Chin spoiler and tire spats

[aerohead]

Originally Posted by Cd

Yup ! It took me by complete surprise,
Not only does the car have the barn door flat front end, but it has the original misaligned moulding around the windshield, stock unshaved door handles, huge gaps everywhere ( look at the wheel wells ! ), no belly or skirts, etc !
It blew my mind, but it was tested in a wind tunnel by a guy that did the aerodynamics on the EV-1

( How ironic that the car has almost exactly the same Cd as the .19 of the EV-1 )

In the HOT ROD article on this car,they said that the nose is completely sealed,as is done with The Cd 0.20 'Blow fish'.That's a 12% drag reduction right there.I think it has an aluminum bellypan as well.
The rear spoiler may help capture a locked-vortex which would lower induced drag do to the separation over the backlight.
Lowering would increase the fineness ratio,always good for drag.

[66sprint6]

Got my chin spoiler finished yesterday. Not entirely happy with it, but with some tweakin itll do for now. If its worth keepin I will do another and try to keep it a bit cleaner. I dont like how the ends by the tires are sitting so I might fab a small straight bracket to flatten them out. I kinda dig the look tho!!!





I also slapped together a small windshield wiper spoiler out of garage door insulator strip.





One thing I noticed drivin it around after the mods is road noise...or lack of it actually. I thought it was the old crappy tires makin all the noise but after these small mods I can actually hear a VERY noticeable drop in noise. I also swear I can coast further to lights and turns than before, Ive had to start re-learning my coast points on my way to work lol. What do you guys think, any feedback would be appreciated!!!
Matt

[California98Civic]

Originally Posted by 66sprint6

What do you guys think, any feedback would be appreciated!!!

I think I like the pics. I always thank the pics. In this case that flare in the lawn-edging is a little like mine. I do not know what if any effect it has. I also saw a decline in road noise, which I understand is a good sign for the operation of the mod. As to the tires poking out a bit beyond the air-dam. I deliberately chose that design to mimic what I found from the tire-spats tests in an article previously posted in this thread: the testers found that spats that did not cover all of the tire produced less lift and increased the effective frontal area of the car less (because they were shooting air less distance off the side of the car). I do not know if what holds for those spats holds for an air-dam. I just made a judgement. I did not test my air-dam (too busy), so I cannot back-up the claim empirically. It's just my experience. The air-dam was associated with new highs in mpg, but it was not an isolated mod (I did others simultaneously). I hope that helps. Others will offer maybe more authoritative opinions...

But I say... nice work!

james

[66sprint6]

I have enough material left over that I might try to take a stab at some spats...but I almost feel like they wont be necessary with the front spoiler. I would like to make some for the rear tho. I too feel like less noise means at least SOMETHING is goin on lol, only time and a couple fillups will tell. Goin into winter I usually see a drop in MPG with my truck, Im hopin maybe with the new mods I will see this drop become less significant. Grill block and a couple other small mods are next.
Matt

[California98Civic]

Rear spats should help too, if you find the right placement for your car. Also those side skirts along the runners under the doors (name?)... those apparently can help keep air from the sides slipping under the car and getting tangled into the rear axel and muffler and bumper and such. Someone on here, I think, made them out of lawn edging, starting fro the front wheel well, to the inside of the tires running out along the edg of the frame, stopping at the rear wheel-wells even with the outside of the rear tires. The curve in the lawn-edging gave the assembly sufficient stiffness to resist wind, I'm sure. It's a design I plan to imitate after I lower my car. But first, I have to get it running normally again. Today I pick up new parts from Autozone. Wish me luck...

[66sprint6]

Best of luck...seems to be the ropes with these older cars lol, cant mod it if the danged thing aint runnin right in the first place!!! Mines got 194K and runs like its brand spankin new so Im very very pleased. I thought about doin the side skirts but havnt liked the looks very much. I wanna lower the car for sure, so I might consider it after that (like you said) but I dunno. I eyeballed the idea when I was doin the spoiler but never mocked it up. Im thinkin a partial undertray might be nice too...when I was under the car I noticed that the entire exhaust runs down the "driveshaft tunnel" up the middle so I might be able to smooth everythingthing up the middle of the car pretty easily as well. For now tho Im gonna move on to grill blocks and see where that gets me!
Matt

[aerohead]

Originally Posted by California98Civic

Ummm... this really needs expert explanation. If that Camaro can accomplish nearly the same Cd as the EV-1 looking like that, and a better number than a 2001 Insight, then... what the hell!

Here are some comparisons:









*GM has downgraded the EV-1 to Cd 0.21,from 0.197.
*The GM Chevy Citation IV might be Cd 0.191 vs 0.18.
*The GM AERO-X might be Cd 0.266 vs 0.25
*The GM Sunraycer is now Cd 0.143 vs 0.089-0.125.
*The Cd 0.19 Ultralite might also now be 0.21.
*The GM Precept may have gone from Cd 0.163,to 0.173
*The GM LSR EV-1,reported by Goro Tamai at Cd 0.14 may be Cd 0.149
*I didn't have the 1980 Z-28 but the Firebird is similar.
*Honda's 1st-gen Insight at Cd 0.25 is reported at Cd 0.30 at A2.
*The Prius III while Cd 0.25 at Toyota,is 0.26 at A2,0.285 at Darko,and 0.32 at GM,Ford,and Chrysler.
*GM and A2 both show Cd 0.28 for the VOLT.
*While GM and A2 are in agreement on VOLT,there is a discrepancy with Prius III.(23%1)
*Wolf Heinrich Hucho says adapted-wall wind tunnels (A2/Darko)can have blockage ratios up to 30% without problems.
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*The HRM Camaro is severely raked,which would affect all angle-of-attack-related flow attachment phenomena for both the forebody,but also the roofline,forcing attachment where it might otherwise separate.
*Lowering would affect it's effective fineness ratio to the good.
*It would also affect frontal area,making the lower air dam less of an aggravation.
*We now know from the "Spirit of Ecomodder.com" what the mirror delete can mean,something EV-1 and Insight would be stuck with.
*And the 100% grille block approaches the EV-1 and exceeds Insight.
*The Camaro's rear Bonneville spoiler also extends the car,bettering the effective fineness ratio.
*The 'zero' clearance air dam is at least 1% lower drag than even with the belly.
*The MOONs were good up to -0.004.
*All the features on the Precept only cost 0.007.
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*Cd 0.201 might only be applicable to the A2 tunnel.But since all the measurements were taken there the number have merit.(And only in this context).
*The bob-tailed Mercedes-Benz C-111 III with open cooling system see's Cd 0.237.With 100% grille-block she might be 0.201.Who knows?