ive used these before and on sheet metal i cant see it working very well, the way these work is you have to have each side of the die on opposite sides of the sheet. and even if you do achieve this it will leave a dent around the hole

crabie I like your avatar looks insane but I reckon datsun 1k and 1.2K where unlucky not to come in a separate chassis like the mazda 1000, 1200s and 1300s do but they came out with horrible noisy ohc engine :)

I was thinking a while ago how to lighten up the ute, there aren't many places to save weight metal wise. Unless you replace access covers/tailgate inner cover/fuel door/tank inspection flap/bonnet bracing with carbon replicas.

David Browns ex Reg Cook car in New Zealand had a few holes in ot to help with weight.

http://www.ozdat.com/ozdatonline/featurecars/Cherry/cherry.html#1

Have a look at the engine bay pics and the interior pic.

i'm trying to think where on a datsun you would even put these holes?

most sheet metal in a datto is not load bearing... but it keeps the wind/weather out

My D-Sports Racer was a tube frame car but it used sheet metal between the chassis tubes in key areas, the sheeted in area had said flared holes and the car was very stiff. The car was was also about 60 lbs overweight for the class at 960 lbs yet I set the class record with it due to it being a stable platform versus flexi flier. A more glaring example is a story I've never forgotten; SCCA GT-3 tube frame cars, one was run for a driver comepteing in national races and was right on the minimum weight, the other car ran for an actress (Marsha Mason I think) and her car was built with extra protection. Well the lightweight car broke so said actress offered up her car for the other driver...........the heavier car was faster due to extra stiffness.

The reality of our cars is that 100 lb reduction equals about 4 horsepower.............you need several hundred holes to get that. A 1200 hood weighs around 30lbs or so most of which is the skin (the underbracing is pretty light)................think of the square footage of a hood and the amount of effort involved making that many holes. You'd be better served to make carbon fiber doors.

Now if you are looking to stiffen the chassis then some strategic flared holes would do that nicely.


Tom

only 3kg? Yet that's how the top racing teams win consistently.

For a street car that is not competing it is less important or let's say non-important.

Well that particular datsun already had its cherry busted :)

I agree its alot of work but it does add strength if done properly to some areas that are flat flimsy steel.

eg. you can have a strip of 1.6mm thick flat stee then add
some speedholes (tapered ones like on truck cabin steps or
suregrip alloy plate) and its much harder to bend.

On further inspection the linked product has no tapered dies?

this is the stronger result of tapered or flared holes
http://espimages.biz/2386/I/525/2/images_k%20851.jpg

here is the hole punch and flare tool
http://www.motorsport-tools.com/hole- ... wage-tool-1-p-268069.html

My dads friend reshelled a nissan works cherry coupe and added the "original" speed holes to the shell and body again. It took him 2 weekends and he had a icecream container full of scrap at the end which weighed about 3kg. A lot of work for little gain. I would be concerned about adding speed holes to a car that didnt already have a cage and be seam welded.

Much easier for the driver to the gym haha.

Add strength?

When properly done, lightening holes do not weaken the structure. They add lightness, which is equivalent to free horsepower.