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2007 ion2 · 09-15-2010, 08:05 AM

so, I have some results to share. I mocked up the upper grill block and nose under pan in one go, then the lower grill block (on top of the existing two mods), then a rear under pan transitioning air from the under side of the car just behind the torsion beam to the bumper cover. all of this yielded some interesting (to me, at least) results. first, I picked my road, forget about flat roads anywhere around here for a perfect coast down test, so I picked a run that gave me a decent distance out for an MPG comparison, and a decently flat run on the way back for a coast down test.

these numbers were obtained by my scangauge 2 (which everyone should know is only good for comparing two runs from the same tank), and a stopwatch on my phone (always lit for the least distraction). the first set of numbers I will give you were from early tuesday morning, the second set was with proper representations of the mods early this morning both mornings were 73 degrees (as measured by my scangauge before the first start up) and mildly breezy. all runs were made as close together as possible, and with the car configured the same every time. the scan gauge got changed twice (fill ups to calculate actual mileage), so only the first two and last two runs can be compared together

ok, as a base, I got these results: (remember, for these first couple mods, overheating was a concern, not so today).

*76F intake temp at 60
*83F intake temp at 40
*warm up time of 6 minutes in 2.9 miles of city driving (40 MPH, a few stops and gos, no lights) to 188F (warmed up for my car)
*MPG test (about 5 miles at 55MPH, using cruise to eliminate human error) *38.7MPG
*70-40 coast down 41.03 seconds
*maximum engine temp was 193 sitting at a stop light during this drive.

second run (front under pan and upper grill block)

*76F intake temp at 60
*85F intake temp at 40
*MPG test (same spot as before) 38.8MPG
*coast down test (same as before) 41.34 seconds
*max engine temp 193 (same spot as before)

I ran it with the upper and lower grill block in place, but had to abandon it after a couple blocks due to excessive heat buildup. for ions and cobalts, this is to be a 40 or below mod ONLY the radiator and fan kept the engine temp down (sort of), but what alarmed me was the huge spike in intake temperature that most people cannot monitor, but will cause detonation.

I then mocked up a hasty rear under pan and got some shocking numbers

*38.6MPG
*47.25 seconds

I doubted the coast down number's accuracy, so I went again

*39.7MPG
*46.6 seconds (starting to get traffic)

and one more coast down test a little later when traffic died down

*47 seconds

then I got a sheet of choro plast yesterday and made the under pans up. I decided to do one more test of without then with the rear under pan.

first run 73 degrees outside, slightly breezy, both front mods in place

warmed up in 5 minutes, 2.4 miles, same rout as yesterday

*40MPG
*41.35 seconds

second run, proper front and rear under pans, and upper grill block

*40.8MPG
*46.3 seconds

now, while the two front end mods do relatively little for aerodynamics (guess saturn did it's homework, here), they seem to keep the car cooler while it is moving (this will possibly reverse in the same magnitude in severe stop and go traffic), so, they stay. the real shock (because of your pessimism on here, and how the rest of the car is, aerodynamically), is how dramatically the rear under pan increased coast down time and still decently increased measured fuel efficiency.

09-15-2010, 08:05 AM	#32 (permalink)
2007 ion2 EcoModding Lurker Join Date: Sep 2010 Location: saint louis Posts: 88 Thanks: 0 Thanked 4 Times in 3 Posts	so, I have some results to share. I mocked up the upper grill block and nose under pan in one go, then the lower grill block (on top of the existing two mods), then a rear under pan transitioning air from the under side of the car just behind the torsion beam to the bumper cover. all of this yielded some interesting (to me, at least) results. first, I picked my road, forget about flat roads anywhere around here for a perfect coast down test, so I picked a run that gave me a decent distance out for an MPG comparison, and a decently flat run on the way back for a coast down test. these numbers were obtained by my scangauge 2 (which everyone should know is only good for comparing two runs from the same tank), and a stopwatch on my phone (always lit for the least distraction). the first set of numbers I will give you were from early tuesday morning, the second set was with proper representations of the mods early this morning both mornings were 73 degrees (as measured by my scangauge before the first start up) and mildly breezy. all runs were made as close together as possible, and with the car configured the same every time. the scan gauge got changed twice (fill ups to calculate actual mileage), so only the first two and last two runs can be compared together ok, as a base, I got these results: (remember, for these first couple mods, overheating was a concern, not so today). 76F intake temp at 60 83F intake temp at 40 warm up time of 6 minutes in 2.9 miles of city driving (40 MPH, a few stops and gos, no lights) to 188F (warmed up for my car) MPG test (about 5 miles at 55MPH, using cruise to eliminate human error) 38.7MPG 70-40 coast down 41.03 seconds maximum engine temp was 193 sitting at a stop light during this drive. second run (front under pan and upper grill block) 76F intake temp at 60 85F intake temp at 40 MPG test (same spot as before) 38.8MPG coast down test (same as before) 41.34 seconds max engine temp 193 (same spot as before) I ran it with the upper and lower grill block in place, but had to abandon it after a couple blocks due to excessive heat buildup. for ions and cobalts, this is to be a 40 or below mod *ONLY* the radiator and fan kept the engine temp down (sort of), but what alarmed me was the huge spike in intake temperature that most people cannot monitor, but will cause detonation. I then mocked up a hasty rear under pan and got some shocking numbers 38.6MPG 47.25 seconds I doubted the coast down number's accuracy, so I went again 39.7MPG 46.6 seconds (starting to get traffic) and one more coast down test a little later when traffic died down 47 seconds then I got a sheet of choro plast yesterday and made the under pans up. I decided to do one more test of without then with the rear under pan. first run 73 degrees outside, slightly breezy, both front mods in place warmed up in 5 minutes, 2.4 miles, same rout as yesterday 40MPG 41.35 seconds second run, proper front and rear under pans, and upper grill block 40.8MPG *46.3 seconds now, while the two front end mods do relatively little for aerodynamics (guess saturn did it's homework, here), they seem to keep the car cooler while it is moving (this will possibly reverse in the same magnitude in severe stop and go traffic), so, they stay. the real shock (because of your pessimism on here, and how the rest of the car is, aerodynamically), is how dramatically the rear under pan increased coast down time and still decently increased measured fuel efficiency.