ryansmoneypit

iTrader: (6)

Looks like he needs more up front.

lightyear

It's got a front splitter/undertray that sticks out 2" past the bumper and goes back to axle centre line (as per rules of an event I was going to enter). Wing is also in front of rear most part of the car.
i will bolt on my side skirts, hopefully they help a bit. If I knew an easy way to get some more front downforce I would do it.

- Video again as its on the last page now.

lightyear

Or maybe I should take off the huge front swaybar and replace with the oem one?

emilio700

iTrader: (3)

No more than 2" splitter allowed? 4" is sort of the sweet spot. Gains past that but at 4" it really starts to work.
If any other front bits are allowed, extend the splitter as wide as rules allow then add fences to trap the air on out outer corners. Lots of drag but huge increase in DF. With some testing, you can build dive planes and canards instead, Still draggy but slightly better L/D ratio when done properly.
Lots more than can be done but that the low hanging fruit for a quick 100 lbs (45kg) @ 180kph or so.

If the car is turning properly, you'll need a bigger front bar, not smaller. This might be a good time to share you entire car setup:

weight w driver
weight distribution
pinch weld heights F/R
wheel width
wheel diameter
wheel offset
tire size
tire compound/model
differential type
coilover model
spring rates
sway bar diameters
camber F&R
toe F&R

lightyear

weight w driver - 2410 pounds
weight distribution
pinch weld heights F/R
wheel width - 9"
wheel diameter - 15"
wheel offset - 32 I think
tire size - 225/50/15
tire compound/model - Yoko A050's
differential type - Torsen
coilover model - Blitz
spring rates - 8kg front, 6kg rear
sway bar diameters - 1 1/4" Hollow front, nothing on the rear.
camber F&R
toe F&R
It has full interior, minus passenger seat, no metal cut out. Still running the oem rubber bushes and motor that have done 132,000 miles. The fastback and trunk are lightweight carbon fibre. Hood is vented oem, radiator and I/C are fully ducted. Wing is 12" chord, cambered and about 55" wide. It puts about 240hp to the rear tyres.
The car is very competitive for what it is, it wins pretty much every event for its class, and is always right up there for the outright win.

Let me get the measurements from when it was corner weighted and I will edit it. This is all I know for now,

lightyear

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lightyear

screen shot on pc

emilio700

iTrader: (3)

Ok yeah, your suspension is "broken".

Step 1
Replace front springs with 12kg.
Replace rear springs with 7kg

I suspect your Chinese dampers (Japan branded) will not have enough damping for these rates but at least your wheel rates will be close. If you were running Xidas, we would recommend 900/500 16/9kg for that application.

Step 2
Install 14mm rear sway bar

Step 3
Install extended lower ball joints. The reason I know you need them is the tires you are running are about 1" too tall. Thus you are probably a good 25mm too high in the front to keep from bottoming tires on the tub. If your tires are not bottoming with such large, sticky tires and soft springs, then you have insufficient bump travel. In either case, you're not likely to have much more than -2° front camber. Those tires will probably want about -3.5°, which won't be possible at your ride height.

Step 4
Fill out the blanks in the setup questions I asked when you get a chance. Wheel offset matters as it is an input parameter to determining roll moment and effective wheel rate.

If your wing has a bunch of camber, it might simply be too much. With only a 2" splitter and airdam, we would only recommend a lightly cambered (low drag) GT250 or similar foil run pretty much level, in order to retain some aero balance. Pic of foil or cross section schematic?

Spats (deflectors in front of tires) are a very good idea, they work. If you are allowed to cant them into dive planes,or add fences, do so.

lightyear

First of all, I appreciate you taking the time to post a reply.
And you are right, there is no paint on the inner front wheel tubs, the tyre bottoms out. I spoke to the guy that did the corner weight. He said the problem is obvious. Too much rear wing. And I should stop playing with this car and finish the other MX5 that has a full cage and built motor with a real turbo on it.
It's worth a shot to fab up some canards. His suggestion is simple, lower the AOA on the wing. But what is the point in having a wing if I can't run it at zero degrees. It won't be very effective at negative angles, but I will certainly try it. He also said the wing is a high downforce wing that is suited to slow tracks, so won't suit Phillip Island so much. I will make a non cambered wing to try out and compare.

Here is the end plate of the wing I am using.


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emilio700

iTrader: (3)

That's a pretty heavily cambered foil and at 12" chord, probably generates a few hundred lbs at 100mph (~170kph). Until you can get some front DF to match, I'd follow his suggestion and dial the AOA back. Even on our much lower camber GT250 foils, we barely run past 0° AOA. You still have quite a bit of setup work to do to get the most out of those tires. If you can obtain a 225/45/15 in a similar compound, you would gain quite a bit in lower CG, increased bump travel, more front camber, lower frontal area, more effective front spoiler and additional slammed-ness.

Gee Emm

I don't know about that section, but the section I run produces low but appreciable lift (DF) at negative AoA, and is still producing DF at -8 and beyond but fast disappearing at that point. The Cl/Cd and Cl/AoA curves will be a good starting point to knowing where to set the wing, as a starting point. However that section is very deep and while you can minimise the drag by winding AoA off, it is never going to be 'low drag'.

You might want to check these curves for your new wing, before you commit to a section for it. Maybe keep this one for places like Winton short, SMP South (if get there) and perhaps Wakefield, and make a new high efficiency wing for PI and Sandown.

I use Airfoil Tools to get my performance curves, let me know if you want a steer on sections etc.

lightyear

I normally run 225/45/15's, but you can't buy anything better than Nitto NT01's here in that size. The other car has15x10 6ul's. I will have to import tyres myself for that car.

It must be awesome to drive a well set up Miata on the track. I just drive the thing as hard as I can to make up for poor set up.

lightyear

The wing works well, just need to make the front aero better to keep it balanced. I am all for a wing to run at Phillip island that is low drag.
Show me what profile you have in mind Gee Emm.

emilio700

iTrader: (3)

Driving it "hard" does not make up for a bad setup. I'm sure you can get it dialed with just a little bit of diligence. Also +1 to Gee Emm's suggestion to maybe review the possibility of building your new foil with less camber.

lightyear

These results (from the day the video was taken) show the car isn't slow compared to others, so the handling isn't that bad. The first 4 cars are full on GT race cars, the EVO is a time attack car. And I only did 2 laps with the wing , and 2 laps without it. Car will do a 1:43 I think. Phillip Island surface is grippy and dead smooth.
i will add a bit to the splitter to increase its size as it would be good to not have to dial the wing down too much. (btw, I am David Wilken)


upload pics

Leafy

iTrader: (1)

That looks like a fairly decent auto-x wing, haha. If you just wacked the top off that like 1/4"ish pas the last weight pocket it would be pretty ok for a low power road race car.

lightyear

I have extended the splitter with plywood, and made some small fences. Didn't want to go too extreme as the bumper may fall off.


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lightyear

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lightyear

The wing is pretty much the same as this one.

Project Mazda RX-8 - Modified Magazine

motormechanic

iTrader: (1)

the COT profile makes decent downforce and is low drag.