Weight reduction
Elise Weight Reduction
Carbon clams are hideous money compared to the weight saved, and dont save much at all unless they are auto claved or vacuum formed. Benetec CF Front Clam 4,95kg Vs std at 15kg but 58k:(
Be very wary of poly side screens. They are very flexible and with the roof fitted flare out dramatically at speeds above 60MPH.
Early rear arch liners are 2.8kg. Later liners are lighter.
Removing the GRP where the reversing light and fog lights are, along with the grilles and the reversing light saves about 1kg.
The rubber seals around all four wheel arch liners (assuming you haven't ditched the arch liners) are about 200g each, and most of the boot lid seal can be removed with just token parts left in to prevent rattle giving about 1kg of saving.
Exhaust Exige/111R Catback: 13kg. Stage 1 11.8Kg(saves 1.2KG), Stage 2 8,2Kg(saves 4.8KG), , Quicksilver Titanium 5,2KG(saves 7,8KG)
S1 Weight Reduction
-12,5kg Titanium Exhaust system(std 16kg Vs 3.5Kg)
-12,2Kg Carbon fibre track seats (2,4kg vs 8.5 kg) x2
-11,2kg MMC discs instead of Iron disks (2,7Kg vs 5,5Kg each)
-8.65kg Race battery (2.7 vs 11.35)
-7,25Kg Lexan front window (5kg vs 12,25kg)
-6,8Kg Speedline Magnesium instead of std AWI 5 spoke (25kg vs 31,8kg)
-6.55K Alloy Fuel Tank
-4.4kg Carbon fibre fixed seat frames(2kg and 3kg vs 0,3KG)
-4.4kg Remove the door reinforcement on 2 doors
-4kg Remove Radio And speakers (Radio ~1,4Kg speakers ~1,6Kg)
-3,695Kg Soft top and mountings (Top 1,807kg, Siderails 1,888kg)
-3,3Kg Lightweight Flywheel
-2.55Kg Lightweight alternator (3.35 kg vs 5.9kg)
-2,5Kg Cat Replacement Pipe (1.8Kg Vs 4,3Kg)
-2,2Kg Billet Aluminium Crankshaft pulley
-2,136kg Back window
-2kg Alu boot lit instead of GRP(Glass Reinforced Plastics)
-2Kg Alu top engine mount
-1.994Kg Rollbarcover
-1,697kg Heat shield baggage compartment
-1.388kg Dressed baggage compartment
-1kg Leather sill covers
-1Kg Carbon fibre steering wheel (1.7kg vs 0.7kg)
-0,872kg Alu Ball joint mounts (1,308kg vs 0,436kg)
-0,8Kg Footwell divider
-0,6kg Handbrake and gear stick cover
-0.55kg Passenger footrest
-0,5kg Front Mud flaps
-0,4kg Alarm siren
-0.23kg Inner Rear view mirror
-1/2 of std Lightweight Starter Motor
-2/3 of std Polycarbonate/perspex rearscreen/sidescreens/frontscreen
-?kg Elispart solid 4-2-1 manifold 6kg std?kg
Other Sorces of Information
http://www.340r.net/technical/weight/weight.htm
http://forums.seloc.org/viewthread.php?tid=91178