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Splitters and Canards
mangogrooveworkshop - 14/6/10 at 01:04 PM

Whats the general opinion on the the effectiveness the use of on a seven.
Want to design and make some for the bec

scootz - 14/6/10 at 01:12 PM

About as much use as a nuclear-powered intercontinental ballistic haddock.

scootz - 14/6/10 at 01:14 PM

... IMHO of course!

smart51 - 14/6/10 at 01:34 PM

cycle wings produce a lot of lift. A little spoiler at the rear of the wing can reduce the lift. I guess a cannard would too. It might even stop your wing stays from breaking.

A splitter stops air the front of the car going underneath. Given the big hole in the front of the nose cone and the open floor, I'm not sure a splitter would do much. A deeper squarer "chin" like a donkevoort or a newer MNR might be more effective.

You might also want to consider panels on your wishbones if you want to reduce front end lift. Angled upwards, they might add a bit of down force to your suspension.

Generally, aerodynamic aids work better on the front of a seven than the rear. That is because the shape of a seven churns up the air so much there's not a lot you can do with it at the back. Front end aero aids should work fairly well though.

richardlee237 - 14/6/10 at 02:00 PM

They're canard to make !!!

eddie99 - 14/6/10 at 02:06 PM

I have got hold of some carbon canards, just to push a bit of air over the wishbones to make it a tiny bit more aerodynamic. Caterham have them so they much do something All little helps

Bluemoon - 14/6/10 at 02:31 PM

quote:
Originally posted by eddie99
... Caterham have them so they much do something All little helps


empty your pockets??

Not convinced by any aerodynamic aids on a 7, if you want aerodynamics you'll end up with a completely different car

As far as I can make out any aerodynamic effects tend to happen at higher speeds >80mph so you generally don't get any benefit (maybe on track??)..

Dan

sucksqueezebangblow - 14/6/10 at 02:36 PM

I have fitted a full undertray and have ordered the carbon sandwich to make my splitter. I suppose to be fully effective it would have to strech back to the back of the bonnet line to split all the air going under the car, but I reckon doing the nosecone should be adequate. Bear in mind also that with a full undertray you will need venting in the bonnet or sides of the engine bay.

I'm not sure how effective cannards will be but they will probably add a little downforce (and drag). I'm also planning to fit Gurney flaps on the back curve of the front and rear arches to break the airflow away and reduce lift.

Alan M - 14/6/10 at 02:37 PM

I agree. Aerodynamic aids do nothing at speeds below 70mph. So unless you have warp drive, don't bother!

Richard Quinn - 14/6/10 at 02:43 PM

quote:
Originally posted by eddie99
Caterham have them so they much do something

... and didn't the Emperor have some new clothes once?

Jumpy Guy - 14/6/10 at 02:51 PM

Hey, if they look good, and dont weigh too much, then what harm can they do?

A little bit of bling doesnt do any harm....

CNHSS1 - 14/6/10 at 02:55 PM

imho aero additions such as canards and to a certain extent, splitters, are trimming devices to balance the downforce F&R. in the case of a 7Type, you only get inherent lift, so pretty pointless, again imho. panneling the underside will reduce lift, especially at the rear axle area, where most 7 types bodywork act as a kite!!
The nose is akin to a tescos bag in the wind, great for trapping air but not much else. the inlet duct for the rad must be well sealed and an escape route for the hot gasses found (bonnet vents, NACAs or ally chassis side panels that are open at the trailing edge. Panelling in the underside of the engine bay often improves engine cooling as the flow through the radiator isnt stalled on its exit by random airflow cascading from underneath the car and buggering up the flow of hot air from the rad.

I think reducing and at best negating lift, is your best goal, real DF without figure hugging full arches, cowlings for the exh system and proper aero bodywork isnt gonna work. There were a number fo race and hillclimb westies that had aero enveloping bodywork (Black Brick rings a bell), but they dont end up looking like a 7 type.
although a 7type is drag city (kiddies climbing frames have a high drag factor) , its not all bad news. If you can reduce say 50kgs of lift at 100mph to 10kg lift, you have a net gain of 40kgs of 'nearly downforce' so that will make the car much more stable at speed.

from what ive done on my hilllclimber, small gains (in lift reduction) are much more confidence inspiring, so worth the effort

[Edited on 14/6/10 by CNHSS1]

T66 - 14/6/10 at 03:28 PM

quote:
Originally posted by scootz
About as much use as a nuclear-powered intercontinental ballistic haddock.





I see your back then.....lol

SeanStone - 14/6/10 at 03:34 PM

There's no real reason why a real splitter couldn't work on a 7 car. You need a flat surface where the air stalls then you need a lip for that high pressure air can be used for downforce. So it'll work but it will need to be well supported. I can't really see it having much use for the normal zetecs/bec/pintos whose top speeds are quite low. Probably better for those achieving 120-130+ where the front really starts to wander

Humbug - 14/6/10 at 04:19 PM

Re cycle wings... I like the look of the ones (Caterham CSR? MNR?) which have vents at the back and maybe they really do let out some of the air build up and reduce lift.

To reduce cost - and a tiny bit of weight - coud you just carefully mark up 3 or 4 lines on the relevant place on the back of the wing and use an angry grinder (carefully" to cut some slits? Would that work, or would you get rain sloshing out of the slits in rain?

Alternatively, some ali louvre vents from B&Q could work, probably best if painted to match the wings though.

Opinions on a postcard

mangogrooveworkshop - 14/6/10 at 05:31 PM

quote:
Originally posted by Alan M
I agree. Aerodynamic aids do nothing at speeds below 70mph. So unless you have warp drive, don't bother!


Its at 70 that we start lifting

Lower speeds I dont care what its doing just want the nose to stay put at the higher cruising speeds.

Cost to me is almost zero its just the time that it will cost me.

I had thought of the panels in the bones...

Ive also got most of the materials to make it.

So if anyone has ideas please tell me

scootz - 14/6/10 at 05:39 PM

quote:
Originally posted by T66
quote:
Originally posted by scootz
About as much use as a nuclear-powered intercontinental ballistic haddock.


I see your back then.....lol


Indeed... you're Rad is in the post!

Bluemoon - 14/6/10 at 06:08 PM

quote:
Originally posted by mangogrooveworkshop
quote:
Originally posted by Alan M
I agree. Aerodynamic aids do nothing at speeds below 70mph. So unless you have warp drive, don't bother!


Its at 70 that we start lifting

Lower speeds I dont care what its doing just want the nose to stay put at the higher cruising speeds.

Cost to me is almost zero its just the time that it will cost me.

I had thought of the panels in the bones...

Ive also got most of the materials to make it.

So if anyone has ideas please tell me



Are you sure it's aerodynamics and not something else in the setup?? My indy is not the best at speed at the moment, main problem is bump-steer that I have yet to dial out and possibly the old caster problem, makes things feel a little light up front at 70mph.

Dan

flak monkey - 14/6/10 at 06:12 PM

I have just fitted Canards to mine, not driven it yet - but I will report back on the findings!

Caterham had positive results in the wind tunnel by fitting them.

They were more designed to channel air over the front suspension than increase downforce from what I understand.

That said mine doesnt start to go light at the front end until well over 100mph....

fha772 - 14/6/10 at 06:13 PM

What is the aerodynamic advantage of fixing French ducks to your car?
Or, have i mis-understood, again?

iank - 14/6/10 at 06:34 PM

quote:
Originally posted by fha772
What is the aerodynamic advantage of fixing French ducks to your car?
Or, have i mis-understood, again?


I almost made the same joke, but I felt it was a lame duck... I'm here all week, try the veal!!

PAUL FISHER - 14/6/10 at 06:58 PM

I had some of the carbon mods canards on my old Indy R ,I can't say they made any difference,but they did look nice

mcerd1 - 14/6/10 at 07:05 PM

quote:
Originally posted by mangogrooveworkshop
Its at 70 that we start lifting


what about 'longer' front wings that cover more of the front of the wheel ?(and stop as much getting undernees them)

mcerd1 - 14/6/10 at 07:08 PM

quote:
Originally posted by scootz
About as much use as a nuclear-powered intercontinental ballistic haddock.


I need one of those - I own a cat in Russia with a a lead lined stomach that I'd like to be able to feed it without leaving the house

T66 - 14/6/10 at 07:31 PM

quote:
Originally posted by scootz
quote:
Originally posted by T66
quote:
Originally posted by scootz
About as much use as a nuclear-powered intercontinental ballistic haddock.


I see your back then.....lol


Indeed... you're Rad is in the post!





Blatant twoc of thread, thanks Scott...

mangogrooveworkshop - 14/6/10 at 11:40 PM

quote:

Are you sure it's aerodynamics and not something else in the setup?? My indy is not the best at speed at the moment, main problem is bump-steer that I have yet to dial out and possibly the old caster problem, makes things feel a little light up front at 70mph. Dan

Na I sorted that s***T out last season with a whole set of new bones that make the car naturaly self center with out springs and bodging carry on.

The air is lifting it as we have done tests running into the wind and running with it....east west runs on the same bit of tarmac.

sucksqueezebangblow - 15/6/10 at 09:30 AM

quote:
Originally posted by mangogrooveworkshop
Its at 70 that we start lifting

Lower speeds I dont care what its doing just want the nose to stay put at the higher cruising speeds.

Cost to me is almost zero its just the time that it will cost me.

I had thought of the panels in the bones...

Ive also got most of the materials to make it.

So if anyone has ideas please tell me



Ok, here goes. I DO believe attention to aerodynamics is well worth the effort. I agree that below 70 the benefits will be insignificant, but I intend to take my car up to 120 or more (depending on which drop gears I fit).

Wings; most locost arches have a nice round curve to them, the top surface acts like the top surface of a wing, and if the air flow adheres to them, which it will, you get lift. Think Audi TT, numerous owners went through hedges backwards before Audi added a small gurney flap to the rear of the car. The simple solution is to break the airflow away using small tabs or "gurney flaps" across the back of the arch, a little way behind the top of the arch. I've got racing arches at the front which have a "kick" at the back but are to my mind too smooth to work efficiently (moulding process does not allow harder edge) so I plan to put small gurney flaps on the back of each kick to break the airflow away properly. I plan to fit similar flaps across the back of the rear arches which being bigger would otherwise create more lift.

Undertray; I think the biggest gains can be made by fitting a full undertray (and even more combined with a diffuser). This will clean up the airflow under the car and stop the engine bay and and rear underside acting like parachutes, with high and low pressure areas shifting about all over the place at high speeds.

Splitter; I also feel a splitter is of value. Essentially when a locost nose cone is stuffed through the air, air is forced over, under and around the 'cone. This creates high pressure air all around the 'cone. The only bit that that may be problematic is the high pressure under the 'cone which will create lift under the cone. A splitter will address this. It is called a splitter because it splits the air going under the car from the air going around or over the car. Like a knife it cuts a clean slice of air that goes straight under the car with no increase in pressure. There is pressure above the splitter, but this now bears down on the splitter creating down force (or reducing lift) as the air is forced to change direction and flow around the cone instead of underneath. Needless to say there is not much benefit if there is no undertray to keep the flow clean under the car.

Diffuser; Diffusers can also be of benefit if you have a full undertray. Essentially the air flowing under the car suddenly finds itself in a venturi (widening cone) and has to expand into it (laws of physics) streching it and lowering its pressure creating downforce. The effect can be further increased by setting the floor height of the front of the car lower by a few inches than the floor height of the back of the car, effectively creating a mild venturi between the floor of the car and the road, for the full length of the car. The front floor should NEVER be set higher than the back as this crams air under the car and creates lift.

Beyond that there is not much more that can be done without adding wings. Cannards probably create some downforce (and drag) but they look cool so why not!

supercat - 28/6/10 at 03:31 PM

Has anyone got pictures or drawings of a splitter on a 7 type car?

vinnievector - 29/6/10 at 09:40 PM

I have made canards to cover up my unsightly lamp brackets and put some down force in at the front to take off the effect of the front wings not sure works but looks nice
they are an inverted wing section made from 22SWG T3 alloy with paxalin end fairings ,they will be painted to match the body work. Rescued attachment Isle of Wight 217.jpg
Rescued attachment Isle of Wight 217.jpg