Some CAD work today

[2000mc]

1- as long as your temps are good, so your fans aren't running more often, should be good. I've never experienced any down side from the grill block, the only down side I can think of is if I should happen to knock off the air dam I would need to remove the grill block almost immediately

2- while the angle the air is coming in at might make it less of an issue, that same angle is funneling more air there, so I think it would work out the be a wash

3- it looked like my grill block was kinda a disappointment, looked like it was only worth about 1-2%. I didn't do a splitter, but I added an airdam near the front edge of the bumper, serves as front tire spats also, and has a large gap at the center for cooling, it was worth about 2-2.5%

the springs worked well for hitting something forward. if you parked over something when you back up, instead of just hearing a scrape, it was nice and quiet, because the springs stretched until the air dam flopped back under the car. Only trouble was, the springs stayed stretched, and then you had a floppy airdam

[aerohead]

Originally Posted by spacemanspif

Praise from the master; thanks aerohead!

Some of my concerns, as I look at it more are:

1: Theory is block = better aero and air flow through the engine compartment; what are some factors that could contribute to not netting better MPG other than increased frontal area?
2: Does the fact that the lower bumper pulls rearward (causing a "<" shape at the front essentially) cause the grill block to be less effective than a purely vertical or even sloped out (wedge/ramp shape like Corvette and Firebird) design?
3: Should this all pan out and net better MPG, would a splitter mounted to the bottom of the lower bumper make things even better?

I'm over thinking things, I know, but this is what happens when you should be working on your thesis and don't motivate yourself properly...

The springs are rusty and fragile, I might switch to bungee cord but then again, if I go deeper (and am thinking wider to block front tires, I'm worried about the extra resistance flexing the springs just while running down the road. Also the shield that dam mounts to is only zip tied to the car up the front because of some damage to the rear of the bumper supports so I'm a little worried about extending anything that would possibly try to rip the zip ties out while on the road.

*Adding frontal area is supposed to be a no-no,unless it's a purely track vehicle.
On a race track,an airdam with 3-inches ground clearance was measured by Feysal Ahmed Adem to be a % lower drag than a non-intrusive design.(This research sheds light on CAR and DRIVER's Crisis Fighter Pinto of 1974,where they used this really low airdam with success).'bondo' fabricated the most beautiful composite airdam only to see his mpg suffer a bit on his F-150,and ended up having to raise it up more flush with all the naughty bits.
Other than the height,the only thing I can think of offhand is wrapping the corners around even with the Saturn's sides,to get the air around the front tires and directed to the rear.
-------------------------------------------------------------------------
*Your approach clearance limits what you can do with air dam placement,so you'll have to just make the best out of what you have.
Chrysler noodled the air dam on their original Daytona Charger,and it's quite a bit like your situation.It's going to reduce lift,help direct air where it's more beneficial,and reinforce your forward stagnation point.Here's the Charger

--------------------------------------------------------------------------*The splitter would be great if you had the clearance,but don't sweat it if you can't.A movable air dam as VOLVO has already done would be a solution,but more intensive as a project.

[spacemanspif]

Thanks gents. I spent the weekend running around the suburbs where my eco usually takes a big hit because I don't drive as carefully as I should while running around with the family and fiancé, not to mention all the red lights I have to contend with. But this tank still looks to be on par with my previous tank and my all time best tank so I'm hopeful for the numbers I get tonight/tomorrow morning. Then we'll continue the test for a few more weeks before building a good, permanent, grill block. Stay tuned kids.

Aero: Funny how you and I thought of the same car. After I made that post I thought "did I explain it well? Should I have referenced the Daytona??" lol

[spacemanspif]

43.2mpg this tank. Pretty good, I think, considering I don't usually do that well when I go up to my parents and end up driving around the suburbs a lot getting stuck at a lot of the lights. We'll see how this week goes...

[spacemanspif]

This is the "waterproof" version of the block. We've has spotty rain forecast the last few days and after I made it home the first day with cardboard still in tact and no cooling issues I thought I should seal up the cardboard in case it ever does rain.

Sorry for the crappy pics, I have a crappy flip phone that takes crappy pics. Did some running around yesterday and got stuck in some bad traffic. I feel like this tank is going to be a wash. My normal commute usually has no traffic and very little lights. Next week might be the first "true" test of my typical, boring, work to home to work, commute.

[aerohead]

Originally Posted by spacemanspif

Thanks gents. I spent the weekend running around the suburbs where my eco usually takes a big hit because I don't drive as carefully as I should while running around with the family and fiancé, not to mention all the red lights I have to contend with. But this tank still looks to be on par with my previous tank and my all time best tank so I'm hopeful for the numbers I get tonight/tomorrow morning. Then we'll continue the test for a few more weeks before building a good, permanent, grill block. Stay tuned kids.

Aero: Funny how you and I thought of the same car. After I made that post I thought "did I explain it well? Should I have referenced the Daytona??" lol

Here's the 'street' version

[spacemanspif]

Little update: If you take a look at my fuel log you'll see that I ran my best tank ever at 47.5mpg! I'm not sure what this is due to however because my previous tank was a lack-luster 41.8 but that was with a pretty bad traffic jam. Also, this tank saw about half the miles at 65mph not my typical pace of 60. Not sure if the extra 200rpm is more in the engine's economy "sweet spot" but it sure seems to not hurt the mpg. Testing continues and we'll see if I can net a increased trend over previous tanks. Any look at my graph shows that I'm pretty inconsistent so as long as I don't see any general decrease in mpg I think the dam and block are going to stay. In the future I'll extend the dam outward to double as wheel spats and just to block more air from going under the car.

[freebeard]

aerohead -- Is that Morse Code in the wake?

[aerohead]

Originally Posted by freebeard

aerohead -- Is that Morse Code in the wake?

Those are embryonic Dollars about to vanish into thin air.
Actually,the hash marks are a convention Koenig-Fachsenfeld used in his book to denote the region compromised by too rapid a pressure rise.You could read it as detached flow,reversed flow,eddies,turbulence,or attached vortices which would not 'show,' looking at the centerline.
Kind of a cheap and dirty way to 'think' about aft-body flow.