Over fenders/aero widebody

[JulianEdgar]

Originally Posted by freebeard

That is the most awesome article: "Also, the massive wheel arches stiffen the car’s suspension and lower and widen it, increasing the centre of gravity."

That's one to remember!

[freebeard]

I noticed but forget to quote that part. Thanks.

[19bonestock88]

I appreciate the input! The main aero benefit I can see coming from the rear panels would be to extend them rearward to break up the large radius of the back of the car for smoother detachment, and the tiny benefit from having wheel skirts in the first place. The front panels would be harder to justify, the only real utilization being that the leading edge could be extended forward to form the inlet of a full height wheel air curtain and possibly some partial skirting of the wheelwell, near the top of the tire

[M_a_t_t]

Have you heard of separation edges ( https://ecomodder.com/forum/fuel-eco...cations.php#49 ) and wheel arch gap fillers (https://ecomodder.com/forum/fuel-eco...cations.php#39 )?

This appears to be what you are describing.

[19bonestock88]

I have separation edges on my bumper but they aren’t full height and aren’t as well designed as I’d like. I could make a gap filler for the front wheelwell (though I could make them more aggressive for the over fenders

[JulianEdgar]

Originally Posted by 19bonestock88

I have separation edges on my bumper but they aren’t full height and aren’t as well designed as I’d like. I could make a gap filler for the front wheelwell (though I could make them more aggressive for the over fenders

Those standard upper separation edges look fine to me! If you haven't already, under the car is where you could achieve much greater gains than with the mods you are describing.

[19bonestock88]

I added the rear lip from a Saab 9-3 to take advantage of its factory underfloor on the passenger side but I really need to work on my underbody. I used to have a front belly pan and mid pans but they were lost one winter and I haven’t replaced them yet. I had planned to do a splitter/diffuser setup when I’m done working on suspension/powertrain mods, but I might push that forward

[JulianEdgar]

Originally Posted by 19bonestock88

I added the rear lip from a Saab 9-3 to take advantage of its factory underfloor on the passenger side but I really need to work on my underbody. I used to have a front belly pan and mid pans but they were lost one winter and I haven’t replaced them yet. I had planned to do a splitter/diffuser setup when I’m done working on suspension/powertrain mods, but I might push that forward

Plenty you can do under there... and never use a splitter with a diffuser! (You want air to go under the car, not stop it.)

[19bonestock88]

I didn’t plan for much other than a ledge protruding out from the bottom of the bumper (an inch or two) to aid in separating the flow that goes over the top of the car, from the air going under it. I used to have a fairly deep air dam but when I switched to the Ion Redline nose I didn’t carry it over. The only other goal for the car (other than low drag and exceptional mileage) is for it to be fairly quick. I drive it really hard from time to time and high speed stability and engine cooling is very important. If I can reduce lift while I’m reducing drag I’m all for it

[JulianEdgar]

Originally Posted by 19bonestock88

I didn’t plan for much other than a ledge protruding out from the bottom of the bumper (an inch or two) to aid in separating the flow that goes over the top of the car, from the air going under it.

You want as much air flowing under the smooth underside of the car as possible, and a splitter moves the 'separation line' downwards, ie more air then goes over the top of the car.

I used to have a fairly deep air dam but when I switched to the Ion Redline nose I didn’t carry it over.

Again, you want lots of air under the car. Stopping airflow going under the car is about 30 years out of date!

The only other goal for the car (other than low drag and exceptional mileage) is for it to be fairly quick. I drive it really hard from time to time and high speed stability and engine cooling is very important. If I can reduce lift while I’m reducing drag I’m all for it

My road-car Gen 1 Honda Insight develops measured downforce, and that is effective from about 100 km/h (60 mph) upwards. The car does a GPS-measured 200 km/h (124 mph) - and that's on a shortish straight, not max speed. Almost all of the downforce is achieved by working under the car ie undertrays and diffuser.

High-speed stability is best achieved by moving the lateral centre of pressure rearwards, ie rear fins or a rear wing with large endplates.

My Insight: