MR2 rear wing - keep or lose? - Page 2 - Fuel Economy, Hypermiling, EcoModding News and Forum

NeilBlanchard · 08-23-2009, 08:10 AM

Hi,

If you look at the wings on race cars, you'll see that they can develop down force -- but this always adds drag. Wings on street cars are superficial -- they cannot develop very much downforce if any; and they still always add drag.

Dump the "wing" thing... Drag is bad.

robchalmers · 08-23-2009, 09:09 AM

Hi Mate, great to see someone else in the northwest! I'd ditch the wing as above 'drag is bad' the bog standard 2.0 doesn't run a wing so the car will be safe without. depending where you're going to put them between the cab and rear axle you shoul improve the neutrality of the chassis. I'd suggest putting a couple of cells in the spare tyre well over the front axle as it will help keep the weight there too. and unlike some mid engined cars petrol cars with a front gas tank the front won't go lighter as the tank empties.

woodsmith · 08-23-2009, 10:02 AM

OK, a good range of replies there.

I do like the look of the wing, I must admit, and removing it will leave holes in the body work including a big one where the body of the electric aerial sits.
However, I've been told that I could sell it for £100 and that would return 25% of the cost of the car. But then there is the cost of the respray to add to the cost of the conversion if I start doing body work.

OK, what I will do is to leave the wing for the time being and wait until it is running. I will then try my set commute with and without (with the holes taped over) to see who is right about the drag at 60mph.

There will be a load of LiFePO4 batteries up front in place of the spare, eventually, so I am hoping that will add weight to the front end. Equally there will be a load of batteries under the boot behind the rear wheels too as well as over the motor.

I have been thinking of changing the wheels, again to recover some of the cost. I could offer them to the owners club in exchange for a set of standard alloys and some cash. Or I could make up a set of 50's style aluminium moon disks to cover them.

I have a project thread here on the diyelectriccar.com forum if you want to follow it to see how I got to where I am now.

Robchalmers, where abouts are you? I'm in Eccles.

winkosmosis · 08-23-2009, 11:03 AM

What kind of holes will it leave? If they're just little circles you can plug them

robchalmers · 08-23-2009, 11:27 AM

just north of warrington. where are you getting your liFe's from??

woodsmith · 08-23-2009, 12:34 PM

Quote:

Originally Posted by winkosmosis

What kind of holes will it leave? If they're just little circles you can plug them

Most of the holes will be screw holes of about 4-5mm diameter but there will be one big one that may be 50+mm that may also be rough cut to allow an aerial to be pushed through to mount on the plastic wing side bit.

Quote:

Originally Posted by robchalmers

just north of warrington. where are you getting your liFe's from??

You're not far from me!

I don't know yet. I figured that the conversion will take a while so by the time I am ready new sources may spring to attention. It is likely that I will import from China either on my own or as a group purchase. A chap on the Battery Vehicle Society forum recently imported a small 24V pack for his bike as a trial to see how the import process works and to see if the goods were up to spec. So far so good.

I am currently using the Thundersky specs to determine physical size and possible cell capacity to work out range and how many cells I may be able to afford and fit in the car.

No doubt they will be cheaper and easier to get in 12 months time.