Can a 2gen chassis w/ engine be made to weight 2,000 pounds? I'm talking of a rolling chassis no nothing ...just engine drivetrain and the essentials to make it run and stop.
If yes, what year or model(S4,S5) would be better.

 

I'll let you know as soon as I get to the scales. I'm expecting my FP car to weigh in about #2250. When I can affored it I'll get the lexan windshield and rear hatch. That should be good for another #50(maybe more) off the total weight. Later this year when I get the car weighed I'll post all the weight reduction I've done to the car and the individual weights of some stuff I pulled out/off the car during the build process as well as some pictures.

 

Mazdatrix might have your answer. Here is a link to a project they are doing on a vert. it's at the bottom. If they can get a vert down that low then a coupe should go lower.

http://www.mazdatrix.com/faq/roadmain.htm

 

If you cut out alot of extra metal, and used the lightest components you could everywhere, ditched the dash, had a hard top (no sunroof) you MIGHT get a FC down to 2k lbs dry...

 

Start with an S4 base or sport, and strip it. That should put you at 2200-2300 lbs. You can save 60 lbs or so from a well made lexan hatch alone, another 20 at least from the windshield. Gut the doors, theres 100 lbs(maybe less on a S4). Sheet metal dash, maybe 30 lbs saved from that.


An S5 body shell weighs 600 lbs(no subframes). Engine and tranny are ~400 lbs(n/a, turbo is a little heavier). The subframes weigh 300 lbs or so. The S4 body shell is lighter than the S5, but I dont know by how much.

 

S4 is lighter as the S5 model has a beefy structural bar running inside the dashboard I have heard.

Make sure you have an alumi hood, the 5 lug 4 piston brakes are lighter as the calipers are aluminum vs. 4 lug, '89-91 T2 rims are only 16lbs and look good, the soundeadening and tar in the driver/passenger compartment is over 50lbs! Carpet is at least another 30lbs, alumi spare or none at all, gut the safety beam in the doors or get fiberglass ones, and ditch the dash with only basic wiring/sheetmetal dash. Sunroof cars weigh 20lbs or so more....

The rear lexan hatch is costly.... $400+ but saves the most weight vs. the front windshield. The front glass is about the same. Both can be purchased from Mazda Competition.

What sources are there for fiberglass doors?

-GNX7

 

SAMPS, in mazdatrix they say that the chassis alone w/o engine weight 1740#.

maybe is posible with a lot of fiberglass and lexan.

 

Just wieghed my ITS car this weekend. Rules say the car has to weigh 2650 w/ driver. Mine scaled at 2660 total with 10 gallons of fuel in it. It's got a mondo cage which I'd hate to guess the weight of. Maybe 200lbs??? No idea. I weigh 220 and my helmett, suit, undies and boots might weigh 15lbs. Figure the car w/ cage at around 2350 dry. Anyway, the car is a S4 with the big brakes. Aluminum hood and the sunroof mechanism has been removed so the weight penalty is very minimal. The dash is gutted. The only part that remains is the heater core because the rules require it. Manual steering rack. All the light stuff basically. The driver's door is gutted and the inner panel removed to clear the cage. The passenger door is more or less intact w/ glass per rules. Check it out at http://community.webshots.com/user/rrxp689

Anyway, the car could be lighter. I had the heavy GXL wheels on at the time, the passenger glass could come out. Wiper are still on and there is ALOT of wiring that could easily be removed if the rules allowed. I'd guess 2000lbs dry isn't nearly impossible, I just wouldn't want to drive it around town.

Chris

 

How competitive do you think your car will be in ITS Ludwin?

Just currious cause my friend is looking for a track car, and would like to start with something that COULD be used in a wheel to wheel racing series (we dont want to Run a 1st gen though)

 

The 2nd gens are very competitive in ITS. IT racing is ALOT about the driver. The 240Zs are kinda thought to be washed up but a good driver has one the last two national championships in a row. The talk is that the BMW 325s are the cars of the future. They definetly have a potential power advantage but the downsides are many. The RX7s have decent power, handling and great brakes. They seem to do decent everywhere. Check out www.improvedtouring.com to find out about all the different types of cars that are racing. I do have to say if I had to do it over again I'd probably start with a boinger. Something like a Honda or a Mustang just has more available in the way of parts availability.

BTW, for those keeping score, I mis-stated the min weight of the car. It's 2680. Looks like I need to add quite a bit of weight!

Chris

 

I was wondering, if you make your car lighter, wouldn't that unbalance the 50/50 weight distribution of the RX-7?

 

I doubt it without gettin REALLY STUPID.
2000# without driver, maybe.
2000# with driver, I doubt it.

"REALLY STUPID" would be all non-structure metal panels cut and replaced with fiberglass.&nbsp NO STOCK GLASS - everything has to go super thin Lexan.&nbsp It'll be unsafe at this point; a roll cage will easily keep it above 2000#.




-Ted

 

I'd like to put my n/a on a diet, but i like my ac....and the power steering...carpet is a plus O-well, guess i'll just look for some more hp. CJ

 

In the case of a proper track car the idea is to make it as light as possible to the point of being well under minimum weight. You then add the weight back in where you want it. Preferably keeping corner weights as even as possible while placing as much weight as possible allong the central axis of the car. Haven't corner weighted mine yet. I'll let you all know when I do.

Chris

 

Yeah.. if you can move weight in to the middle, that reduces the polar momentum of the car, making it easier to turn and more responsive.. and the lower the weight, the better. Just tack on lead weights on the top of the driveshaft hump..heh

-Tesla

 

I'm worried about the BMWs, but I'm really worried about the Acuras.

Fortunately here in Norcal is a RX-7/240 war at the moment.

PaulC

 

Yeah, I fogot about the Acuras. My secret sleeper car is, don't laugh, a Contour. I just got rid of my SVT street car because the wife didn't like it, but man it was a blast to drive. The SVT isn't classed but it would be too easy to use the high-zoot parts on a base 24V car. The only downside is a lot of weight in the front (all FWDs?). Doubt you'll see a comptetive car built but I hope someone does.

Chris

 

Buahahaha!! Boy that's refreshing....the ole Acura Integra's aren't so bad afterall....I hope all you honda/FWD haters are reading this


<---owns one

 

Well, consider, both cars are required to weight 2680lbs, but the Integra gets 10 more HP stock, double A-arm suspension all around, and better gear ratios in 3rd and 4th gear. Plus you're legally allowed to go .040 overbore, as well as legally "accidentally" bumping the compression up .5 point, both things an RX-7 can't do. The RX-7 has a bit of a steeper first gear (3.31 vs 3.48) which helps on a standing start, as well as correct wheel drive But believe me, I respect the 'tegs.

PaulC