GB: Aluminum Undertrays E9x M3 by Euro Parts Power Motorsports and POW3R Motorsports

[majdi]

Hi all! We recently received Aluminum Undertrays from POW3R Motorsports for the E9x M3 and looking to pass them on to our fellow group members with a promo code! You may use E9XM3OWNERS during check-out and we will provide you a discount ($40 off) and upgrade your shipping to 2nd Day Air! *please choose ground shipping during check-out*

These undertrays are constructed from 2mm 5251 Aluminum, powder coated in a satin black finish. These undertrays are designed to withstand increased levels of protection, and reduce oil temps while on track. The rubber trim on the undertrays cooling aperture seals onto the OEM plastic cooling shroud, drawing heat away from the oil cooler through the effects of venturi.

If you have any questions, please feel free to DM me or post in the comments. Thanks!

https://europowermotorsports.com/product/e92-m3-undertray-skid-pan/

[Deen HK]

What’s it weigh? Does it come with hardware?

[Dash1]

Website states 6lbs. Anyone know how much the stock weighs?

Stock: 1.7 lbs
AM: 6 lbs

[IamFODI]

I've torn up my stock undertray a bunch of times. What I haven't torn up is the bumper. And TBH I wonder if that's part of why the stock pieces are fragile – i.e. to break before damaging the bumper.

Also, this one (like some other aftermarket ones) seems to be completely flat on the bottom whereas the stock piece has some shaping to it. I guess being flat mitigates the damage risk somewhat, but there must be some aero effects involved, no?

Seems like there's also a weight penalty this, per Dash1.

And you can buy the stock pieces from FCP Euro and have them replaced when they break.

I doubt this mod is a good idea. Happy to be convinced otherwise if I'm wrong.

[Tbonem3]

I, too, contemplated one of these or another brand's (I've seen like 4), but saw a similar concern about damage to bumper or liners. I need all 3 pieces, so it was tempting. In the end, I've bought two new corner pieces, and I'm going to attempt to fix my stock tray with flex seal tape (idea from an e90post member) before shelling $220 on aother one that may very well break again in short order.

I was also concerned with possible negative effect on aero and cooling since all thee aftermarket pieces are flat, and sit higher versus the factory which is a bit lower and is curved. None of these companies, understandably, are going to put their product in a wind tunnel. Though some have said there are cooler oil temps reported. I don't see how that's possible, but you know...

[Epoustouflant]

I've torn up my stock undertray a bunch of times. What I haven't torn up is the bumper. And TBH I wonder if that's part of why the stock pieces are fragile – i.e. to break before damaging the bumper.

Also, this one (like some other aftermarket ones) seems to be completely flat on the bottom whereas the stock piece has some shaping to it. I guess being flat mitigates the damage risk somewhat, but there must be some aero effects involved, no?

Seems like there's also a weight penalty this, per Dash1.

And you can buy the stock pieces from FCP Euro and have them replaced when they break.

I doubt this mod is a good idea. Happy to be convinced otherwise if I'm wrong.

We have the same issues on the E9x M3 undertrays.

This E9x M3 skidplate is as light as OEM - but there are many on the market that are much heavier than stock.

This isn't heavy enough to tear the bumper. It's purely bolted to the fender liner and bumper.

[bigjae46]

One problem with the oil cooler opening design. Its flat.

It is the flow under car that draws air through the cooler, not the flow through the cooler. You need to lower the air pressure on the backside of the cooler. The OEM part has a gurney flap in front and a rounded back edge on the oil cooler opening which improves air extraction behind the cooler and improves oil cooling. I'm not an expert but I'd have to guess that outer OE parts sit lower to manage airflow around the tires.

All of the flat plates except for the turner part are flat on the bottom which reduces the extraction of high pressure air above the plate. The turner part incorporates a gurney flap and angled back edge to improve extraction of high pressure air behind the oil cooler to the low pressure region under the car. Thus, flow is improved through the oil cooler which improves cooling performance.

[bigjae46]

Things come up and got working on other things. I tore up my first carbon version over the summer on a road gator. No bumper damage. The carbon ends have held up WAY better than the OE part. The part resists abrasion really well.

Finally figured out the center cover...mostly. Making the V2 mold was such a pain in the arse! I've incorporated the gurney flap which is bonded onto the part. I need to get bigger clamps. I managed on the one in the picture. I've been doing some aero testing on my E46...the gurney is going to be important for oil cooling.

As you can see the first part of V2 is far from perfect. The area around the duct is quite tricky to layup. Since cosmetics aren't important, I am just going to stuff some carbon strands into the tighter areas. I could use a prepreg but that adds a lot of cost without much benefit. Yeah, it will save maybe a .1oz since I can use less fabric and it will look better...but it adds about $100 to the cost to make one.

I'm going to make the end caps with an outer layer of Kevlar on the bottom and then I think the experiment will be complete.

The OE speed clips don't work really well. I installed rivet nuts and used M5 hardware. I think this will be a massive improvement - M5 hardware will be much easier to find and replace.

Overall, I think this is a win-win-win. My carbon parts are lighter, significantly more abrasion resistant, and will thus last a lot longer and cost less.



The end cap has seen over 10k miles



Installed with the gurney and autozone hardware. I haven't had a chance to think about the best approach for hardware. Corrosion resistance is important to prevent seizing and rusty bolt heads. I can use stainless rivet nuts. Not sure black stainless fasteners exist. I can get black oxide steel hardware - torx button heads to drive everyone nuts! lol