What do you think, is there any Gain/improvement to "copy" the front wings with a "spoiler" like on the new Caterham, to reduce front end lift?

And also, would it have any effect at all to have the underside of the car covered and flat?

/Hasse

Yes. Gains will be made in both areas - if you can measure it, you will be surprised on how much the lift is reduced.

If you can introduce a slot IN THE NOSECONE behind the radiator and duct the air through it (and not into the engine bay) you will get further improvements...

[Edited on 3/1/06 by tadltd]

A flat bottom on the car is a definite aerodynamic advantage.

By having a totally flat floor and running the car in rake ie. nose lower than tail. The air passing under the car will expand as it flows to the rear sucking the car to the floor.

This effect can be improved by adding a diffuser at the rear of the car.

The effect can be quite impressive infact F1 cars can get more downforce from the undertray than from their rear wings hence the FIA introducing barge boards etc to limit this.

Reduced drag = less power needed at all speeds (but much more at the top end).
There are 100 things you could do to improve a seven but then it wouldn't look much like a seven anymore.
A tear drop shaped bubble instead of a cycle wing would be best. Think of a down hill skier's aero crash helmet. It would look a bit odd though.

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Originally posted by tadltd
Yes. Gains will be made in both areas - if you can measure it, you will be surprised on how much the lift is reduced.

If you can introduce a slot behind the radiator and duct the air through it (and not into the engine bay) you will get further improvements...

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Apart from changing the engine, from a C to a D, aerodynamics are this years project for the Indy.

Looking at panelling underneath of the engine bay with ali, with removable panels for access, vents at the back of the engine bay to let the air out, a rear diffuser in ali like the one from Fisher and other trial and error bits.

Mike

A guy at uni did a year at Caterham last year. He had quite a bit of input on the new CSR caterham (with aero cycle wings)
He was saying that back to back wind tunnel tests showed that the old wings created lift in suprisingly high 10's of kilos and that the new wings actually were giving slight downforce! This was mainly achieved getting the wings to run a lot closer the wheel and rolling them forward a lot, so things can be greatly improved even with normal wings.
Having said that, i wouldn't really want too much downforce on the wheels and suspension!

Flat bottom is a nice idea too. What about a some sideskirts and maybe even a big fan at the back!

Andy

A problem with creating downforce on the front wings will be even more broken wing stays . Remember reading an article years ago about a 7 with clamshell wings that had vents in the wing to reduce lift /drag

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Originally posted by rusty nutsA problem with creating downforce on the front wings will be even more broken wing stays.

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How come all these yank tanks get away with having bare tyres all round?
Also, will rotating the wings forward round the wheels not help to decrease lift?

emsfactory: Yes, if the arch is rotated forward it should 'scoop' less air. As I mentioned above, caterham found this to be the case with running it closer to the tyre. Apparently it was also found that the air that was being thrown up by the back of the tyre into the arch was also part of the problem, as when it met the air coming in from the top and it had nowhere to go but force the arch up!

Andy

Ok. So is there any regs as to how much of the tyre has to be covered by the wing?

Why can't someone make a stick on aerodynamic wing for all our normal arches?

Pat...

Like a mini version of the billet jobbies you see on corsas?

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Originally posted by emsfactory
Ok. So is there any regs as to how much of the tyre has to be covered by the wing?

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Y'know just the mention of these cycle wings makes me twitch like Dustin Hoffman in Rain Man. The cycle wings on the Caterham CSR bear a striking resemblance to those which I designed for Caterham several years ago as part of an agreement between them and the company I work for whereby we would produce a 'zero lift' car and they would produce the associated parts as a special edition upgrade kit with our logo embossed into them.

We did an 8 hour wind tunnel test which some of you may remember was covered in Autocar magazine (complete with a picture of a younger but chubbier version of me). We managed to reduce the lift of the car from around 40kg at 100mph to almost 30kg of downforce at the same speed. With a decent reduction in drag too.

Caterham then went away and refined the parts to make them more production and sales-friendly. The version they came back with is very close to what has become the CSR. I have their original styling sketch of it on my wall at work in fact - complete with our company's logo.

Unfortunately they decided that tooling costs were too high and that they couldn't go through with it. Around 3 years later there was an article in Evo magazine where they were wind tunnel testing a new car. It was very similar to what we had done for them. I approached Jez Coates (Caterham's Tech Director) at the wind tunnel and made that point but he said that their truckie had designed it having been inspired by formula 1...

I've always been unhealthily bitter about this because the tie-up with them was my idea in the first place and I had to push quite hard at work to get the thing set up. Now something that bears the fruits of our labours (and a free wind tunnel shift) is being sold without the accreditation we originally agreed.

Yes the wheelarches do work. Very well in fact. Shame though that every time i see them i don't feel pride but instead just disappointment.

Sorry to rant like this but the therapy just ain't shifting this cloud of bitterness

Cheers

Rob

Rob, don't you hold original drawings,that are dated that you could use against them, surely you could do a 'caterham' on them for a change !!

Jason

House bricks just aint aero dynamic though, if you want less drag a full body is the best option

Rob

Don't suppose you would like to post some drawings would you ??

Mick

I remember that article in Autocar, that's before building a car ever crossed my mind, it was that good.

Mark

Unfortunately there were no 'official' drawings at the time as the whole thing had to be done at minimum cost so we just worked with hand-drawn sketches. Equally there was never a written version of the agreement, just the gentleman's handshake variety. Needless to say we don't do that anymore.

I've talked to numerous people since then about the various ways to improve the aero of 7-type cars but, as Triton says, you're fighting a hopeless battle and are better off with a closed body. That said, it's still possible to have the same awful lift balance in a closed car f you don't sort out your front wheels or cooling system properly.

Sorting the front arches on a 7 can make up to 65% reduction in front lift from the normal arrangement (about 20kg less lift at 100mph). It's not that they generate downforce but they just eliminate the mechanisms which would otherwise generate lift. This means you could get away with weaker mounts, not stronger ones.

Andy Lancaster's right about the description of those mechanisms. It's all about preventing a build up in pressure underneath the cycle wing. Those wings were designed to prevent air getting in and venting any that did get in along with whatever was dragged up from the rear. You'll see something very similar around the front wheels of Le Mans prototypes and it's taken to the extreme on DTM cars.

You can get almost half the benefit just from having your normal-shaped wings as close to the tyre as possible and running with them rotated forwards around the wheel so their front edge is about half way up the front of the tyre. That's 10kg less lift at 100mph for no extra cost. Bargain!

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Originally posted by Rob Palin


You can get almost half the benefit just from having your normal-shaped wings as close to the tyre as possible and running with them rotated forwards around the wheel so their front edge is about half way up the front of the tyre. That's 10kg less lift at 100mph for no extra cost. Bargain!

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Originally posted by Rob Palin
I approached Jez Coates (Caterham's Tech Director) at the wind tunnel and made that point but he said that their truckie had designed it having been inspired by formula 1...

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Originally posted by andyps

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Originally posted by Rob Palin
I approached Jez Coates (Caterham's Tech Director) at the wind tunnel and made that point but he said that their truckie had designed it having been inspired by formula 1...

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Interesting - you see lots of wheel arches in Formula 1.

Maybe you should let us have drawings of your design - maybe if someone started making them to your design and Caterham were to file a complaint things would get sorted....

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Originally posted by Deckman001

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Originally posted by Rob Palin


You can get almost half the benefit just from having your normal-shaped wings as close to the tyre as possible and running with them rotated forwards around the wheel so their front edge is about half way up the front of the tyre. That's 10kg less lift at 100mph for no extra cost. Bargain!

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Dam, Ive just bolted mine in the normal place !! Oh well another change after sva !!

Jason

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I first saw wimgs similar to this on a Freestyle Caterham. Now on Ebay in GRP.




Any good?

Just been looking these up, they appear to have a sculptured design to the upper surface, what wiould be the benefits of this?




ATB Dan.

I tried all sorts of things to either enforce the agreement or do it ourselves independently but the company i work for wasn't interested. They said it wasn't worth it - to be fair we do get screwed over on a much bigger scale than that from time to time so they have a point. It was just that in this particular case i'd invested a fair amount of effort in the project personally. I'll get over it eventually

I've looked at using brushes to seal wheelarches on a number of different types of cars but no-one's ever keen on it. They'd have to be very stiff bristles though as you'd have a heckuva pressure on them at the kind of speeds where you'd really need them to be doing their thing!

Don't know the reason for the raised bit at the front of those wheelarches on e-bay. The louvres are very nice, although i'd prefer to rotate the arch further around the wheel and have those louvres further back.

As a rough guide, and using an image of the outside face of the wheel as a clock, you want the wheelarch to be tight to the tyre and extending down to at least 3 o'clock and have the louvres between 11 and 1 o'clock.

The squared-off bit on the top of the CSR arches would be less important if you've got louvres but is still a good idea. The boxy bit at the back just reduces the drag of the wheel from to

Start doing them yourself and let C*terham come after you for copying if they are bothered, then all you have to do is defend yourself by showing the originals to a court.

Have the louvres been tried? Interested because TVR's excuse for having closed louvres on the Sagaris was because of the amount of grit that got thrown up through the holes, just wondering if it would be the same on a seven.

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Originally posted by andyps
Have the louvres been tried? Interested because TVR's excuse for having closed louvres on the Sagaris was because of the amount of grit that got thrown up through the holes, just wondering if it would be the same on a seven.

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