Interesting article on caterham aerodynamics

[solstice]

An old autocar feature towards link towards the bottom of this page

http://csr200.blogspot.co.uk/search/label/aerodynamics

seems like the challenge is reducing front lift, I would have thought that some aero clams would make quite a difference, possibly along similar lines to the morgan aero 8.

[6speedmanual]

Pity the "trackday kit" never cam to fruition.  Some of the concepts such as the front mudguard design did make it on to the CSR.

[The_ASH]

Thanks for posting, makes for interesting reading.

Common sense and the basics are always worth applying like an undertray between the front of the chassis and the sump, lowered wing stays and continuing the floor to the back of the car. Reducing the frontal area also pays dividends, removing the screen by going aero and Freestyle inboard front suspension.

Nice to see it all layed out and tested in a proven way, for instance the way standard chassis rake generates 'some' downforce (but I'd bet lowered floors cock that up somewhat), truly fascinating to read nevertheless.

IF you went mad and applied it all you'd end up with a Lotus 79 or 11 or on a budget a Black Brick spyder perhaps?

[KRL]

Yes thanks very interesting reading.  This prompted me to look up if caterham do an S3 undertray and indeed they do!

 

http://caterhamparts.co.uk/product.php?id_product=775

 

Has anyone fitted this to their S3 and if so did you have any heat problems?

[The_ASH]

Fitted one to my last Seven, which was a 1600K with Piper 633 cams, verniers and 52mm TB so 130-something hp and no cooling problems at all. Reading on old Blatchat led me to believe the exit of air from the engine bay was only obstructed by a full length undertray from front of chassis to back of engine bay on both sides as there's not enough space for the air that comes in the front to get out through the tunnel if the bottom is all but sealed up, so, if you must, go as far back as the side skin exhaust exit and no further.

To attach I used riv-nuts but this time I'd use rubber insulated P-clips, resist the temptation to rivet the plate to the chassis as you might find it gets in the way at some stage. One thing it reveals once installed is how open to damage the K-series sump front edge and oil sender to the side is, so it's tempting to fit some kind of defector plate to ping all but the worst *carp out of the way.

The man on here who manufactures everything from titanium may be able to help for the whole plate otherwise it's £36 + del from C'ham as you have linked. If you are feeling flush ISTR that Fluke Motorsport did something in Carbon that could be trimmed to fit as well but wasn't a buy and fit option as the OEM one is (ish).

[OliverSedlacek]

The issue of heat is interesting. I fitted an undertray to the rear of my '88 XFlow, mostly to keep the road muck off the fuel tank and the like. My subjective opinion is that it restricts the air flow through the tunnel, which now gets much hotter. Unfortunately the other changes I made at the same time make it difficult to be sure.

Anyway, thanks for the links to the articles.

[thompster]

The undertray fits under the front cruciform and is, I think, standard fit on academy cars where its main purpose is keeping gravel away from the belts.  I have one on mine, no overheating problems.  Not sure how much it will affect aerodynamics but it keeps a lot of muck out.

[Stridey]

But... Are the overall performance figures improved with the undertray, or negated by the weight?