S40 (New) Engine Turbo : Help with exhaust mods

[Justas14]

Hello,
this is a bit of a weird thread in advance

So as I'm a fan of a bit more aggressive exhaust sounds, I've removed my catalyst (I've added a Simons round exhaust instead) and whole trunk area exhaust block.

So basically the exhaust is currently at:
Engine -> Simons exhaust tank -> Original resonator -> My added resonator at the end (seen at the photo top left and mid right)



The sound is lovely, but it also provides an incredibly low pitch annoying sound at 2K-3K RPM in interior - anything above or below that area is great and not that loud

I did add additional soundproof isolations at the trunk (even externally too) as well as in all the doors


Now I wonder how to solve this:
1) Making it a single exhaust instead of two - the exhaust comes as one piped from the engine Please tell me someone has tried this
I believe this as a fix maybe, as my friend has a 850 T5, the whole exhaust pipe only has Simmons tank and one resonator - nothing else The sound is pretty loud outside, but it doesn't reflect too much inside Especially the low pitch (bass) noise which I'm trying to remove! and it doesn't have any aftermarket soundproof isolations.

2) Redoing the trunk area - especially the area where the split occurs?



Did anyone done this before/know a solution maybe? Or is this engine simply have flaws in such sides as this (as I do know a person who has a Ford S-Max that has an exhaust like this and the low pitch noise is something he can't get rid of either (having dual exhausts as well)).

[Markos01]

How many miles have you driven with this set up?

I had a smaller back box fitted to my C30 T5 and it gave a really nice deep tone, but around 2200rpm in the wrong gear it gave a horrible droning effect that you felt right in your head. I was going to add another small resonator to deal with it but after a couple of thousand miles the exhaust sooted up a little I guess and that dealt with the drone, so it sorted itself.

I've no idea if going single exit would solve your drone, bit it will alter the length of pipe so will alter the sound. I did some research and discovered some people added a 'J' shape closed pipe which got rid of the drone, but there's some maths you need to know to understand how long that must be to effectively deal with the drone... was beyond my C grade GCSE maths for sure!

[Welton]

I'm assuming your car is Petrol-engined and non-turbo?

Non-turbo exhausts can be extremely loud without enough silencing.

My only observations with your system are:

The bend after the rear axle is very tight (to make room for the Y-piece ready for the twin rear exits) - this could be a source of unusual sound.

There could be a 'resonance' between the two rear exits - a harmonic sound amplifying the noise problem.

I'm guessing the exhaust system has been fabricated to suit what you asked for as a 'one off' design rather than tested out for use with this car.

Have you increased the diameter of the tubing from the standard system?

[Justas14]

Originally Posted by Markos01

How many miles have you driven with this set up?
I had a smaller back box fitted to my C30 T5 and it gave a really nice deep tone, but around 2200rpm in the wrong gear it gave a horrible droning effect that you felt right in your head. I was going to add another small resonator to deal with it but after a couple of thousand miles the exhaust sooted up a little I guess and that dealt with the drone, so it sorted itself.

Around 4000 miles, but no change in sound yet

Originally Posted by Markos01

I've no idea if going single exit would solve your drone, bit it will alter the length of pipe so will alter the sound. I did some research and discovered some people added a 'J' shape closed pipe which got rid of the drone, but there's some maths you need to know to understand how long that must be to effectively deal with the drone... was beyond my C grade GCSE maths for sure!

The J thing actually was tried on Ford, but it didn't help - moreover I believe this would definitely result in some big power loss as the passage for gas becomes harder

Originally Posted by Welton

I'm assuming your car is Petrol-engined and non-turbo?
Non-turbo exhausts can be extremely loud without enough silencing.

No, it's a turbo petrol with a stage 1

Originally Posted by Welton

My only observations with your system are:

The bend after the rear axle is very tight (to make room for the Y-piece ready for the twin rear exits) - this could be a source of unusual sound.

There could be a 'resonance' between the two rear exits - a harmonic sound amplifying the noise problem.

I'm guessing the exhaust system has been fabricated to suit what you asked for as a 'one off' design rather than tested out for use with this car.

Have you increased the diameter of the tubing from the standard system?

The bend is indeed tight, but mostly all aftermarket (even stock ones) have a huge bend in this area.

The problem indeed is that resonance, I'm trying to figure out if it indeed can be caused so much due to dual exhausts (as mentioned previously, friend's T5 850 has one exhaust (yes the engines are slightly different, but I doubt that on such a high level)) so single pipe might sort it out maybe?

The diameter wasn't changed - the size is the same as it comes from the engine

[domhart10]

what engine is yours? did you put on a 3" exhaust?

I have had 3 aftermarket exhausts on my car.

First one was a 2.5" powerflow / jetex system, this was exhaust had 0 drone and was perfect.

I also had a straight piped single exit 3" exhaust, this was not just incredibly loud and full of bangs and flames, but it droned awfully!

have another custom 3" exhaust made and it is quieter but still drones at around 3k - 4k

This is mine
https://www.instagram.com/p/B-WV17el...on_share_sheet

[Justas14]

Originally Posted by domhart10

what engine is yours? did you put on a 3" exhaust?

I have had 3 aftermarket exhausts on my car.

First one was a 2.5" powerflow / jetex system, this was exhaust had 0 drone and was perfect.

I also had a straight piped single exit 3" exhaust, this was not just incredibly loud and full of bangs and flames, but it droned awfully!

have another custom 3" exhaust made and it is quieter but still drones at around 3k - 4k

This is mine
https://www.instagram.com/p/B-WV17el...on_share_sheet

Is the exhaust in instagram the powerflow/jetex one? Also as it has no drone as you say, but is it louder than the stock one though?

Also did you remove everything before the trunk? A.k.a the catalyst and the original resonator? Or left something there as well?

Edit:
Sorry, haven't noticed the 3'' mark in the instagram. Can you give more info about the ideal 2.5'' one which didn't drone?
something like this?

[domhart10]

Originally Posted by Justas14

Is the exhaust in instagram the powerflow/jetex one? Also as it has no drone as you say, but is it louder than the stock one though?

Also did you remove everything before the trunk? A.k.a the catalyst and the original resonator? Or left something there as well?

Edit:
Sorry, haven't noticed the 3'' mark in the instagram. Can you give more info about the ideal 2.5'' one which didn't drone?
something like this?

Sorry I wasnt clear, that instagram photo is of the custom 3" exhaust. The 2.5" Jetex system was the one that didnt drone. But yes that link is correct.

With my current setup I just have those rear mufflers, previously on the single exit system, it was a complete straight through with everything gutted out.