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

[dogbone]

Originally Posted by M3 Number 86

yeah so im wondering at lowest setting, if i get the larger one, do i need some serious front aero? because i can 't be plowing snow (driveways) as an option lol

You know my opinions on this topic, but I'll say it again. If you go with the large wing, but you do not have front aero, there will be understeer in high speed rounders---and the understeer will get worse the faster you go. If you dial the wing's angle back to reduce the understeer, then you will be dissatisfied with the wing's performance. There is no way around this. If you pay lots of attention to the rear, and ignore the front, you will not like the car's feeling in high speed rounders above 80mph---Turn 2 and 8 at Big Willow and Riverside at Buttonwillow will feel shitty. The steering wheel will be a useless decoration and you will curse the wing as your car's nose wanders towards the outside edge of the track. I am telling you this from firsthand experience. From June to Oct 2015, I drove with only a big rear wing and no front downforce. I was not setting any new fast lap times. Then, I put the front aero on and my times plummeted instantly by 2-3 seconds at every track I visited. And they've continued to drop further as I've learned to control the car even more. I have been posting my times in the Lap Times thread since 2012. You can see the history of my times dropping.

But as I've also mentioned before----you just can't drive a real splitter on the street---at least not one that is appropriate for balancing out the rear wing.

There is no free lunch in Motorsport! Well, except for when I bought everyone lunch who visited me at Super Lap Battle last week. In that case, yes, there was a free lunch in Motorsport, but it was actually lunch and had nothing to do with car setup.

[M3 Number 86]

Originally Posted by dogbone

You know my opinions on this topic, but I'll say it again. If you go with the large wing, but you do not have front aero, there will be understeer in high speed rounders---and the understeer will get worse the faster you go. If you dial the wing's angle back to reduce the understeer, then you will be dissatisfied with the wing's performance. There is no way around this. If you pay lots of attention to the rear, and ignore the front, you will not like the car's feeling in high speed rounders above 80mph---Turn 2 and 8 at Big Willow and Riverside at Buttonwillow will feel shitty. The steering wheel will be a useless decoration and you will curse the wing as your car's nose wanders towards the outside edge of the track. I am telling you this from firsthand experience. From June to Oct 2015, I drove with only a big rear wing and no front downforce. I was not setting any new fast lap times. Then, I put the front aero on and my times plummeted instantly by 2-3 seconds at every track I visited. And they've continued to drop further as I've learned to control the car even more. I have been posting my times in the Lap Times thread since 2012. You can see the history of my times dropping.

But as I've also mentioned before----you just can't drive a real splitter on the street---at least not one that is appropriate for balancing out the rear wing.

There is no free lunch in Motorsport! Well, except for when I bought everyone lunch who visited me at Super Lap Battle last week. In that case, yes, there was a free lunch in Motorsport, but it was actually lunch and had nothing to do with car setup.

Thanks.

I'm guessing go with the smaller one.

Did you continuously add more up front until you got to your set up now? E.g. Started with splitter then made it bigger then added canards, etc until you were satisfied? Just trying to get a reference of what's a better balanced solution. Or I should just call apr lol

[dogbone]

Originally Posted by M3 Number 86

Thanks.

I'm guessing go with the smaller one.

Did you continuously add more up front until you got to your set up now? E.g. Started with splitter then made it bigger then added canards, etc until you were satisfied? Just trying to get a reference of what's a better balanced solution. Or I should just call apr lol

WARNING: I sound like an advertisement, but I'm just giving you my opinion......I'm not beholden to any single shop. I've been very clear that I work with Racewerkz for fabrication and race-specific stuff, minicorsa for all daily non-fabrication tech work and maintenance, and EAS for dynos, supercharger maintenance and aftermarket parts (and rod bearings, spark plugs, drive belts...anything that touches the supercharger). Those 3 shops have demonstrated a consistent ability to provide quality workmanship, reasonable pricing and I feel welcome to hang out at any of the shops and shoot the breeze.

For this, I really suggest calling a shop like Racewerkz. Casey, the owner, was out there at Super Lap Battle last week drawing and cutting a new front splitter right there at the track for the M4 race car he built for Jeff Bader. I watched him do it. And then he was going out on track and driving the splitter to feel it out. I mean, c'mon, that is some serious hands-on/real-world experience, and that's what you NEED when you're looking for opinions on aero. He lives and breathes this stuff every day. Other places may suggest things based on convention. Casey is out designing the stuff on-the-fly at the track and driving the results in competition a few minutes later---and hitting the podium. His work on that M4 and his driving put me into a distant 4th place. I was 2.3 seconds off his pace.

Look, all I'm saying is that you've been coming onto this forum for months, posting in multiple threads asking some very specific advice on a very technical topic from a bunch of hobbyists. Can any hobbyist here REALLY answer your question with the kind of depth of knowledge that you're seeking? I don't think so. And I doubt any experienced race shop is gonna blab the info for everyone to see on a forum. They want to protect their proprietary experience and knowledge. It's what keeps them in business.

So, again, I say call someone like Racewerkz. It doesn't have to be them. But you're a SoCal guy so it's not a stretch. If you know some shop that you respect more, then call them.


My front aero was initially decided by Racewerkz to be 5" from the tip of the OEM bumper. This would allow me into Limited Class in most time attack, and it would have a decent chance of surviving if going off-track. Then later, I added canards, but canards are very minor. The splitter is doing the heavy work. I could probably benefit from extending my front aero. But you run the risk of tearing the splitter, lip and bumper (plus who knows what else) if you go off-track. For me, my motorsport equation has to balance the desire for speed with the requirement that it be somewhat practical and that it doesn't just rip off the car the first time I go off into the desert.

[M3 Number 86]

Originally Posted by dogbone

WARNING: I sound like an advertisement, but I'm just giving you my opinion......I'm not beholden to any single shop. I've been very clear that I work with Racewerkz for fabrication and race-specific stuff, minicorsa for all daily non-fabrication tech work and maintenance, and EAS for dynos, supercharger maintenance and aftermarket parts (and rod bearings, spark plugs, drive belts...anything that touches the supercharger). Those 3 shops have demonstrated a consistent ability to provide quality workmanship, reasonable pricing and I feel welcome to hang out at any of the shops and shoot the breeze.

For this, I really suggest calling a shop like Racewerkz. Casey, the owner, was out there at Super Lap Battle last week drawing and cutting a new front splitter right there at the track for the M4 race car he built for Jeff Bader. I watched him do it. And then he was going out on track and driving the splitter to feel it out. I mean, c'mon, that is some serious hands-on/real-world experience, and that's what you NEED when you're looking for opinions on aero. He lives and breathes this stuff every day. Other places may suggest things based on convention. Casey is out designing the stuff on-the-fly at the track and driving the results in competition a few minutes later---and hitting the podium. His work on that M4 and his driving put me into a distant 4th place. I was 2.3 seconds off his pace.

Look, all I'm saying is that you've been coming onto this forum for months, posting in multiple threads asking some very specific advice on a very technical topic from a bunch of hobbyists. Can any hobbyist here REALLY answer your question with the kind of depth of knowledge that you're seeking? I don't think so. And I doubt any experienced race shop is gonna blab the info for everyone to see on a forum. They want to protect their proprietary experience and knowledge. It's what keeps them in business.

So, again, I say call someone like Racewerkz. It doesn't have to be them. But you're a SoCal guy so it's not a stretch. If you know some shop that you respect more, then call them.


My front aero was initially decided by Racewerkz to be 5" from the tip of the OEM bumper. This would allow me into Limited Class in most time attack, and it would have a decent chance of surviving if going off-track. Then later, I added canards, but canards are very minor. The splitter is doing the heavy work. I could probably benefit from extending my front aero. But you run the risk of tearing the splitter, lip and bumper (plus who knows what else) if you go off-track. For me, my motorsport equation has to balance the desire for speed with the requirement that it be somewhat practical and that it doesn't just rip off the car the first time I go off into the desert.

Yeah I understand and totally get that. I know Casey from a few years ago I actually lent him my spare wheels at the track since he wrecked his at Buttonwillow and I got a free corner balance out of it!

I like to get as much feedback as possible and especially here at the hobbyist level. Like I said I'm not trying to build an all out machine like most people but something just a tad more. I look at socal and the aero and tire game are massive but then I look at the Europeans and they're still fast with less so that always has me thinking.

I'm ready to pull the trigger and I'm somewhat a OCD paranoid impatient person haha.

The shop I go to has recommended a setup but just wanted to feel things out everywhere I can. Never a bad thing to use as many resources as possible.

Thanks for the response it's appreciated for sure. @redpriest Ferrari is ready for Petronas come Buttonwillow e9x F1 Grand Prix in December is what I'm preparing for (a fun joking competitions amongst some of us).

[macdude357]

Has anyone tried a gurney flap or wickerbill on their spoiler? The Ford GT500 has one. I also found a YouTube video where a guy did some flow modeling comparing no spoiler, with spoiler and spoiler with gurney flap and found that the latter did reduce lift over just a spoiler alone.

[roastbeef]

Originally Posted by macdude357

Has anyone tried a gurney flap or wickerbill on their spoiler? The Ford GT500 has one. I also found a YouTube video where a guy did some flow modeling comparing no spoiler, with spoiler and spoiler with gurney flap and found that the latter did reduce lift over just a spoiler alone.

Interesting you would mention it. I was taking to AriuSen about this aeromotions adaptive wing at Laguna Seca last week. While admiring it, I noticed it had a gurney flap which they don't use. He told me he bought it from APR and affixed it to the wing and it made significantly more downforce than without it.

[AriuSen]

Originally Posted by roastbeef

Interesting you would mention it. I was taking to AriuSen about this aeromotions adaptive wing at Laguna Seca last week. While admiring it, I noticed it had a gurney flap which they don't use. He told me he bought it from APR and affixed it to the wing and it made significantly more downforce than without it.

Ohhh you are roast beef hahaha. Nice to meet you twice!

[AriuSen]

Originally Posted by roastbeef

Interesting you would mention it. I was taking to AriuSen about this aeromotions adaptive wing at Laguna Seca last week. While admiring it, I noticed it had a gurney flap which they don't use. He told me he bought it from APR and affixed it to the wing and it made significantly more downforce than without it.

Originally Posted by macdude357

Has anyone tried a gurney flap or wickerbill on their spoiler? The Ford GT500 has one. I also found a YouTube video where a guy did some flow modeling comparing no spoiler, with spoiler and spoiler with gurney flap and found that the latter did reduce lift over just a spoiler alone.

Yes. The gourney flap is like an "extension" of the wing. It makes significant downforce and also reduces drag since it avoids mixing the air coming from the bottom of your car. I can feel night and day if I have the gourney flap.
Talked to a pro driver once and he said gourney flap increases your downforce by 30% depending on the size.

Here is a video of my wing with the gourney flap.

[M3 Number 86]

Originally Posted by roastbeef

Interesting you would mention it. I was taking to AriuSen about this aeromotions adaptive wing at Laguna Seca last week. While admiring it, I noticed it had a gurney flap which they don't use. He told me he bought it from APR and affixed it to the wing and it made significantly more downforce than without it.

Originally Posted by macdude357

Has anyone tried a gurney flap or wickerbill on their spoiler? The Ford GT500 has one. I also found a YouTube video where a guy did some flow modeling comparing no spoiler, with spoiler and spoiler with gurney flap and found that the latter did reduce lift over just a spoiler alone.

Grays garage is cool but here's a 5 minute video vs a 30 min video. I do like the grays garag Le channel using the little bubbles on model cars. Check out Kyle engineering. I've watched all his videos and for sure I am YouTube certified in aerodynamics now.

Gurney flaps create swirling flows on either side of it (vortexes) which in effect pushes back where the airflow from above and below the foil meet again (the extension ariusen is talking about). Equals moar downforth.

[roastbeef]

i wonder what would happen if you were to put a gurney flap towards the back of the roofline where it meets the window.

[jid2]

Originally Posted by roastbeef

i wonder what would happen if you were to put a gurney flap towards the back of the roofline where it meets the window.

The roof isn't the trailing edge of a wing, not the same effect. Roof lines use small fins for vortex generators like on the EVO MR.

[macdude357]

Originally Posted by roastbeef

i wonder what would happen if you were to put a gurney flap towards the back of the roofline where it meets the window.

He actually has another video showing how bad roof spoilers are. They disrupt the airflow and cancel any benefits of the trunk spoiler. I would imagine a gurney flap on the roof would have much the same result.

[roastbeef]

Originally Posted by jid2

The roof isn't the trailing edge of a wing, not the same effect. Roof lines use small fins for vortex generators like on the EVO MR.

there is some infomercial company selling stick-on vortex generators under the guise of improving mpg.... they were sort of marketed towards prius drivers though.
sure, they could be functional, but placement is key. what suck about aerodynamics is- aerodynamics doesn't look like what we think it looks like.

[M3 Number 86]

Testing on Friday.

[roastbeef]

Originally Posted by M3 Number 86

Testing on Friday.

apr mounted?

[M3 Number 86]

Originally Posted by roastbeef

apr mounted?

Front aero. Lol

[macdude357]

So I got a new left side under tray corner piece to replace my broken one for the umpteenth time and ripped out one of the screw hole just putting it it. I'm so done with this stupid felt crap. Does anyone make a splitter that replaces the whole under tray that is not insanely expensive? I've seen the APR splitter mentioned but when I go on their website, the splitter doesn't seem like it would extend back to the front axle.

[roastbeef]

Originally Posted by macdude357

So I got a new left side under tray corner piece to replace my broken one for the umpteenth time and ripped out one of the screw hole just putting it it. I'm so done with this stupid felt crap. Does anyone make a splitter that replaces the whole under tray that is not insanely expensive? I've seen the APR splitter mentioned but when I go on their website, the splitter doesn't seem like it would extend back to the front axle.

hey tim,
apr does make a splitter that replaces the entire front end, but i think it is one of those parts that you have to call and ask for... and it isn't going to be cheap.
i used to have the shorter splitter they have online and it doesn't even extend back to the side felt pieces.
turner makes an aluminum piece, i'm sure you've seen it.

what i recently did, was buy all three undertray pieces from FCP Euro. they were slightly more than ecs tuning, but with free shipping, they were only about $30 more or something like that. ecs tuning wanted $50 for shipping. i was willing to pay a little more because of FCP's lifetime warranty. so all i have to do it send them back the jacked up felt pieces if i go off at the track and they replace, no questions asked.

[M3 Number 86]

Originally Posted by macdude357

So I got a new left side under tray corner piece to replace my broken one for the umpteenth time and ripped out one of the screw hole just putting it it. I'm so done with this stupid felt crap. Does anyone make a splitter that replaces the whole under tray that is not insanely expensive? I've seen the APR splitter mentioned but when I go on their website, the splitter doesn't seem like it would extend back to the front axle.

Drill and ziptie. I was looking at the inside of mine and it looks like fiberglass layup. I might add a couple layers on top to make it more sturdy.

[inTgr8r]

Originally Posted by roastbeef

hey tim,
.....
what i recently did, was buy all three undertray pieces from FCP Euro. they were slightly more than ecs tuning, but with free shipping, they were only about $30 more or something like that. ecs tuning wanted $50 for shipping. i was willing to pay a little more because of FCP's lifetime warranty. so all i have to do it send them back the jacked up felt pieces if i go off at the track and they replace, no questions asked.

Isn't the warranty for part failure?
I'm not sure they would replace damaged parts.

[M3 Number 86]

Originally Posted by inTgr8r

Isn't the warranty for part failure?
I'm not sure they would replace damaged parts.

you can even exchange old oil with them. just pay for shipping lol

[roastbeef]

Originally Posted by inTgr8r

Isn't the warranty for part failure?
I'm not sure they would replace damaged parts.

I suppose it depends on how you articulate it.