sburkett

Picked up an '04 base today that we are going to prep for SCCA Touring 3 racing.

For anyone's reference who is interested:

'04 base, no options. Floor mats and tire fill kit removed. Otherwise as delivered from dealer this morning. 13.4 gallons of gas in tank (filled to shutoff after weighing, took 2.5 gallons). Weighed on Rebco racing scales. Floor was not exactly even, but we were mostly looking for total weight, corner weights are approximate.

Total weight 2914.

LF 773
RF 766
LR 686
RR 689

This is pretty good news. Subtracting AC, stock muffler, drivers seat, air bags and radios, then adding roll cage and safety equipment and 185 pounds of driver should put us very close to the 2980 SCCA minimum weight.

Steven

murix

I have been wondering this for some time. I would like to get mine weighed. Thanks for the info!

So 2914 with 13.4 gallons in the tank? That is very good. The corner weights look pretty good stock as well.

alnielsen

iTrader: (4)

This is different than I would have expected. Mazda advertises this car as having a 50/50 front to back weight ratio. Yet the front weights 160 pounds more and this is with a full tank of gas at the rear of the car. Also, is ballisting allowed in Touring class. Add a driver and the FL corner will be much heavier.

TrackAddict

Wouldn't adding a driver shift weight to the back more?

sburkett

I did check corner weights with driver, but didn't write them down. Driver did add slightly more weight to the rear than to the front. Corner weights were about the same with driver.

I was also a little surprised that the nose was so heavy. Hopefully we can get far enough below minimum weight tocompensate with the cage design. Ballast has to go in the passenger footwell so that won't help front to rear distribution.

Steven

murix

I always thought the marketing slogan was 'near 50/50' and not quite 50/50.I always thought it was like 48/52 or with driver 49/51. Not sure where I got that from but it is in my head.

alnielsen

iTrader: (4)

I just went to the Mazda USA webpage and, in a couple of places, they are saying it is a "Weight Distribution % front/rear 50 / 50". This quote is from the Features & Specs page.

murix

perhaps it is on the GT model with the additional weight of all its extra features in the cabin and driver?

murix

Thinking about it, if the weight with 13.4 gallons in the tank is 2914, using a wieght of 6lbs a gallon, this is saying yourr base model weighs about 2833lbs? That is really light.

ZoomZoomH

iTrader: (1)

definitely well under 2900lbs if running only 1/4 tank of fuel.

dplore

Removing the AC compressor and condenser will take some meaningful weight off the front.

I would like to race an RX8 as well. T3 might be cool for a year or two, and then go E-Production. I understand there are 3 requests in to classify the RX8 into E-Production. Given the power output at stock, even with a motec and so on, the car should fit into e-prod. The hardest question is what tires/wheels to use.

For the sport package brakes, you need 17" wheels. I haven't found any appropriate true racing slicks in the right 17" or 18" size. Just DOT's.

sburkett

I'm not sure the DOT's give that much up to the slicks, especially in production where you can get enough negative camber to make the radials work and last.

Are you the dplore that sends me mail when I get private messages on the production forum? (I run an EP RX-7 currently).

Steven

alnielsen

iTrader: (4)

The RX8 has far to much horsepower and being a 4 door car wouldn't fit into a production class. I would fit better into GT2. E Prod is where the 1st gen RX7's are placed and they have half the power of the 8. I have a "85" GSL-SE inwhich I ran in ITS. The stock 8 is superior to my race car. It makes me sick to think about all the time and money I spent on the 7.

cgrx

thats the 350Z

dplore

Steven, yes, the same dplore... Darren in Colorado.

I understand the renesis motor makes about 255hp at the flywheel with the
best engine management (motec) and open exhaust. Say, about 190-200hp at
the wheels. Luis might be able to comment on what the new star mazda cars
are putting out at the flywheel for comparison.

That is definitely not too much for E-Prod, at the right weight. 2nd gen RX7's,
and 240z's are making more power than that already. Miatas are making
near that power as well. Given the nice suspension and larger wheels on
the RX8, it would perhaps fit in at around 11.5/lb per horsepower. Take
the 200hp at the wheel number and you get 2300lbs base weight for the
RX8. There are several cars running in the sub 10lb/hp range, so 11.5
might be a good starting point for the RX8.

I race a 1st gen EP RX7 myself and have stupid amounts of money in it
as well. (although not as much as Steven it seems! )
An RX8 would be even more money. But really, that's only because it is
currently much more expensive the acquire the base chassis because it
is so new. It would likely not be any more expensive to race once prepared.

I actually believe slicks are significantly better than DOT's. They are definitely
lighter than any DOT of similar size which is a significant advantage right
there. When in their very short prime period (2nd and maybe 3rd heat cycle),
I believe slicks are far more sticky than DOT's. DOT's may last better throughout
a full length race though. But I doubt anyone has done back to back testing to
prove anything other than the weight part, I know I haven't.

-Darren

sburkett

Darren,

I agree that the RX-8 would be fine in production. My 12A 1st gen is well under 10 pounds per horsepower. In fact, I think it should be cheaper to run in the configuration you describe, since the drivetrain isn't being pushed to twice its design horsepower.

If the DOT's are actually substantially slower than the slicks, though, that would really mess things up. It'd be like an A Sedan car out there. On the other hand, the suspension is probably better than 90% of production cars (full or limited prep) so maybe it could make up in geometry what it loses in tire compound.

Anyway, I have a few years in T3 before I have to worry about it (I had to make a two year "one race car" commitment to get spousal approval). Now if someone would just buy my #$^&! production car....

Steven

dplore

You might try parting our your current race car. You might even make more
money that way. Few people seem to want to buy already made production
cars, even if it would cost them a lot less and be less work. They want to build
their own because that's part of the whole experience.

And yes, I think racing in T3 with your RX8 for two years is a good idea
before going production.

-Darren

sburkett

I had been toying with the idea of parting it out too, you tipped me over the edge. So buy my engine! :D

rev-2-9k

Mine weighed in at 2883 with me and a 1/4 tank of gas. I have taken out only the jack, air kit, tow hooks. RB suspension. I weigh 160. I thought that had to be wrong and am looking to confirm that weight. Oh yeah and I have the base car no options as well.