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[Didge3]

It seems I am on the cusp of returning to the Smart(er) side of life...
Having let go of my 1.1 Forfour 2-3 years ago which I thoroughly enjoyed but it started to need lots of consumables (suspension arms, bushes, brake discs etc etc) and its lack of creature comforts, namely working aircon and excessive road noise, I decided to get rid.
A few cars later and I'm considering a Brabus... Everytime I spot a Forfour out in the wild they always catch my eye and I figured why not try the spicier version?
A few questions that I can't find the answers for, 70mph in top comes at what RPM? I'm assuming it's geared a little taller than the buzzy 1.1?
Anyone applied sound deadening to theirs? As mentioned my 1.1 was pretty noisy on the motorway, I think if I took the plunge on a Brabus I'd want to try dynamat or similar to make it a bit more peaceful at speed.

[Bari87]

70mph=112kmh=about 2700rpm @454.034
No need for noise isolation at this speeds

[mr singh]

70mph...
No need for noise isolation at this speeds

i would beg to differ. having bought another car (a 2015 Jaguar XF TDV6) and then doing 400 or so miles to Ace and back... there is a fair amount of road noise, even at 70, in the 454, brabus or not.

[Bari87]

Thats why the Jag is fat and 454 is 1,1Tonnes.
Choose your weapon and dont compare apples with grapefruits. 454 is not louder then other MiniCars from thar year.

If you want a travel car buy a boring limousine etc. At 70mph even the crap audio system in 454 is louder then driving noise. Car gets loud at more at 160kmh, but thoose speeds dont affects you in countries with law & police.

Get tyres with 67db rather then with 70db and you have half less sound intensity pressure (logarithmic)

[Didge3]

70mph=112kmh=about 2700rpm @454.034
No need for noise isolation at this speeds

2700rpm sound reasonable, iirc the 1.1 was more like 3300.
Just because it doesn't strictly need noise isolation doesn't mean the car wouldn't benefit from it.
I'm coming from an EV where I have gotten very accustomed to relative quiet at speed. I'm never expecting a Brabus to be even remotely as quiet but if i can make it quieter than my old Forfour I would be more comfortable on longer trips

[Ocracoke]

The three cylinder thrum in the 1.1 will make it a little louder compared to the more balanced 4 cylinder engines, including the Brabus. My 1.3 is happy enough at 70mph where the loudest noise isn't the engine but more tyre roar though having an S-A, I don't know if 6th gear in that translates into the same RPM as a manual 5 speed. I think the steel wheels were marginally quieter than the Grandlines but it has been a while.

[Didge3]

Yep not so worried about engine noise although it's nice to know it should be quieter than the 1.1, it is the road noise I'm worried about as that also overcame the engine noise at 70mph in my old one. I'm very familiar with the 1.3, as your very car (assuming you still have DTU?) was my Mums for 3 or 4 years, it too not loud in engine but in road/tyre/wind noise. I'm just of the opinion something like dynamat under the carpets, in the doors, boot floor etc might help with this.

I'm guessing Brabus' are no less reliable than the rest of the range?
My new (to me) car choice is between a Abarth Grande Punto and a Forfour Brabus, the Abarth will be more refined but I prefer the Forfour so if I could bring its refinement levels up a bit it'll be a serious contender (that's if I can find a decent one for sale...)

[Ocracoke]

Yup, still have DTU.

[jmariog]

Go for the Brabus, very little rust, and at this time you should get a nice one for little money. And can only go up in value. Got mine 4 months ago and I am well happy, its used as a family car with the odd bit welly when I am on my own. I have kept my 1.5 AMT 454 as well.

[Didge3]

Go for the Brabus, very little rust, and at this time you should get a nice one for little money. And can only go up in value. Got mine 4 months ago and I am well happy, its used as a family car with the odd bit welly when I am on my own. I have kept my 1.5 AMT 454 as well.

They are tempting at pretty low prices although finding one isn’t that easy and most have lofty mileages where I expect they’ll need a lot of suspension renewing.
I did really enjoy my 1.1 and miss it bar the harshness, good car for momentum driving. It’s a testament to how good the Forfour is as I’d stepped out of a 240hp Saab into the 75hp Smart and still had fun!

Yup, still have DTU.

Good to hear, the iQ it was swapped for has gone and a Prius is in its place, the iQ and now the Prius have been just as rock solid as DTU was 👍🏼

[mr singh]

Thats why the Jag is fat and 454 is 1,1Tonnes.
Choose your weapon and dont compare apples with grapefruits. 454 is not louder then other MiniCars from thar year.

ok, if you want a similar comparison, i have driven a new Corsa, and that was still quieter than the forfour at 70mph!!

[Bari87]

So you compare a 'new' car with a car from 2004?! Apples and grapefruits.

Corsa C and 454 from 2004 is the same crap in that point. If your 454 is louder then a Corsa C then go and do maintance. After almost 16yrs on streets you are NOT comparing cars, you are comparing maintenance levels.

Once again: Even if your tyres are not the same, you can have easily 3-4db difference which is DOUBLE sound intensity. Even the belts you are using make difference, just compare crap OEM vs Ratorback etc

But since sound feeling is different to each ear here some hard facts:

Smart 454 1.5 measured noise inside:

50kmh/100kmh/130kmh = 59db/66db/72db

Corsa C 1.4 measured noise inside:

50kmh/100kmh/130kmh = 57db/66db/71db

So once again = identical crap at this speed as i told already. Just put quieter tyres on the 454 and its less noise. Put louder tyres at the Corsa C and its louder etc.

And finally as for the Brabus:

50kmh/100kmh/130kmh = 61db/68db/72db

Its truly visible that the 454 chassi is not louder then other MiniCars from the - same - age. Identical crap / not S-Class / Jaguar / Bentley.

[jmariog]

Have seen a few with around 80000 miles and looked after. They were £2500, also seen a few with lower miles , but one needed a little body work the other I got 😁£2400.

[mr singh]

Its truly visible that the 454 chassi is not louder then other MiniCars from the - same - age

so you are comparing YOUR brabus with cars of similar age? i know YOUR brabus has been sound proofed. comparing YOUR brabus to 'standard crap' as you so kindly put it is apples and grapefruits!

how a car has been maintained has no influence of the road noise. a car that has been poorly maintained could be quieter than a car that has been well maintained and vice versa.

i have been in fiestas/corsas of similar age to my forfour and they have been quieter than my 454 (which has been 'well maintained'). i get that tyres will make a difference but you cant get away from the fact that the panel gaps around the doors on the 454 are BIGGER than a fiesta/corsa of similar age. bigger panel gaps = more noise entering the cabin.

[Bari87]

What are you talking about?

I compared hard facts, measured by ADAC Germany as everybody can see and read who can handle Google.com. Dont even need to know german since its a simple comparison kmh to db.

I dont even have the tortoise 1.5 N/A so obvisiouly the mesaurument dont come from me.

I never measured my own Brabus cause i dont even hear the f**cking police sirens when its next to me when i drive. I just feel the bass kick in like it should be and getting my shoulders massage: https://tinyurl.com/kxa6w9u5

Just accept the Facts:

Smart 454: https://www.adac.de/_ext/itr/tests/Autotest/AT1179_smart_forfour_1_5_passion_softouch_plus/smart_forfour_1_5_passion_softouch_plus.pdf

Opel Corsa C: https://www.adac.de/_ext/itr/tests/Autotest/AT1090_Opel_Corsa_14_Twinport_Cosmo/Opel_Corsa_14_Twinport_Cosmo.pdf

Measurement tells:

Smart 454 1.5 measured noise inside:

50kmh/100kmh/130kmh = 59db/66db/72db

Corsa C 1.4 measured noise inside:

50kmh/100kmh/130kmh = 57db/66db/71db

So can we now accept that the measured noise
by professionals is identical to both crap cars? Both cars 66db at 62mph and 1db difference on 80mph - for the little more powerful 454.

Nobody with >20yr old untrained ears will ever tell in A/B Test the difference from 1db. Just play a 18-20Khz sinus tone to your >30yrs old ears and you will hear, that you hear nothing. Then play a tone with 71db and 72db and try to tell which one whas louder..

And here the same test for 454.034: https://tinyurl.com/3kv8wjd7

Can we now accept that

50kmh/100kmh/130kmh = 61db/68db/72db

is measured by professionals for any 454 Brabus in stock and new condition and NOT for my car? Thanks. And as for sound proofing, it has nothing to do with noise it is necessary for two important things in HiFi:

- Avoid the acoustic short circuit while a speaker produces the same signal / two waves with 180degrees difference while moving forward/back (thats why bass speaker need always enclosure)
- Convert as much as possible electrical Energy to acoustic energy and NOT to kinetic energy with speaker chassi wobble

And for last comparison the 454 twin with steel doors better known as Colt Z30:
https://www.adac.de/_ext/itr/tests/Autotest/AT1269_Mitsubishi_Colt_1_5_Instyle/Mitsubishi_Colt_1_5_Instyle.pdf

Has exactly same 72db @ 80mph

how a car has been maintained has no influence of the road noise. a car that has been poorly maintained could be quieter than a car that has been well maintained and vice versa.

Totally disagree. Even the belts are making a noticeble difference. Ever compared your stock crap belts with Poly-V? Sure not. Ever compared dying bearings neither from alternator or wheels with new one? Ever compared wear suspension parts with brand new ones? Hydraulic lifters, fuel pump etc etc