I weighed my car tonight at work on a 4-wheel in-floor scale. The results were not exactly as expected.
fyi: The readings were in kilograms and read to the nearest 1/2 kg. I then converted the numbers all to lbs.

Basically, it came out that my overall weight (without me in the car) was 2967.5 lbs with a distribution of 52.5% Front and 47.5% Rear. I do NOT have a spare tire. Could Mazda have been quoting a 50/50 weight distribution ONLY if you had the worthless spare tire!?

How much gas was in the car? Typically the measurement is taken with a full tank of gas. What you will find on scales is that each wheel can have very different readings. On some of the RX-7s you would see more than 100 lbs difference just betwen the left and right front wheels.

EDIT: I see now that you were almost full. Those numbers are more balanced than many other cars. Apparently it is a little front heavy.

Your b and b midpipe probalby took 10 pounds off the car, not sure how much of that was in the rear. Also you have the appearance package- that might be a factor.

Your b and b midpipe probalby took 10 pounds off the car, not sure how much of that was in the rear. Also you have the appearance package- that might be a factor.
No, I don't. I just have the wing (in the rear) and the mud flaps (at each wheel).

The B&B Midpipe is in the middle of the car.

http://dictionary.reference.com/search?q=curb%20weight


curb weight
n.

The weight of a fueled automobile with standard equipment but without cargo or passengers.


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I am surprised that your car's weight was 60 lbs under the official curb weight from Mazda for a base 6 speed manual. It makes me wonder if those scales are that accurate- meaning the tenth of a lb read is false precision. Did you try weighing the car revcersed on the scales to see if the weights matched the previous readings?

I seem to remember someone weighing in around 2880lbs, or something like that. I wanna say it was Xyntax.

read the advertising again- it says near 50 50 and the published distribution by several sources has it at 52 48. ask ikewrx he'll tell you real quick:D:

I seem to remember someone weighing in around 2880lbs, or something like that. I wanna say it was Xyntax.


That can't be correct. That's just a 100lbs more than a new Civic EX sedan.

I'm pretty sure that is correct for the Base 6spd, but I don't think that was with a full tank of gas.

* 1 gallon of water equals 8.33 lbs.
* 1 gallon of gasoline equals 5.8 to 6.5 lbs.
* 1 gallon of ethanol equals 6.59 lbs.

I seem to remember someone weighing in around 2880lbs, or something like that. I wanna say it was Xyntax.

http://dictionary.reference.com/search?q=curb%20weight


curb weight
n.

The weight of a fueled automobile with standard equipment but without cargo or passengers.


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I am surprised that your car's weight was 60 lbs under the official curb weight from Mazda for a base 6 speed manual. It makes me wonder if those scales are that accurate- meaning the tenth of a lb read is false precision. Did you try weighing the car revcersed on the scales to see if the weights matched the previous readings?

Well, I was down a bit of gas. Maybe a little oil, too? I know the scales are good. I've been using them in testing and they were calibrated this year. I work for a major automotive manufacturer, so this isn't a cheapie scale.

The catalytic converter is a very heavy piece. I might have close to a 40lb weight savings there. That definitely would account for the bulk of it.

Well, I was down a bit of gas. Maybe a little oil, too? I know the scales are good. I've been using them in testing and they were calibrated this year. I work for a major automotive manufacturer, so this isn't a cheapie scale.

The catalytic converter is a very heavy piece. I might have close to a 40lb weight savings there. That definitely would account for the bulk of it.

Cheapie or not- it still needs to be calibrated. We have a $250k saw at the plant that can easily be off by inches and 10 degrees if not calibrated regularly.


Did removing the cat make more power? Just ... I am in an area that does not have ANY vehicle inspections........ But I should not even consider going there... :nono:

hello??? is this thing on?

read the advertising again- it says near 50 50 and the published distribution by several sources has it at 52 48. ask ikewrx he'll tell you real quick

Cheapie or not- it still needs to be calibrated. We have a $250k saw at the plant that can easily be off by inches and 10 degrees if not calibrated regularly.


Did removing the cat make more power? Just ... I am in an area that does not have ANY vehicle inspections........ But I should not even consider going there... :nono:

Read my statement again. It was calibrated this year. The thing is not often used and it zeros out with no weight on it, which accounts for something.

Yes, I got a bit more power since I removed the cat (~8hp). More then a cat-back system will give you (2-5hp). It's a lot lighter than the cat, and it shoots flames :mdrmed: The fumes are suffocating, though, if you're in an enclosed area. They're just really strong, otherwise.

http://www.scottbarton.net/anthony/Misc/FlameThrower!.wmv

Well if you figure a gallon of gas is about 6lbs, and you're missing about 2 gallons according to your numbers, and you add the weight of the spare tire and kit in the back, you're probably missing about 50-60 lbs of weight in the back that Mazda would have used to calculate the distribution.

Well if you figure a gallon of gas is about 6lbs, and you're missing about 2 gallons according to your numbers, and you add the weight of the spare tire and kit in the back, you're probably missing about 50-60 lbs of weight in the back that Mazda would have used to calculate the distribution.

That's what I'm thinking. I'm just a little upset that it only has 50/50 weight distribution if you have the OPTIONAL spare tire kit and a full tank of gas.

I am surprised that your car's weight was 60 lbs under the official curb weight from Mazda for a base 6 speed manual. It makes me wonder if those scales are that accurate- meaning the tenth of a lb read is false precision. Did you try weighing the car revcersed on the scales to see if the weights matched the previous readings?

The curb weight in Mazda's brocure is 3029 lbs for a 6-speed "with popular options", which might make up more of the 60 lb difference. Also, the scale read to the 1/2 kg and I did straight conversions of every number and rounded to the nearest 1/2 lb. So, the numbers are within a pound of actual.

Relocate the battery to the trunk...that should help some.

hello??? is this thing on?


:Freak_ani

I bet Zoom44 would have some good info :lol:

That's what I'm thinking. I'm just a little upset that it only has 50/50 weight distribution if you have the OPTIONAL spare tire kit and a full tank of gas.

The difference between a full and empty gas tank is going to move the CG more than the spare tire kit. And since CG changes with fuel level, it's only natural to measure the "official" CG with a full tank. I guess you could measure without fluids, but wouldn't reflect driving conditions. I'd say 52/48 is pretty close. I guess they weren't quite as maniacal about balance as the original Miata guys; I think I read they actually would hang the car by a hook. Notice where the battery (and *cough* spare tire) ended up in the Miata....

If you think you're noticing a difference, I'd say get the spare. I think it's worth the weight. I never realized it was moving me more towards perfect weight balance, but I'll take it :)

Get the tire, replace the battery with a big honking Optima AGM in the trunk, and I think you'd have the balance plus increased reliability.

I think I've read somewhere that optimal handling is actually had with something a little different than 50/50. Maybe the 52/48 is actually better.

its a conspiracy!!!! IGNORE ME AT YOUR PERIL :evil_laug i have my finge ron the button and ill use it!!!! :Eyecrazy:

Zoom who?? I keep hearing these faint mumbles from the basement... :)

mazda's advertisement is "near" perfect 50/50 weight distribution in most conditions. Notice how having the driver in the car shifts the weight rearwards.

The weight will shift farther rearwards with 4 people in it, so basically the car stays nearly perfectly balanced regardless of passenger load.

I guess they weren't quite as maniacal about balance as the original Miata guys

Yes, they were almost exactly as maniacal about weight distribution - despite the advertising copy, the original Miata was never 50/50 either. Just ask all the guys who've corner-weighted their cars!

*hugs his box and 2 10's* lol.

not to be off topic, but i believe a member on the forum weighted their car at a "truck weight" station here in california. his car came out to be around 2870, and he doesnt have any packages what-so-ever, just the base manual.

not to be off topic, but i believe a member on the forum weighted their car at a "truck weight" station here in california. his car came out to be around 2870, and he doesnt have any packages what-so-ever, just the base manual.

Now, I wouldn't be surprised if that were off. A truck scale would have a range of accuracy that would be much higher than the weight of a car. It would be like trying to measure the weight of a paper clip on the scale that I used. It wouldn't be accurate. (I'm exaggerating, obviously, but you get the point.)

However, maybe the weight WAS right, and he had very little gas in it.

If I recall correctly, Mazda claims 50-50 weight distribution when there are two people in the car, so this may explain it?

I hear you zoom! :)

I'll bet it is damn near 50:50 if you are accelerating like you are supposed to. The weight shift will probably equalize it.

finger on the ban button finger on the ban button :Eyecrazy: :hahano:

If I recall correctly, Mazda claims 50-50 weight distribution when there are two people in the car, so this may explain it?

the new 3rd gen miata is around 52/48 and with 2 150lb adults in the car, it comes out to almost 50/50 exacaly.

zoom is right, the 50/50 for this car is just 'nearly', there really isnt much handling differnece with 52/48. the weight difference can easily be shifted with the throtle.

Also, something else to think about, does the rx8 in japan have any differnt crash structures, such as front crush bumper or anything that may be different on the US spec version?

Maby you shoul change to a lighter-weight engine oil....5w20 is to heavy. :hahano:

[QUOTE=Also, something else to think about, does the rx8 in japan have any differnt crash structures, such as front crush bumper or anything that may be different on the US spec version?
QUOTE]


When I installed my REVi and Ram Air Duct I did notice my Australian spec car has a different front crush bumper compared to the US spec that came with the Racing Beat instruction manual. I had to make some mmodifications to keep the Ram Air Tube firmly in place. I also noticed that the CAI is very flushed with the airbox air entry point. I've also read some people using some sort of foam to seal the gap in the US.

However, it's very superficial to make any difference in weight distribution.

When mazda quote cars its with a passenger in it...

Unfortunately they design it for small Japanese drivers. When we test drove the mx-5 at zoom-zoom live the guy said the car was designed for perfect 50/50 with 150lbs person driving. two passenger is even better then one he said.

get a battery relocation kit :dunno: theres nothing wrong with a bit of weight towards the back....except it maybe scary when breaking hard and turn ins. lol like a couple pounds would mean that much but on a miata its gram strategy and every bit helps.

Ya that's wierd... In my RX-8 Brochure it says:
Weight distribution %(fr/rr) 48/52

Well I'm sure his scale has a margin od error. Besides he never stated what scale and how he did it.

No scientific proof. If he's not using a truck scal or a scale that measures scrap then I don't know what he is using.

How in the hell you weigh the front vs the rear? Drive the car on half the scale?

Well I'm sure his scale has a margin od error. Besides he never stated what scale and how he did it.

No scientific proof. If he's not using a truck scal or a scale that measures scrap then I don't know what he is using.

How in the hell you weigh the front vs the rear? Drive the car on half the scale?

It was a 4 WHEEL scale. That means there were 4 scales, in reality, and the individual wheel weights are displayed digitally, as well as the overall weight, accurate to the 1/2 kg. I was using this scale for vehicle testing at work. It is owned by one of the largest auto manufacturers in the country (without specifying who I work for). I'll give you a hint, though... I might as well be one of the folks in the lab coats in the Mazda commercials :wink2:

It was a 4 WHEEL scale. That means there were 4 scales, in reality, and the individual wheel weights are displayed digitally, as well as the overall weight, accurate to the 1/2 kg. I was using this scale for vehicle testing at work. It is owned by one of the largest auto manufacturers in the country (without specifying who I work for). I'll give you a hint, though... I might as well be one of the folks in the lab coats in the Mazda commercials :wink2:

And it also adds up - if you indeed weigh about 160lbs, that's an impressive scale to be able to measure that on top of a 3000lb offset. It must be quite accurate.

BTW, I'd be curious to see if bmw's have the same situation. My 330 coupe is supposedly 50:50 but a 60lb sandtube in the back made a nice positive difference on snow handling.

I'm more interested in total weight than distribution at this point. We already know the car handles quite well around a track, removing or adding a few lbs. here or there isn't going to ruin the balance of the car.

FWIW I've had my Rx8 conner weighed and adjusted before, and after installation of a set of Tien Coilovers. Sorry, the shops notes don't indicate where the fuel level was; and the car has had a rear trailer hitch installed to pull a track trailer with spares tire sets etc. for track days ~

Before:

LF 784 RF 788 Front total - 1,572l
LR 780 RR 764 Rear total - 1,544
3,116 total

After Tien Coilover install & adjustments:
LF 768 RF 768 Front total - 1,536
LR 748 RR 762 Rear total - 1,510
3,046 total

an additional data point. In my case, the Rx8's front to rear weight distribution seems to be within 30 lbs. The rear trailer hitch probably adds @ 25 to 30 additional pounds all hung out over the rear overhang. HTH someone.

Hummmm... Well Mazda said the new MX-5 has 50/50 with 2 people in it. Can that be it?

Depends.

Is J-Lo one of the two people?