Honda Insight w/Acura TSX engine - Ecomodding

[California98Civic]

Love how capable you have made this little car. When you think about it, this is a great, economical way to combine your "truck," your DD, and your "race car." And all the great learning. ...

How did all that weigh affect handling and stability. It felt safe? Did you drive slow?

[Ecky]

Originally Posted by California98Civic

Love how capable you have made this little car. When you think about it, this is a great, economical way to combine your "truck," your DD, and your "race car." And all the great learning. ...

How did all that weigh affect handling and stability. It felt safe? Did you drive slow?

It felt like it wanted to wag the back of the car a little at 48mph when I got off the throttle. I expect to rear of the car isn't heavy enough to control that kind of load. I took back roads and drove slowly, tried a few hard braking maneuvers at lower speeds to convince myself I wasn't insane.

I bet with some bricks in the car it would have handled better.

[samwichse]

Did your trailer have brakes? Because I can imagine that heavy trailer pushing your light back end right around and jackknifing under even moderate emergency braking...

Trailer brakes make such a huge difference in the weight disparity you can tow with anything. I used to tow a 12k lb trailer (2 axle trailer + tractor + implements + spray tanks loaded with lots of mix) with a late 70's Dodge Ram 2500. Checked those brakes every. single. time. I was leaving because turning them off, you could feel the back end wanting to come around giving the brakes a solid tap at 10mph, and I was towing through central PA.

[Ecky]

Originally Posted by samwichse

Did your trailer have brakes? Because I can imagine that heavy trailer pushing your light back end right around and jackknifing under even moderate emergency braking...

Trailer brakes make such a huge difference in the weight disparity you can tow with anything. I used to tow a 12k lb trailer (tractor + implements + spray tanks loaded with lots of mix) with a late 70's Dodge Ram 2500. Checked those brakes every. single. time. I was leaving because turning them off, you could feel the back end wanting to come around giving the brakes a solid tap at 10mph, and I was towing through central PA.

No trailer brakes, and I don't plan to load it up that much again.

I wasn't aware it was as heavy until I got home, but it was an interesting proof of concept. I've seen others who've broken their rear bumper bar off carrying a bicycle rack on their Insight, and I'm glad to see my design is so much more robust.

[MetroMPG]

This thread continues to impress!


You're enjoying that car.

[hayden55]

Originally Posted by Ecky

It felt like it wanted to wag the back of the car a little at 48mph when I got off the throttle.
I bet with some bricks in the car it would have handled better.

Sounds like the trailer is loaded wrong. Did you load the tongue at 10-15% of total? My Ranger is loaded worse and tows a 3000lb boat just fine weighing less than your Acura. I had a flat bottom that was loaded like 5% on the tongue and it trailered horrible, swapped to a bass boat triple the weight on the same Prius and it was loaded 12% on the nose and it was smooooooth.

[Ecky]

Originally Posted by hayden55

Sounds like the trailer is loaded wrong. Did you load the tongue at 10-15% of total? My Ranger is loaded worse and tows a 3000lb boat just fine weighing less than your Acura. I had a flat bottom that was loaded like 5% on the tongue and it trailered horrible, swapped to a bass boat triple the weight on the same Prius and it was loaded 12% on the nose and it was smooooooth.

I had no choice; I was putting 16ft boards in a 4x8 trailer. It almost certainly had a poor weight distribution.

[Ecky]

Ordered an EGT sensor! I don't know if it's precise, but as long as it's accurate that's good enough for me.

https://www.amazon.com/Sensors-Digit...816451&sr=8-19

I plan to use it to more finely dial in my part throttle ignition timing. Right now, holding the car at 65mph burns around 1.35 gallons per hour, or ~48mpg. Holding the engine at 2150rpm in neutral burns around 0.8 gallons per hour, which basically gives me an upper limit of 81mpg @ 65mph if the car weighs nothing and has no drivetrain losses or parasitic drag. If my ignition timing is off, adjusting it could measurably improve these low-load situations.

Ideally a bung is welded upstream of the catalyst, as close to the exhaust ports as possible. I planned to just get an adapter and put it in the downstream O2 sensor hole. I don't particularly car if it's getting temperature readings 300F below what's coming out of the engine, so long as I can tell if what I'm changing causes it to rise or fall, all else being equal.

[California98Civic]

Originally Posted by Ecky

Ordered an EGT sensor! I don't know if it's precise, but as long as it's accurate that's good enough for me.

https://www.amazon.com/Sensors-Digit...816451&sr=8-19

I plan to use it to more finely dial in my part throttle ignition timing. Right now, holding the car at 65mph burns around 1.35 gallons per hour, or ~48mpg. Holding the engine at 2150rpm in neutral burns around 0.8 gallons per hour, which basically gives me an upper limit of 81mpg @ 65mph if the car weighs nothing and has no drivetrain losses or parasitic drag. If my ignition timing is off, adjusting it could measurably improve these low-load situations.

Ideally a bung is welded upstream of the catalyst, as close to the exhaust ports as possible. I planned to just get an adapter and put it in the downstream O2 sensor hole. I don't particularly car if it's getting temperature readings 300F below what's coming out of the engine, so long as I can tell if what I'm changing causes it to rise or fall, all else being equal.

$20 is a good price. If your upper limit is about 81 mpg, well then, it seems with a few more aero mods and your careful tuning, you should be able to get a staged 70 mpg single run average for sure.... a few miles in good conditions should be doable with minimal hypermiling (once you get everything dialed in). A coveted "70 mpg Club" sticker picture awaits you. hahaha...

[Ecky]

Originally Posted by California98Civic

$20 is a good price. If your upper limit is about 81 mpg, well then, it seems with a few more aero mods and your careful tuning, you should be able to get a staged 70 mpg single run average for sure.... a few miles in good conditions should be doable with minimal hypermiling (once you get everything dialed in). A coveted "70 mpg Club" sticker picture awaits you. hahaha...

I certainly hope so. It looks like at 65mph, 60% of the gasoline burned is just spinning the engine and the remaining 40% pushes the car down the road. Engine mods seem like the low hanging fruit here.

70mpg would require that 0.13 gallons per hour propel the car and 0.8 gallons per hour spin the engine, if I can't get the engine losses down or do pretty extreme EoC.

Edit: maybe taller tires, more EoC, and lower speeds, but I'll need all of it. This was a car that was delivering 100mpg for hundreds of miles prior to the swap, so it's already running very "lean". Lower speeds will help more because engine RPM is low than because of reduced drag.