Are dive planes useful?

[scooby151]

Was interested in sticking on a pair of dive planes to the front of my car, but have my doubts over their effectivity during hill climbs, where speed isn't that high, especially in corners. Any thoughts / feedback on this?
Cheers

[Josh Smith]

Hi,

Tristan at Arc Angels does them in three different sizes for the PR6. I use the medium ones in the wet which I find a useful balancing device when adding more rear wing.

Josh

[splitpin]

scooby151 said:

Was interested in sticking on a pair of dive planes to the front of my car, but have my doubts over their effectivity during hill climbs, where speed isn't that high, especially in corners. Any thoughts / feedback on this?
Cheers

Given your particular discipline, probably worth studying some photos of "Black Betty".

[LCM]

scooby151 said:

Was interested in sticking on a pair of dive planes to the front of my car, but have my doubts over their effectivity during hill climbs, where speed isn't that high, especially in corners. Any thoughts / feedback on this?
Cheers

Assuming that we are considering the sorts of things that you see attached to the front of LMPs (rather than thin foil delta wings), then the simple answer is YES! Within limits.

The relevant principles involved in their operation are:

• upper surface - resolution of forces in respect of an enhanced flat plane/Newton 2 from the TE
• lower surface - Coanda and Newton 2 from the TE wash (assuming that you have nice thin section pieces with a mirror finish on both sides)

However, they are not a primary source of downforce but sit alongside rear wing and RWEP Gurneys as useful tuning tools to refine F:R balance or to add that final 20 or 30 N that you need in the sort of extreme situations that are so often the norm in hilclimbing.

Only 20 or 30 N you cry, but their supporters claim much more than that!

Well, lets apply the sort of LCM global test that washes all sorts of excretum tauri out of fora by having a look at some dive planes.

As Josh has already mentioned one supplier (is he on a symbiotic deal, I hear you ask) lets have a look at theirs: http://the-arc-angels.co.uk/shop/index.php?route=p... Nice shiny bits of carbon that look like 1.5mm gauge with something like a 10-15mm upstand designed to be fixed to the body with say 4 pop rivets or 2mm bolts. Ask yourelf "would they be able to transmit hundreds of N (let alone the thousand or so that I would be looking for from a primary downforce source) to the tyres without breaking or falling off?".

BTW the one on the left bears an uncanny resemblance to the planes that Martyn @ MVS and I developed for Betty so I know that they work!

Now, if you're very clever it is possible to generate vortices off the planes which can have a disproportionate synergistic effect on the flow down the sides of the car. But, as we're talking about Radicals, that is probably beyond the scope of this forum.

[radical78]

the old type are horible . sr3 carbon ones fit most other radicals and help with understeer

[scooby151]

Thanks to all for the feedback. Will consider them as my next 'upgrade' then ;-)

[scooby151]

Wide hillclimb diveplanes ordered. :-)

[BioBa]

Arc Angles do not make them for SR3s. Is there another aftermarket company I could contact? I had purchased some from ATG but but their fit was horrible.

[LCM]

radical78 said:

the old type are horible . sr3 carbon ones fit most other radicals and help with understeer

They certainly are . One wonders whether they possibly have more to do with "styling"/customer expectations than aerodynamic function (for "Honours Students" - they only use the top surface to any effect). I started off with them as that was all that was available at the time and didn't notice a lot of difference whether they were on or off the car!

When Martyn @MVS and I developed the first thin foil planes the difference was amazing and at best a double set added in the region of 5-10mph to the speed at which I could transit a difficult 65mph bend by dialling out initial understeer. The story of how we dealt with the concomitant corner exit oversteer is one for another day!

A bientot mes eleves!

[dunc_sx]

Hi folks,

Are these the infamous "old style" dive planes on my car? If so would I be better off removing them and saving drag/weight?



Any responses appreciated,

Dunc.

[LCM]

dunc_sx said:

Hi folks,

Are these the infamous "old style" dive planes on my car? If so would I be better off removing them and saving drag/weight?



Any responses appreciated,

Dunc.

Hi Duncan.

Yep, they're the old type.

BUT I wouldn't just bin them and hope. Remember that a conventional sports racer naturally wants to fly when it moves through the air. A wiser first step would be to replace them with the thin foil type which are available from Josh's friends or Martyn in Westest Wales. I can't remember whether you're running a diffuser FUT and extractor side pods, but if you're not that would be my next step to help nail the front down.

Funnily enough, those horzontal side skirts that we have on Clubbies and Prosports are remarkably effective in reducing the propensity for sports racers to fly and flip when in yaw and roll. Their use doesn't seem to have impressed the AOC enough to appear in LMP regs but IIRC when Angus Loft was head of aero at MIRA he was a fan of them (if you'll forgive the somewhat painful wind tunnel pun). Sometimes the old remedies are the best!

[Laurence7]

Hi Dunc
I'm going to bang the drum for the Clubsport/Prosport/PR6 dive planes produced by The Arc Angels ("Josh's friends")!
They're relatively thin and with sharp edges (good for promoting the formation of the desirable vortex trail on the underside; it's the low pressure in the vortex on the lower surface that generates the down-force more than than the high pressure on the upper surface).
Also, they're produced with some clever matched tooling, so that both the upper and lower surfaces are (smooth) mould-tool surfaces - very nice quality.
Laurence
P.S. I'm not on commission

[splitpin]

Laurence7 said:

P.S. I'm not on commission

Nor Sponsorship?

[dunc_sx]

Cheers

[Laurence7]

splitpin said:

Nor Sponsorship?

Well no, not really.

Unless of course you count the private jet they provide to fly me to international circuits around the world, or the five-figure start money to compete against other renowned superstar drivers... in my Radical Clubsport

[Martin B]

How much drag do dive planes (older and newer types) generally produce typically on a Clubsport/Prosport/PR6?
Does anyone know what the L/D ratio is for them to see how efficient they are as aero devices?
I have always been a bit reluctant to fit them as I don't want to sacrifice top speed but could do with a bit more down force now (for circuit racing) so am starting to consider some.

[andylaurence]

Dive planes will vary in efficiency. They're generally very efficient as they help extract high pressure air from the front of the wheel well. Most importantly, they help balance the front/rear aero as the front is normally where it's hard to get enough downforce.