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Home Made Splitters/undertrays

zebra

By zebra,
in Motorsport Discussion & Builds

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zebra Grand Master

zebra

Posted
Posted

In the coming weeks I aim to embark on making an undertray for my R33.

Thinking about making it out of 3-ply with a fiberglass overlay.

But what I would like to see is how people have mounted theirs under the car and if you have made any channels in it for super mega downforce.

Cheers

Andrew

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Dale FZ1 Veteran

Dale FZ1

Posted
Posted

Composite signboard, approx. 4.5mm thick and reasonably flex free. Runs back to the steering rack.

No fancy channels. No splitter section as yet. I consider it is simple design.

Was a bit fiddly to get the whole thing in place. Time permitting I will put some pics up on my R33 build thread.

Duncan Grand Master

Duncan

Posted
Posted

will it have to meet any CAMS regs? Prod cars, IPRA and Sports Sedans all have very specific rules about allowable sizes

BTW James has what seems to be a good one on his car, seemed to be a bit fiddly to put on but is working well

zebra Grand Master

zebra

Posted
  • Author
Posted

will it have to meet any CAMS regs? Prod cars, IPRA and Sports Sedans all have very specific rules about allowable sizes

BTW James has what seems to be a good one on his car, seemed to be a bit fiddly to put on but is working well

Nah,

Just track days and the odd hill climb

If it means running SV than I'll run SV

MBS206 Grand Master

MBS206

Posted
Posted

James (GrumbleBee) said he found a noticeable gain in front end grip when he fitted his. I'd say designed properly there are definite gains to be had. Designed poorly, well, you could end up with less downforce!

  • 2 weeks later...
Russman Grand Master

Russman

Posted
Posted

Simple setup I ran for a couple of years.
I like ally as it's easy to work with even though it's not the lightest. Very noticeable gains at PI and EC through long fast sweeping corners even though it was just flat underneath.

post-10715-0-72359600-1406810077_thumb.jpg

post-10715-0-04651600-1406810087_thumb.jpg

post-10715-0-99314600-1406810100_thumb.jpg

  • Like 2
GTR-N1 Grand Master

GTR-N1

Posted
Posted

At speed...

1) If front splitter and connecting undertray are flat with negligible air disturbance > negative pressure under front of the car > front 'sticks' to the tarmac.

2) If the rear wing is set up to create downforce > rear 'sticks' to the tarmac.

1) + 2) > all's good

gtr jet Veteran

gtr jet

Posted
Posted

At speed...

1) If front splitter and connecting undertray are flat with negligible air disturbance > negative pressure under front of the car > front 'sticks' to the tarmac.

2) If the rear wing is set up to create downforce > rear 'sticks' to the tarmac.

1) + 2) > all's good

What if one works a lot better than the other?

Dale FZ1 Veteran

Dale FZ1

Posted
Posted

The sort of front end device we're talking about won't really produce downforce to the extent that aero loading increases the effective vehicle weight above static.

An effective splitter design should protrude a fair bit, and its height above the ground has a big bearing on efficiency/effectiveness.

The outcome I found with my undertray (no splitter) is noticeable reduction in high speed understeer, less tendency to run wide through high speed sweepers. More front grip at speed is good :yes:.

gtr jet Veteran

gtr jet

Posted
Posted

The sort of front end device we're talking about won't really produce downforce to the extent that aero loading increases the effective vehicle weight above static.

An effective splitter design should protrude a fair bit, and its height above the ground has a big bearing on efficiency/effectiveness.

The outcome I found with my undertray (no splitter) is noticeable reduction in high speed understeer, less tendency to run wide through high speed sweepers. More front grip at speed is good :yes:.

That's exactly what I wanted to hear.

I don't even have the factory undertray atm and my car is horrible at taking high speed corners.

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