[tylerhart_21]

I was looking online and found this diagram, which lead me to look for aerodynamic parts for the e92 besides going full race car mode. Does anyone know of aero parts you could put on the e92 non-m to improve the aerodynamics? Also, how much will they improve the cars aerodynamics?

[tcphoto]

It looks like the difference starts around the windshield and gets worse at the shark fin. It doesn't state if the M3 is a slick top but I would guess so and the 335 most likely has a sunroof and no trunk lip. The PO added an Aero lip, rear window and trunk lip on mine. I almost immediately pulled the rear items off and replaced them with a carbon fiber lip on the trunk.

[streetpro]

You have to define what to improve...
if Cd (coefficient of drag, basically how smoothly the car goes through the air) then take a closer look as basic shape has better Cd then M3 (and it makes perfect sense as M is optimized for performance, not consumption).
If more downforce is asked, it comes with a price tag of higher drag and additional spoilers/wings...
and yes, the basic shape has light front at high speeds (over 180 kmh let say), anyone on autobahn has experienced this phenomena when chasing a P911T I guess :-)
Vented hood improves the matters a bit, at least for me it has worked fine (the vents/louvers must be in the front section of the hood, where the low pressure area is, not at the rear where is the M3 intake opening and people have feelings that it ventilates the engine - in reality it does the opposite).

[Thumbie]

That is a cool comparison.

So from what I am gathering, and assuming you are talking about downforce per streetpro's comment, adding a little downforce to the front would be my first step.

I personally am considering swapping to M3 front bumper or adding a like a lip/dam. Next would be rear spoiler or, and I haven't done research yet, cutting up the rear bumper to relieve pressure buildup (this is common on miatas).

From there you could get into more advanced things like vents in the fender and brake ducting, etc.

[tylerhart_21]

Originally Posted by streetpro

You have to define what to improve...
if Cd (coefficient of drag, basically how smoothly the car goes through the air) then take a closer look as basic shape has better Cd then M3 (and it makes perfect sense as M is optimized for performance, not consumption).
If more downforce is asked, it comes with a price tag of higher drag and additional spoilers/wings...
and yes, the basic shape has light front at high speeds (over 180 kmh let say), anyone on autobahn has experienced this phenomena when chasing a P911T I guess :-)
Vented hood improves the matters a bit, at least for me it has worked fine (the vents/louvers must be in the front section of the hood, where the low pressure area is, not at the rear where is the M3 intake opening and people have feelings that it ventilates the engine - in reality it does the opposite).

I know with the m3 they have a front vent on the belly pan. Could something like that help or not really?

[tylerhart_21]

Originally Posted by Thumbie

That is a cool comparison.

So from what I am gathering, and assuming you are talking about downforce per streetpro's comment, adding a little downforce to the front would be my first step.

I personally am considering swapping to M3 front bumper or adding a like a lip/dam. Next would be rear spoiler or, and I haven't done research yet, cutting up the rear bumper to relieve pressure buildup (this is common on miatas).

From there you could get into more advanced things like vents in the fender and brake ducting, etc.

With aero on the car would the aerodynamic kit work from bmw? I can see the front lip doing something but the rear diffuser and the spoiler I am not sure about.

[Thumbie]

Originally Posted by tylerhart_21

With aero on the car would the aerodynamic kit work from bmw? I can see the front lip doing something but the rear diffuser and the spoiler I am not sure about.

Depends on if they were designed for "style" or function. I am not familiar with bmw's aero kit. If it is BMW brand I assume there is some function there. For example the M3 rear bumper has built in diffuser. that vent above the exhaust tips does serve some function.

Overall the key is a balanced setup, obviously. Adding a massive spoiler to a non-M will give you too much rear downforce, you would also need front air dam or something to balance it out.

Depends on what the goals are for the car.

[streetpro]

Again, it depends on the definition of a massive spoiler. Because the rear wing on the trunk lid may reduce lift, it is rarely able to generate significant downforce because it is in the area of the swirled air. That's why DTM/GT cars have wings on high struts to get them into a "clean" airflow.
A splitter on the front will definitely help, both to increase downforce and to reduce drag (under certain conditions).
The lower openings in the front part of the engine cover allows a much higher flow through the radiator (the pressure difference between the part in front of the car, where the air is in positive pressure, while behind the radiator, through which it is slowed down and is further sucked under the car by faster moving air/low pressure zone - Venturi effect).
That's why M cars put transmission coolers etc in there, which would otherwise have to be in front of the water/air cooler.

[tylerhart_21]

Originally Posted by streetpro

Again, it depends on the definition of a massive spoiler. Because the rear wing on the trunk lid may reduce lift, it is rarely able to generate significant downforce because it is in the area of the swirled air. That's why DTM/GT cars have wings on high struts to get them into a "clean" airflow.
A splitter on the front will definitely help, both to increase downforce and to reduce drag (under certain conditions).
The lower openings in the front part of the engine cover allows a much higher flow through the radiator (the pressure difference between the part in front of the car, where the air is in positive pressure, while behind the radiator, through which it is slowed down and is further sucked under the car by faster moving air/low pressure zone - Venturi effect).
That's why M cars put transmission coolers etc in there, which would otherwise have to be in front of the water/air cooler.

So in short if you get a gt style wing it will be able to generate downforce, while a spoiler may reduce lift. The front splitter would help, when it comes to certain situations. Now with the vent on the engine cover, it helps with air flow thought the radiator etc. Correct me if I am wrong but would that help the radiator become more efficient or make it able to take in more air? So lowering oil temps?

[tylerhart_21]

After looking at the 918 Cayman gt4 MR, I have seen the underbody aero. Manthey racing and Porsche will sell you the aero parts but it’s 250 dollars. What does the underbody aero do?

According to Manthey:

1. Guide air out from underneath the car
2. Avoid to get air in from the side of the car

The first point is probably clear, the second one means that by creating a “air curtain” underneath the side skirt will avoid “dirty” air to get under the car from outside.

The aero could be more complex with getting the angles and the placement as well. However I have made a prototype with paper and duct tape and have someone that is measuring the MR fins to get the length close. I will keep y’all posted, but if y’all have any comments to add or suggestions let me know.

The aero on a gt4 soon below:

[tylerhart_21]

After some testing, the rs aero is not the most practical thing right now. I have made a some prototype based of the gt4 aero. The goals is block off the diviet behind the wheel and push the air to the side skirt. If anyone knows more about this topic let me know. I have attached the prototype and the small divet.

[tylerhart_21]

Does anyone know how much the front air dam from BMW (aerodynamikpaket) reduces the lift in the front? The Alpina b3 front air dam dropped the lift by 30kg. But I'm not sure about the Aerodynamikpaket air dam since it is a different design.