Testing: WAI's effect on engine warm up

[RobertSmalls]

In theory, there should be a little improvement in heat retention with a WAI. Your WAI uses heat that was going to go to waste out the tailpipe, so there's no way it could hurt warm-up times.

Bear in mind that a 1.5L engine ingests about 750g of air per minute at 1000RPM. You probably ingested some 15lbs of air during the test, and it was an average of only 30°F warmer. If your coolant system + engine weighs 225lbs, in theory, it should be two degrees warmer at the end of your test with the WAI than without.

With a hot air intake, such as one that reaches 120°F in ten minutes, and 2000 RPM instead of 1000RPM, you should see +8°F to coolant temps in ten minutes.

[user removed]

Trust me on this one, 60,000 hours experience.

Start the engine cold with the radiator cap off.

You should see virtually no circulation until the thermostat opens.

If you see circulation before the stat opens the stat is bad.

Even with a properly working stat, you still have way too much heat loss through the radiator.

Completely block the radiator with a piece of cardboard. Carry a pair of scissors to trim the size of the cardboard if it actually gets to hot (I doubt it).

Use the block to get the operating temps up as high as you can (without being to hot), before you even mess with the thermostat.

As you get the operating temps up higher you can actually test it by placing your hand on the bottom radiator hose (the one the coolant comes out of the radiator through).
In summertime the bottom hose is usually around 110 degrees. In winter time it is much colder and that same much colder coolant goes into your engine and keeps it to cold.

The more the thermostat restricts the flow of coolant the colder the coolant going from the radiator back into the engine.

It could make a very significant difference in your mileage, especially based on your distance to temperature graph, which shows 5 miles before it even gets close to warm enough. The temp should actually be very close to the thermostat rating.

regards
Mech

[user removed]

Assuming you completely block the radiator and it still does not warm up enough, consider using the pipe insulation available for home use on your heater hoses. I am talking about the flexible foam wrap that has a glue that connects it together.

If the heater core alone is enough to keep the engine cool, then you want to get as much hot coolant to the heater core as possible.

You have the means to monitor coolant temps and fan activity, and assuming you can actually get the temps above the thermostat rating by restricting heat losses, you can either use more cabin heat or reduce the radiator block area to get the temps down.

The fan operates off the temps from the area where coolant exits the radiator, so if the fan comes on you know the exit coolant temps have reached the level where you should allow more heat radiation.

It's possible that if you can get operating temps high enough the WAI may actually work better. I am basing this assumption on the possibility that the engine is running rich due to the fact that your coolant is not hot enough on any part of the graph illustrated.

regards
Mech

[thatguitarguy]

An idea that I posted in another thread, that I haven't tried yet but am considering for my Metro because there is so much open space in the engine compartment, is molding some foil around parts of your engine that you would like to insulate, similar to configuration 3 in your pix, and then spraying on some "Great Stuff Fireblock" foam. I'd give it plenty of time to cure because of the temps, and the fact that this stuff seem to cure unevenly if you try to mess with it too much while it is curing.

You could do it in sections, and then you have a custom fitted insulating shell that can be easily lifted away for maintenance and warm weather use, and could also be trimmed with a utility knife if areas, like around the exhaust, are retaining too much heat.

[Daox]

You guys got some good ideas to try out. Thanks!

For reference, it was 0F when I left the house this morning. Peak coolant temp was up to 177F on the drive in today. At that point, I turned up the fan/heat to better defrost the windshield and windows and it started dropping slowly but surely. At that point, I was maybe halfway to work.

[Daox]

Ouch, just filled up the Paseo this weekend since doing these tests. This tank plumeted 15 mpg (58 to 43 mpg). I sure hope this helps people out.

[thatguitarguy]

Maybe this belongs in the "You know you're an Ecomodder if.." thread, but it's amusing to me when people complain about "only" getting 43mpg...

[Tygen1]

Originally Posted by Daox

You guys got some good ideas to try out. Thanks!

For reference, it was 0F when I left the house this morning. Peak coolant temp was up to 177F on the drive in today. At that point, I turned up the fan/heat to better defrost the windshield and windows and it started dropping slowly but surely. At that point, I was maybe halfway to work.

Are you EOC'ing during your drive? If you don't, then we must assume your cooling system is not working properly. If not, then you should try completely blocking the radiator, front and back, with cardboard to help with the heat retention. I believe Old Mech. mentioned this.
It's 20 degree's F here and with a complete grill block my radiator fan still kicks on several times on the way to work, that means 225F.
Why aren't you using a block heater??? I'm at 90-130 degrees by the time I leave in the morning, depends on ambient. I get to 195 in just two miles. I also use trans and oil pan heaters

[Daox]

Yeah, I EOC a lot while driving. I had the Paseo this weekend on my trip to see some relatives, about a 200 mile drive on the freeway. I averaged 60 mph and in the 15F weather, the coolant fan never even came on. Coolant temps were quite high (~200F). However, heat was being used the entire time too.

Why aren't you using a block heater???

I dunno, I'm stubborn. Most of the time I only use the car once a week. Getting a block heater setup for that doesn't seem real worth while, plus I'd just like to play around and try to find alternative ways to heat up the car faster. Its not really a problem, more of a nuisance and something to work on.

Blocking the radiator I'm sure would help. However, there is a huge difference between a 0F day and 25F day it seems. I have to be able to accommodate for each circumstance. I know I could simply remove the cardboard block, and I may end up doing that.

[thatguitarguy]

Years before I ever knew anything about the aerodynamics of blocking a grill, I used to block my radiator just to get some heat inside the car. I don't know what it's like on a Paseo, but it was very easy on my old Subaru. I just slipped piece of cardboard in front of the radiator, and I could move it around to adjust how much air it got. I know some other cars don't give you such easy access to the front of the rad.

It's nice when you can be sure that you're running efficiently enough to not be losing energy to heat, except when you're trying to keep your windshield from frosting up from your breath.