Transmission options.

[Ecky]

Originally Posted by Honda

Update:
I bought the transmission I was talking about but it turned out to be from 1999 Civic EX.
At the same time I put stage 1 Exedy clutch, light weight flywheel, 15'' alloy rims (heavier than stock).
I know that some of the above may not help to increase FE but I wanted to see what will happen by transferring the inertia from the flywheel to the wheels.
The car traveled farther while on neutral but the overall MPG dropped from 37 to around 34, could be the cold weather is to blame I don't know.
While driving at 65mph the rpm is around 2700.
I am still shopping around for obd1 trip meter that can help me get more accurate result.
Also I couldn't use the highway most of the time due to HOV, so I was stuck in traffic in the morning.

What you need is an MPGuino.

http://ecomodder.com/forum/showthrea...able-6914.html



I calibrated the distance/speed on mine within ~0.05% over a few extended trips using highway markers and GPS.

[California98Civic]

Originally Posted by Honda

Update:
I bought the transmission I was talking about but it turned out to be from 1999 Civic EX.
At the same time I put stage 1 Exedy clutch, light weight flywheel, 15'' alloy rims (heavier than stock).
I know that some of the above may not help to increase FE but I wanted to see what will happen by transferring the inertia from the flywheel to the wheels.
The car traveled farther while on neutral but the overall MPG dropped from 37 to around 34, could be the cold weather is to blame I don't know.
While driving at 65mph the rpm is around 2700.
I am still shopping around for obd1 trip meter that can help me get more accurate result.
Also I couldn't use the highway most of the time due to HOV, so I was stuck in traffic in the morning.

The wheels/tires are like a gear in the transmission in some ways. Larger and heavier wheels will lower actual mpg and apparent mpg. You now have more rotational mass, farther from the wheel hubs. That will make the engine work harder, effecting mpg especially during acceleration, but you will also coast better because of the rotational mass. What size tires do you have? Larger wheel/tire combos will lower your "apparent" mpg by reducing the number of miles your odometer measures. Use a good GPS to calibrate your odometer readings. The difference could be 5% or 10%--or nothing depending on your tire size.

[Honda]

Ecky, how can I order one? I looked at that site a while ago but I don't know how to place an order.
California98Civic, the difference is about 4.83% and the overall diameter is about ~1'' difference according to this table https://www.1010tires.com/Tools/Tire...0R13/185-60R15
The engine seems to respond quickly due to the light weight flywheel, the wheels are not super heavy, they are 10 spokes from 2003 Civic Si EP3.

[Ecky]

Try here: MPGuino trip computer - MPGuino

Or here: Fuel economy gauge, MTH-Tek

I purchased one from a member and assembled a second one myself, which wasn't any cheaper and ended up being a bit larger.

[Honda]

Originally Posted by Ecky

Try here: MPGuino trip computer - MPGuino

Or here: Fuel economy gauge, MTH-Tek

I purchased one from a member and assembled a second one myself, which wasn't any cheaper and ended up being a bit larger.

Thanks, I will consider the above links if I can't find one locally in the US.

[California98Civic]

Originally Posted by Honda

Ecky, how can I order one? I looked at that site a while ago but I don't know how to place an order.
California98Civic, the difference is about 4.83% and the overall diameter is about ~1'' difference according to this table https://www.1010tires.com/Tools/Tire...0R13/185-60R15
The engine seems to respond quickly due to the light weight flywheel, the wheels are not super heavy, they are 10 spokes from 2003 Civic Si EP3.

That site's calculation of "speed variance" does not make sense. A larger tire/wheel will produce a slower indicated speed, not faster. But also, when you look at manufacturers size and weight data for tires at tirerack.com, you see that apparently actual tire size varies significantly within a given official size category. And then there is the variation auto manufacturers are allowed by the regulators as far as how accurate the odometers are. The only way to know how far off your odometer is, is to measure with a GPS over a significant distance, say 25 or 100 miles or more, and compare the odo reading to the GPS. Do it several times, like on your regular commute or something. You can probably find a good wheel weight figure at wheelweights.net ...

[Honda]

Let say we have 2 gears connected, one represents the odometer and the other is the wheel, in one complete turn the bigger the wheel gear the faster the odometer gear will spin. I could be wrong though but that's how I think it works. I will confirm this by using GPS.

[Ecky]

Originally Posted by Honda

Let say we have 2 gears connected, one represents the odometer and the other is the wheel, in one complete turn the bigger the wheel gear the faster the odometer gear will spin. I could be wrong though but that's how I think it works. I will confirm this by using GPS.

A larger wheel has a larger circumference. Imagine a hypothetical wheel with a circumference of 100 inches, and another with a circumference of 200 inches. Both of these wheels are connected to an odometer that reads "1 turn = 100 inches". One complete turn of the bigger wheel would take you 200 inches though, or, to go 100 inches, you would only need half a turn. This half of a turn would only show as 50 inches on the odometer, thus the bigger wheel would make the odometer read low.

[Honda]

Originally Posted by Ecky

A larger wheel has a larger circumference. Imagine a hypothetical wheel with a circumference of 100 inches, and another with a circumference of 200 inches. Both of these wheels are connected to an odometer that reads "1 turn = 100 inches". One complete turn of the bigger wheel would take you 200 inches though, or, to go 100 inches, you would only need half a turn. This half of a turn would only show as 50 inches on the odometer, thus the bigger wheel would make the odometer read low.

Half turn will show as 100 inch not 50 on the odometer.
What about time? let say within one hour each wheel complete 1 turn, so the odometer will read 200 inch per hour for the big wheel and 100 inch per hour for the small wheel. means the bigger wheel is faster?!!

[Ecky]

Originally Posted by Honda

Half turn will show as 100 inch not 50 on the odometer.
What about time? let say within one hour each wheel complete 1 turn, so the odometer will read 200 inch per hour for the big wheel and 100 inch per hour for the small wheel. means the bigger wheel is faster?!!

If the odometer is set to read one turn as being 100 inches with the small wheel, putting the bigger wheel on the same odometer will take you 200 inches while the odometer only reads 100 inches because it read only one turn, and it's set to read one turn as 100 inches. Going the actual 100 inches on the big wheel would only show as 50 on said odometer, because it only sees half a turn.

Time isn't a factor here, odometers are simply dumb "turn = this many mile" displays.


EDIT: Another way of looking at it is this: If 2000RPM = 50MPH with the stock wheels, if you replace the wheel with one twice as large you'll be moving at 100MPH even though your tachometer is still reading 2000RPM and your speedometer still shows 50MPH.