MetroMPG's 1998 Chevrolet Metro (Pontiac Firefly) mods & repairs kitchen sink thread

[MetroMPG]

I actually have a paper copy - and all it says is the car "may" have a low fuel light.

But I think Stubby79 may be on to something: the location of the flicker was where the parking brake/low brake fluid light is.

[arcosine]

I could have been the G-force limit light, warning that the side air bags may deploy. Of course the new super cars have a feminine voice, " Warning, lateral traction coefficient about to be exceeded". Cant wait to see what the belly pan does.

[MetroMPG]

Originally Posted by Stubby79

brake light (low fluid) comes on in my firefly when I go sliding around a corner...

Ding ding ding! We have a sideways-sliding winner!

I saw the light (I saw the light!) in the exact same corner a couple of days ago. It's that brake light.

---

Also, I did my second long-ish drive (~200 km / 120 mi.) since putting on the race car suspension, and the improved MPG numbers are holding up.

The only time I've seen better MPG on this particular trip is when I had the tail on, or with the alternator disconnected.

On some of the nearly flat portions of the return trip (very slightly downhill), the car is now pulling 70+ mpg at over 80 kph / 50 mph. I have *never* had to worry about speeding while getting 70+ before the race car suspension!

I like to spend my efficiency dividends partly on better MPG, and partly on going a little faster.

[freebeard]

Tell us more about this boat tail.

[Stubby79]

Originally Posted by freebeard

Tell us more about this kitchen sink.

FTFY.

[MetroMPG]

80.4 MPG US!

(That's also the 2nd best tank in 8 years, not counting short competition fills.)

This is the first full tank with the car lowered.

I'm prepared to say the lower race car suspension has had a positive effect, even though I haven't done the ABA test (and probably won't get to it this year).

I've been monitoring my trip log on multiple routes from before/after lowering, and I'm seeing either:

- higher MPG at the same average trip speed, or
- similar MPG to pre-lowering, but at higher average speeds

EG: I just did a 180 mile / 290 km round trip, and it was my best fuel results ever on that trip... AND my average speed was higher by a couple of MPH. Same exact route and driving style.

[MetroMPG]

I've also noticed the coolant temp is running a bit hotter than it used to.

I'm seeing cruising temps (~80 km/h = 50 mph) around 200-202 F on the level. The cooling fan kicks on at 204, and it has been coming on on some gentle climbs. Pre-racecar, I was used to seeing ~198.

As a result, I've actually been doing less engine-off coasting on the highway, to avoid hot soaking the engine. Need an electric water pump to keep the coolant moving when the pistons aren't!

Is it possible air flow under the car has been altered enough to affect cooling flow? Seems like it.

[freebeard]

Same amount of air below the stagnation point into a smaller slot? Could be. Maybe there's a 'ground cushion' effect lower than 6in?

Is 6° enough to be a problem?

[MetroMPG]

Good questions.

It'd be neat to see a smoke test to reveal the stagnation point & what's going on at the cooling inlet.

[Stubby79]

Originally Posted by MetroMPG

Is it possible air flow under the car has been altered enough to affect cooling flow? Seems like it.

Hmm...less air flowing underneath...

possibly means less air swirling in the engine bay.

or, more likely, maybe no longer an easy way for the air that passes through the grill to escape, so there's air pressure pushing back against the incoming air.