Posted: Wed Aug 25, 2010 9:14
GR-8 wrote:Intresting. I would like to make CF peices. Even a dash. Wonder what weight savings that would net me? That is my next direction I am going with the 8. Light weight. Problem is I want full interior still.
Slowly making the 8 ligther is my goal for the next 3 or so years. I just need to find out how much CF doors (front & rear) and fenders weigh compared to stock. (They will be painted)
I messaged a guy who sells the doors on ebay and he said the box he ships them in is rated at 15lbs w/packaging and all. So if he is telling the truth it's about 7lb.s per door compared at 36lbs stock.
I just need to save up $. Going all CF will cost more money than I spent on my turbo kit. Will it be worth it if only 100Lbs of body panel will be shed?
Guess the only thing to test it would be making a pass at bandimere with just me then either have 100lbs added to the car or have a person that weighs 100lbs less than me drive it down the track.
Not to break your heart, Jimmy, but the bod panels on the 8 are pretty light weight. The fenders are a very thin gauge (22g) stamped steel and weight less than 10lbs a piece. I had my fenders off a lot and actually weighted them.
The front doors are steel and have integrated crash bars, which adds heft, but also protection. The main weight in the door is the window, however, and the speakers, the power window motor, power door lock system, and wiring harness still weight more than the door itself. Gut the door and replace the heavy window with a Lexan window and you'll save more weight.
The other problem with the CF doors is they aren't pre-drilled or anything for mounting the power window/door lock equipment, speakers, etc, so you have to fab mounting brackets. When it's all said and done, you'll be lucky to save 10lbs by going to Carbon fiber front doors...not to mention they don't have the crash bars in them like the OEM doors do, drastically reducing safety. Remember, the RX-8 has no B-Pillar due to the dual doors, so the doors actually form the B-Pillar.
The rear doors...fughitaboutit. They are aluminum and were specifically designed by Mazda to be lightweight. The CF piece will save you about 2lbs if you're lucky per door. It's just like a CF hood on the 8...the OEM hood is 2-piece bonded aluminum and a lot of CF hoods out there actually MORE than the OEM hood. My CF trunk actually saved me about 10lbs, however.
A carbon fiber dash would be interesting, but hella expensive. I don't think it would save you much, if any, weight. The only way it could would be if you ditched the stereo, the HVAC system including the ducting and heat exchangers, and airbags. You could save an easy 60-80lbs there, but at the sacrifice of no air (even vent), no heat, no radio, etc. Too extreme for a street car, IMO.
Honestly the RX-8 is pretty lightweight from Mazda- the only way IMO to strip more weight while keeping an interior is to do a small lightweight race battery in the trunk, 2-piece brake rotors front/rear and monoblock 4piston calipers like the ones from RacingBrake (saves a BUNCH of weight, and it's un-sprung weight which counts for double), lightweight wheels (which you already have), lightweight exhaust- preferably titanium, and starting with a Base Model car. Since you have the GT, swapping in base non-power seats will help you, too.
/end threadjack LOL