Over and Under or around the sides

[greenpower dude reloaded]

Good news!! Bad News too I'm afraid,I'll give you the good news first as it reads better.

We took the car to Rockingham Motor Speedway last thursday for our 1st event since the aero mods, lead the first few laps (over the fastest car in the whole competition) we peaked at around 40mph and were averaging lap speeds of around 33mph a vast improvement over our previous lap average speeds of 27mph on its first outing.

Unfortunately we lost out due to the chain jumping over the chain guards twice, meaning we only spent about 40 mins in the race, still covering 24miles and were therefore well on the way to breaking the previous record of 48miles, also worth noting is that the batteries looked as though they'd barely been touched.

i'll get some vids up later

[Carlos]

I liked the good part best - although overall - the 2009 season sounds promising. Didn't you have the problem with the chain jumping the sprocket last year too? How about trying a chain tensor to locate it, similar to what they use to keep tension on a camshaft drive belt. A slotted carrier, spring and gear is about it. Sounds simple ... which means it'll take the rest of the season to perfect. It's always this way

[greenpower dude reloaded]

As promised here are a couple of clips..

[youtube]http://www.youtube.com/watch?v=ODbxWJkg1wg[/youtube]

[youtube]http://www.youtube.com/watch?v=jnA5JR5njzA[/youtube]

Chain jumping was a problem in 07 which we overcame using chain gaurds, now.. it turns out they're not enough so it's either a tensioner or heavy industrial chain to over come it.

I forgot the worst part of all on saturday I leant the car out to my old school as they got me in to all this stuff and had trouble finishing their car. Needless to say the car is almost a write off with the rear end having nearly snapped off...

It was shaping up to be a good season but with one of our 3 races we're able to attend down, we're well out of the running.

[flynfrog]

You could do some coast down testing to test your mods to see if htye are good or bad.

Much better than the butt dyno

[Ciro Pabón]

Congratulations on a better design. I'm sure you will fix the chain issue.

[greenpower dude reloaded]

Sorry guys, i've been really lax recently. I managed to pop home for a day today and have spent it working on the car, it's a long way off being ready and we really need to think about the body.

I think the shape we ought to go for really, would be similar to slimjim's drawing and as we'd intended for this vehicle, a drop tank style body i don't know what are all your thoughts?

The challenge though, lies in moulding that shape, it's really complex and we don't have much time any ideas?

[wesley123]

imo you need a car with the least possible frontal area.

Give it a bit of a single seater look, center the car, give it just enogu space for the driver. Give the wheels just enough clearance and make the rest between as smooth as possible, also look a bit 'between the rules', imo a closed top design without a roof is more aero efficent then just an open car, but it is still defined as a open roof as a closed top car does have a roof. Place a smuch behind the driver as possible. Also raise the car like 5 cm above the asphalt, like those cars with solar panels do.

[greenpower dude reloaded]

Closed top without a roof, how do you mean? We've got a surprisingly small FA area, one of the smallest FA's for a wheels in car, as it is at the moment. We are however always looking to minimise that interestingly I think the fact it's white makes it look much bigger.

This will however be reduced once we start to round off the corners etc.

In my experience wheels in cars are inherently faster, there hasn't been a wheels out car win since 2003 and even then it only had the 2 rears tucked away.

We currently run the car at 6cm above the track but may adjust that over the next few weeks.

[wesley123]

I mean that you chop the top off, so remove the part above the driver, then it isnt actually a coled top design.

I think tht making an open wheel design would help, as there arent wide covers needed for steering clearance.

Pack everything in the car as close as possible, best would be behind the driver, and then the rest as flat a spossible, that would reduce FA alot.

[flynfrog]

some one mentioned the tank car

[greenpower dude reloaded]

ahh i see so you still have windscreens etc, unfortunately that's all been banned too. It has to be a head out of the cockpit jobby.

Wheels out is the wrong way to be heading in my opinion, at the moment we are already quicker than all of the wheels out cars and it's between us and about 3/4 other wheels in vehicles. I know frontal area should never be underestimated but you can get a far cleaner shape with the wheels in.

You add a lot of drag from the tops of the wheels as well because on a day with no wind they are going twice the speed and if you double the speed you quadruple the drag..

[flynfrog]

ahh i see so you still have windscreens etc, unfortunately that's all been banned too. It has to be a head out of the cockpit jobby.

Wheels out is the wrong way to be heading in my opinion, at the moment we are already quicker than all of the wheels out cars and it's between us and about 3/4 other wheels in vehicles. I know frontal area should never be underestimated but you can get a far cleaner shape with the wheels in.

You add a lot of drag from the tops of the wheels as well because on a day with no wind they are going twice the speed and if you double the speed you quadruple the drag..

its not ideal just a cool car.

[greenpower dude reloaded]

That's funny Flyn I was looking at pictures of that just yesterday and i think we were simultaniously posting. we always wanted to get hold of a drop tank but never had much luck. I'm currently thinking something along the lines of a wheels in version of that. with a much flatter bottom though.

[flynfrog]

That's funny Flyn I was looking at pictures of that just yesterday and i think we were simultaniously posting. we always wanted to get hold of a drop tank but never had much luck. I'm currently thinking something along the lines of a wheels in version of that. with a much flatter bottom though.

they have some F-18 drop tanks for sale down the road from here. They are longer and skinnier that the old ww2 p38 tanks. Ive been eyeing one for a salt flats car.

[greenpower dude reloaded]

they have some F-18 drop tanks for sale down the road from here. They are longer and skinnier that the old ww2 p38 tanks. Ive been eyeing one for a salt flats car

Unbeliveable! the things i'd do for a drop tank.... ahh well looks like i'll have to make my own body from scratch instead then.