How the heck... (weight reduction)
- Thread starter boxedfox
- Start date
Roger,
He wouldn't be able to answer much for you, since I built it. When it left me in January of 2011, it weighed about 2400lbs, with ~15lbs of fuel in it and no driver. When the 4th gen Prelude Si got its weight dropped back in about 2007 or so, we put our car on a serious diet.
- Entire sunroof assembly was removed and replaced with a .060" thick piece of sheet metal.
- The passenger side door was completely gutted (re-did the passenger side door bars to go inside the door, to be legal per the rules). Drivers side already was gutted.
- Completely removed the side mirrors and replaced with small convex mirror attached to the roll-cage A-pillar bars
- Replaced the entire exhaust system with a 2ft Thrush, ~4ft of "damn near aluminum can thickness" pipe, and a turndown all before the gas tank (but still behind the driver, per rules).
- Pulled out the entire dashboard and removed everything underneath or attached to it that didn't absolutely have to be there per the rules.
- Removed any and all wiring that didn't absolutely have to be there.
- Removed the entire ABS system (wiring, pumps, lines, everything) and ran completely custom lines from the master cylinder to the four corners. Prior it had only been disabled, per the minimum rule on ABS.
- Removed any last bit of trim, seal, bracket, weather stripping, sound deadening, etc. that was anywhere on the car.
- The Kosei K1's helped.
I'm sure I'm still forgetting some other things we did. I was actually amazed at how much we were able to cut from that car, once I really started looking at it with a fine tooth comb. The best part is, most of that stuff cost next to nothing but time (if one did it themselves). The car still had an 8-point, fully-welded, safe rollcage too.
Wow. Thank you. That's actually extremely helpful.
I already have the aluminum sunroof plug, NASCAR bars both sides, and entire ABS system gone except the ABS Module (to be removed soon). I think it reinforces that I need to go through the entire car this weekend with the GCR in hand and get rid of everything that I'm allowed to. And to continue the whole diet and exercise thing.
This is going to be fun.
adamjabaay
New member
I believe your sunroof replacement needs to be the same material as surrounding roof....
have you dry-ice-then-smack-with-hammer'd the sound deadening "melt sheets"? You'd be surprised how much it can all weigh. What wheels ?
have you dry-ice-then-smack-with-hammer'd the sound deadening "melt sheets"? You'd be surprised how much it can all weigh. What wheels ?
Yup, you are correct. Per the rules, if you remove your sunroof panel, it has to be replaced with something of the same material. That's why I specifically said "replaced with a .060" thick piece of sheet metal".
Well, I'm back from a weekend of working on the car. I forgot to take pictures, but I found a chunk of weight in random spots:
- Removed random wiring left over from the SRS, ABS, and audio system that went from nowhere to nowhere
- Removed windshield washer bottle
- Replaced the alum sunroof plate with a steel one
- Removed the passenger side seatbelt reel (I completely forgot about that)
- Removed some leftover soundproofing carpet on the firewall
- Power side mirrors are apparently 5 lbs each. Replacing them with manual replacements would make a surprisingly big difference
- Apparently, I have what appears to be the heaviest battery I could possibly get for my car. Switching to a NAPA or Walmart equivalent with the same amp rating and group size would be a 10 lb diff, an Optima Red Top is a 15 lb diff
I also noticed that my wedge racing seat brackets are tremendously heavy. Are we allowed to mount seats to the floor or weld/cut into the stock seat mounting humps? I've got a good 20 lbs there that could go away real easily.
lateapex911
Super Moderator
I think you can make simple mods for seat mounting, IIRC. Read the good book to be sure.
Not sure how comprehensive your "NASCAR" bars are. They only NEED to be any kind of bar that protrudes into the door cavity to qualify for gutting the door and the door interior panel. Don't go overboard here. I've seen insane setups with a gazilion bars and gussets get t-boned....and the driver still got injured because the whole setup was attached to the roll hoop which was attached only at the floor location. Those door bars could have been eliminated nearly completely, and a transfer bar added and the result would have been safer AND lighter.
Concentrate on the front. I imagine thats where the weight savings will make the most difference.
Hollow sway bars? The solid ones weigh a ton. Camber plates aluminum? The steel slabs are heavy, high up, and in the front.
sometimes cars have oversized radiators. Remember, it's not just the radiator, it's the coolant that weighs as well.
Some of those intake tubes weigh a ton, and sink heat INTO the incoming air. Aluminum is a GREAT heat sink...
If you are running an airdam and splitter, look there as well.
And tires. Look at weights of tires. Hoosiers are known for being light. As mentioned above, thats a triple benefit...less unsprung weight less static weight and less rotating mass.
There's even possible weight to be saved in the dampers....
Divers seats can vary greatly.
Headlights: plastic lenses instead of glass.
Not sure how comprehensive your "NASCAR" bars are. They only NEED to be any kind of bar that protrudes into the door cavity to qualify for gutting the door and the door interior panel. Don't go overboard here. I've seen insane setups with a gazilion bars and gussets get t-boned....and the driver still got injured because the whole setup was attached to the roll hoop which was attached only at the floor location. Those door bars could have been eliminated nearly completely, and a transfer bar added and the result would have been safer AND lighter.
Concentrate on the front. I imagine thats where the weight savings will make the most difference.
Hollow sway bars? The solid ones weigh a ton. Camber plates aluminum? The steel slabs are heavy, high up, and in the front.
sometimes cars have oversized radiators. Remember, it's not just the radiator, it's the coolant that weighs as well.
Some of those intake tubes weigh a ton, and sink heat INTO the incoming air. Aluminum is a GREAT heat sink...
If you are running an airdam and splitter, look there as well.
And tires. Look at weights of tires. Hoosiers are known for being light. As mentioned above, thats a triple benefit...less unsprung weight less static weight and less rotating mass.
There's even possible weight to be saved in the dampers....
Divers seats can vary greatly.
Headlights: plastic lenses instead of glass.
backformore
New member
Just to reiterate: Wheels. It is not an inexpensive change, but Enkei RPF1 wheels at 9.5 pounds each will save 5 pounds per corner. That's 20 pounds total, 13% of your 145 pounds needed and it is all unsprung.
Again not cheap but I got 4 brand new delivered for $700. Used ones can be found but you have to be quick!
Again not cheap but I got 4 brand new delivered for $700. Used ones can be found but you have to be quick!
Bill Miller
New member
C'mon Greg, we all know that a formulaic approach to setting weights in IT will never work.
Kirk,
With all due respect, if that is the case, why did the New Beetle end up in ITC?