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OK guys, here is how you snake the wire into the car very easily:
The rubber grommet that you can access is the one I'm pointing to:
To pull through into the inside, you need to pull out the top shelf trim that is right up against the window. If you have bucket seats and a cage, you're gonna need a little helper. If you don't a little helper, you're gonna have to remove the seats in order to get back there.
Just wanted to thank Mech33 again for this how-to. I finally assembled the device and will test it at Laguna on Jan. 30.
Hope it works for you! If you didn't already, I'd highly recommend putting the "debug" firmware on the unit and double checking that the valves switch open and closed every few seconds (don't forget to make sure the sport exhaust button I stressed otherwise valves will stay quiet the whole time during the test).
If that works then running the GPS-based firmware at the track should be good to go.
This mod as described in this post is for the *991 GT3* only. Some folks have reported it working as-is on the 981 Cayman S, but I haven't not confirmed it first-hand. This mod is confirmed to *NOT* work on the 997.2 GT3 as described in this post, as that car switches the low side (ground) of the valve instead of the high side (battery voltage). The GPS switch wiring and harness need to be modified to work for the 997.2 GT3 (which I've done by hand for one 997.2 owner). If there is significant interest in this for the 997.2 GT3, I can describe how the wiring is modified for folks in another thread.
For those already using this device, I've rev'd the Laguna Geofence software to version 6. This now includes a built-in diagnostic mode at startup to allow debugging of potential exhaust control issues at the track.
Upon every initial power-up, the unit will go through a diagnostic sequence where it switches between "quiet mode" and "OEM mode" every 2 seconds for a total of 4 sequences. To make use of this diagnostic mode after flashing version 6 onto the system, start the car and press the PSE button to idle the motor in the loud exhaust state. Then power the GPS board, and it should toggle the exhaust between quiet and loud every 2 seconds a total of 4 times. If the exhaust simply stays loud during this time while PSE is active, then check the wiring / function of the mods. If the idle sound correctly switches between quiet and loud, then the valve override control is working.
If the valve control is working but you are failing sound, double check that the GPS fix LED on the board is blinking at a rate of once every 10 seconds. It initially blinks once per second until it gets a location lock. Double check that the top of the board isn't obstructed by metal objects if you can't seem to get a fix within 5 minutes of waiting (an initial fix after a long time between power-ons can take a while).
Mech33, what you did is just great! Thank you! I recently built it for my Cayman GTS. It works! I must note though that at least in my car "+V_ECM-side" and "GND" are reversed compared to what you indicated in your build instructions. I know that some guys with Caymans build it exactly following your instructions and it works! I guess it works even if the ECU is being backdriven by external 12V.
Originally Posted by Mech33
*UPDATE*
This mod as described in this post is for the *991 GT3* only. Some folks have reported it working as-is on the 981 Cayman S, but I haven't not confirmed it first-hand. This mod is confirmed to *NOT* work on the 997.2 GT3 as described in this post, as that car switches the low side (ground) of the valve instead of the high side (battery voltage). The GPS switch wiring and harness need to be modified to work for the 997.2 GT3 (which I've done by hand for one 997.2 owner). If there is significant interest in this for the 997.2 GT3, I can describe how the wiring is modified for folks in another thread.
P.S. That's my first post here on rennlist. But I've been active on planet-9 for some time now.
The valves in my exhaust were not working right - looked like a vacuum leak. I did not get it fixed before my Laguna day, so I just ran it with valves shut by a paint bucket handle. Worked well, except it came off once, and the car was pulling timing just after a few laps. So I'll do my best to get it sorted out before the next track day.
I was at Laguna Seca yesterday for a 90db day and one of my coworkers ran his 991GT3 with the GPS controlled valves and simple turn-up pipes and he had no problems passing 90db.
I didn't use the GPS-controlled valve solution but turn-ups with supertrapps and was able to pass 90db without issues too... picture below
08-28-2015, 07:45 PM
