cpa7man

iTrader: (2)

This is what you have to start with:

Fiberglass fenders, hood, front airdam, lighten or remove stock bumpers, minimal wireing. Lexan all around, doors are just skins. I might have too much cage to get to 2050 with me in it so we will just have to see. Look at that link I posted above. There are a bunch of RX7's at 2100 with driver and fuel (end of race fuel).

speedturn

iTrader: (1)

The handling improvements caused by a full 12 point road race cage cannot be over-emphasized. I was amazed at the increase in feel that I had for what the slicks were doing when I installed a very stiff cage. It cost me some weight, but it made for a better car.

j9fd3s

iTrader: (3)

+1! or more accurately -1, second!

back in the por7 hayday they started putting really big structural cages into the cars, and they were loosing 1-2 seconds a lap.

Zyrano

I'm wondering what the original question is really asking. different series allow different levels of weight reduction, there are also things like whether you will be running at night that would affect the level of race reduction you can do. You can remove a lot of stuff to get the card down to like 2000 lbs, but you'll end up with a car that does not have headlights, windows, etc.

Boswoj

My '79 based EP car comes across the scales at about 2200 pounds at the end of a race, and I weigh a gazelle-like 260. That puts my car at just about 1940 pounds with very little left to remove. I have full fiberglass front end, gutted doors, all sound deadening removed, lexan rear window, a nearly non-existant front bumper assembly, interior gutted to the firewall and replaced witha minimal aluminum dash, aluminum race seat, and the rear floor gutted for a very large fuel cell. I have a damaged fiberglass hood, so while it is awaiting repair it still has a steel hood on it, the small rear quarter windows are still glass, and I still like the convienience of running an alternator. With he aforementioned changes, I could get to about 1900# for the car only. Only path to lighter starts being carbon fiber and a chromoly cage. There is essentially no way my car will ever get to minimum race weight without those things and some fairly massive weight loss by the driver. A better path is to take the weight penalty and add an alternate transmission or 13B motor.

mperformance

Ok I actually weighted mine too on a very accurate race scale and it tipped it off at 2150lbs with a 180lbs driver. With basic door panel, power window motors and carpet gutting, but I did take off all of the AC system out <---AC systems are very heavy to begin with, specially the AC compressor bracket. Car is a heavy to start 12a 85 GSL with power everything and sunroof.

With fiberglass body panels, gutted dash, lightweight seats, no headlight motors, etc and a race fuel cell I'm sure 1900lbs is easy. 1700lbs is really pushing it, that would involve cutting holes and some heavy duty fabrication. I think we all agree that '79s are the way to go as far as weight savings. Boswoj has the numbers right on the money.

f/p79

My 1979 Limited F/P autocrosser was weighed at certified scale at 1960. It has a 13B and an Autopower bar. I've removed the tar sound deadner and everything else I could. Unfortuneatly, the front and rear bumpers are metal. I spent several hours lightening an 83 bumper, only to find it didn't fit. I still have stock seats (2). I'm hoping to try plastic windows and possibly a cheap race seat this winter.
I think I'm pretty close to minimum for the class now.
As an earlier post stated, it becomes difficult to go much further.

peejay

My old '80 weighed 2200lb with just the spare tire, jack, and inconsequential interior plastic removed. Still had A/C and everything in front of the B-billar interior-wise. This was with a header and a Lincoln Continental rear muffler, no more thermal reactor or nuclear-grade muffler.

My '85 GSL weighs 2320 after removing the (much MUCH heavier) spare tire and jack, P/S pump and lines, A/C compressor/condensor/lines, the incredibly heavy P/S pump bracket, rear swaybar, not insignificant amounts of sheetmetal, insulation, amplifiers, cruise control, water injection system, and the car has a too-small battery besides. Exhaust is the same header as on the '80, with a 24" glasspack, 14 gauge pipe, and a Dynomax muffler made for a Fox-body Mustang.

What the hell? Only thing I can figure is that the Series 3 shell weighs a lot more than the Series 1. No way that the rearend weighs over 120 pounds more.



Only

woodonastick

iTrader: (1)

these are considerably good numbers. if its one thing we have advantage of is weight. where do u guys weigh your cars? i was thinking about going to the dumpster on those truck scales to see.

(and having nothing to do with the topic)
after watching balboa i felt like going on training for a self weight reduction.

Boswoj

I got to thinking about it and realized that I also run the old fashioned dual Racing Beat pre-silencers becasue they are bulletproof and it's the only way I have found to NEVER have any troubles making sound. Problem is that it probably costs me just a tiny bit of power, and it weighs a bunch!

Sorry "mperformance" but I have to disagree. With a reasonably safe cage and the equipment to really go fast I don't think 1900 will ever be easy, and 1700 will take the removal of actual structure. How much can you do without? You must be running a car without a cage to get anywhere near 1900 "easily". 1700 may actually require something "easy" like replacing the stock chassis with a tube frame! "E" production is the last stop in sports car racing before moving into purpose built race cars. They should approximate the rational (depending on who you ask!) limits of development for a tub chassis, production based car. Yes, there are definitely cars that are able to make the 2050# weight limit with driver, but those guys are also making tough decisions about what they can afford to safely leave off of their cars, like instrumentation and cage bars. They are also having to decide how many dollars per pound they can afford to spend and still be able to run a decent schedule. If 1900 was easy, everyone would be there and believe me - they aren't!

peejay

Not when you are running against completely stripped/gutted 1st-gen CRXs with Integra engines, or VW Super Beetle shells with healthy 2200cc engines.

If I lost 500lb from my car, I'd be almost at parity with the others in my class, except for the lack of power.

j9fd3s

iTrader: (3)

only what? yeah the s3's are porky, not sure why, my manual steering gsl-se was 2540, 83 limited 2330....

maybe my SA will be lighter, no ac....

riceburner1r2001

iTrader: (4)

on my fc all motor drag car i have weighed it w motor n trans 2065 w/o me n it. i am gutting more as we speak

Stevan

iTrader: (17)

From what I've have found(read online), the SA weighs more than the FB. Full size spare, steel bumpers, additional reinforcement in the rear.
Here's a thread I started about it ,
https://www.rx7club.com/showthread.p...ghlight=fb+lbs

I have read(on here) that the sunroof/moonroof, and roof reinforcement adds 100 lbs to cars equipped with them, after looking at my parts car gsl with the interior gutted I find it hard to believe it would add even 50 lbs., though I haven't looked at a gs roof stripped.

speeddemon32

iTrader: (3)

My FC was 2200 pounds. that was a full roll cage & full sheet metal interior. little cutting to the car was required. I could have done more.

of course I had striped the car down to nothing, I even took the tar on the floor pan off. the hood bracing was removed. (it was a steel hood skin) the sun roof was the same. the side windows were lexan, the front and rear were still glass.

of course only one seat, it was alluminum. 5 gal fuel cell. ohhh yeah, and It was carbed so I didnt have all teh injection weight. the car had maybe 10 wires total. ignition, fuel pump, fan, alternator, starter, that was about it. pretty clean little car. let me see if I have some pics.

I wanted to get it down to 2,000 pounds. I KNOW this would have been possible with a little more cutting, and the window replacment. just never got around to it. now of course I dont own that car anymore

peejay

The bumpers themselves weigh about the same as FB.

The SA spare is LIGHTER. The fullsize spare is the same as the road wheels, but even the steel wheel equipped cars have lighter wheel/tire combos than the FB minispare. The minispare has a full-section wheel and it feels like it is made out of thicker material, as well as being larger in diameter. The only reason Mazda went to the minispare was to get more fuel capacity.

Even so, as noted, my SA still weighed a whole bunch less than my Series 3, with both cars having no spares. (What's the point of having a spare if you cannot jack the car up without a floor jack?)

The additional reinforcement in the rear amounted to two pieces of 22-gauge metal about 1 1/2 square feet each. Not very much at all.

trochoid

iTrader: (6)

Excellent work and craftsmanship Speed demon. Nice to see this level of quality and detail on a build. I hardly recognize it as being an FC on the inside. Dropping 600+ lbs. is quite an accomplishment on a pig heavy 2nd gen. If this was a 1/4 mile car, what kind of times did you manasge to get out of it?

speeddemon32

iTrader: (3)

well see that is the crappy part. after building the car I just couldent get the car to run as it should. the car would crap out severly at about 4,000RPMs. long story short after 3 years, 2 engines, 3 ignition systems, 8 carbs, blah blah blah, I just finally gave up. it was to be a 1/4 mile car. with the big bridge she had in it I was expecting low 12s. I have no idea what she would have run, but that is what i figure to be a good honest start. I had a nitrous system that was ready to install once I got her up and running, figured that would get me in the 11s.

again I have no Idea, that just what I figured it out to be.

I sold her on ebay, took a HUGE loss. she is not a pikes peak car with a turboed 4 banger. hate to see a piston in my old car, but nice to see it getting some action. that car deserved better then just sitting in the garage.

and thanks for the compimants. it was a lot of work. nice to see someone else thought it was nice. oh yeah, and you should have seen it in person. everyone that saw pictures of it then saw it in person said you dont realize how nice it was untill you get to see it up close.

T Rex

hummm i wonder what wheel and tire combos are weighing in at? if you take that number for example and times it by four that would explain some of the variation in the stripped 1st gens