Good bumper for Aero?

[Arith2]

I was wondering if anybody found a good bumper that doesn't direct air straight into the tires but also doesn't look kinda funny like the gtr bumper. I know on stock and CSL this is done for looks but at high speeds, it really can cause problems. I had to add some wheel spacers so now my tires stick out into the wind even more.

[Ruley]

Add some canards maybe?

[Arith2]

Add some canards maybe?

They're very inefficient, they don't really look good, and if I added some CSL splitters, they'd work even less while creating more frontward drag than actual downforce. Yes, they will help the wheels, but will almost counteract any real gains from this. I'm not a fan of them and I don't have a wind tunnel to test which angle of attack is perfect for them either. Just slapping some on could literally just create drag with minimal downforce.

That would be the cheapest solution and this case and I do believe start from the simplest and easier method first. With canards the benefits just don't outweigh the costs however, your train of thought seems to be in the right direction.

[elbert]

I was wondering if anybody found a good bumper that doesn't direct air straight into the tires but also doesn't look kinda funny like the gtr bumper. I know on stock and CSL this is done for looks but at high speeds, it really can cause problems. I had to add some wheel spacers so now my tires stick out into the wind even more.

I found the DIY below for fender flares. There was a Racecar Engineering article about a while back about this type of fender flare, and it was pretty effective reducing drag from a rotating front tire.
You would also need a full width (and then some) front splitter that would spill into the flares. IIRC, small fences (being z-plane if the splitter were x-plane, and the tangent of the flare at the junction were y-plane) where the components intersect helped as well.

I have wanted to try this out for quite a few years, but even with the Covid shutdown I haven't had time.

https://www.corvetteforum.com/forums...y-version.html

[Ruley]

So you’re looking for more aero at high speeds instead of adding grip at high speeds? I feel everything out there is pretty well track oriented. Not sure what to tell ya. Maybe someone else will chime in.

[Arith2]

I found the DIY below for fender flares. There was a Racecar Engineering article about a while back about this type of fender flare, and it was pretty effective reducing drag from a rotating front tire.
You would also need a full width (and then some) front splitter that would spill into the flares. IIRC, small fences (being z-plane if the splitter were x-plane, and the tangent of the flare at the junction were y-plane) where the components intersect helped as well.

I have wanted to try this out for quite a few years, but even with the Covid shutdown I haven't had time.

https://www.corvetteforum.com/forums...y-version.html

This is an amazing idea! Seems quite cheap and I definitely have the tools to do it. It won't look as good on an E46 because that angle really helps the ugly factor. I think this will actually reduce drag which seems ridiculous considering it's flat. I may attempt to taper it and prevent a break up while also creating some sealing vortices along the bottom. This will definitely reduce drag as I'm sure the rear underneath cause a lot of break up. It makes me wonder if a CSL diffuser even has enough decent flow to work.

So you’re looking for more aero at high speeds instead of adding grip at high speeds? I feel everything out there is pretty well track oriented. Not sure what to tell ya. Maybe someone else will chime in.

What I'm trying to combat is the tire slamming into the wind and smashing it into the ground as it rolls forward. This creates a high pressure zone right where the tire contacts the road. At the top is the equal and opposite reaction of a low pressure zone. High pressure moves towards low pressure, which in this case is up. This lift can cause instability and definitely hurts everything. There is nothing good about a tire being exposed to the wind. F1 cars have to be that way due to platform regulations but even their front wings are designed to negate this effect.

[Obioban]

Why not address the underlying issue, instead (tires poking out)? Stock, the e46 m3 is super stable-- more stable than my M5 (which is a car known for high speed stability) or former e9X.

[Slideways]

Why not address the underlying issue, instead (tires poking out)? Stock, the e46 m3 is super stable-- more stable than my M5 (which is a car known for high speed stability) or former e9X.

It's the standard thing to do these days. Take a street car designed to run a front 8-8.5" wheel with a 225-235 tire and 1-1.5 degrees neg. camber and change all that out for a 9.5" wheel with a 265 tire and 2.5-3 degrees neg. camber. That will feel great on every road that is not perfectly paved twisties

[elbert]

It's the standard thing to do these days. Take a street car designed to run a front 8-8.5" wheel with a 225-235 tire and 1-1.5 degrees neg. camber and change all that out for a 9.5" wheel with a 265 tire and 2.5-3 degrees neg. camber. That will feel great on every road that is not perfectly paved twisties

... or the track, which is where my car spends its time.

[Slideways]

... or the track, which is where my car spends its time.

That's good. I was mainly referring to cars driven on the street with freeways and imperfect roads.

[Sharocks]

OP puts on spacers now wants a bumper to go with his spacers. Ok.

A lot of track guys in Europe are running the Matty Evans front bumper that has a built in belly splitter so it's more sturdy than two CF flippers on a CSL bumper. After which you can add canards etc. make it look like a ZL1 1LE etc.

Too bad Matt won't ship to the US. I've tried many times lol.

[Obioban]

... or the track, which is where my car spends its time.

Most people end up with different wheel/tire setups for track use, and high speed stability isn’t really a consideration there.

[Onefastsicilian]

OP puts on spacers now wants a bumper to go with his spacers. Ok.

A lot of track guys in Europe are running the Matty Evans front bumper that has a built in belly splitter so it's more sturdy than two CF flippers on a CSL bumper. After which you can add canards etc. make it look like a ZL1 1LE etc.

Too bad Matt won't ship to the US. I've tried many times lol.

I wanted to buy his rear bumper but he wouldnt even respond.. i feel like because I mentioned in my email shipping to the USA he was like F that lol I'd love both of his bumpers actually.

[Arith2]

[QUOTE=Sharocks;n39574]OP puts on spacers now wants a bumper to go with his spacers. Ok.
/QUOTE]

Let me be clear. I DO NOT want spacers. I need them. Look at a stock bumper, it's a bad areo design already. The E46 has an aweful friction coefficient as well. Canards are not good at what they do and they look bad on our cars

[shibui]

You could try the carbon GT4 splitter that all the Nurburgring regulars put on their Ringtool M3s. It's rare to see Nurburgring M3s utilizing canards, most of them strap on this splitter and call it a day.

http://www.mk-motorsportteile.de/M3-GT4-lip-/-Splitter-BMW-M3-e46

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