I just picked up a Gtech to play around with my Coupe's performance stats in the absence of a Dyno. The manual says to calculate the car's weight including mods, gas, driver, etc. in order to get accurate readings. Are "car" scales common?

I guess I can calculate the weight based on curb weight (3,486 lbs.) plus me (240 lbs.) plus 10 gallons of gas (~60 lbs.?) minus spare tire/jack (~40 lbs.). And how do I figure the weight difference of things like aftermarket wheels, flywheel, exhaust, etc. I've searched and have not been able to find weights for 19" Racing Hart C4 wheels, stock 19" wheels, stock exhaust, Stillen exhaust... You get the idea. Has anyone gotten their car weighed or calculated their car's weight? Thanks guys (and gals).

 

If you can find a gravel pit or asphalt plant where you live they will have a scale that can weight your car accurately. Just be nice and offer the guy in the scalehouse a couple bucks and shouldn't be an issue.Coffee never hurts either.

 

Click on this link:
https://g35driver.com/forums/intake-exhaust/50541-borla-evo2.html

Look under my post for the weights on the stock and aftermarket exhaust. It's for a Z, but it's close enough to give you an idea of how much additional weight you need to adjust for.

You're on your own for the wheels and tires. It's pretty difficult to get those specs unless you weigh them yourself.

 

the G-tech isn't as accurate as the G-timer, and even then +/- 100lbs isn't going to offer any real difference in your outcome (you are in the 2 - 3% range)

The onlything useful from these devices is 0- 60 1/4 mile times, etc....
The HP readings are pretty much BS, a far larger factor is the drivetrain loss, which if you are off by 1% will effect your readings far more.

If the G-tech has the option, remove more of the inaccuracy by setting it for WHP rather than guestimated Engine HP... it is still not that accurate, but it is closer and more consitant.

 

Put it on a scale. Anything else is a SWAG. Most truck stops have scales - look in the phone book.

I took my rig (truck and camper) down and got axle weights, tounge weight, individual weight for each vehicle and total weight for $4.

No more guessing.

 

Cool, thanks for the good info guys. I agree that the Gtech is more useful for 0-60 and 1/4 mile than HP or torque. The Gtech is effected by wind drag, road conditions, driver skill, atmosphere, etc. Still fuin though! I wonder if there anre any dynos around Austin?

 

there are absolutely dynos around, crack your phone book, you'llfind something.

If you get the chance, (I haven't yet) go to a track, and make some runs. Then you dial in the Gtech to match, ad know your times are accutrate.

I got the G-Timer, and it is fun. It helps when doing mods and such, gives you an idea how things are going.