Terrible mpg's = new interest in old ideas.

[Tygen1]

It makes me sad to hear these stories. It happens though... Time for you to start becoming more competent at engine work, then you can save all that money for good ecomods.

Hooked up a HAI last night, saw 110 degree temps, compared to the usual 90 degree temps. Not as much as I hoped for, I think the header wrap is working too good Got to find a better source for heat. I also tried ducting off the rad and it was the same, however when the fan kicked on, the temps kicked up to 120-130, so maybe I need to seal the duct up against the rad?
Also worked on fiting up some rear fender skirts. Gonna try and finish them tonight and if I have time get the HAI to work better.
While I was in there, I cut the hole for a ram air system, so I can measure the difference in mpg between the three, HAI, underhood, and CAI. Also, I intend on using the Ram Air to get some better times thru the 1/4
I was hoping to get a front and rear undertray built, but there just isn't time. Only have tonight to finish it all...

[Christ]

I wonder about heated ram air... like pushing radiator air through the intake... ya know?

Once you get up to 60MPH, that pressure at the front of the car can make some nice gains because it's forcing air in, rather than air having to be sucked in... You get rid of some pumping losses at highway speed. You also get more air in there with your fuel, which we know is a good thing to prevent the occurrence of pre-ignition and knocking/detonation. Then, on top of that, it's warm air, which doesn't require as much energy to heat up and expand, leaving more energy from the explosion to move the piston.

RamWAI FTW?

[Tygen1]

If I could figure out a way to make a WRA (Warm Ram Air) without hacking up my car, I might try it. Although I'd probably try it anyhow if I thought it would work. My perception is that there might not be enough heat transfer in a 5 to 6" duct through a heater core type radiator. Maybe I'm wrong though because my heater can blast out some real hot temps...It's all about CFM's and BTU's and I don't care to do the math. Just gotta make loop of hose before the heater core to run down below the bumper, duct thru a heater core and see what happens.... Might not need a radiator after that

Anyhow, fender skirts are on and drove them to work this morning. No strange looks yet... Did get my best to work commute mpg since the winter gas hit. 47.5mpg, almost 48 but a couple stop lights really got me. The change is not huge, but it is noticeable. I usually coast the down side of the bridge, 1.5 miles, I'm at 50mph at the top and in the summer I'm about 55mph by the bottom. As soon as it got cold I'm struggling to keep it above 40mph. But it's been warmer the past couple days so I expected it to slow down to 45mph, but it kept 50mph the whole way. I also noticed my fuel consumption to be just slightly less. The skirts are quick release so I'll be able to do some coast down tests when I get some time.

[mhmitszach]

Originally Posted by Tygen1

If I could figure out a way to make a WRA (Warm Ram Air) without hacking up my car, I might try it. Although I'd probably try it anyhow if I thought it would work. My perception is that there might not be enough heat transfer in a 5 to 6" duct through a heater core type radiator. Maybe I'm wrong though because my heater can blast out some real hot temps...It's all about CFM's and BTU's and I don't care to do the math. Just gotta make loop of hose before the heater core to run down below the bumper, duct thru a heater core and see what happens.... Might not need a radiator after that

Anyhow, fender skirts are on and drove them to work this morning. No strange looks yet... Did get my best to work commute mpg since the winter gas hit. 47.5mpg, almost 48 but a couple stop lights really got me. The change is not huge, but it is noticeable. I usually coast the down side of the bridge, 1.5 miles, I'm at 50mph at the top and in the summer I'm about 55mph by the bottom. As soon as it got cold I'm struggling to keep it above 40mph. But it's been warmer the past couple days so I expected it to slow down to 45mph, but it kept 50mph the whole way. I also noticed my fuel consumption to be just slightly less. The skirts are quick release so I'll be able to do some coast down tests when I get some time.

Pictures please! I'm curious as to how you did this. Maybe I'll put them back on and make them full skirts. I'd only need 4 more L brackets.


I'm planning on getting a large sheet of coroplast to put under the car next week. My serpentine belt is squeaking in this wet weather without a splash guard.

[Christ]

I was thinking that you could remove the fan shroud and put a box inside it with a duct to your intake... that way, all the air that makes it into that box gets forced down the intake piping.

If not that, you could box off like half of the radiator, pipe that section to the intake, then let the fan have the other half. Just make sure that you're not blocking the grille on the half that has the intake on it.

I guess half the radiator wouldn't be ideal, though.

And yes, a heater core setup would work wonders. The blower fan can move more air than your engine needs at low RPM/throttle angles, easily, and it doesn't really develop too much pressure in the piping before the core. Those cores can flow some serious air, especially newer ones, and they exchange heat like a mofo.

In some cases in the winter, I've seen people use only the heat in the vehicle (on full blast, with a rear window down) and a full grille block. The heater core keeps the car from overheating. I didn't believe it, but the dude turned off the blower fan, and within about a minute, he got high up in the temps... he turned the fan back on and lowered the engine speed, and within a couple mins, it was fine again.

[mhmitszach]

Driving in southern indiana is great for gas mileage!

I was just barely trying to drive well and pulled 42 mpg over about 45 miles. It's only like 45 degrees outside. I can't remember ever getting that good of gas mileage in cold weather. I would imagine putting an undertray on the front end would only help a huge amount, temps and aero.

[Tygen1]

We'll I was away for a wedding this weekend. Took the ZX2. Drove into a headwind the whole way down VA Beach. Really stuggled to get it over 46mpg. Not normal. I think the PCM may have gone open loop and it was running a little rich. Then I ran thru this big dip in the road, bottomed out and (didn't know it at the time) killed my O2 sensor. It ran terrible after that and it took me about 100 miles to figure out what was going on, mpgs really suffered during that bit. It's difficult to draw any conclusion as to how much the skirts help. I need to do those coast down tests.

I just might try this WRA thing after all....it's really had me thinking?

I'll try and post some picks of the skirts tonight. They only took about 4-5 hr's to make and probably 30 bucks for both in materials.
What interesting is that I surprised my wife with the skirts, it's the first time she saw them and then there was a Gen1 Insight at the wedding, and she commented that this guy did the same as I did. So I got to explain the whole concept to her using the Insight. I'm glad she doesn't really care what I do to the car

[Arragonis]

Originally Posted by Tygen1

If I could figure out a way to make a WRA (Warm Ram Air) without hacking up my car, I might try it.

Hi - Newbie so this may be rubbish.

In my old Mini (circa 1989 so thats Mini not BMW MINI) here in the UK the air intake had just such a device. The pipe just before the air filter had 2 intakes, one from just behind the grill and one from just above the exhaust manifold. The junction between the two had a bimetalic strip which had a piece of air-filter style sponge on it. The idea was that when cold the engine would take air from around the manifold (at the back of the engine, transverse - FWD) and when warm would take air from behind the grill.

The strip was springy enough so that on full throttle, well full throttle for 998cc and 40 Hp (DIN), the junction would open from either side.

A performance "mod" was to remove the strip to increase airflow, mainly as temps didn't really drop below -2 or 3 deg C. Now due to global warming they are usually around -3 or 5 deg C. It added around 0BHP really but helped the stupidly efficient SU carb a bit more that usual - my MPG went from ~40 to ~45 (Imperial) and the SU was helped by allowing the pressure to drop a lot so more fuel went in so response was much better. Ok I was a boy racer then (even with only 40 BHP).

I've kind of thought about something similar for my current motor (Diesel hatch) but there doesn't seem enough room under the bonnet plus there is a turbo and an intercooler to disrupt matters anyway.

As an aside my friend with a carb-feb (SU) Mini with 1litre and an SU carb can make more MPG than a new Hyundai i30 with 1litre and fuel injection which makes me think of the extra weight of moderns, the extra "carp" they carry (air con and so on), and also how good the 1920's design of the SU really was.

[Tygen1]

We have something similar on older carburated cars here in the states. Bi-metalic spring and a little foil hose running to the exhaust to get things running well in cold temps. Same idea, except I have a heat wraped header, so I'm not building up enough heat Thanks for the input!

[Christ]

Is your header in front or back?

I think the best way to do an "WRAITH"** so far is probably another heater core in the OEM airbox with a flow valve in the fluid line, and monitoring the IAT sensor. Pipe the OEM airbox to the nose of the car, so you get the ram effect.

** Warm Ram Air Intake THing.