02 G1 Insight with many ecomods- 999.6 mile tank @ 105 MPG

[The donkey CRX]

I have mentioned before that one of my goals for maintaining lean burn in the Insight is to keep the water temp in the 180 to 190 degree range at all times. Even with a 100% blocked grill (manually adjustable) I was not able to meet this goal in winter, especially while using EOC for as much as 20% of the miles driven.

So I designed a system that uses a 3 way "T" valve to modulate the amount of coolant flowing through the radiator from 100 percent to as little as 0 percent that can be adjusted from inside the car.

For safety, I also have a digital temp sensor where the coolant exits the upper radiator hose and another where the coolant re-enters the engine in the lower radiator hose.

The 3 way valve never blocks the flow of coolant out of the engine, it just diverts as much as 100 percent of the flow around the radiator.

Here are some pictures

The T valve is attached in line with the upper radiator hose between the engine and radiator. The bypass hose attaches inline with the lower radiator hose between the radiator and the engine,





Attached to the T valve is a push-pull cable with 3 inches of "throw". This cable extends into the passenger side of the firewall.




Here is the valve being test fitted in the car.





Here is the in-car adjustment handle. It is the lowest cable with the long lever handle. Above it are the knobs for adjusting the warm air intake and the adjustable grill block detailed previously in this thread.




This system worked flawlessly all winter. One morning with an outside temp of18 degrees, I was able to make my 54 mile commute to the shop while diverting 100% of the coolant past the radiator. The highest water temp was 190 degrees.

[Fat Charlie]

Now that's a grille block!

[The donkey CRX]

Thanks Charlie

[cowmeat]

Being a lazy, cheap ecomodder, and living in Florida where I don't have the issue of needing to heat my water temps up, I have what may be a stupid question:

That seemed like a lot of work and expense (and it'll look like the center console got hit with buckshot if you ever remove the gadgets to try to sell the car) - is there no way to just fake a signal to the sensor to make it think the water temp is at 160 degrees so it will go into lean burn even before the car warms up?

[The donkey CRX]

Getting the water temp up to 180 degrees + quickly has other benefits other than enabling lean burn. The engine runs more efficiently at higher oil and water temps being one. So no, I don't want to "fool" the computer into just thinking the water temp is higher.

You are correct in that I only have experience with this one Insight in my current environment, and what is happening may well not apply to any other Insight.

My goal is to maximize MPG, and some of my modifications may add only slightly toward that goal. I do it for the fun and the challenge.

[Fat Charlie]

Blocking the grille for aero and temp is great. Controlling plumbing is the next logical step.

I loved running my grille block last winter because I was finally able to take my hat and gloves off after 20 miles. But enough cooling air gets through that I can be stuck in traffic in August and not have to get out and tear off the block.

But I haven't even done my kill switch yet, I don't think I'm ever re-routing my plumbing.

[Xist]

Arizona here. I cannot imagine rerouting my plumbing.

[Natalya]

This past winter I drove about 120km on a day where it was -23°C and even with a radiator block the car never got to normal operating temperatures. This mod looks really useful for cold environment drivers.

[NoD~]

So is the t stat that terrible at holding back coolant? Why not block instead of bypass?

[Ecky]

With a full block, I was able to get up to temperature within ~5 miles when it was around -15F / -25c.