MyLaps Transponder Mounting Options

[evanevery]

Put the M4 up on the lift last night to put on my track wheels and find a mounting location for my new MyLaps transponder...

There really doesn't appear to be any good option for mounting the transponder. The car has so much aero body work under the car there is no way to get a clear line of sight of the track from within the engine bay. I also have the fall line oil cooler guard which basically eliminates any option of seeing the road fwd of the radiator.

So what is anyone else doing on the F8X? I have a rechargeable transponder so I'm thinking maybe I can fabricate a temp (track day) mount using the front or rear tow hook socket. I have ordered a couple of cheap tow hooks from Amazon and I'm going to see if I can cannibalize one of them to fabricate a cheap mounting bracket (kind of like the license plate tow hook bracket). I think the trick may be getting the mounting plate fwd or aft enough to see down past the bumper...

Anyone else have any other ideas?

[evanevery]

OK, so no feedback on this. But here is what I have ultimately done to mount the X2 transponder on my M4.

1. Got a really cheap Front Tow Hook for the M4. This one is made from aluminum and a cosmetic piece rather than a functional one. The good part is that its cheap, light, and has a standard M12 male thread which is used to attach the hinged tow loop to the post. Effectively, after removing the hinged loop, I now have an aluminum stud with the all important M20x3 BMW proprietary tow hook male thread on one end and then a standard M12 Male thread on the other.

http://www.amazon.com/Dewhel-Aluminu...rch_detailpage

2. Then I got a 15mm aluminum tube which has a 12mm female thread on one end. The tow hook stud itself is not long enough to put the transponder out past the front bumper - so I needed a little more length (as usual ;-). Anyway, the photo industry seems to use 15mm threaded aluminum tubes for many applications so I bought one of those and then just cut it down to the minimal length to reach out just past my front bumper:

http://www.amazon.com/Smallrig%C2%AE...rch_detailpage

3. After measuring and cutting the 15mm tube to the proper length, I coated the 12mm threads on the tow hook stud with threadlock and screwed the tube firmly onto the stud.

4. I also needed some sort of an adjustable mount for the transponder so I could rotate it around the tube to the proper orientation once the tow hook stud was screwed into the vehicle. This lets me mount the transponder on the face of the clamp, slide it over the end of the tube, and then lock it down in the proper orientation. I purchased one of the following 15mm clamps (again from the photo industry) which works very nicely for this purpose:

http://www.amazon.com/Clamp-Holder-T...rch_detailpage

5. The final trick here was to design and 3D print a little block to help make the attachment of the transponder mount to the tube clamp a little easier. However, I think it would be possible to attach the X2 mount directly to the tube clamp, its just that this block makes it a little easier. I have also attached the STL file if anyone wants to print one of these blocks. (PM me if you want the original DWG)


So - get to the track, pop out the front tow hook cover, screw in the transponder post, and clamp on the transponder!

I also have a design I used to make a similar mount that can be used with the U.S. Millworks Tow Hook Front Plate mount (with quick release). If anyone is interested in that please drop me a PM...

[xander85]

I usually just zip tie it to one of the screw holes on my license plate. Your setup does look much better though!

[M3 Number 86]

shouldn't you just ziptie is somewhere and use the tow hook for when you need to get a tow? i see so many people put something on their tow hook location when it is used to tow you in case you get off track?

[evanevery]

Thanks!

I don't run a front plate (although my state says I should). That is why I also have a "U.S. Millworks quick release" option in the trunk and ready to go if I get pulled over. The U.S. Millworks option is actually even easier to implement (although it still requires some 3D printing). I was even going to send U.S. Millworks a couple of photos and the 3D design for the transponder in the vent they wanted to distribute a kit of their own. So, if I get forced to run a front plate, I already have the U.S. Millworks quick release kit with the front plate pre-mounted in the trunk. ...and if that happens, then I also have another transponder mount that will work with their quick release kit as well. Just take the plate off and swap it for the transponder when I get to the track...

...and I think the rear plate is too far recessed for the transponder to properly see the track....

[evanevery]

Originally Posted by M3 Number 86

shouldn't you just ziptie is somewhere and use the tow hook for when you need to get a tow? i see so many people put something on their tow hook location when it is used to tow you in case you get off track?

The transponder mount, although secure, will unscrew without much effort (by hand). Then I can just screw in the tow hook... Hopefully, it never comes to that...

There really isn't a good place to mount the transponder under the body, or in the engine bay, with a zip tie anyway. I put the car up on the lift and looked around underneath for a while. Its all pretty well aero-covered with no really good mounting point for the transponder. ...especially if you have a rechargeable transponder and need to take it on and off occasionally.

I know some people mount the transponders in their wheel wells but that just seems too problematic to me. With all the tire boogers and such flying around during track events.

[M3 Number 86]

Originally Posted by evanevery

The transponder mount, although secure, will unscrew without much effort (by hand). Then I can just screw in the tow hook... Hopefully, it never comes to that...

There really isn't a good place to mount the transponder under the body, or in the engine bay, with a zip tie anyway. I put the car up on the lift and looked around underneath for a while. Its all pretty well aero-covered with no really good mounting point for the transponder. ...especially if you have a rechargeable transponder and need to take it on and off occasionally.

I know some people mount the transponders in their wheel wells but that just seems too problematic to me. With all the tire boogers and such flying around during track events.

are you allowed to get out of the car to switch to the tow hook?

just ziptie it to your windshield wiper. or you can buy a pouch for it with holes so that you can zip tie to grill or the mess in the front air dam?

[evanevery]

Originally Posted by M3 Number 86

are you allowed to get out of the car to switch to the tow hook?

just ziptie it to your windshield wiper. or you can buy a pouch for it with holes so that you can zip tie to grill or the mess in the front air dam?

The transponder documentation specifically states it needs a clear view of the TRACK/PAVEMENT. The orientation and printing on the transponder itself also supports this ("down toward track"). I believe its triggered/detected by a loop or strip in the pavement. According to the docs, you can't place it anywhere on top of the car if it can't see the pavement (like the windshield)...

[evanevery]

From the transponder documentation:

Make sure the X2 Transponder has a clear view to the track. Metal or carbon fibre underneath the transponder could block the signal.
Do not attach the transponder near the engine or the exhaust due to heat and vibrations.
Do not attach the transponder near high current AC wiring and/or systems e.g. KERS or other electric motors, xenon lights.

https://www.mylaps.com/data/sitemana...%20v2%2001.pdf

[M3 Number 86]

Originally Posted by evanevery

The transponder documentation specifically states it needs a clear view of the TRACK/PAVEMENT. The orientation and printing on the transponder itself also supports this ("down toward track"). I believe its triggered/detected by a loop or strip in the pavement. According to the docs, you can't place it anywhere on top of the car if it can't see the pavement (like the windshield)...

i guess it depends where the receiver is but doubt that it's placed on the ground. might be at pit wall if there is one. not sure.

the ones we use with our group we can put anywhere and it reads fine.

i'm trying to find a way how to start the lap with the transponder in the rear and then cross start/finish with it at the front. it should be a solid tenth. ha

[C-Mu]

I was wondering the same thing. Going to Auto Club Speedway for my first outing this weekend and rented a transponder. It seems like zip tied to the honeycomb lower front grill would work fine?

[evanevery]

I guess it depends on your car. In my M4 the (steel) bumper and oil cooler are located below the grill. In addition, I have the Fall Line Oil Cooler Guard down there as well. So the grill, for me, is likely not a good spot.

The nice thing about this transponder mount is I can use it in the front or rear tow hook location. The rear location requires the rod to be about an inch longer though to get the transponder out past the rear bumper. So if I need/want to run with a front tow hook in place, I can always mount the transponder out back. It won't matter for lap times as its position is all relative anyway...

The other thought which occurred to me was some sort of a soft mount which wraps over/around the passenger door handle. That should be out far enough to see down to the track as required.

...just following the guidelines in the documentation.

[evanevery]

Originally Posted by M3 Number 86

i'm trying to find a way how to start the lap with the transponder in the rear and then cross start/finish with it at the front. it should be a solid tenth. ha

The F8X is about 185" long (15.4 ft). 15.4 ft in a tenth of a second means 154 ft/sec which is about 105 mph crossing the line. So I think your estimate may be pretty close for many tracks!

Sorry - I just had to run the numbers...

[M3 Number 86]

Originally Posted by evanevery

The F8X is about 185" long (15.4 ft). 15.4 ft in a tenth of a second means 154 ft/sec which is about 105 mph crossing the line. So I think your estimate may be pretty close for many tracks!

Sorry - I just had to run the numbers...

Lol nice

Or maybe I have to finally buy a selfie stick to gain another tenth. Start further back and finish further forwards!

[evanevery]

What you want is a small catapult on the front of the vehicle. The transponder stays attached to the pre-loaded catapult until you come back around the front straight. Then, once the car is fully aimed down the front straight, you trigger the catapult to launch the transponder way down the track in front of you and over the start/finish line.

Of course, this will likely work only once...

[C-Mu]

This worked great yesterday. Sorry for the poor photo quality but it's a crop from a larger photo.

[scottn2retro]

When we permanently mount one in a car for the 135 and the e90 M3, we put it in the front wheel well along the inside wall where they put the ABS connectors and such and find a place where it can see the ground with no control arms in the way, but that is because we normally have a metal type splitter. We'll have to see where we go with it on this car, but we'll start looking in that same place

[ninekrpm]

this up

going to run a few TT's this year and just purchased a hard-wired transponder

given this thread is 8ish years old, wondering if there are updated suggestions on where to permanently mount a transponder

[GuyLedouche]

Originally Posted by ninekrpm

this up

going to run a few TT's this year and just purchased a hard-wired transponder

given this thread is 8ish years old, wondering if there are updated suggestions on where to permanently mount a transponder

From reading the previous comments on this you should get one of these and start with the transponder in the back then end with it in front. Worth a few thousandths for sure.

[OG Shark]

Originally Posted by ninekrpm

this up

going to run a few TT's this year and just purchased a hard-wired transponder

given this thread is 8ish years old, wondering if there are updated suggestions on where to permanently mount a transponder

I always like them to be on the external front - even hardwired. If its not meant to be permanent then use zip ties for easy on off and then unplug the wire to remove. Not a fan of them stashed somewhere inside the body.