Hi guys,

Searched through DamonB and Damian's threads and can't find what I am looking for. I remember one of them made a thread about the fab of an alum undertray for the MS GTC bumper. I was wanting to find that thread because I am making myself one for the Sanai bumper and wanted to know what gauge to use and also the type of fastners he used were really cool and I would like to use them but can't remeber what they are.

Any help would be great thanks,

Alex

 

ttt

 

first , i would not use solid aluminum, to heavy... use skinned aluminum core or somthing

the fasteners are called 'Dzus':
http://www.racerpartswholesale.com/dzus.htm

 

Thanks for the reply Damian.

I will look into that.

I think the best would be alum. honeycomb stacked with FRP top and bottom (to compensate for FRP's weak strength when not formed in curvature). But its expensive for the honeycomb.

 

Other materials to consider would be plastic (such as acrylic) and plywood (don't laugh, it's actually a good material when you think of it). Either one will do the job just fine, as they're quite strong, somewhat flexible to absorb impacts and are tolerant of abrasion if you happen to scrape it anywhere. Many racers use these materials.

 

hey even F1 uses a plank of wood on the bottom of their cars.

 

Maybe Lotus...... in the 1970's

 

Try everyone, currently. I think it's some special plywood though, it's part of an FIA rule, if too much is worn off at the end, then the car was too low and it's diqualified.

 

I believe FIA recently switched to a composite piece because there were complaints about consistency from piece to piece. Works the same way though.

 

Plywood would really surprise me.

Maybe something like balsa wood....

I was under the impression that for the longest time they were made from Carbon & alum. honeycomb. Maybe that is just CART/IRL because that is what I read that Aerodyne makes....

 

It's not a structural part, it's there purely to protect the chassis from being damaged when the car bottoms out. In a use like that you want it to be consistent all the way through, so a honeycomb wouldn't be that good. I've heard that it's not exactly building grade plywood, but some special expensive wood.

Anyway, lots of racers use plywood splitters quite successfully.

 

Just watched Top Gear and the BMW they raced for 24 hours was using a plywood undertray, guess I was wrong.

 

I also recommend some type of plastic material such as acrylic. I'm been playing with some on my car.

 

Acrylic is really brittle and hates chemicals. Check out ultra high molecular weight polyethylene (UHMWPE) or "poor mans teflon"
it's super slick, cheap as polymers go and is really tough.