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Installing CSL DRLs on the G80 M3

I head back to TySpeed to install some sinister-looking CSL DRLs from the M4 on my M3. Also - how's the M Performance suspension?

One of the many cool features of a CS or CSL BMW are a set of yellow DRLs, or Daytime Running Lights. I wondered if it would be possible to get that look on my own, and a company called Bayoptics was happy to help. This story will go through the installation with TySpeed, and show the results of how an easy mod can make a big impact. I am not lost on the irony that 20 years ago, we used to hunt for Sylvania bulbs that gave off pure white light. Now here we are replacing the stock units for yellow ones. But I don’t make the decisions on what’s cool. CSL DRLs are.

First, a few questions from the masses on my previous mods.

M Performance Suspension update

G80 M3 M Performance Suspension
I love the M Performance Suspension so far.

I’ve put about 500 miles on the car since the M Performance suspension has been installed, and feel as if it’s just about perfect.

The look isn’t as aggressive as some setups are, but I’d rather maintain the car’s full function than have it be “slammed”. Any lower, and the wheels would hit the inner fender walls when at full lock. The OEM+ look the suspension offers is just right.

In the rear, lower springs have a tendency to bottom out, which can cause the ride to be harsh and unsettled mid-turn. The G80 already has what some call a “firm” ride from the factory, and this essentially made it worse (though not unbearable)

Only true masochists will ride around in Sport+ mode, but beyond that, it’s given the car a greater sense of precision and maneuverability.

M Performance Suspension
12mm spacers all around. The HAS kit can be lowered more if desired.
M Performance Suspension
The rear is about perfect.
G80 M3 interior
The car’s maneuverability has greatly improved, but the steering feel remains unaffected.

Does the AWE Track Exhaust drone?

AWE G80 Track Exhaust
This setup has also been a great add.

The AWE Track mid-pipe and exhaust has been on for a few thousand miles now, and I can’t imagine having any other setup. It’s not buzzy at all like so many other systems I hear for this car.

If you’re in sixth at about 80mph, there is some slight drone, but it’s by no means unbearable. Competition models probably won’t even have this issue due to additional gears. The Borla setup on my E92 was worse, and that had mufflers.

AWE exhaust tips

If you’re someone that finds themselves reaching for the Sport+ button on your stock exhaust and driving like that all the time, you’ll love this setup.

Onto the lights.

Why yellow CSL DRLs?

The M4 GT3 has yellow DRLs. Photo: BMW.

This is no poseur look. Yellow DRLs are installed on BMW’s M4 GT3 race car, and have been since the days of the E92.

Yellow lighting, or Selective Yellow, helps your eyes to adjust to darkness better. In GT races such as the one the M4 participates in, it helps to distinguish cars in certain classes. The Prototype Class is faster on track, and it’s easier for the drivers to make out who is who at night.

BMW first did it for a production car on the F90 M5 CS, and it made everyone go “ohhhh”. So the M4 CSL and M3 CS both get the treatment.

Now my puny stick car does too.

F90 M5 CS
Yellow DRLs.

How do you install Bayoptics yellow CSL DRLs on a G80 M3?

It’s not too challenging if you’re so inclined mechanically, but I headed to Tyspeed once again to document the process. Everything is easier with a lift, and the guys made quick work of it.

Today, we’ll be working with Adam, shop foreman and master BMW tech. Let’s get to it.

Tyspeed BMW M4
We’re back at TySpeed for this install. Tyler sports a G82 M4 himself.
G80 M3 Bayoptics install
Here’s the stock setup. The pic is left intentionally dark.
G80 M3 Bayoptics install
We start with the removal of the top two lighting units. They simply unscrew with two bolts.
G80 M3 Bayoptics install
The plugs are delicate. Press the clip and tug.
G80 M3 Bayoptics install
These are the heat sinks, meant to dissipate heat from the chip itself.
G80 M3 Bayoptics install
The car then gets raised, with the front wheels going off.
G80 M3 Bayoptics install
Remove the front fender wall. A few bolts will do it.
G80 M3 Bayoptics install
Behind the wall sits many things, but we need the second LED unit in the upper corners.


G80 M3 Bayoptics install
Right here.
G80 M3 Bayoptics install
The stock chips are held on with thermal glue. We need a heat gun to warm them up and remove them.
G80 M3 Bayoptics install
Adam warms up each chip to ease removal. Still, some muscle is needed to pop it off.
G80 M3 Bayoptics install
To install the Bayoptics chips, we use the provided thermal tape. It works the same as the glue, but is easier to handle.
G80 M3 Bayoptics install
Adam carefully cuts each piece to the shape of the circuit board.
G80 M3 Bayoptics install
Clean the base of each unit of glue to make sure the tape will stick.
G80 M3 Bayoptics install
Once each chip is installed, we simply reverse the steps to plug them in and bolt them up.
G80 M3 Bayoptics install
Reinstall the top two lighting units.
G80 M3 Bayoptics install
That’s all! Here’s the final result.
Tyspeed M4
Tyler has the same lights on his M4.

Bayoptics CSL DRLs results

Here’s the final result with the car in proper lighting.

Bayoptics yellow CSL DRLs Bayoptics yellow CSL DRLsBayoptics yellow CSL DRLs

Quite dramatic, and easy enough if you can access the fender wall on your own. Now, what to do about that nose…

Want your car reviewed?

If you live in the tri-state area and want me to check it out, send me an email! 

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I use Nikon camera bodies and lenses, a Westcott Ice Light 2, Manfrotto tripod, B + W filters and an iMac Pro to make the art you see here.

Follow along on Instagram @machineswithsouls

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