Transponder Mounting Location

[Rick Iverson]

Gents;

I was thinking about this.

I intend to mount my non-hardwired xponder in the fore section on my RF95 crush structure. Hole diameter vs mounting height, anyone?

Say the hole diameter is 1.00” OD, with the xponder 0.50” above the inside bottom of the crush structure. As there is a ton of aero monkey business at the nose of these cars at speed, any need for a some sort of a slightly curved air dam on the bottom of the box to prevent laminar airflow being introduced into the box? Overthinking?

[DaveW]

See post #4 - that one (supposedly the same link address) worked for me.

[alangbaker]

https://www.apexspeed.com/forums/sho...onder+mounting

For some reason, that link doesn't work for me.

[DaveW]

That's funny - it came up in a search, but it didn't work for me when I just tried it either.

Searched for "transponder mounting" again and the same thread came up: https://www.apexspeed.com/forums/sho...onder+mounting

This time the supposedly same link (above) worked for me.

That search also turned up a number of other threads, but the above is the only one I referenced.

[Hardingfv32]

The transponder signal is magnetic. The output is not a cone shaped. Made the hole as big as the unit and mount as close to the hole as possible. Cover the hole with duct tape or glue on a thin sheet of plastic.

Brian

[dereklola]

I always mounted mine at the rear - less signal obstruction.
Having it in front doesn't help you win!

[Lotus7]

... less signal obstruction.
....

how so? Thx

[racerdad2]

I always mounted mine at the rear - less signal obstruction.
Having it in front doesn't help you win!

First transponder across the line wins... Having scored a podium by 5 milliseconds in karting, every inch matters when you're side x side, wheel to wheel & it's too close to call by sight at finish.

[Peter Olivola]

First transponder across the line wins... Having scored a podium by 5 milliseconds in karting, every inch matters when you're side x side, wheel to wheel & it's too close to call by sight at finish.

That may be how they do things in karting. SCCA, not so much. Timing is by transponder. Scoring is by Mk 2 eyeballs.

[bob darcey]

The wires in the track loop are supposed to be ~24" apart. If both wires have to "see" the signal simultaneously (and I don't know if that is so), the mounting geometry would have to accommodate that. Bigger hole, transponder closer to the hole and elongating the hole fore to aft might help.

[Hardingfv32]

Magnetic signal... both wires would see the same signal strength at only one track position... say at an equal distance apart. I believe the unit trips at a specified strength level each time. Somewhere along a output curve but usually well below the top of the curve.

Brian

[EYERACE]

Mine is mounted slightly up inside one side's pod.....that way it looks out at the track in front of the opening. It used to be on the side of the front nose crush box

[racerdad2]

That may be how they do things in karting. SCCA, not so much. Timing is by transponder. Scoring is by Mk 2 eyeballs.

Thx for clarifying that. I'll move mine to a "safer" location

[Zonker]

Magnetic signal... both wires would see the same signal strength at only one track position... say at an equal distance apart. I believe the unit trips at a specified strength level each time. Somewhere along a output curve but usually well below the top of the curve.

Brian

The timer trips when the signal level is equal on both wires; that should be exactly half way between the two. As Long as the signal is equal in both the actual level of the signal is not important.