Z4 35i vs 35is exhaust pops and bangs

[Limmys10]

Hi all, Just got my Z4 35i 09 DCT 2 days ago. The previous owner changed the backboxes for non-valved ones as it 'sounded better' but it seems to muffle the pops a lot.

I was considering fitting the IS exhaust, but looking at the parts (18307647050 & 18307647055). They don't seem too different so I was wondering if anyone knew what the differences were?

Essentially I want to be able to hear the pops bangs and burbles more as they sound very muted and muffled right now but don't want it too loud for my 6AM mornings hence wanting a valved system.

Also, if anyone knows where I can get an IS exhaust for under a grand as I really don't need a new one, that would be awesome!

Thanks

 

[mr wilks]

Don't waste your time or money sourcing 35is boxes if you want what you describe above , there was barely any audible difference (if any at all) between my 35i & 35is & the 35i with traditional remap was easier to get pops / cracks from than the 35is with MHD tune (though i opted for all settings at low & never tried raising them )
For around £150 MHD flashtune should suit you better as you can manipulate burbles & pops https://mhdtuning.com/ with this you can also tweak the wastegate setting if yours are at all rattly .
Welcome to the forum

 

[sunnydays]

Don't waste your time or money sourcing 35is boxes if you want what you describe above , there was barely any audible difference (if any at all) between my 35i & 35is & the 35i with traditional remap was easier to get pops / cracks from than the 35is with MHD tune (though i opted for all settings at low & never tried raising them )
For around £150 MHD flashtune should suit you better as you can manipulate burbles & pops https://mhdtuning.com/ with this you can also tweak the wastegate setting if yours are at all rattly .
Welcome to the forum

This op

MHD also let's you set pops and bangs in specific modes. Ie on in sports mode but off in normal. Also has a cold start noise reduction option for your 6am morning starts

 

[Limmys10]

Well it looks like I'm going to check out MHD Flasher BUT I don't have the standard BMW exhaust system as the backboxes were replaced... not sure how different it will sound with the pops in sport. we shall find out.

How safe is it? my car is on 50K so don't want to kill it after 2 days haha

 

[mr wilks]

Well it looks like I'm going to check out MHD Flasher BUT I don't have the standard BMW exhaust system as the backboxes were replaced... not sure how different it will sound with the pops in sport. we shall find out.

How safe is it? my car is on 50K so don't want to kill it after 2 days haha

Stage 1 would be totally safe , once loaded to your car via android device its very easy to access via the diagnostic port to alter / customise settings

 

[gwatson]

35is exhaust is supposed to be 10db louder which is quite a lot in theory.

I have one sitting in the garage, but not fitted it yet. Can't decide to go down that route or after market. I have a 30i not 35i

 

[mr wilks]

35is exhaust is supposed to be 10db louder which is quite a lot in theory.

I have one sitting in the garage, but not fitted it yet. Can't decide to go down that route or after market. I have a 30i not 35i

You are unlikely to get much by way of noise out of them from a 30i na compared with twin turbo , on both 35i / 35is i did the golf tee mod yet still had to work the car to get decent cracks / pops out of them on overrun , both gave a purposeful tone on cold start but quietens considerably after that

 

[gwatson]

Yes and no.

From my various test drives, I'd say a standard 30i exhaust is louder than 35i as we know turbos mute sound.

My thinking behind it was the 35is exhaust is basically the equivalent of the M performance exhaust, so if it's louder on a turbo car could be even higher dB with the NA engine. But yeah, it's a bit of a gamble if it'll give me the results I want.

 

[Limmys10]

So, turns out using MHD tuning is a little harder than I thought as I have to order a few things. Judging by what people have said I dont have valves in the back to do the golf tee mod so I think the back boxes are muting the sound more too but still don't really want to spend £1000 on the IS exhaust... besides custom exhaust I'm not sure what other options I have.

If I can easily find the MHD tuning bits ill try that but I think it will still be muted.

 

[mr wilks]

So, turns out using MHD tuning is a little harder than I thought as I have to order a few things. Judging by what people have said I dont have valves in the back to do the golf tee mod so I think the back boxes are muting the sound more too but still don't really want to spend £1000 on the IS exhaust... besides custom exhaust I'm not sure what other options I have.

If I can easily find the MHD tuning bits ill try that but I think it will still be muted.

Take the centre cat out , if you do so make sure its easy enough to bolt back in :wink:

 

[gwatson]

I could be tempted to part with mine, problem is shipping.

 

[mr wilks]

I could be tempted to part with mine, problem is shipping.

Wrapped well cheap enough with Paisley Freight https://www.paisleyfreight.com/

 

[Limmys10]

Wrapped well cheap enough with Paisley Freight https://www.paisleyfreight.com/

Just had a look and its too big, would need a pallet which is around £180 for delivery...

May have a look at some other options first haha

 

[Phoenixboy]

just stick a cd in that plays loud popping noises, and if your really adventurous , you could throw in some turbo weeeeeeehhhh :wink:

 

[gwatson]

Hi Liam,

www.parcel2go.com will do it for £24 (plus insurance if required) plus a mountain of bubble wrap. 3 day delivery.

Dimensions are 190 x 150 x 40 and weight is 20kg if you want to validate.

 

[mcbutler]

MHD is essentially a DIY map, unless you actually put it on a dyno you have no idea what you are getting performance wise. You also get no warranty against engine damage from the product (that I am aware of).
Regarding 'pops n burbles' I have the std pipes on my 35i and I just removed the vacuum pipe from the exhaust flap on the right tailpipe, opened the valve by hand and blanked the vacuum ports with silicone caps.
It sounds fabulous, in my (slightly) boy racer opinion

 

[sunnydays]

MHD is essentially a DIY map

Erm no. MHD is a DIY flasher, but not a DIY map. The out of the box maps are provided by wedge performance in germany, who are well known for their tuning of the N54 engine.

, unless you actually put it on a dyno you have no idea what you are getting performance wise.

What? It literally states, on the MHD website, the downloadable PDF guide, all over the E90 forums, and a quick google of "MHD Stage XX Power" will give you a very good idea of the power range to expect depending on your mods.

You also get no warranty against engine damage from the product (that I am aware of).

Given that the MHD maps have literally been through hundreds of revisions, I don't see why this would be needed. On top of this MHD has a monitoring module that allows you to monitor parameters of the car in real time, such as boost psi, waste gate duty cycle, fuel rail pressure etc. On top of this MHD has access to many of the inner tables that define important parameters, that many other flashers do not. It also has a code reader built in.

Regarding 'pops n burbles' I have the std pipes on my 35i and I just removed the vacuum pipe from the exhaust flap on the right tailpipe, opened the valve by hand and blanked the vacuum ports with silicone caps.
It sounds fabulous, in my (slightly) boy racer opinion

I am glad you are happy with the sound, but the golf tee mod does not give the level of pops and bangs as MHD does or the customisation.

 

[Limmys10]

Hi Liam,

www.parcel2go.com will do it for £24 (plus insurance if required) plus a mountain of bubble wrap. 3 day delivery.

Dimensions are 190 x 150 x 40 and weight is 20kg if you want to validate.

Ah its smaller than I put in and I thought it would weigh more than 20kg! Well parcel2go sounds pretty good then, just waiting for you to get the price of the eissenmann now

 

[Limmys10]

MHD is essentially a DIY map, unless you actually put it on a dyno you have no idea what you are getting performance wise. You also get no warranty against engine damage from the product (that I am aware of).
Regarding 'pops n burbles' I have the std pipes on my 35i and I just removed the vacuum pipe from the exhaust flap on the right tailpipe, opened the valve by hand and blanked the vacuum ports with silicone caps.
It sounds fabulous, in my (slightly) boy racer opinion

Boy racer opinons are entirely valid

I think with the exhaust and the MHD it could sound great, I'm just not sure where to buy the MHD parts at the moment. Need to look into it to see if anywhere sells the bits I need in the UK! Kept finding american sites.

 

[gwatson]

Yeah 17.1kg (plus packaging) according to http://bmwfans.info/parts-catalog/18307647050

I need to call Roy, will do that later this afternoon hopefully.