Custom Bumper Stone Guard

[DumpsterBaby]

Hey all,

I just bought a F83 M4 and was going through regular maintenance. I took the bumper off to clean the radiators, there were a lot of tiny rocks lodged between the fins.

After clearing out the rocks, I wanted a more permanent solution so I don't have to do this again. I grabbed some grill mesh panel off Amazon and made these stone guards.

If you want to try this yourself, you will need
- Mesh panel
- Pattern
- Shers
- Clamps
- Black zip ties

Take the bumper off, take off all the inserts, make patterns, cut the mesh according to patterns, tie the mesh to the back of the inserts and you are done. All in all it took me about 5 hour to do all 5 inserts (2 sides, shown in photo; 2 kidney grills and the large center grill)

[F80RN]

Subbed for later.

Any photos of it installed ?

[DumpsterBaby]

Originally Posted by F80RN

Subbed for later.

Any photos of it installed ?

Will update once installed. I need to wrap the bumper and do the lip. This will take a few days. Stay tuned.

[uncle ben]

Did the same thing after watching a Farkel video of him doing the same. It’s a fun affordable mod that is 100% reversible and pretty easy to do.

[YASBBYM3]

This has to affect air flow

[DumpsterBaby]

Installed

[DumpsterBaby]

Finished wrapping today

[uncle ben]

Originally Posted by YASBBYM3

This has to affect air flow

Depends on the mesh size. The size I went with is more open than the OP’s mesh. It’s very similar in size to the mesh they run on the gt4 race car. So I don’t think it will hinder cooling performance. Also I have a few track days on my car after installing my mesh. No issues with cooling.

[YASBBYM3]

Originally Posted by uncle ben

Depends on the mesh size. The size I went with is more open than the OP’s mesh. It’s very similar in size to the mesh they run on the gt4 race car. So I don’t think it will hinder cooling performance. Also I have a few track days on my car after installing my mesh. No issues with cooling.

How do you think any mesh inserted when none is originally there will not change/limit air flow.

[hellokitty]

Here is another option if you don't want to DIY.

https://www.zunsport.com/us/bmw-m3-a...ront-grill-set

[Jbrown7403]

Originally Posted by uncle ben

Depends on the mesh size. The size I went with is more open than the OP’s mesh. It’s very similar in size to the mesh they run on the gt4 race car. So I don’t think it will hinder cooling performance. Also I have a few track days on my car after installing my mesh. No issues with cooling.

I find this thread interesting and I’ve thought about doing something like this myself. Do you have pictures of the installed mesh that you used? Thanks.

[DumpsterBaby]

Originally Posted by YASBBYM3

How do you think any mesh inserted when none is originally there will not change/limit air flow.

A couple of things to consider. First, you are assuming 100% of the air going through the grill are sucked in for cooling, which I highly doubt it is the case. Second, the ratio of air to cooling is not linear. Meaning, there’s a diminishing return from air volume to temperature. If you lose 10% of the air volume, maybe you only lose 3% of cooling power. Third, without the mesh insert, more tiny rocks can lodge between the fins, which blocks air altogether, thus reducing cooling.
It’s a complex equation involving many variables. IMO the loss of air from the mesh is less important than the increase in radiator protection.

[DumpsterBaby]

Originally Posted by DumpsterBaby

I find this thread interesting and I’ve thought about doing something like this myself. Do you have pictures of the installed mesh that you used? Thanks.

AggAuto Universal 40"x13" Car Grill Mesh - 100x33cm Aluminum Alloy Automotive Grille Insert Bumper 3x6mm Rhombic Hole https://a.co/d/fT0fxv5

[DumpsterBaby]

Originally Posted by YASBBYM3

How do you think any mesh inserted when none is originally there will not change/limit air flow.

Lastly, if you think about it, the moment air hits the mesh (which is behind the grill BTW), air cannot turn back, right? Because the car is going forward. What end up happening is air gets separated by the mesh and rush through the opening. Theoretically, the mesh would not reduce airflow volume, but rather slightly increase air speed. This theory can be tested using water since water and air behave similarly

[YASBBYM3]

Originally Posted by DumpsterBaby

Lastly, if you think about it, the moment air hits the mesh (which is behind the grill BTW), air cannot turn back, right? Because the car is going forward. What end up happening is air gets separated by the mesh and rush through the opening. Theoretically, the mesh would not reduce airflow volume, but rather slightly increase air speed. This theory can be tested using water since water and air behave similarly

The air speed would increase but the volume would decrease, which results in less air entering your intake and cooling critical parts.

[hC1001]

Did this a couple years ago. Now i have sticks, leaves, etc between the mesh and front plastic grill lol. It usually builds up on the bottom...

Still better than debris getting stuck inside the radiator fins. I spent 4 hours with small tweezers clearing out small rocks and sticks when i had the front bumper off. I also realigned some fins that were dented/deformed. Yes, i guess im OCD...

[DumpsterBaby]

Originally Posted by hC1001

Did this a couple years ago. Now i have sticks, leaves, etc between the mesh and front plastic grill lol. It usually builds up on the bottom...

Still better than debris getting stuck inside the radiator fins. I spent 4 hours with small tweezers clearing out small rocks and sticks when i had the front bumper off. I also realigned some fins that were dented/deformed. Yes, i guess im OCD...

That’s exactly what I did!!! Lol I spent a good 5 hours on those fins

[NORAGRETS]

Originally Posted by DumpsterBaby

That’s exactly what I did!!! Lol I spent a good 5 hours on those fins

lol would it not make more sense to put the mesh over the radiators to just protect those fins?

[NORAGRETS]

Originally Posted by DumpsterBaby

Finished wrapping today

Originally Posted by hellokitty

Here is another option if you don't want to DIY.

https://www.zunsport.com/us/bmw-m3-a...ront-grill-set

OP’s looks way way better than the zunsport imo. And more functional.

[NORAGRETS]

Originally Posted by DumpsterBaby

Lastly, if you think about it, the moment air hits the mesh (which is behind the grill BTW), air cannot turn back, right? Because the car is going forward. What end up happening is air gets separated by the mesh and rush through the opening. Theoretically, the mesh would not reduce airflow volume, but rather slightly increase air speed. This theory can be tested using water since water and air behave similarly

You’re forgetting one very important basic physics principle…drag.