Exhaust flap switch
#196
This one on the picture seems to be grounded on the nut to the left of the cargraphics unit. I mounted mine on the left side of the trunk compartment, behind the carpet and grounded it on the coolant filler cap mount screws. I was afraid that the double sided tape would wear off with time on the engine heat and vibration and the thing would be hanging by the engine.
#197
I’ve only driven with the top down so far.
On the positive side, the exhaust is considerably louder from 2-4K and it’s nice not to have the abrupt transition when the valves open ~4K with the stock setup; the linear increase in noise with engine speed makes the car easier to drive, and now you can hear the exhaust when in 5th or 6th cruising at 60-70 mph, as opposed to hearing mostly wind noise previously.
On the slightly negative side, I can’t say I’m that pleased with the tone of the exhaust from 2-3K. It still seems slightly flat and buzzy to me.
So, more exhaust mods are coming...
The following users liked this post:
SpeedySpidey (09-26-2020)
#198
Rennlist Member
OPF is only part of the issue. The stock rear silencer is far more of a bottle neck than the OPF and due to no mixing from bank 1-2 with valves open (as per pretty much all of the aftermarket systems) the main cause of the flat and uninteresting sound.
Remember you're hearing 2x 3cyl sound rather than 1x 6cyl sound with this stock exhaust arrangement. Think of it like the exhaust sound is akin to a pair of 2.0 3cyl engines, not really what any Porsche owner is looking for.
See image below for a visual demonstration. Green flow is valves open, the gasses will always take the path of least resistance. Red is valves closed.
Removing the OPF will just accentuate the OEM exhaust note, it gets louder with the OPF removed but louder doesn't always mean better. In many cases, as with the 718 rear silencer arrangement, the sound is even more 'tractor' low frequency tone than ever.
Just a word of warning as to what to expect if you remove the OPF with factory exhaust or swap to any exhaust with no proper merge between bank 1-2 of cylinders.
Making an exhaust loud is easy. Making an exhaust add power, sound great and be quiet / loud when you want it to really isn't.
JC
Remember you're hearing 2x 3cyl sound rather than 1x 6cyl sound with this stock exhaust arrangement. Think of it like the exhaust sound is akin to a pair of 2.0 3cyl engines, not really what any Porsche owner is looking for.
See image below for a visual demonstration. Green flow is valves open, the gasses will always take the path of least resistance. Red is valves closed.
Removing the OPF will just accentuate the OEM exhaust note, it gets louder with the OPF removed but louder doesn't always mean better. In many cases, as with the 718 rear silencer arrangement, the sound is even more 'tractor' low frequency tone than ever.
Just a word of warning as to what to expect if you remove the OPF with factory exhaust or swap to any exhaust with no proper merge between bank 1-2 of cylinders.
Making an exhaust loud is easy. Making an exhaust add power, sound great and be quiet / loud when you want it to really isn't.
JC
1. Is the green flow line (valves open) strictly correct? i.e. with the valves open does the exhaust flow effectively bypass the bulk of muffler as shown.
2. With valves closed (red line), how much mixing actually takes place inside the muffler.
3. do you have a picture of exactly what is inside the muffler box
Thanks
#199
Basic Sponsor
Rennlist
Site Sponsor
Rennlist
Site Sponsor
Looping back to this earlier post of yours JCR-Porsche, I have a couple of questions regarding the OEM Muffler.
1. Is the green flow line (valves open) strictly correct? i.e. with the valves open does the exhaust flow effectively bypass the bulk of muffler as shown.
2. With valves closed (red line), how much mixing actually takes place inside the muffler.
3. do you have a picture of exactly what is inside the muffler box
Thanks
1. Is the green flow line (valves open) strictly correct? i.e. with the valves open does the exhaust flow effectively bypass the bulk of muffler as shown.
2. With valves closed (red line), how much mixing actually takes place inside the muffler.
3. do you have a picture of exactly what is inside the muffler box
Thanks
With our system all exhaust gasses head via the merge in the centre prior to exiting the tips. Any system which doesn't have this will sound flat as per the OEM exhaust which in my opinion sounds terrible.
JC
__________________
WE'RE NO LONGER ACTIVE ON THE RENNLIST FORUMS - FOR ALL ENQUIRIES PLEASE CONTACT US VIA THE JCR WEBSITE BELOW
/ / / JCR PORSCHE \ \ \
contact@jcr-developments.com
Facebook | Instagram | Youtube
/ / / JCR PORSCHE \ \ \
contact@jcr-developments.com
Facebook | Instagram | Youtube
#200
bumping this thread to hear from anyone who has experienced this mod long term, any issues?
#201
for those who have done it, is it as simple as it appears in this vid at the 6 min mark on the 4.0s?
#202
Rennlist Member
You are much better off with the "collar" mod because it is adjustable and doesn't require you to remove anything. See this post
https://rennlist.com/forums/718-gts-...l#post18054149
https://rennlist.com/forums/718-gts-...l#post18054149