Are front panel seals and tyre spats worth the effort?

[cprobertson1]

I'm thinking of doing my first f few minor aero mods for my Ford C-Max, but Im wondering how much of an effect I'm likely to see?

Mod 1: sealing panels around the bonnet and headlamps. Plan is to use silicone tubing so it makes a flexible seal and can be replaced or removed with ease, but still deforms and seals.

Mod 2: front tyre spats - 3D printed, mostly hollow - bolted onto mudflaps and held onto the frame with strong magnets or adhesive, or even just another bolt)


My suspicion is that mod-1 will yield a small but noticeable difference, and mod-2 will be hardly noticeable at all.

What are your thoughts?

[freebeard]

"In theory there is no difference between theory and practice. In practice, there is."

Yogi Berra [allegedly]

IIRC aerohead found no benefit to taping the seams at the Darko wind tunnel.

The spats might yield a small but noticeable difference, depending on the implementation.

[aerohead]

Originally Posted by cprobertson1

I'm thinking of doing my first f few minor aero mods for my Ford C-Max, but Im wondering how much of an effect I'm likely to see?

Mod 1: sealing panels around the bonnet and headlamps. Plan is to use silicone tubing so it makes a flexible seal and can be replaced or removed with ease, but still deforms and seals.

Mod 2: front tyre spats - 3D printed, mostly hollow - bolted onto mudflaps and held onto the frame with strong magnets or adhesive, or even just another bolt)


My suspicion is that mod-1 will yield a small but noticeable difference, and mod-2 will be hardly noticeable at all.

What are your thoughts?

1) If there are no electronics behind the gaps, which might rely on air 'leakage' for cooling, then you could temporarily seal them with painter's tape to see if there's a 'showing'. Then go from there. Some bonnets have weatherstripping applied to their perimeters, which create a hidden seal when closed. Renault demonstrated a minor drag reduction sealing the nose of one of their research vehicles. No specific data was given, but your instincts are good!
2) For the 'spats,' are you talking about the plastic flow deflectors in front of the front and rear tires? Or some modification to mudflaps behind the tires?

[cprobertson1]

Originally Posted by aerohead

1) If there are no electronics behind the gaps, which might rely on air 'leakage' for cooling, then you could temporarily seal them with painter's tape to see if there's a 'showing'. Then go from there. Some bonnets have weatherstripping applied to their perimeters, which create a hidden seal when closed. Renault demonstrated a minor drag reduction sealing the nose of one of their research vehicles. No specific data was given, but your instincts are good!
2) For the 'spats,' are you talking about the plastic flow deflectors in front of the front and rear tires? Or some modification to mudflaps behind the tires?

1) I don't think there is anything behind the gaps - certainly nothing obvious! Only thing I can really think of are the headlights. I like this painters tape idea for testing! Many thanks!

2) Aye, contoured flow deflectors on the mudguards in front of the wheels. I've not decided on the exact shape yet, I'm just brainstorming at the moment - I'll do a bit of research and modeling before I build anything.

[aerohead]

Originally Posted by cprobertson1

1) I don't think there is anything behind the gaps - certainly nothing obvious! Only thing I can really think of are the headlights. I like this painters tape idea for testing! Many thanks!

2) Aye, contoured flow deflectors on the mudguards in front of the wheels. I've not decided on the exact shape yet, I'm just brainstorming at the moment - I'll do a bit of research and modeling before I build anything.

The FORD Probe-III had a series of sculpted flow fairings on this concept car. They are similar to what you have in front of the rear wheels on the C-MAX.

[cprobertson1]

Right - I think I will only try mod-1 (panel sealing) for now.

It's easy to test, and has fewer variables. Spats/flow deflectors will have a ton of geometric variables to work out - so I'll keep that for a future project when I can do lots of iterative tests on different shapes (I might even go as far as to look at a scale model and a mini wind tunnel, though, that is a lot of effort...).

For now though, I'll try taping the panel seams and see what happens. Going to try to get access to an old derelict industrial road with about a mile of straight ways and zero traffic - failing that, It'll work something out