M40i aftermarket exhaust

[R10 WST]

Hi hopefully only a couple of weeks before I get my my m40i, and I was wondering if anybody has replaced the rear back box yet. This is a mod I'm interested in as I think the car could be a little louder.
Also has anyone had one mapped or chip box tuned. I have seen a video from racechip, which upped the power to 408bhp.

 

[Adil_3]

I think the supra forums would be a better help to be honest :lol:

 

[Fletch]

Hi, not sure about the exhaust mod it seems fine to me but everyone is different, good luck if you decide to do it. Regarding tuning the B58 it’s a very good engine for tuning, however be careful with your insurance/warranty I’m not sure how this would be effected, if anyone knows please comment. If you decide to go to racechip then it’s a very straightforward mod as shown on this video and they can increase the hp by 63bhp and improve the MPG by 20%, so they say. I wouldn’t re-map the engine as your changing your car engines computer (ECU), the benefit of the chip is you can fit and remove yourself.

https://m.youtube.com/watch?v=MB90GK_MI98

 

[Matlough]

Evolve in Luton would be the people to speak too. They are experts in BMW tuning products and are also developing a Supra at the moment.

I have used them in the past for various BMW tunes and they are a very professional outfit.


https://www.evolveautomotive.com/makes/bmw.html

 

[AndyT]

I'm also interested in exhaust mods as it is a bit on the quiet side.

AC Schnitzer do an exhaust but not sure what it will sound like (but shouldn't invalidate warranty if BMW fit it) although I love the sound of the manhart one
https://youtu.be/Y9IhZuji-RY
But this one probably will invalidate the warranty.

If anyone else has any other suggestions I'd also love to hear.

 

[Spro]

I would also like a fruitier exhaust note on G29 M40i but a Titanium back box for 10% of the total car value is too much for me .
On my E89 I just removed the vacuum pipe and the exhaust flaps stayed open.I wonder if you can un plug the cable to the exhaust flaps or would that mess up the engine management ?
Andy

 

[Number5]

We've touched on this on the G29 market Watch thread.
Below are a couple of images that I think look much better than the box sections, but with modding a brand new car, you need to consider voiding any manufacturers warranty

 

[john-e89]

You’d think the AC Schnitzer system would let you keep the warranty wouldn’t you. Whether it’s loud enough is another matter, especially when compared with the Manhart crazy. Always difficult to judge from videos but probably zero chance of hearing one in the flesh even when we’re free again. Tough choice but once you’ve heard what can be done with an aftermarket system I’d guess it’s hard not to want one, they do sound fruity..!

 

[Smartbear]

Hi, not sure about the exhaust mod it seems fine to me but everyone is different, good luck if you decide to do it. Regarding tuning the B58 it’s a very good engine for tuning, however be careful with your insurance/warranty I’m not sure how this would be effected, if anyone knows please comment. If you decide to go to racechip then it’s a very straightforward mod as shown on this video and they can increase the hp by 63bhp and improve the MPG by 20%, so they say. I wouldn’t re-map the engine as your changing your car engines computer (ECU), the benefit of the chip is you can fit and remove yourself.

https://m.youtube.com/watch?v=MB90GK_MI98

Remapping is more sophisticated than a plug in box & considered better for the engine
Rob

 

[M1k3yC]

You may want to be careful if the car is on finance, too:
https://www.thisismoney.co.uk/money/cars/article-7140919/Can-modify-car-finance-dangers.html
https://www.parkers.co.uk/car-finance/advice/modifying-cars-on-pcp/

Admittedly, Ricky went to the extreme and was very public about it, but it's worth checking out I would have thought.

 

[john-e89]

When I went to enquire about a new car just before lockdown I asked the sales guy to check wether the AC Schnitzer system would keep the warranty but I hadn’t thought of the fact the finance broker would own the car as well so the above post is very informative so thanks for posting.

 

[Nictrix]

Just read that link, wow, he got the car on PCP so if Im right in saying he was renting the car for a period of time with the chance of buying it at the end of the contract. He has basically modified a hire car. It seems a bit stupid to me.

 

[sunnydays]

Hi hopefully only a couple of weeks before I get my my m40i, and I was wondering if anybody has replaced the rear back box yet. This is a mod I'm interested in as I think the car could be a little louder.
Also has anyone had one mapped or chip box tuned. I have seen a video from racechip, which upped the power to 408bhp.

I would explore mhd and bm3 as avenues of remapping, very popular on the m3s and m4s which also use the b58.

You may want to be careful if the car is on finance, too:
https://www.thisismoney.co.uk/money/cars/article-7140919/Can-modify-car-finance-dangers.html
https://www.parkers.co.uk/car-finance/advice/modifying-cars-on-pcp/

Admittedly, Ricky went to the extreme and was very public about it, but it's worth checking out I would have thought.

Ricky's car was running hybrid turbos and methanol injection, hardly comparable to a simple exhaust swap or remap.

 

[R10 WST]

I'm going to have a rethink about tunning, might just go with a race chip tuning box, or a MHD flash. That way I can revert back if need be. But I'm going to ask if I can install a either Remus or Ac shnizter back box. Without it affecting my warranty.
I had taken my car to a tuner up in Yorkshire to be remapped, but the couldn't de code it. Said it had a different encryption to a M140i . Really I'd be happy with a little bit more umph and more burble.
But on the whole I'm happy with the car

 

[john-e89]

Take it over to Manhart in Germany for a 440 tune up and their utterly mad as a box of frogs ‘Zorsts....Stay 2 nights there, eat some sausage, drink some beer, home again with a bonkers Zed...

 

[craig3.2]

Take it over to Manhart in Germany for a 440 tune up and their utterly mad as a box of frogs ‘Zorsts....Stay 2 nights there, eat some sausage, drink some beer, home again with a bonkers Zed...

Good option,I like Manharts stuff/mod'd cars,as you say John,it would be a bonkers z

 

[john-e89]

Take it over to Manhart in Germany for a 440 tune up and their utterly mad as a box of frogs ‘Zorsts....Stay 2 nights there, eat some sausage, drink some beer, home again with a bonkers Zed...

Good option,I like Manharts stuff/mod'd cars,as you say John,it would be a bonkers z

If not already have a viewing of “Hi I’m SHMEEEEEEEEEEEEEEE....” on the Manhart M40i Craig....I’d seriously consider gambling the warranty on this conversion...it sounds truly bonkers...!

 

[Spro]

I agree the M40i exhaust in Sport Plus is not that fruity. This is my Third Z4 and all suffered the same issue.The E89 was easy to fix just remove the vacuum pipe from the rear that actuates the flaps. Improves by about 10%.
I find new systems are too expensive at £2,000 plus.
I do think the four tail pipes look good , if only the sound on the stock system was more like the F Type , although they are too
loud and annoying after 20 minutes driving .

If there is a cheap option I would be interested .
Andy

 

[handymanuk]

This was an interesting video where Rory Reid talks about exhaust noise and the law in the UK/EU:

https://youtu.be/bQVOkpLDEtU

All of these aftermarket systems, are they legal? For people that straight pipe their exhaust, how do they still pass the MOT? I'm a bit confused.

 

[R10 WST]

I've been in talks with Litchfield, and they suggested the Remus axle back system. With a stage 1 remap. And say that would give around 440bhp.the Remus has the 4 tail pipes and is supposed to be a deeper sound.
I'll let you know what it sounds and looks like.
Rich