockwise for 2 other sessions (June 2015 & 2016). I figure part of the second 2 seconds is from getting to know the track better and since it was wet on the first session, how about a 3 second improvement with wing and splitter.

:party:

Wow- 2 seconds is sensational. Consider the cost for the return on lap time improvement and it's a bargain.

This thread has so much win. I'd like to see more pics of Ryan's bottom while he's into group sharing. :pitlab:

The one and only set of uprights I've made that are replicas of my own COT setup.
:likecat:

Thank goodness! I was really wondering who on Earth would put that much work into aero, and then run on street tires. Good street tires, maybe. But still street tires!

Neal
(all about the purple crack...)