Spank

iTrader: (1)

Hi guys I am posting this here in hopes of getting help in my search for light weight parts. My car is going on a diet this winter and I am looking for the lightest stuff I can find.

Please help with what you know for light stuff.

How makes the lightest wheels?
Exhaust?
How about parts for our car, alternator, generator etc.

Thanks for your help.

Mahjik

iTrader: (1)

Volks has some of the lightest plus sized wheels I've run across.

ptrhahn

iTrader: (9)

Just about the lightest wheels around are SSR Competitions... some of the titanium exhausts like GReddy's or Rotary Extreme's tend to be the lightest... There are lightweight carbon body panels from a variety of sources, but i doubt you'll find lightweight stuff like alternators and generators... and there won't be much weight to be saved there.... you could eliminated things like A/C, sterio, power steering, soundproofing, extra trim, and so forth

Fatman0203

Out of curiousity? What the lowest someone has gotten an FD and it still be an FD and not some tube chassis?

jimlab

Brad Barber's track-only car had no interior (but did have some sort of roll bar, I believe), no door glass, a single seat, no headlights or turn signals, ABS, airbags, power steering, A/C, heater, stereo, dash, or most of the wiring and he claimed weight as about 2,500 lbs. That's about as stripped as they get, short of replacing the windshield and hatch glass with Lexan and shaving a few more pounds with carbon fiber, and it was already nowhere near street legal.



Eric Cheatham (Resource, Gargamel) on the other hand, has interior, 2 seats (aftermarket), door glass, dash, and a body kit, but did remove his ABS and windshield wipers (why, I have no idea) and replaced the rear suspension with a Ford 8.8" solid axle and pseudo-4 link setup and claimed 2,350 originally, although he later retracted that and said the real weight was 2,660. He now says 2,400 and claims 3 scales have registered the same. Of course, his reputation isn't anywhere near Brad's.

Now, either Brad's car was nearer to 2,300 lbs., or Mr. Cheatham was reading his numbers off a gas pump (which would account for their changing so often).

turbojeff

iTrader: (30)

2500-2550lbs should be relatively easy to achieve in a street car.

Adding big brakes, wheels and a cage will add to that.

SpeedKing

iTrader: (4)

Mazda OEM. The early non-reinforced wheels weighed ~13.8 lbs. You'd be hard pressed to find anything aftermarket that weighs the same or less.

DamonB

If this is for the SM2 car then the exhaust isn't going to get any lighter than a short pipe off the downpipe that exits with a turn down just under the passenger door...

Mahjik

iTrader: (1)

Spank is a VERY competitive AutoX racer. He's already running 285's in the front so he's looking for light aftermarket rims, most likely keeping the same amount of rubber around the car for competing.

Mahjik

iTrader: (1)

Spank, here's the "big list" of rims with weights:

https://www.rx7club.com/suspension-wheels-tires-brakes-archive-112/wheel-weights-add-your-wheel-weight-if-not-listed-dont-chat-thread-87008/

skunks

if you take a plasma cutter to the car, it probally is possible to get it down to about 2200lbs. i have seen first hand a fc which went from stock weight (which is just about as heavy as fd's are) down to about 1900lbs (although it does have a s2k engine in it but that weights just about as must as a rotary does) although it was missing a drive shaft, radiator plus water/radiator fluid and fuel in its 8-16 gallon fuel cell. its amazing how much weight you can cut out of the doors alone when you gut them (i doubt you will get a lot more weight savings with carbon/fiberglass doors oppose to cutting out the frame and gutting them) as well as going with lexan windows.

oh i forgot to mention that at the tiem of weighing this car, it did have a full 10 pt legal cage (which actually went thru the fire wall and connected the front strut bars to the rear) and floor reinforcement bars as well as being seam welded in over 1000 points. that setup must have weight at least... well not really sure, how much do 10pt chrome-moly cages weight?

gnx7

iTrader: (10)

CF rear hatch with FAL glass or Lexan will shed lots of weight.....

http://7parts.com has CF doors (race only with no window frames) that weigh 7.5lbs each.

-GNX7

skunks

does anyone know the weight of a rear hatch with or with out lexan/glass?

r1dreamer

iTrader: (4)

first off carbon fiber body panels arent lighter than the stock aluminum panels...and the the stock wheels are about the lightest you'll get without spending *** loads of money.
my car is a base with mods in sig, no a/c. i still have a full interior and everyhting in the trunk. i weighed in at 2620 with out me. this weekend when i install my hks coilover system ill be able to take the spare tire adn jack out of the car, im hoping for 2580 or so with that.

brandon

r1dreamer

iTrader: (4)

honestly id say our hatch with the glass is no more than 40 lbs, when i had my car apart for the paint, i alone was able to pick up the hatch, being so big and all

brandon

skunks

i remember when i was working on a fd with blown rear shocks (the little ones which hold up the hatch) and took them off and had to hold the rear hatch. i remember it to be much more then 40lbs but i guess i could be wrong. i would say it is closer to 60lbs or more

jimlab

First off, the only aluminum panel on the car is the hood.

You are right, though, that with the exception of the gutted doors (no windows, mirrors, speakers, etc.), the available CF parts are not substantially lighter than the stock parts. If I had to guess, I'd estimate total savings (fenders, hood, bumper, doors that allow use of the stock windows, and hatch) at around 40-50 lbs. by going to carbon fiber. Consider the cost, though. The Panspeed doors which allow keeping the factory windows are in the $3,500 ballpark, I believe.

The glass "budget" for the FD was 50 lbs. total for everything, so you can save a significant amount by eliminating the glass, but good luck keeping water out of the car or driving in the rain.

After that, you can get rid of the "creature comforts", like A/C and power steering. If you think you're gifted, you can eliminate the ABS and do your own brake modulation. Eliminating the power brake booster for twin master cylinders can save a couple pounds also. Toss the jack, spare tire, and tools, because the car doesn't weigh enough to collapse a 30-40 series tire anyway. Toss the stereo, too, while you're at it.

Someone posted that the stock seats are fairly heavy (with a picture of the scale they were on), and stated that aftermarket seats (mounting is always a problem, of course) can save another 30-40 lbs.

The exhaust can be lightened by going extreme (Titanium), or just by getting rid of the stock cats in favor of stainless steel. Some cat-backs are heavier than others, of course, depending on their design and number (N1 Dual) of pipes. The Rotary Extreme Ti cat-back is reported to weigh only 8-9 lbs., I believe.

You can't get much lighter than the stock wheels, but you can improve grip by running wider tires without gaining that much weight. Volk and other options for even wider tires are very lightweight, but cost a substantial amount. Some tires also weigh more than others, I'm told. Especially my Pole S-03s.

And finally, another way to get rid of a considerable amount of weight is ditching the stock turbos. The cast iron exhaust manifold and stock sequential turbo assembly weigh a significant amount. You could lose 20-25 lbs. easily by going to a single turbo, depending on the size.

turbojeff

iTrader: (30)

We just installed the glass on my project CYM last night, the rear hatch glass is not really heavy, side windows aren't very big either.

Spank

iTrader: (1)

GREAT info. Some of what you guys are suggesting I have already done. My tires are 285/30/18 up front and 315.30/17 in back so I need big wheels.

I have put together a chart and I think I can get down to give or take 2450 legally in SM2. It will be tuff buy I am already working on it.

My last item if I really have to will be the single turbo due to weight savings.

I cannot list everything I will be doing due to my competitors also read my posts.

Thanks for all your help guys and I am looking at this everyday.

Allan

VQracer

lightweight pulleys?, lightweight flywheel? carbon driveshaft? aluminum suspension parts.

jimlab

The suspension parts already are aluminum.

Spank

iTrader: (1)

Already have lightweight pulleys, 9.5 lb flywheel, carbon driveshaft if I need to, and like Jim says suspension is already aluminum.

Allan

BOTTLEFED

iTrader: (1)

Hey Allan,
I could help you get rid of all the A/C system. I think that would save a lot of weight. The compressor by itself is heavy (about 10lbs ?).

I know you would probably like to keep your ABS, or so it sounded last time we talked, but how about your power steering? I helped a fellow FD owner eliminate his PS and he said it was easy to get used to.

I think you could also find a lighter exhaust syst. than your Apexi.
I don't know if you could find much lighter wheels than the ones you have, but Volk does make some of the lightest rims. You could check theirs compared to yours.

Also, eliminating the stock sequential twins would save a whole LOT! I know you like the twins (and so do I), but there is a lot a hoses and electronics that are cluttering your engine bay, not to mention the heavy stock cast iron manifold and turbo housing. I don't know exact numbers (maybe someone else has some) but I think that is the only way you are going to save a significant amount of lbs. at this point.

Tim

Spank

iTrader: (1)

Na, I will keep my PS and ABS, I want the car on a diet but I feel those items are required for autoxing.

Thanks

Allan

the_glass_man

iTrader: (2)

I think you could get the car down to 2300 lbs or so with enough work.
First start off with the free and easy modifications.
Remove Power steering, AC, air pump, emissions, pre cat, cat, jack, spare, tools, speakers, stereo, air bag, lights, interior pieces from back, glove box, carpet, heater core, blower motor, wipers, side windows, bumper supports, mirrors go NS get rid of the solenoids and passenger seat.

If you want to spend a little money you can get a battery,exhaust, or run with no exhaust or have a dump tube to just dump the exhaust. Get a hatch with FAL window. Get doors from the same place or Panspeed carbon or fiberglass doors (the fiberglass are 1/2 the price).
A lightweight flywheel modified at a machine shop to make it lighter. Carbon fiber driveshaft. Recaro SPG seat mounted directly to the floor with out sliders. A sleek light kit with no lights. Fuel cell, light weight ecenctic shaft, lightened rotors, RB aluminum housings, light weight brake kit, lexan for the other windows, remove the dash/custom dash, SSR Comps with Toyo T1-S tires, light weight lugs. Single turbo (smaller) with inconel manifold. Custom intake manifold. Replace all bolts and nuts with ones made out of Ti.

Thats a few for now, I'm sure I'll think of more soon.