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84 rx-7 Ultra wieght reduction options?

Old 11-12-07, 10:22 PM
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84 rx-7 Ultra wieght reduction options?

Anyone in here with a very light Fb? For the classes i want to run in local drag events i can be 2300lbs with me and gas. Anyway looking for options to remove serious wieght, I've already thought of just cutting crap off of it so looking for other racing products i may not have heard of.

Thanks for any idea's.
-Mac
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Old 11-12-07, 10:47 PM
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2300 pounds on an FB is pretty simple really; strip the interior including the dash, ditch the power steering and AC (if equipped) rip out all the wiring and put back in just what you need. Even just that should probably get you pretty close.
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Old 11-13-07, 11:18 PM
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sorry i shoulda mentioned the car is caged with a Ford 8.8 in the rear and an all Iron engine in the front. Also i am over 200lbs so i would like to try for 2100 without me in it.
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Old 11-13-07, 11:20 PM
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I don't want to state the obvious, but all the glass has been replaced with Lexan?


-Ted
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Old 11-13-07, 11:44 PM
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Heh, start with a 79?
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Old 11-14-07, 03:28 AM
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2300? isnt the fb like...2400 stock curb weight? lets start by removing a/c, then remove interior/ sound deadening, and change the stock seats to buckets. that should loose a significant amount i believe. then theres fiberglass hoods and lexan.
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Old 11-14-07, 09:45 AM
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In my experience, it's not easy to remove a lot of weight. One good option though is to remove most of the factory exhaust if you still have it, that stuff weighs a ton.
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Old 11-14-07, 11:32 AM
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Folks, please read his earlier post - the car has a ford rear end and what sounds like a small-block up front. So, "remove the AC" isn't really applicable here. I assume that the exhaust is already about as minimalist as you can get.

So, it's pretty much a matter of "fiberglass and Lexan are your friends". Gut the interior (if not already), doors, door glass, fiberglass hood and fenders, ditch the sunroof (if any), windshield and rear hatch. That should get you a long way there.

Good luck,

-bill
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Old 11-14-07, 11:34 AM
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Sure it is. Incorporate tubes into the roll cage that go to the front subframe and top of the shock towers (with proper bracing) and cut out any sheetmetal you don't need to make it look like a car from the outside. Voila! Then redo any body part that unbolts in fiberglass, using only a layer of two of cloth (make sure to keep people from leaning on it) and gut the doors while you're at it.
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Old 11-16-07, 07:21 PM
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yes lexan will be my friend i have figured that out already but thanks, i was figuring to remove whatever i can from the doors and source some fibreglass parts. Any pre-cut lexan kits out there? google hasn't served me well in this area.

Any actuall parts out there made for the purpose of being light? besides windows and fiberglass panels that is. control arms maybe?
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Old 11-16-07, 07:48 PM
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ISC Racing sells windshields and they've got some rear side glass on sale in the garage sale section along with a fiberglass hood and nose. Those will help loose weight. You can just cut yourself a piece of Lexan for the hatch, it's basically flat on an FB is it not? If you haven't already get rid of the headlights and just retain the covers for aero purposes. I don't know of anyone making stock like fiberglass fenders though, most would want widebodies if they're getting FRP. Get a smaller and lighter battery, run a smaller radiator if you can.
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Old 11-17-07, 09:50 PM
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^ looking over the site rite now
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Old 11-19-07, 02:20 PM
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Hi,

Perhaps your looking for parts something like that?
http://80.121.201.109/drtmoto/team/t...rosse_zs_1.jpg
http://80.121.201.109/drtmoto/team/t.../verbr_roh.jpg

Weight is about 820kg at the moment.

See more on our site
http://www.drt-motorsport.at.tt
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Old 04-16-10, 09:52 PM
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i never found any lexan windshields for the first gen. it would be graet because i just cracked my windshield
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Old 04-20-10, 07:54 AM
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I replaced my rear hatch with 1/8" lexan. Lexan will bend in a sheet metal brake. If you put two slight bends in it, about where the stock hinges are, the rest of the lexan sheet will bend enough to approximate the curvature of the rear hatch opening.
Stock rear hatch glass 28 lbs
Lexan + alum stiffeners rear hatch 8 lbs
weight savings 20 lbs

The stock doors are very heavy. If you remove everthing; glass, regulators, inside panels, and side impact beams, you can get the weight from 60 pounds each down to 20 pounds each.

Get rid of the steel bumpers

Fiberglas hood will save you 18 to 20 pounds

1/4" thick lexan front windshield will save you 8 pounds. My pre-bent lexan windshield cost almost $500, that weight savings cost me about $60 per pound saved, the most expensive thing I did to lighten my car.
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Old 04-23-10, 12:55 PM
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Just food for thought

My road race team mate with full cage (2 intrusion driver; 1 pass), sheet metal dash, stock suspension and full turbo engine/tranny w/ intercoolers, oil coolers, full glass and 10gal steel fuel cell came in at 1975 w/o driver.

My new car has a 3 intrusion bar cage pas and driver so I think it's going to come in at 22-2300 or so.
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Old 04-23-10, 03:47 PM
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Hmm, my car weighed in at 2280 with me in it (170 Lbs). All of the weight savings came from under the hood, and replacement of the exhaust system. I still have full interior.

However, that was starting with a '85 GS, which was fairly light to begin with.

Have you considered swapping in a rotary?




.
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Old 05-06-10, 07:38 PM
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Originally Posted by Kentetsu View Post
Hmm, my car weighed in at 2280 with me in it (170 Lbs). All of the weight savings came from under the hood, and replacement of the exhaust system. I still have full interior.

However, that was starting with a '85 GS, which was fairly light to begin with.

Have you considered swapping in a rotary?




.
Yeah...he might actually win with one of those
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Old 05-15-10, 01:27 AM
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Originally Posted by woodonastick View Post
2300? isnt the fb like...2400 stock curb weight? lets start by removing a/c, then remove interior/ sound deadening, and change the stock seats to buckets. that should loose a significant amount i believe. then theres fiberglass hoods and lexan.
The stock glass weighs very little, and the fenders and hood are also very light.

Interesting: My '80 with A/C and carpeting - basically the rear seat cover (SAs did not have bins) and spare tire were the only things removed - weighed 2210lb. This includes both sway bars.

My '84 weighed 2500lb last time I weighed it. This is with no A/C, no carpeting, no P/S pump (still P/S box), no sway bars, but tall radiator + oil cooler and 13B engine.

Near as I can tell, they added more metal to the Series 3 chassis. And the Series 3 rear is supposed to be a good 50lb heavier. It certainly seems heavier - I can heft an all-up Series 1 by myself, hoisting a Series 3 disc rear almost requires two people.

Drum brakes are lighter than discs, and I wouldn't doubt if the Series 1 dash is a lot lighter as well. I don't mind the heavy rearend as that is "muscle mass" but still...
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