Cupra ST 4x4 300 with Fox Exhaust!

p.eco

Active Member
Jun 24, 2014
227
16
Ireland
I come back with my impressions on the JeDesign flap exhaust, I have it mounted for two days now. In terms of sound, I would rate the flaps closed mode to a 5-6 out of 10 in terms of loudness (original would be a 2 out of 10) while the Cupra mode/flaps open is a full hooligan mode something like a 9 out 10 with clear pops and bangs when revving down, strong roar on accel and loud dsg booms when upshifting (definitely not 'farts').

But, there are two issues... I am not completely happy with the look of the new tips (a bit too visible, could not be pushed to the inside like stock, they stand out). And the annoying part is the deep low frequency tone in low RPMs, and when cruising at highway speed. The only way to mute the noise is to set cruise control to 62 mph/100kmh, that is the sweet spot. Anything more comes with constant humming.

Will consider musli's option to soundproof the back, did itvreally make a difference or not ? Was it worth it or is it money thrown away and extra weight ?

In any way, I see a pattern with 4drive exhausts suffering from these low frequency tones, even stock it was the only thing I could hear in terms of sound.

Edit: if it weren't for these annoying low freq sound I would have considered it the perfect upgrade, even though expensive (close to 3k euros in total with labour)

the constant low frequency droning at certain revs is the biggest issue of performance exhausts. Soundproofing will help, but the result depends of product that you use. The effect on estate cars is not as good as on sedans due to open space in the boot...
 

madvello

Active Member
Jul 6, 2017
38
0
Estonia
But in general, better then you expected or waste of the money?
I have also sound proof (all doors, boot), but should do back seats also.
 

p.eco

Active Member
Jun 24, 2014
227
16
Ireland
But in general, better then you expected or waste of the money?
I have also sound proof (all doors, boot), but should do back seats also.

I was expecting more, but i did only boot with wheel arches & back door. maybe if i decide to do whole car the result will be better... If you want performance exhaust you must also love the noise that it makes ;)
 

musli

Active Member
Aug 12, 2015
62
0
Czech Republic, Prague
I've extended the soundproofing to complete cabine floor and also the inner sides of the boot and have to say its now nearly perfect, even my wife is ok with the new exhaust so its not just my placebo. Its no problem to drive 180 - 220km/h, the annoying deep sound is not there. I still dont have the middle resonator replaced so we'll see how will that change the sound more. Will post some pics later, they had to remove all the seats and everything so it was a lot of work.
 

musli

Active Member
Aug 12, 2015
62
0
Czech Republic, Prague
And few photos for those interested.

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gamer555

Active Member
Dec 6, 2008
133
0
Brussels
Nice work you have done there, I assume it also had a certain cost. How would you define the sound of the exhaust now, is it not too low now? How is it in high revs?

Here is my video with sound comparison https://youtu.be/vjlNWlgtGRI . I must admit I am getting quite fond of it and push the car all the time to enjoy the sound :) Still did not do long trips yet.
 
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musli

Active Member
Aug 12, 2015
62
0
Czech Republic, Prague
Nice work you have done there, I assume it also had a certain cost. How would you define the sound of the exhaust now, is it not too low now? How is it in high revs?

Here is my video with sound comparison https://youtu.be/vjlNWlgtGRI . I must admit I am getting quite fond of it and push the car all the time to enjoy the sound :) Still did not do long trips yet.

Very nice sound on the je exhaust! I am still waiting for the middle resonator so my exhaust is not complete yet. The soundproofing helped a lot with the lowest noises but i can still here the exhaust quite well and like it :) Actually my fuel cons went up by 10-20% because i tend to drive it on higher revs now :) the soundproofing was approx 800 eur.
 

madvello

Active Member
Jul 6, 2017
38
0
Estonia
Nice work you have done there, I assume it also had a certain cost. How would you define the sound of the exhaust now, is it not too low now? How is it in high revs?

Here is my video with sound comparison https://youtu.be/vjlNWlgtGRI . I must admit I am getting quite fond of it and push the car all the time to enjoy the sound :) Still did not do long trips yet.

But for everyday car? Would you recommend or not? I mean driving with family is different when you drive in Cupra mode usually. I like the JE sound, but normal driving it must be quiet, not loud.

I have similar sound proofing setup as Musli have, but not the floors.

I would rate the flaps closed mode to a 5-6 out of 10 in terms of loudness (original would be a 2 out of 10) while the Cupra mode/flaps open is a full hooligan mode something like a 9 out 10 with clear pops and bangs when revving down, strong roar on accel and loud dsg booms when upshifting (definitely not 'farts').
2x times upto 5x times diffrents from the original.
 
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gamer555

Active Member
Dec 6, 2008
133
0
Brussels
I only did city driving until now to leave the small one at the kindergarden, my wife is actually asking for Cupra mode all the time, the young one loves it as well. He manages to fall asleep when tired even with the car booming :)
Still the car cannot go completely quiet now, I accepted this aspect. For this reason I've bought the extra DB silencers from JeDesign to mute the flaps closed mode, in case we find it unusable for highway driving. Maybe will go for the dynamat proofing as well, but not a full one (too many kilos will slow the car on trackdays)
 

martpold

Active Member
Jun 23, 2018
1
0
Very nice sound on the je exhaust! I am still waiting for the middle resonator so my exhaust is not complete yet. The soundproofing helped a lot with the lowest noises but i can still here the exhaust quite well and like it :) Actually my fuel cons went up by 10-20% because i tend to drive it on higher revs now :) the soundproofing was approx 800 eur.

Did you install the middle silencer by Fox?
Did it change anything
 

Damo H

Remind me, what's an indicator?
Staff member
Moderator
Oct 3, 2012
4,710
2,804
Car Length In Front
Never seen this thread before till now.

I really wanted the JE Design exhaust, but it was just too expensive. I looked at the Fox exhaust a few times, and nearly bought one on eBay
- in fact their site gave me the idea to paint the rear plastic.

So glad I avoided both now.

The BCS powervalve exhaust is perfect. Unlike the JE design where you can choose when to open the valve, it only up opens on boost.

This means it’s nice and quiet when cruising, no drone etc. But on boost sounds like the car should have an ASBO.

Other advantage of this setup is apparently low end grunt not being sacrificed for top end power. Not sure if it impacts with a standard cat, but the fact the freer flowing route of the exhaust is kept closed when off boost, means it still builds up the boost quicker lower down the rev range.

Also no button pressing if you want a bit of noise, just use your right foot.

Only disappointment, the pops and cracks I was expecting on lift off aren’t really there, as the valve closes off, when off boost, so naturally they’re muted quite quickly.
 
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