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Old 05-25-2008, 11:08 AM   #13 (permalink)
lunarhighway
Master EcoModder
 
Join Date: Feb 2008
Location: belgium
Posts: 663

vectra a - '95 Opel Vectra GLS
90 day: 37.51 mpg (US)
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@adrive7 looks like a fine tool, but it's a bit expensive... it would sort of cancle out any financial saveings the undertray could have. if this thing delivers an actual 1% improvement in overall FE it might pay for itself 1 or two years... of course the higher fuel prises go the sooner it'll pay off, and i hope i'll save more gas, but it's not that big an area so i try to be realistic.


for the construction apparently sometimes it also pays of to look at a problem from the other side... i always envisioned the tray had to be removable from below, but when i opened the hood i saw there was plenty of room to reach down so i might suspend the undertray by just slideing it underneath the back of the bumper, suspend the other side from an alluminum L beam that rests on top of the subframes at the back and than use a conveniently located screw in the middle to hold a bracket that the whole assembly from shifting backwards and detaching.

to attach everything i'll drill holes trought the undertray, put some bolts trought it from below, and secure these to the tray with nuts from the top and than run these trough the L beam and the bracket and finally secure them with wing nuts.

to detach the undertray i would simply have to undo a couple of wingnuts and the whole thing would fall off with all the bolts staying in the undertray. i'll use some rubber wachers to dampen the vibrations a little to keep things from shakeing loose.

since te aluminum sheet might be a little floppy (i'll go for the things i can get as thats cheapest and lightest!) i might need to rivet some L beams along the edges.

anyway that's the plan.

i think i'll construct the frame and than cover it with some corrugated plastic. if that gives some measurable gains i might build a more solid version.
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