rear spoiler..? does it work?

[pistol pete]

In the name of weight saving in the mk2 rev5
does the spoiler actually do anything when pushing on track?
only over a certain speed or help stability or just show?

cheers

[2mad]

I would think it gives you some straight line stability .. theres a vid on youtube of an evo doing a high speed run thats bins it .. reason .. he removed the spoiler ... just my thoughts hope someone has actual data , im interested too.

[pistol pete]

yeah on the sprint a very very rarely see over 100.. might see 105, maybe slightly more now its lighter

[2mad]

I would probably just pull the spoiler .. do a sprint and see if the car seems more unstable .

[acf8181]

I heard it helps with cooling of the engine bay due to creating a low pressure zone

As for downforce....no way! Even if it created a decent level of downforce (which i seriously doubt it does) you'd never feel it with the weight of these cars.

[Nic]

If it did have any aero effect on the rear would it not also lighten the front end? I removed my Rev5 rear wing and noticed no difference on the road, it's quick and easy to remove so perhaps try doing laps with and without it to see if you can feel a difference

[ashley]

I reckon all it does is create a bit of drag, almost certainly no tangible downforce or stability benefits. The low pressure zone behind the roof is created by the shape of the roof and boot lid, so it shouldn't affect cooling either.

Purely aesthetic from what I can tell- the only way to be sure would be to stick a couple of load cells under the spoiler legs and measure it.

[Marf]

http://www.motorworldhype.com/2009-10-2 ... rce-meter/

[ashley]

http://www.appmeas.co.uk/

[nickg07]

http://www.motorworldhype.com/2009-10-2 ... rce-meter/

testing done here!

http://mx5cartalk.com/forum/viewtopic.php?t=55368

[shinny]

You know, a guy did some CFD analysis on the SW20 body: http://www.mr2oc.com/showthread.php?t=410768&page=6

This was testing modelled at 100kph / 62mph and the results are very interesting...

MR2 stock. Rev 5 wing. Drag force 238 N. Lift force 95 N.
Velocity

Pressure

Temperature


MR2 stock without rear wing. Drag force 223 N. Lift force 161 N.
Velocity

Pressure

Temperature



So rev5 spoiler appears to be entirely functional in significantly reducing lift without adding too much more drag. I certainly wouldn't be taking it off for anything going around a track!

You can see he put together a fairly decent model for it... it's not half-baked!

[pistol pete]

that mate is exactly the answer i was looking for thanks you

[2mad]

I was hoping there would be some info/data .. but thats outstanding ^^ .

[ashley]

Awesome! I take it all back, who would've thought such a small blade would have any impact!

Did they model the rev3/4 wing as well?

[shinny]

Did they model the rev3/4 wing as well?

Alas not. The thread makes for a very interesting skim-read. It started out with a guy called Alex W doing some basic modelling on the rev2 stock body. This inspired a guy called Outlaw to transfer the model to some different software and improve it a bit. The main focus was aerodynamic modifications, so I don't think either of them modelled the rev3 spoiler I'm afraid.

There's some other interesting information on there, such as those fastback style engine covers actually being detrimental, while cutting a big hole in your frunk is a massive win.

Engine bay cover. Drag force 236 N. Lift force 130 N.
I was sure that it doesn't improve drag force a lot, but i was surprised that it actually increase lift.

Pressure

MR2 with big venting hole hood and sealed bottom. Drag force 226 N. Lift force -16N. Wow, here we go with downforce and what is most interestin reduction in drag too!


Pressure

So, who wants to help me cut up my frunk??

[Ryan S]

that might actually be a good location for a chargecooler pre-rad without the hassle of taking the bumper off etc

[Ryan S]

although I guess you'd need a hole in the bonnet too


EDIT:

MR2 with big venting hole hood and sealed bottom

Never mind

[Gullzter]

That is really interesting Shinny, the frunk is definitely a great idea, got to be alot better than speed flaps for lift

[synXero]

Sealed frunk floor? So basically air in through nosecone out through frunk lid?

[Ryan S]

Sealed frunk floor? So basically air in through nosecone out through frunk lid?

that's how the border bumper/bonnet work together