Mobius

iTrader: (2)

Are there any pictures of Crusher's foglight ducts? I'm about to build mine and looking for ideas.

emilio700

iTrader: (3)

Just a standard duct flange. Nothing fancy. Google it.

jacob300zx

How did the Thermo-Tec hold up?

emilio700

iTrader: (3)

Just fine.

ScottFW

iTrader: (4)

Emilio please see here:
https://www.miataturbo.net/engine-performance-56/re-milling-01-vvt-valve-cover-cops-62094/

Basically a Crusher-related question on valve cover milling to accommodate COPs. I made a separate thread a few days ago when I didn't want to derail the discussion of enduro domination.

emilio700

iTrader: (3)

Good fun in the first race with the new motor. 134mph in the banking.

Preproduction prototype APR 2D 64" wing. It has a slightly better L/D (lift to drag ratio) than the GTC-200. It's designed to be a lower drag wing for low downforce requirement and best suited to free stream mounting location. Thus we mounted it up so the foil is about an inch or so below the roof and completely behind the bumper. Wing mounts are something we quickly threw together having only received the wing 3 days before the event. Had to add the cross brace after realizing the stubs we fabbed up weren't quite stiff enough. We'll redesign the frame mounts and probably have some carbon stanchions made for the new car being built.

We tested a few different AOA with both the GTC-200 and the new 2D as well as no wing at all. With no wing, the car was a bit spooky in T1-2 above 125mph. With the same aero balance as a given GTC-200 setup, the high mount 2D gave several MPH more terminal speed at the end of the front straight. That is exactly what we're looking for to cut drag for endurance racing. Very happy with the wing set up and it looks kinda cool too. No pricing or specs on anything as the as yet, un-named APR 2D is 1-2 months away from release.

APR has no plans for a Miata specific version of this wing as the required mounts would be rather involved and possibly expensive. If we get enough interest, we may develop a race mount that bolts to the bumper support studs at the end of the frame rails.





Video loading now, may take a few hours to display on youtube..

curly

iTrader: (25)

Hmm, interesting mount. Are you worried about it being damaged over the course of a 24 hour race? Seems a bit more exposed than a "traditional" trunk area mounted wing. Sorry if I missed the explanation, but why was this mount location chosen?

Also, it appears to be a simpler design than a GTC-200, aka cheaper. Let's hope I'm right. With front DIY aero so cheaply available, I would think rear aero prices are holding up a lot of us from applying it to our cheap track day cars.

triple88a

iTrader: (2)

No splitter Emilio?

emilio700

iTrader: (3)

Not needed at this point. Testing other variables. New enduro car we're building will have a higher downforce front end.

greeenteeee

The 2D vs 3D airfoil info isn't new, thanks for sharing first hand on this chassis, but at what power level would you say a wing (2D or not) is beneficial over a spoiler at low (single digit) AOA at the banking?

FWIW with my 1.6L, I don't think the car really needs a splitter. Surprising to see that the Crusher doesn't need it.

emilio700

iTrader: (3)

Yes the info is not new but you are not me . I can not simply post something vague about our projects without people from all over the world asking me very fundamental questions like "what does 2D mean". I find it saves time and confusion to simply answer the anticipated questions in the OP.

A trimmed out wing will almost always be a lower drag option than any functional wing. The break point needs to be determined by testing. It isn't a power level thing, it's simply what downforce you want and how much drag you are willing to tolerate to get it.

On many 500-1000whp drag cars the giant wings you see are usually trimmed at 0° AOA to the trunk lid on most production bodies but 2-4° to ground plane. Super low drag and almost not downforce. Crusher as an E1 car will barely have more power than a good CSP car yet a lot less downforce. If your average CSP could get it, they'd give up 20mph of top speed to get another 50lbs downforce.

The flat spoiler we ran at T25 was tested on the T1-2 banking. At low angles, it was lower drag than the wing. When brought up to match the downforce levels of this 2D, it started to get slower. Much past a few degrees, the L/D ratio isn't good for a huge spoiler.

So figure out what you need in the car for the tracks you run on and car configuration then decide how much top end speed you can afford to give up,

The ACS config was as low drag as I could get while still doing T1-2 flat on the apron. For normal tracks like Thunderhill and Buttonwillow, we'll crank in 2-4° more rake to generate more -L since we won't need the 140mph top end.

greeenteeee

Exactly, and people will listen to you and not me. =) E.G., does my 1.6L really need aero? Is my primary concern drag redux over dF warranted? People say it's stupid, I disagree. But if you were to address it, it'd indubitably sway their opinions. FWIW, I've reduced drag and lift has decreased enough to vastly improve high speed stability. It hasn't seen ACS, but it's visiting BW 13CW this Saturday. =)

I've read articles about these same issues you've tested (spoiler vs wing) on a NASCAR, with the exact results you're posting, but Miata-specific info is what we've been missing on. Thanks for that!

emilio700

iTrader: (3)

To add to the report, we basically saw the same top speed with the wing as without. Our guess is that the wing is helping draw air down across the trunk lid which reduces drag from the body of the car. This partially balances the drag losses from the wing itself. A local aero guy that has done quite a bit of instrumented data collection on Miatas including tuft testing has observed the wing helping flow over the roof with other wings.

So a low drag wing can ostensibly, "pay it's own way" with improved overall body drag. A spoiler doesn't do affect the airflow over the roof this way so there may be a certain point where a low drag wing, properly configured, nets a better L/D ratio overall.

j_man

Here is the data of the new wing - I think the full setup is a 2 element design:

http://www.amb-aero.com/files/APR004_public.pdf

Also, there are Miata specific setups being prepared (rear fender mounts, Miata specific mounting hole placement on the elements, etc.)
APR don't sell them directly on their site but through Ciro:

http://www.cirodesignracing.com/Ciro...cing/WING.html

APR also still make the old 2 element GT-II based setup - it is not discontinued as people believe but now they sell it only through Ciro too.

emilio700

iTrader: (3)

Some fun last weekend. Won the enduro and sprint race, only because no one else entered. Still, a win is a win.

Wet restart in the enduro. A few laps on wet track behind the pace car on 2 hour old R6's = zero grip. A great opportunity to channel Senna a bit and run away from everyone in the field except the Radical. Good fun.



Saturday sprint race, harassing some faster GTS BMW's. None of the other PT cars were anywhere close so I had to find someone else to play with. Broke two improperly torqued wheel studs just as I caught the BMW I had been chasing. Doh!

mr_hyde

iTrader: (4)

Aw, dammit!! You passed him right as you lost a wheel! Probably pissed him off to see a miata in his mirror every lap though. You are very polite not to tap him after he squeezed you (almost) into the wall on the 2nd lap.

GeneSplicer

iTrader: (14)

Define 'improperly' - just didn't get them tight enough, too tight? Which wheel(s)? Wishing I had more time (and money) to get competitive - looked fun out there

emilio700

iTrader: (3)

Torqued when hot instead of cold. Aluminum wheel, brake hat and lug have much higher thermal expansion than steel stud.

arildh

What is the correct tq when mounting the wheel cold, 6 UL and 949 lugnuts ? (ft/lbs)
Do you use anything on the threads ?

emilio700

iTrader: (3)

80-85 ft/lbs for ours or any other lugs on a Miata. Dry