CAV Front Canards

[Ian Clark]

Maybe I should have made this a poll topic? So far 4) #39 1) 43 1) 61 Do we have a trend or too early to call... Thanks for the votes, hopefully more will chime in.

It would be nice to avoid the struts as on some versions and keep the mounting as clean as possible too. I'm leaning towards high temperature vinylester, handlaid glass, most likely cored and bolts anchored in for no visable fasteners. This will produce a strong, light dimensionally stable part that will take paint well.

What about carbon fibre? too much for the "period correct" look? Opinions please

 

[Ian Anderson]

A question on these canards

Are they also used to deflect some air sideways around the front tyre (start the airflow moving sideways)

After all the Tyrrell 6 wheeler used small front tyres due to better aerodynamics and a GT40 type tyre is not exactly "small"

Ian

 

[Pat Buckley]

I was thinking some .060 aluminum?

 

[Jack]

Aluminum please!

 

[Ian Clark]

Hmmmm, aluminum? could be done with laser or waterjet cut sheet tig welded to a curved flange. The "fin" would be centered on the flange. Very interesting... different manufacturing processes but well worth considering.

Besides the general shape and construction details there are contour issues to ensure a close fit on different bodies ( generation loss, different sources etc) and where to put the dang thing.

There is probably an arc midpoint on the nose where shape differences are minimized to get the fit, higher or lower positions IMHO would be harder to get to an adverage shape so non CAVs would accept the part.

About deflecting the air around the tire vs say working as a proper wing, the benifit is probably more from reducing lift in front of the tires than downforce due to the ramp angle or low pressure under the fin. Of course I have no data to subsantiate.

Ian, viewed from strait on the canards would not change the frontal area so no benifit as in the small tires of the Tyrrell 6 Wheeler. I saw the car run at Mosport as well as the UOP Shadow CanAm car, another racer using small tires looking for an advantage. Cool stuff.

Seems to me that a small lip on the trailing edge of the fin might improve separation of the flow reducing the dirty air trying to reattach to the body in front of the tires. Another suposition, anybody have a CFD suit or windtunnel we can borrow - cheap

Keep it coming guys, more to ponder thanks. Would be great to come up with a quality part that functional, looks fabulous and installs easily. Carbon Fibre?

 

[Jimmy P]

Ian, Some interesting comments and ideas coming forth. Aluminum vs Carbon....a good question. I assume the originals used way back when were aluminum as carbon fibre was nothing more than a twinkle is some young engineers eye so aluminum would satisfy the purest. ( I guess they could have been fibreglass?) As for mounting, I noted someone offered a two piece canard. The mounting flange was separate to the wing and once you got the mounting flange shaped correctly you welded the wing to the flange. I would think the mounting angle of the canard would also be critical. In speaking to Fran he stated he "bolts" the canard to the body of the car. This insures a solid fit. Riveting is an option so all of us contemplating adding this have to consider that fact. Once you go with it....its on. I'm sure the angle will have a lot to do with ones driving needs. Me personally, I love the way the car handles but I admit I do get up to some pretty good numbers (speed wise) when the road allows for it. This is what prompted me to ask about the canards in the first place......lift!

 

[Ian Clark]

Hi Jimmy,

Does anyone know definatively what the canards were made of on the later JWA cars? We do have choices and budgets both as manufacturers and customers. Fiberglass would be the least expensive, weakest and probably require the most fiddling to make fit and look right.

Aluminum would be next and with the correct average curve would most likely fit all brands with only a thin gasket under the flange, a tig welded asssembly ready for paint or leave alone.

Carbon fibre would cost the most especially done properly and left bare for all to see. Time to break out the lasers and carboard, see what kind of mischief I get into...

Cheers

 

[Jimmy P]

Ian, Not sure about the JWA cars....have to do more research. Personally, I'd like aluminum. Looks period correct, can be left unpainted and still look good, would be easier for you to work with (I would guess) and wouldn't be as pricey as the CF.

 

[Ian Clark]

Jimmy, looks like I'll create a "trial" fit template on a PDF or DXF file you or anyone can have printed locally, transfer to cardbard and fit up to the nose. See where the gaps lie or find the sweat spot to fit the most cars. Then we'll figure out what to make them out of. The aluminum is growing on me, it's just not gonna be cheap... Cheers

 

[Jimmy P]

Ian, Good idea on the templates. Look forward to seeing them. Will go from there as to fitment and let you know. I noted the new CAV GT (Johann posted a picture of) has neither canards or a front spliter/diffuser fitted. Ummmm?

 

[Ian Clark]

Jimmy, Splitters are another thing. To be effective they must be very close to the ground, or scraping as in Nascar, great for a track car built for fun. A period correct GT40 track car wouldn't have one fitted whereas a "new" style GT40 replica might.

We've seen splitters with side edges that fair the underside of the nose ahead of the tires. Obviously works for some people, depends on where you want to go with your car. A good splitter will cost you ramp angle, already in short supply on these cars.

So different strokes for different folks. I'd like to get the canards settled first. My ideas for a splitter would definitely run waaay afoul of the period correct look Cheers

 

[Jimmy P]

Having seen the BDR CAV GT with a splitter at a recent show I was not impressed with the overall look. Not really my cup of tea as they say. So I agree with you on the non period look. I'll stick with the canards.

 

[Jack]

aluminum canards please......

 

[Howard Jones]

Mine are made of steel and painted with silver/aluminum header paint. I have a subconscious feeling they do a little at about 100 mph. At least I think they put a little down force on the front. A 110 MPH corner at my favorite track SEAMS better.

 

[Ian Clark]

Cool pics Howard, had to download them, thanks. You probabably are getting some downforce from the canards along with the areodynamic pressure centre moving forward a bit. So it's partly downforce (or reduced lift) and areo balance favouring the front somewhat more. And they look fabulous too! Cheers

 

[Jimmy P]

Ian, Glad you chimed in with Howard....and Howard good of you to post the pictures. I'd seen your car some months back and I think I PM'd you about the canards on your car which is what prompted me to initally post. I too have some lift issues at over 100mph and went looking for solutions. Ian, like you, I like the look of Howards and it appears he's gotten some real testing done with them. Howard, is yours a CAV car or other make?

 

[Ian K]

Ian, Glad you chimed in with Howard....and Howard good of you to post the pictures. I'd seen your car some months back and I think I PM'd you about the canards on your car which is what prompted me to initally post. I too have some lift issues at over 100mph and went looking for solutions. Ian, like you, I like the look of Howards and it appears he's gotten some real testing done with them. Howard, is yours a CAV car or other make?

An old GTD - but a good one

Ian C. - I'll see if we have a wind tunnel here on campus. The Mechanical Engineers and
the SAE students might like to see some testing in action ...

Ian K.