vortex generators.. on the back edge of the spoiler?

Ok, check it out..

one of the competitors at our last autoX event put some of those individual vortex generators ( http://www.ebay.com/itm/Vortex-Generator-Spoiler-Shark-Fins-Set-of-10-Mitsubishi-Lancer-EVO-/290621855684?_trksid=p2054897.l4275 ) on the back edge of the spoiler itself (right up against the gurney flap) on his evo 9. his reasoning: "they look cool"

as far as I was concerned, I can;'t see how they give any aerodynamic advantage there. BUT we had some people complaining and saying that they should put him in ASP (from STU) no matter if they do anything or not, because they are considered aerodynamic devices.

so, anyway.. could there be ANY advantage to putting them there? I can't think of any.

Here is a pic I made up real quick... the yellow things on the spoiler is where he added his "vortex generators"

The closest functional thing I can think of to that would be the fins on a diffuser.

yeah, but WOULD they provide any function whatsoever?

we are talking about teeny tiny sharkfins.. about 1" tall, and 2.5" long on the back edge of the 8-9" deep spoiler.

at what point does some ricecarmod make someone have to jump to a prepared class?

Vortex generators absolutely can't do E36 M3 on the very trailing edge of the car. All he did was increase his car's drag.

They make sense on the leading edge of the back glass (cuts lift & drag), the leading edge of the diffuser (increases downforce, could affect drag either way depending...), or on the flat bottom (same).

^2nd paragraph. In the Evo application, the vortex generators on the rear edge of the roof at there to keep flow attached to the rear window longer so the rear wing gets cleaner air. Blocking the gurney with them is dumb on a number of levels. Point and laugh time.

And to pre-empt anyone who will post pics of the trailing edge bubbles on some LeMans cars, those were to get around the rules requiring a gurney and requiring it to be 90-degrees to the wing surface (goofy bubbles alter the surface so that the gurney in those areas can be leaned back, reducing drag).

They create lift..technically when on a flat plane. like if you put the on the front edge of a spoiler... that spoiler will have less downforce....and o0n the rear, yes, all he did was eliminate the usefullness of the gurney.

he was protested and moved to a new class (ASP) for them by another region... and had a guy say he should be moved in our region too.. because they moved him.

I stopped that, because honestly, I couldn't see them doing anything other than slowing him down.

Top of the wing does less than the bottom as well

SCARR wrote: he was protested and moved to a new class (ASP) for them by another region... and had a guy say he should be moved in our region too.. because they moved him.

Tell the protesters to get a life.

SCARR wrote: at what point does some ricecarmod make someone have to jump to a prepared class?

You mean like a CF hood on an evo8/9 that weighs more than stock and tosses it all the way to Street Modified? Welcome to the scca, the hardcore douchebags that ruin the sport live by the mantra of "If we can't beat you, we'll find some reason to protest you out"

On a local level, I don't think I've ever seen someone protested out here.

This is why I've never gotten seriously into autocross. My cars are always slightly modified in some way, and it inevitably puts me into some stupid class I'm not competitive in. Like, right now, my E46 would be perfect for STX, but because I had to install aftermarket cats (OEM units are like $1200 for a $4000 car, hell no) and the only place they can physically fit is at the rear of the transmission, it's not technically legal. There's a line that says replacement catalytic converters have to be within 6" of the OEM location. But it also says headers can be replaced. So, by design, if you replace headers on an E46 (or similar car), you're not legal for ST classes because you can't physically get the cats to within 6" of the original location.

Most people are not willing to put the amount of time/work in that it takes to get the most out of VG's. A lot of people also look at em as voodoo, but if your goal is clean attached air. They'll do the trick.

Now putting them out on the wing like that is just plain stupid.

unevolved wrote: This is why I've never gotten seriously into autocross. My cars are always slightly modified in some way, and it inevitably puts me into some stupid class I'm not competitive in. Like, right now, my E46 would be perfect for STX, but because I had to install aftermarket cats (OEM units are like $1200 for a $4000 car, hell no) and the only place they can physically fit is at the rear of the transmission, it's not technically legal. There's a line that says replacement catalytic converters have to be within 6" of the OEM location. But it also says headers can be replaced. So, by design, if you replace headers on an E46 (or similar car), you're not legal for ST classes because you can't physically get the cats to within 6" of the original location.

I've heard the story where an aftermarket cat was responsible for the loss of a National Championship because it was 1" out of spec.

I've always been stuck in SM because I usually have a mild cam or headwork done. "Internal Engine Modifications" automatically put you in SM.

I'm just in it for fun anyway. But you never know, I won the regional SM championship in my as the total underdog. I even did the National Tour this year and was only beat by a National Champion in an S54 swapped e36 and a GTR. Not bad for a 150HP SOHC 240sx. Sometimes it's good for the ego

I'm no aerodynamicist, But I can't see those vortex generators helping anything (where they are) and they could quite possibly be detrimental.

How often do AX courses have speeds high enough for Aero aids to really be effective?

The SCCA would have a fit if I ever brought my 900 to a national event. Its like Johnny Cash's Cadillac, except with SAAB c900, ng900, 9-3 and 9000 parts.

unevolved wrote: This is why I've never gotten seriously into autocross. My cars are always slightly modified in some way, and it inevitably puts me into some stupid class I'm not competitive in. Like, right now, my E46 would be perfect for STX, but because I had to install aftermarket cats (OEM units are like $1200 for a $4000 car, hell no) and the only place they can physically fit is at the rear of the transmission, it's not technically legal. There's a line that says replacement catalytic converters have to be within 6" of the OEM location. But it also says headers can be replaced. So, by design, if you replace headers on an E46 (or similar car), you're not legal for ST classes because you can't physically get the cats to within 6" of the original location.

Check section 14.10.H

It states multiple cats can be replaced by a single unit as long as it is within 6" of the most down stream OE location.

lol they look cool, to no one but him.

yamaha wrote: Welcome to the scca AUTOCROSS......"

Correction. I've seen a ton of (SCCA) rallycross cars with things that aren't technically legal in their class. And nobody seems to care at all as long as they aren't making the cars obviously faster. In three seasons running with 3 different regions, I can't recall ever hearing about a protest.

If rallycross had autocrossers as classing scrutineers, I'm pretty sure everyone would have to run in Modified

Just for clarification: A spoiler has air passing over only one side of it. A wing has air passing over both sides of it. That is a wing.

And especially at the local level, there is absolutely no reason to bump him from the class even if they are technically a prohibited modification. Thankfully it sounds like your logic prevailed, on that day at least.

Ugh. Here come the anti-SCCA Autox whiners. Its one incident. Yes, those protesting him probably have a stick up their butt and should find better things to do with their time.

Would he be protested at 99% of local regions? No. Because most people realize that what he has done has little to no effect.
Would he be protested at 99% of national/divisional events? No. Because he likely wouldn't be winning anything, and nobody feels like protesting the guy in 32nd place in class. Also see above.

I've run events in cars with illegal mods plenty of times. Competitors were well aware, but did not care as the mods gave me no advantage (lightweight flywheel on a 2.5rs, aftermarket steering wheel on a STR Miata [the horror!], etc.)

Lancer007 wrote:

unevolved wrote: This is why I've never gotten seriously into autocross. My cars are always slightly modified in some way, and it inevitably puts me into some stupid class I'm not competitive in. Like, right now, my E46 would be perfect for STX, but because I had to install aftermarket cats (OEM units are like $1200 for a $4000 car, hell no) and the only place they can physically fit is at the rear of the transmission, it's not technically legal. There's a line that says replacement catalytic converters have to be within 6" of the OEM location. But it also says headers can be replaced. So, by design, if you replace headers on an E46 (or similar car), you're not legal for ST classes because you can't physically get the cats to within 6" of the original location.

Check section 14.10.H It states multiple cats can be replaced by a single unit as long as it is within 6" of the most down stream OE location.

Yeah, that's the rule I'm talking about. OE location is right up against the block, which is impossible to replicate in an aftermarket setup.

Anyone have any insight into WHY this rule exists? I can't think of how it would be beneficial to have cats further back.

In reply to unevolved:

You're missing what its saying. You can delete the cat in the exhaust manifold as long as you retain the second stock cat or put one within 6" of the second/most downstream cat.

From an aerodynamics standpoint, I think it's safe to say there is no benefit to this. Vortex generators are used to delay flow separation. This would occur on the bottom surface of a wing used in an automotive application, not on the top, so you would want the vortex generators on the bottom. Also, they would need to be upstream of the point of flow separation (somewhere near the leading edge or, at most, mid-way down the wing).

There's also little to no chance that there's any flow separation on a wing with this type of design at autocross speeds anyway. The wing profile and angle of attack are not nearly aggressive enough for that to be an issue at 60 mph or whatever you're going to get to on an autocross course.

Lancer007 wrote: In reply to unevolved: You're missing what its saying. You can delete the cat in the exhaust manifold as long as you retain the second stock cat or put one within 6" of the second/most downstream cat.

On an E46, there's only the catalytic converters in the exhaust manifold. There are no downstream cats. According to the OEM part numbers/diagrams, the three masses downstream are mufflers, although some call one of them a resonator. There isn't another option.

I wouldn't really have a problem with this rule if I could discern the logic behind it. Why does it matter if a cat isn't in a stock location?

In reply to unevolved:

Oooooooohhhhhhhhhh, I gotcha now, I misunderstood. I didn't know that about the E46, I see where your ire for this stipulation comes from now. I honestly can't see that being a big deal at a local level if you try your best to get it close. Its certainly not an advantage putting it a couple more inches down the line.

Edit: Wahoo, I have achieved dorkdom!

ProDarwin wrote: Ugh. Here come the anti-SCCA Autox whiners. Its one incident. Yes, those protesting him probably have a stick up their butt and should find better things to do with their time. Would he be protested at 99% of local regions? No. Because most people realize that what he has done has little to no effect. Would he be protested at 99% of national/divisional events? No. Because he likely wouldn't be winning anything, and nobody feels like protesting the guy in 32nd place in class. Also see above. I've run events in cars with illegal mods plenty of times. Competitors were well aware, but did not care as the mods gave me no advantage (lightweight flywheel on a 2.5rs, aftermarket steering wheel on a STR Miata [the horror!], etc.)

I have to agree with PD. I've been in the SCCA autocross program for 31 years and haven't seen anybody protested at anything less than Nationals for at least 20 of those years. Those who claim that they don't autocross because of protests are just using that as an excuse. Getting good at this game takes real commitment; you can't just go out a couple of times and expect to dominate. There's a steep learning curve.

Ignore whether or not you're competitive and just have fun. Doesn't matter what class you're in; even in the street classes there will be someone experienced that will clean your clock. Enjoy the adrenaline rush and your times will start dropping with seat time and good instruction.