Front felt undercarriage

[ra2289]

Originally Posted by ///M3Fresh

This is exactly what I was thinking. The purpose is to keep debris out more than aero so a flat sheet of aluminum (one piece or three would be ideal).

We actually discussed doing a completely flat version, if I recall correctly, but decided to go with a stock like piece first. I'll pass this along to verify.

[r8ders]

Interested in this as well in either a the 3pc or 1pc design.
I have a JT Design aluminum under tray on my e36 M3 and its been great

[admranger]

Yeah, I'm interested too. Hopefully something is available soon!

[ra2289]

Talked to my buddy that's making these, we had discussed making a flat version like I thought. He says he's thinking about offering both a stock like and flat version.

[///M3Fresh]

Originally Posted by ra2289

Talked to my buddy that's making these, we had discussed making a flat version like I thought. He says he's thinking about offering both a stock like and flat version.

Any idea of when he might have a few for sale or at least on a car with fitment pictures?

(i did see the ones of the product itself)

[alist11]

Valet @ the parlor in hollywood obliterated my drivers side felt undercarriage piece last night.... I too am also very interested in these possible aluminum replacements as the mental stress of continually scraping on the teeny tiniest of dips here in la is making me go nuts!!!....

[NYBulldog]

We are all foaming from the mouth for aluminum replacements

[Hujan]

The problem with aluminum is that the felt undertray is used to prevent electro-magnetic interference (EMI) with the DME. In fact, I believe the parts are identified as such on Real OEM. Aluminum might thus cause EMI that would affect the function of the DME.

Also, the undertray is a form of active aero. It has a little scoop that gets pulled downward as speed (and thus) airflow increases. You can see little cable suspension pieces inside the tray for this purpose.

The tray actually helps airflow through the oil cooler as well.

In short, while I would love to see a more robust solution that offered better ground clearance, I'm not sure it's feasible to make it out of aluminum without impacting the function of the undertray.

Instead of aluminum, perhaps it could be made from injection-molded plastic. This would make them more durable than felt without EMI from a metal item, plus cheaper to mass produce.

[Beemdog]

Originally Posted by Hujan

The problem with aluminum is that the felt undertray is used to prevent electro-magnetic interference (EMI) with the DME. In fact, I believe the parts are identified as such on Real OEM. Aluminum might thus cause EMI that would affect the function of the DME.

As an EMI shield to either high frequency interference entering the engine compartment or electrical noise radiated out from the car, aluminum will work fine and would in many ways be superior to graphite-filled or ferrite based fiber panels. I have worked in the EMI industry in the past so not just blowing smoke.

There may be other reasons BMW chose not to use metal in these pieces-- for one, impacts would still damage aluminum and more of the energy would be transferred to the expensive fascia and other body panels. The soft and pliable undercarriage parts have somewhat of a "sacrificial" mode now. They also were cheap to replace for the lifetime of the M3 production and only started to take off in price around mid-2014.

[UPSROD]

They are already a very flimsy molded plastic with a felt like substance sprayed on (flocked) much like the inside of your glove box. They are not just felt! And I believe they are designed to be sacrificial. A more rigid part will destroy more then the tray when you smack the ground with it!

[Hujan]

Originally Posted by Beemdog

As an EMI shield to either high frequency interference entering the engine compartment or electrical noise radiated out from the car, aluminum will work fine and would in many ways be superior to graphite-filled or ferrite based fiber panels. I have worked in the EMI industry in the past so not just blowing smoke.

There may be other reasons BMW chose not to use metal in these pieces-- for one, impacts would still damage aluminum and more of the energy would be transferred to the expensive fascia and other body panels. The soft and pliable undercarriage parts have somewhat of a "sacrificial" mode now. They also were cheap to replace for the lifetime of the M3 production and only started to take off in price around mid-2014.

I don't have any expertise whatsoever re: EMI interference so I'd defer to you on that. If you're right that aluminum is no worse in that regard and may be better, then that'd be great.

But as you say, it may present other issues since the tray would be more rigid and might thus translate more impact to the plastic attachment points. But perhaps there would be a way to reinforce those attachment points as well?

I would love to see a more robust option that offered better clearance so long as it didn't compromise the function too much. I think there is a real market for it.

[M3 Number 86]

Originally Posted by ra2289

I'll definitely keep you guys posted. The pieces are off getting powder coated black then we'll shoot for a fitment test.

any update on test fitment yet?

what's the word on pricing options. There is a company that makes one for the e46 and it is less than $200.

[M3 Number 86]

Originally Posted by Hujan

The problem with aluminum is that the felt undertray is used to prevent electro-magnetic interference (EMI) with the DME. In fact, I believe the parts are identified as such on Real OEM. Aluminum might thus cause EMI that would affect the function of the DME.

Also, the undertray is a form of active aero. It has a little scoop that gets pulled downward as speed (and thus) airflow increases. You can see little cable suspension pieces inside the tray for this purpose.

The tray actually helps airflow through the oil cooler as well.

In short, while I would love to see a more robust solution that offered better ground clearance, I'm not sure it's feasible to make it out of aluminum without impacting the function of the undertray.

Instead of aluminum, perhaps it could be made from injection-molded plastic. This would make them more durable than felt without EMI from a metal item, plus cheaper to mass produce.

I got to 160mph on the straight and took the bowl at 130+ at autoclub speedway with jacked up undertrays so the aero part I think is insignificant. I thought it would be so I drilled holes and ziptied the parts that were hanging but the result was gaps of holes everywhere for air to pass through. Made no difference though.

[ra2289]

Originally Posted by M3 Number 86

any update on test fitment yet?

what's the word on pricing options. There is a company that makes one for the e46 and it is less than $200.

As of right now we're looking at the end of the week for a fitment test.

[admranger]

Originally Posted by Hujan

Instead of aluminum, perhaps it could be made from injection-molded plastic. This would make them more durable than felt without EMI from a metal item, plus cheaper to mass produce.

The mold for injection molded plastic would be cost prohibitive ($50k-ish?) iirc. They aren't cheap, but I get what you're thinking.

So this damage issue to the fascia, etc. from a more robust part. Could we substitute low strength fasteners for the screws that are currently used? Those would then be the sacrificial lambs. If nuts were integrated into the aluminum under tray, then we could use something like this: M3 pan head machine screws

[Hujan]

Originally Posted by M3 Number 86

I got to 160mph on the straight and took the bowl at 130+ at autoclub speedway with jacked up undertrays so the aero part I think is insignificant. I thought it would be so I drilled holes and ziptied the parts that were hanging but the result was gaps of holes everywhere for air to pass through. Made no difference though.

Yeah, I'm not sure if it's aero from a handling perspective, cooling, or both. I will say that since my undertray has been damaged, I do show slightly higher oil temps than when it was in pristine condition.

Originally Posted by admranger

The mold for injection molded plastic would be cost prohibitive ($50k-ish?) iirc. They aren't cheap, but I get what you're thinking.

So this damage issue to the fascia, etc. from a more robust part. Could we substitute low strength fasteners for the screws that are currently used? Those would then be the sacrificial lambs. If nuts were integrated into the aluminum under tray, then we could use something like this: M3 pan head machine screws

Yeah, it wouldn't be practical for anyone to buy an injection-molding machine for this project alone. I was more thinking that a design could be given to a shop that has a machine for them to fab up some units. Something like what "Metak" did with his diffuser.

But assuming that's not feasible, I like where your head is at with making the mounting hardware the weak point in the assembly. Heck, that's not a bad idea regardless of what's used for the tray.

[Mikulski]

I ran without the front felt undercarriage for 30K+ miles lowered on KW springs and never had any problems. I had to take extra precaution around bumps and road debris though.

Buddies of mine reported having the front felt undercarriage replaced to only have it rip off consistently in the near future. If you drive the car with precaution I don't believe you need it unless you are tracking the car or speeding excessively.

[amsu]

Count me in depending on price!

[Time Lord]

a few of my buddies made a plastic version using a plastic clip board and dremel. It looks original and strong. I believe he still has the template. ill make a few and let you guys know.

[crypticc]

Originally Posted by admranger

The mold for injection molded plastic would be cost prohibitive ($50k-ish?) iirc. They aren't cheap, but I get what you're thinking.

So this damage issue to the fascia, etc. from a more robust part. Could we substitute low strength fasteners for the screws that are currently used? Those would then be the sacrificial lambs. If nuts were integrated into the aluminum under tray, then we could use something like this: M3 pan head machine screws

Fair idea but then won't the aluminium just fold up and take out whatever it can as it passed under your car. Thinking exhaust, dtc cover, diff cover,

[admranger]

Originally Posted by crypticc

Fair idea but then won't the aluminium just fold up and take out whatever it can as it passed under your car. Thinking exhaust, dtc cover, diff cover,

Fair point to bring up! If it is thin aluminum sheet, it won't harm the exhaust (steel) or diff cover (I hit curbs on the race track with the big diff cover on my old M3 race car -- it just scratched -- it's one tough piece).

I have a real gearbox, so I don't know about the DTC cover.

[joneffingvo]

Just spent about $400 bucks for all pieces! Damnit...