Toying with idea of taller Metro 5th gear (to go with the already taller final drive)

[3-Wheeler]

Darin,

I was reading the earlier comments in this thread and got the part where you discussing what gears to use to achieve about 1200 rpm at 55 mph, if I recall correctly.

So I used one of the ScanGauge channels to show rpm, and in the Insight this turns out to be 1200 rpm at 35 mph.

Now in the summer, this creates a very easy load for the engine, but in winter driving it is close to the bottom rpm I can run without the engine "throbbing" from the 3 cylinder engine pulses.

I guess I am wondering out loud if you could actually drive the car with a wind load at 55 mph and still maintain this engine rpm?

Seems pretty low to me.

Jim.

[MetroMPG]

It is low, and to be honest, I was probably just thinking out loud when I posted that.

This thread has turned into a bit of a monster and the unfortunate thing is: while I did actually start on having a custom set of gears made, I never finished the project.

Proceeding further isn't on the radar since the Firefly was relegated to "backup vehicle" status after I got the Insight. It's not even on the back burner... it's right off the stove!

[M_a_t_t]

What ended up happening with this project (like current status of the parts that you ended up with)?

I'm looking into attempting this because I've actually got a wire EDM at work as well as we do some heat treating. We also have induction machines (is that the proper name?) that I might be able to use to heat treat the teeth atleast.

[Tahoe_Hybrid]

Originally Posted by 3-Wheeler

Darin,

I was reading the earlier comments in this thread and got the part where you discussing what gears to use to achieve about 1200 rpm at 55 mph, if I recall correctly.

So I used one of the ScanGauge channels to show rpm, and in the Insight this turns out to be 1200 rpm at 35 mph.

Now in the summer, this creates a very easy load for the engine, but in winter driving it is close to the bottom rpm I can run without the engine "throbbing" from the 3 cylinder engine pulses.

I guess I am wondering out loud if you could actually drive the car with a wind load at 55 mph and still maintain this engine rpm?

Seems pretty low to me.

Jim.

got you beat 1000rpm at 35-42mph

85mph =1800rpm 4 banger mode


with low end power it's a non issue is your insight VVT? you could gain some low end power using higher octane fuel you will also gain some MPG as they use summer gas for the higher octane

[me and my metro]

As like many others Geo Metros are wearing out or rusting away. I have moved on to a Saturn L and am happy with the change. I played with Metros for 8 years and most Metro people are Mitsubishi Mirage owners now. The quest for mileage continues.....

[MetroMPG]

Originally Posted by M_a_t_t

What ended up happening with this project (like current status of the parts that you ended up with)?

Project Status: abandoned!

The only step I actually had done was having the teeth machined off one of the gears.

This is one of those things that was going to cost a lot more than I could justify.

Also, if it isn't done perfectly, metal contamination of the trans oil could ruin the rest of the gearbox (gear failure happened to another car I know about which did this mod).

[M_a_t_t]

Alright.

Atleast the curiosity has been satisfied. Thanks