New undertray design - Page 3 - Fuel Economy, Hypermiling, EcoModding News and Forum

Christ · 02-10-2010, 01:52 AM

You're going tank by tank and testing mods with each tank?

Why not try eliminating some variables and running each mod for more than one tank?

If you get a 5% increase from a mod, with your 22mpg, it's only going to equate to ~1mpg, Mike.

You'll likely dismiss it as "noise", but you'll have a better test bed if you had some sort of instrumentation that could quantify changes in the way your vehicle operates, even a vacuum gauge. IF you're getting better MPG, you should notice lower vacuum numbers while cruising.

Stickers is remarkably clean underneath, by the way.

MetroMPG · 02-10-2010, 08:18 AM

(Merged the 'testing' of the belly pan thread with the building thread.)

AeroModder · 02-10-2010, 11:02 AM

Thanks for merging them. It works better this way...

I've actually been thinking about getting some kind of guage, but I'm not sure what would work on a 1991.

Ideally, I should be testing each mod for 3 tanks with no other variables to give myself a better average to work with. However, seeing as how much I enjoy working on my car, It's hard for me to go two weeks without touching up things.

Though I probably will end up pulling panels off one at a time, run it for a few tanks without it, and see what kind of a difference each one makes. If I get better economy without one, then my design was flawed.

stonebreaker · 02-10-2010, 11:16 AM

As Christ mentioned, a vacuum gauge would work:
Sunpro CP7803 Actron Vacuum & Pressure Tester

Christ · 02-10-2010, 11:59 AM

Talk to dcb - a MPGuino should work on your car, I'm fairly certain you either have CPI or MPFI on there?

MetroMPG · 02-10-2010, 12:22 PM

I'm not a fan of tank-to-tank testing. Still too many variables (weather, being the biggest, but not only one).

See: http://ecomodder.com/forum/showthrea...ery-11445.html

I'd be more inclined to do A-B-A coastdown testing, where you're only looking for a relative difference in coastdown time/distance in relatively controlled circumstances, rather than trying to measure MPG change in the real world.

AeroModder · 02-10-2010, 02:41 PM

Christ: I believe the 2nd Gen Tempos have MPFI. I'll look into the MPGuino too, since I've been interested in mapping MPG vs. speed for a while. Without the proper instruments, I've mostly been running blind.

Stone: Thanks for the link. That's not very pricy at all, so I just might get that when I get some money.

Metro: I've actually been doing some coastdown tests using speed limit signs as a guide. It definitely seems to be slowing more gradually from 45 to 35 than before, but the mileage still isn't as high as I'd like. I'm going to try pulling out the K&N filter and put the Fram back in and see what that does for a couple tanks. Maybe I can do some simple, reversable changes to the engine and see what that gets me.

Christ · 02-10-2010, 09:54 PM

Quote:

Originally Posted by AeroModder

Christ: I believe the 2nd Gen Tempos have MPFI. I'll look into the MPGuino too, since I've been interested in mapping MPG vs. speed for a while. Without the proper instruments, I've mostly been running blind.

Stone: Thanks for the link. That's not very pricy at all, so I just might get that when I get some money.

Metro: I've actually been doing some coastdown tests using speed limit signs as a guide. It definitely seems to be slowing more gradually from 45 to 35 than before, but the mileage still isn't as high as I'd like. I'm going to try pulling out the K&N filter and put the Fram back in and see what that does for a couple tanks. Maybe I can do some simple, reversable changes to the engine and see what that gets me.

Mike (That is your name, isn't it?)

I think you'd be able to tell quickly if you have MPFI by popping your hood. If you've got an intake manifold that's about the length of the engine, and curves up over the valve cover kinda, it's MPFI.

AeroModder · 02-10-2010, 10:10 PM

Yes, it's MPFI. I wasn't sure what the difference between the different fuel injection types were.

Christ · 02-10-2010, 10:13 PM

Quote:

Originally Posted by AeroModder

Yes, it's MPFI. I wasn't sure what the difference between the different fuel injection types were.

CFI - single injection point, basically an electronic carb.

MPFI - individual runners/injectors for each cylinder and a main plenum, to which there is a throttle body attached.

If you have MPFI, you should be able to use the MPGuino.

After reading this message, click the word MPGuino and it will take you to the thread that explains what it is and where/how to get one. dcb makes them pre-assembled, so you can get one and just hook up 4 quick wires and spend some time calibrating it, and you're golden.

EDIT - Seems like it's not autolinking?