Exhaust Modifications

4.2 V8 32v Naturally Aspirated - 414 bhp
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jamiej
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Joined: Tue Apr 03, 2018 4:06 pm

Exhaust Modifications

Post by jamiej » Fri Jul 05, 2019 7:02 am

So apologies as I am sure this may have been asked in a round about way before but...

Modding my standard exhaust.

Every part of me say "delete the centre resonator and replace with straight pipes, with or without an X or H pipe".

However, I was having my Kuga (oh yes!) undersealed by a custom Shop in Emsworth yesterday and discussed my RS4 exhaust with them.

They seemed to know a fair bit about the RS4 and scoffed at the thought of deleting the mid boxes, but instead recommended deleting the rear boxes?

Less drone and a better noise, I'm told, and if my back box valves aren't working anyway (they are not) then that functionality will not be missed.

What's the thoughts?

Are this chaps comments a little out of date, or is there a real argument for deleting the rear boxes and leaving the middle section on place?

All to be tig welded by a robot. Sounds futuristic!

Lastly, these guys seem to know how to custom build things, so a full system is definitely not out of the question. Does anyone know what back boxes the JC Weldfab guys use, my memory tells me they are from a Bentley.

Cheers chaps.

Happy Friday everyone.

J

Sent from my ONEPLUS A6013 using Tapatalk


Last edited by jamiej on Fri Jul 05, 2019 7:02 am, edited 1 time in total.
Current
'07 - Audi RS4 Avant Daytona Grey
'16 - BMW M135i F20 (LCI)
Gone
'02 Audi 8L A3 1.9 TDI (PD)
'03 Subaru Impreza WRX STI
'96 VW Golf VR6
'91 Toyota MR2 NA
'90 Peugeot 205 GTI 1.9
'90 VW Mk2 Golf GTI 8V

coffey555
5th Gear
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Joined: Wed Aug 17, 2011 2:41 pm

Re: Exhaust Modifications

Post by coffey555 » Fri Jul 05, 2019 9:22 am

Deleting the central resonators is the single best modification I have done to my car. No drone and the noise is wonderful.

You could try doing things the other way around but it is a risk as I don't remember anyone else doing it before.

There was one guy that had no cat, no centre res and no back boxes but my guess would be that it sounded very loud and very <beep>.

If I remember rightly JCWeldfab will add or remove wadding from the back boxes to change the exhaust sound as required. If you don't have back boxes, you can't do that.

Not sure about the TIG welding robot, my straight centre pipes were done on the car to make sure everything was aligned.
Misano Red RS4 B7 Avant

**wilkie**
Neutral
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Joined: Thu Jan 24, 2019 8:54 pm

Re: Exhaust Modifications

Post by **wilkie** » Fri Jul 05, 2019 3:13 pm

I replaced my resonator with an ECS H pipe last week. The sound is great for me, deeper and +25% volume I would guess. You can also hear a bit of rasp above 5k with the rear windows open.
During the process I ran the engine briefly with the resonator in place but with the rear boxes disconnected to see how it sounded. Obviously it was loud, but it sounded good to me.
Unable to test it above 3-4k as it was on the ramps on my drive, but I imagine it would be very loud at higher revs.

I initially ran the back boxes with the vacuum lines plugged so the valves were permanently open but I noticed some drone when in higher gears and coming on/off the throttle slightly which got a bit annoying, so I've reconnected the valves and now it's ideal as I have the choice.

asifg
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Posts: 287
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Location: Milton Keynes

Re: Exhaust Modifications

Post by asifg » Fri Jul 05, 2019 5:17 pm

coffey555 wrote:
Fri Jul 05, 2019 9:22 am
Deleting the central resonators is the single best modification I have done to my car. No drone and the noise is wonderful.
This.

I said exactly the same on here when I did my RS4. Trust us and don't hesitate! You won't regret it!

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MikeFish
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Joined: Tue Aug 31, 2010 9:23 pm
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Re: Exhaust Modifications

Post by MikeFish » Fri Jul 05, 2019 7:56 pm

asifg wrote:
Fri Jul 05, 2019 5:17 pm
coffey555 wrote:
Fri Jul 05, 2019 9:22 am
Deleting the central resonators is the single best modification I have done to my car. No drone and the noise is wonderful.
This.

I said exactly the same on here when I did my RS4. Trust us and don't hesitate! You won't regret it!
Yep me too. After spending thousands and thousands on various combinations this is what I ended up with; the cheapest of them all.

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MikeFish
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Joined: Tue Aug 31, 2010 9:23 pm
Location: The Middle of Somewhere

Re: Exhaust Modifications

Post by MikeFish » Fri Jul 05, 2019 7:57 pm

jamiej wrote:
Fri Jul 05, 2019 7:02 am
So apologies as I am sure this may have been asked in a round about way before but...

Modding my standard exhaust.

Every part of me say "delete the centre resonator and replace with straight pipes, with or without an X or H pipe".

However, I was having my Kuga (oh yes!) undersealed by a custom Shop in Emsworth yesterday and discussed my RS4 exhaust with them.

They seemed to know a fair bit about the RS4 and scoffed at the thought of deleting the mid boxes, but instead recommended deleting the rear boxes?

Less drone and a better noise, I'm told, and if my back box valves aren't working anyway (they are not) then that functionality will not be missed.

What's the thoughts?

Are this chaps comments a little out of date, or is there a real argument for deleting the rear boxes and leaving the middle section on place?

All to be tig welded by a robot. Sounds futuristic!

Lastly, these guys seem to know how to custom build things, so a full system is definitely not out of the question. Does anyone know what back boxes the JC Weldfab guys use, my memory tells me they are from a Bentley.

Cheers chaps.

Happy Friday everyone.

J

Sent from my ONEPLUS A6013 using Tapatalk
I think that will make it very very loud.

JC Weldfab make their own complete exhausts to my knowledge but use Bentley valves.

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jamiej
2nd Gear
Posts: 204
Joined: Tue Apr 03, 2018 4:06 pm

Re: Exhaust Modifications

Post by jamiej » Fri Jul 05, 2019 9:17 pm

Thanks guys. Knew I'd get the answer from here! Will report back!

Sent from my ONEPLUS A6013 using Tapatalk

Current
'07 - Audi RS4 Avant Daytona Grey
'16 - BMW M135i F20 (LCI)
Gone
'02 Audi 8L A3 1.9 TDI (PD)
'03 Subaru Impreza WRX STI
'96 VW Golf VR6
'91 Toyota MR2 NA
'90 Peugeot 205 GTI 1.9
'90 VW Mk2 Golf GTI 8V

Seattle-squash
2nd Gear
Posts: 182
Joined: Sun Jun 21, 2015 5:33 pm

Re: Exhaust Modifications

Post by Seattle-squash » Sun Jul 07, 2019 8:12 am

Drop the center box, replace with X!

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