E30 Aerodynamics

[squidmaster]

Sides are helpful, but the front is really the best help

Nah, I understand they probably need different spacing than mine, just weighing in from what I saw in the CFD testing

[2mAn]

From my testing I found diminished results anything over 5 on the roof. Of course, I'm using my design as reference so I could be mistaken for those.

This article was linked earlier in the thread and it had similar results after 6

http://www.autospeed.com/A_111110/hDg34uLtp_1/cms/article.html

When I talked to the guy selling the airtabs he mentioned the spacing of them, so I felt 7 was the a good number to max out the benefits of the airtabs.

Whats the spacing of your 5?

Is there any benefit placing any on the side of the car? Ive seen people place them on the front sides and rear sides too

[squidmaster]

From my testing I found diminished results anything over 5 on the roof. Of course, I'm using my design as reference so I could be mistaken for those.

[2mAn]

Ok guys I have quite few Air Tab vortex generators left from when I purchased it for my enclosed trailer, where would be good location to mount these on e30 roof? I mean how far from rear window? I have huge ARP wing mounted in the back.

Heres how I mocked mine up, but honestly I have yet to actually mount them

Untitled by 2mAn

Untitled by 2mAn

[vitiokas95]

Ok guys I have quite few Air Tab vortex generators left from when I purchased it for my enclosed trailer, where would be good location to mount these on e30 roof? I mean how far from rear window? I have huge ARP wing mounted in the back.

[2mAn]

E30 Aerodynamics

There is a guy making full carbon fiber rear window assemblies, but you would also need the trunk lid as well (I think)



Will

Good place to shed weight.

Is this the guy and parts?

https://www.ebay.com/itm/192122072296

[BlackbirdM3]

Mine cost about the same , and like I said if I knew you were going to start producing them I would rather support a forum member than some random person.





I've looked into adding that c-pillar as I'd get the benefit of the air turbulence and, more importantly, the angle of the rear window, but it's a NLA part now

Wish I had an M3 lol

There is a guy making full carbon fiber rear window assemblies, but you would also need the trunk lid as well (I think)

Will

[2mAn]

oh no dude that's not why I asked. I was just curious how to price mine competetively

Yours are priced right, I meant nothing by my comments except that I'd prefer to keep the money here rather than outside sources

[squidmaster]

oh no dude that's not why I asked. I was just curious how to price mine competetively

[2mAn]

Simon, how much did you pay for your airtabs? I've sold a couple of sets of my 3d printed VGs at $35 shipped for 8, and you get a credit for the injection molded product when it's finished with manufacturing

Mine cost about the same , and like I said if I knew you were going to start producing them I would rather support a forum member than some random person.

The step above the rear window on an M3 does this same thing. They spent a lot of time in the wind tunnel working out the best setup.



Will

I've looked into adding that c-pillar as I'd get the benefit of the air turbulence and, more importantly, the angle of the rear window, but it's a NLA part now

Wish I had an M3 lol

[BlackbirdM3]

Vortex generators are interesting and highly effective in some applications. You don't need big pieces of molded plastic to have a vortex generator, the ones you see on aircraft are mostly little pieces of bent aluminum installed at an angle with respect to air flow. They don't have to be very tall, since they only act to keep the boundary layer attached, I've seldom seen them more than 1.5" in height on private and small commercial aircraft. I have even seen them put on RC planes and have seen a noticeable difference in stall characteristics. When you look at the roofline of an E30 from the side, you can tell that there will be serious flow detachment on the rear window because of how steep it is. An A/B tuft test is simple, and some small vortex generators placed along the roofline in a manner similar to what you see on an old Mitsubishi Evo would most likely make a noticeable difference in air flow over the rear window. How much of a difference this would make on the track or for fuel economy would have to be seen. I suspect not much.

I've thought about putting them on my E30 before, just never got around to it, finding some cheap ones or fabricating my own.

The step above the rear window on an M3 does this same thing. They spent a lot of time in the wind tunnel working out the best setup.

Will

[squidmaster]

Simon, how much did you pay for your airtabs? I've sold a couple of sets of my 3d printed VGs at $35 shipped for 8, and you get a credit for the injection molded product when it's finished with manufacturing

[2mAn]

the ones I got from airtab are cheap, though if squid had his when I was looking, I wouldve just bought his. I like supporting r3v

[varg]

Vortex generators are interesting and highly effective in some applications. You don't need big pieces of molded plastic to have a vortex generator, the ones you see on aircraft are mostly little pieces of bent aluminum installed at an angle with respect to air flow. They don't have to be very tall, since they only act to keep the boundary layer attached, I've seldom seen them more than 1.5" in height on private and small commercial aircraft. I have even seen them put on RC planes and have seen a noticeable difference in stall characteristics. When you look at the roofline of an E30 from the side, you can tell that there will be serious flow detachment on the rear window because of how steep it is. An A/B tuft test is simple, and some small vortex generators placed along the roofline in a manner similar to what you see on an old Mitsubishi Evo would most likely make a noticeable difference in air flow over the rear window. How much of a difference this would make on the track or for fuel economy would have to be seen. I suspect not much.

I've thought about putting them on my E30 before, just never got around to it, finding some cheap ones or fabricating my own.

[Panici]

blender solidworks and a little fusion 360

You're doing the airflow simulation in Blender?

From some quick research, it looks like Blender is geared towards doing visual simulations for aesthetics, and it doesn't do accurate computational fluid dynamics (CFD).

Again, this is only what I gleaned after 5 minutes of googling.