I have picked up a free 89 n/a and my friends and I have a project planned, its going to be full race. I was wondering, fully stripped and gutted, we would need it to be as light as absolutely possible.

what is the lightest a rx7 could be? we have found an alternative motor, sorry guys but I wont be sticking with a rotary, I have something else in mind. relax its not a v8, they are too heavy for this project and not an sr20, its too common.

other than removing things that are not required and fiberglass body panels, what can be changed for lighter weight? my friends laughed and then we were kinda serious, i am going on a diet, if im taking all this time and money to shave 20lbs here and there, I could shave 20 or 30lbs my self.

 

Get the rear hatch replaced with Lexan. That should shed quite a few pounds. Also, using a hole saw, cut holes in your firewall, front bumper, & rear bumper. That should be a decent start aside from completely stripping the interior, all emissions, and convience related doo-dods.

 

a base s5 n/a, with interior still in can be taken down to about 2450 lbs give or take a little, another 150 lbs or so if you gut the interior. how much the motor swap adds or subtracts from that will depend on you.

there are quite a few weight reduction threads to get you started, but dont get too gung-ho, or the car can become dangerous and impractical (removing bumper suports and tow hooks).

unless you are putting in a b-series honda, or other small 4-banger, i doubt it will weigh less than a stripped down n/a 13b.

 

erm, what motor then? v8s are great, just its sacrilege to most. depends on the reasons

about 2250 or so for a stripped out racecar

wheels. they have CF hoods, personally id build a very thin skeleton and overlay it with fiberglass and just use pins. ditch the hood hinges, latch, the cable.

there are reinforcement bars in the front bumper and doors, and im sure in the rear too. take out the foam also.

replace the hatch with lexan, you can do the front window too. and compeltely remove the side windows. start cutting unnecessary sheetmetal from the car that doesnt seem like it supports anything.

remove all interior panels, remove all of the sound deadening with dry ice and a hammer. theres a 10lb rubber pad covering the fuel pump

if you're not super gungho, keep the front dash and doorpanels. then remove the carpet and sound deadening and replace the carpet w/ lightweight outdoor stuff, and just the front carpet at that. gut the hatch area

single sided exhaust will be lightest of course.

guess you gotta keep the towhooks if its going to be a racecar


-ben martin

n/a trannys are about 35lbs lighter but very weak. the rearends are 7", turbo are 8" but the n/a rearends are strong and take v8 swaps with no problem.

 

cool, you're in scottsdale too? where at? im around thomas and 101
there are tons of second gen RX-7s and other rotarys in the area.

 

What engine are you using?

 

Cutting holes in the firewall would be a massive retard move. Not to mention the safety issues and probably wouldn't pass tech at any decent track.

If the car car is race only, you can remove the dash and make a facia for your gauges. However, the steering column attaches to the dash framework and will need to be supported by some other means.

The climate control system and the companion wiring can be removed, but you may want to keep the blower and some ducting in case the winshield fogs. Or just install a cigarette lighter and mount a 12v fan.

I don't recommend removing the door bars unless the car is getting an 8 point cage, with door bars or the Nascar style door bars. Frankly, it's not worth the effort to cut them out for the few pounds they save and the inherrent danger with them removed. If caged, you can cut the inner door steel and bars out. If you remove the inner door steel, you will lose the window mechanism. Then you can put a fixed lexan window on the passenger side and a window net on the drivers.

 

All out race effort, you can get an FC down under 2000# My EP car raced last year with about 140# of lead and me (165#) at 2350# It had a lot of cage, full size battery, stock fuel injection, stock rear bumper cover, gutted steel doors, gutted steel sunroof... I'm sure I could find more areas to shave weight beyond that. BTW this chasis is for sale.