aero tech- wings, lips, diffusers, canards, etc.

[roastbeef]

so i recently picked up a flat apr lip and i'm going to be affixing it to my car. its a shorter lip, so not crazy. originally i was going to run it with my oem performance carbon decklid spoiler. i'm confident the decklid spoiler helps some- its not huge, but i'm confident it helps a tiny bit.

so the other day, i found a deal on a rear wing and jumped on it. i know little about wings- just little snippets i get to read on here. from what i understand, a longer wing width can be set at less of an attack angle and create more downforce and less drag than a shorter width wing at a high attack angle with more drag. is that accurate?
what effect do the size of the winglets have on the end of the wing?

whats a good way of determining how to tune your rear wing?

has anyone that tracks their car noticed anything significant with a diffuser?

[okusa]

As with all aero, how much is strictly a trial and error process.

That is accurate as to width but if you are adding a wing of any kind without a longer front splitter you will induce understeer. My splitter currently sits at about 7" (well in excess of what time attack rules allow) and I'm still getting understeer with 295 TDs up front. I will next dial out some rear wing and see how that helps.

The "winglets" (side plates) which are actually add quite a bit to the overall effect of the wing, though the technical explanation is way too much for me to comprehend. Again, part of the trial and error process.

Adding a real (vs the typical bling type) diffuser will only compound the understeer issue.

[Richbot]

Splitters need to be on the pavement to be truly effective. The pitch and angle don't matter near as much as focusing on whatever shape you can run that keeps air out from under the car. The front shape of most cars is a natural downforce generator if you can keep air out from under it. Production based racecars that have permissive splitter rules which allow them to run within an inch or so of the pavement fight the opposite problem if they are not allowed a wing - splitter induced ovah. Just a word of caution that a conservative splitter that still allows you to drive the car in the real world isn't doing a whole lot on track

I wish it was easy to test what effect louvering the front fenders on these cars would have. Very easy to execute with plastic fenders. It's so easy to add downforce to the rear and there aren't a lot of low hanging fruit for the front

canards are worth it (once again, one of the few things you can do at the front short of adding a gigantic wing on 5' tall pylons) but They do have a drag trade off though

Another thing that might be worthwhile and relatively possible without ruining the car is ducting the radiator up and out the hood. You would have to build an assymetric duct or ditch the upper rad support and would have to cant the rad forward, but it could be done. Custom hood obv. But right now half the front rad opening gets ducted through the oil cooler and straight out the bottom, lots of air there

[roastbeef]

This is the wing I picked up. Not sure of the brand or the width, but it doesn't appear to be as wide as the big daddy apr wing.

The last pic is the wing on the previous owners car. He has the same front splitter I happened to pickup.

[roastbeef]

Originally Posted by Richbot

Splitters need to be on the pavement to be truly effective. The pitch and angle don't matter near as much as focusing on whatever shape you can run that keeps air out from under the car. The front shape of most cars is a natural downforce generator if you can keep air out from under it. Production based racecars that have permissive splitter rules which allow them to run within an inch or so of the pavement fight the opposite problem if they are not allowed a wing - splitter induced ovah. Just a word of caution that a conservative splitter that still allows you to drive the car in the real world isn't doing a whole lot on track

I wish it was easy to test what effect louvering the front fenders on these cars would have. Very easy to execute with plastic fenders. It's so easy to add downforce to the rear and there aren't a lot of low hanging fruit for the front

canards are worth it (once again, one of the few things you can do at the front short of adding a gigantic wing on 5' tall pylons) but They do have a drag trade off though

Another thing that might be worthwhile and relatively possible without ruining the car is ducting the radiator up and out the hood. You would have to build an assymetric duct or ditch the upper rad support and would have to cant the rad forward, but it could be done. Custom hood obv. But right now half the front rad opening gets ducted through the oil cooler and straight out the bottom, lots of air there

makes sense. i'm just an occasional weekend warrior that likes to tinker with my car, so i'm not going to move the radiator for a hood vent just yet.

i don't have any plans to run spats or canards just yet... just thought i'd ask.

i'm happy with my turn-in at the moment. i think i'm at -3* camber up front and running square 275 nt01's. oem suspension. i just don't want this wing to ruin that.

[M3 Number 86]

Just picked up a splitter too (replaces undertray as well). I'm gonna pick up a high kick spoiler first to see how it feels since I don't want a huge wing on my car yet.

Reading from above, I should ok since its doesn't stick out a lot nor is mounted under a lip to be as close to the ground as possible.

[macdude357]

Originally Posted by M3 Number 86

Just picked up a splitter too (replaces undertray as well). I'm gonna pick up a high kick spoiler first to see how it feels since I don't want a huge wing on my car yet.

Reading from above, I should ok since its doesn't stick out a lot nor is mounted under a lip to be as close to the ground as possible.

I'm in the same boat. I don't want a big wing. I'm considering this one.

What front lip do you have? If someone made a functional rear diffuser for the E90 that would be ideal to combine with a high kick spoiler but I haven't found one yet.

[roastbeef]

well, the splitter that i posted pics of is in the mail. i also came across a deal on a gts style wing and jumped on it. so now i have two wings.

i'm going to get a spare trunk. what i may do, is keep both wings, and get painted bumper plugs for the drilled holes. that way i can experiment with both wings and swap wings for different tracks if it works out that way... not sure what i'm going to do yet.

i have a feeling i'm going to like the less aggressive gts wing. i wouldn't like understeer.

[M3 Number 86]

Originally Posted by macdude357

I'm in the same boat. I don't want a big wing. I'm considering this one.

What front lip do you have? If someone made a functional rear diffuser for the E90 that would be ideal to combine with a high kick spoiler but I haven't found one yet.

That spoiler looks pretty good and is used on their own cars too!

Was also looking at the high kick versions that you can get on the coupe but is only available for sedans in aftermarket.

I have an apr splitter.

[macdude357]

Originally Posted by M3 Number 86

That spoiler looks pretty good and is used on their own cars too!

Yeah, that's what I was thinking. It has to be at least somewhat effective if they used it on their own race cars. I really wanted to find a version of the spoiler that they used on the GTS cars last year but it looks like Bimmerworld only makes it for the E92.

[M3 Number 86]

Originally Posted by macdude357

Yeah, that's what I was thinking. It has to be at least somewhat effective if they used it on their own race cars. I really wanted to find a version of the spoiler that they used on the GTS cars last year but it looks like Bimmerworld only makes it for the E92.

I found a pretty cool article on aero (I'll post the link in a bit) where it showed spoiler vs wing air flow and that's when I decided a high kick version was good enough.

NASCAR run spoilers so was thinking good enough.

[SYT_Shadow]

If I were doing aero I'd probably just ask BW to build a balanced package for me. First I have to learn how to drive so it's still far away

I would looooooooove to have an M Power rear wing

[M3 Number 86]

http://oppositelock.kinja.com/wings-...ong-1665312667

[GabeS]

I think some front canards could compliment that E92 posted very well!

[will.c]

Aero tuning is just like dampers (or anything else) - start small and keep adding small increments until it feels good.

Front & rear DF has to be balanced. Front aero parts are typically not as adjustable as a rear wing, so I'd start with 0 angle of attack (AoA) on the rear wing, and see how the car behaves at med-high speed cornering. If you get oversteer, you need more rear DF so then I'd add 0.5 or 1 deg of AoA and repeat. Add 0.5 to 1 deg AoA each session until a desired high speed over/understeer balance is achieved.

That said, I think it's good to have a tad bit of high speed understeer to increase stability, which translates to predictability, confidence, earlier throttle, lap time, etc.

You'll see a significant increase in braking performance and overall dynamic stability.

Also, I'd block off or seal the gap between splitter/lip & front bumper to increase its effectiveness.

FYI

[cenix]

Originally Posted by M3 Number 86

I found a pretty cool article on aero (I'll post the link in a bit) where it showed spoiler vs wing air flow and that's when I decided a high kick version was good enough.

NASCAR run spoilers so was thinking good enough.

The E90 CRT high kick spoiler looks promising for its purpose. I always thought the Turner Motorsport Grand Am wing on their E92 M3 race car looked decent and functional, too (although for the coupe and not sedan).

[M3 Number 86]

Originally Posted by cenix

The E90 CRT high kick spoiler looks promising for its purpose. I always thought the Turner Motorsport Grand Am wing on their E92 M3 race car looked decent and functional, too (although for the coupe and not sedan).

How much is that crt spoiler ? 2k? Lol

[roastbeef]

I'm sure someone makes a rep.

[roastbeef]

More track paraphernalia showed up at my house...

[Richbot]

Contraband

[roastbeef]

this is the second wing to show up to the house this week. girlfriend took it better than i thought she would (she didn't kill me).

i located a second trunk at a reasonable price and i just need to get it painted, source inner tail lights, and get a badge (so people know its a real m3) and i'm good to start this experiment.

[leo95se]

has any manufacturer justified their spoiler or wing design? we have plenty of understeer on these cars. are these big wings just adding more?