Brabus Engine differences over standard ?

[sparkyman]

Hi All,

Another curiosity that maybe somebody could answer - I've discovered that the Camshaft for 452 & Brabus version is the same.

Also discovered that Brabus injectors appear to be different (higher flow ?)

So does the extra HP of the Brabus engine purely come from fuel/ignition maps ?

What other differences account for the extra 21 HP ?

Thanks

[10:45PM]

http://smartmaniacs.co.uk/forum/general/introductions/874903-newbie-looking-to-buy-first-smart-couple-questions

[sparkyman]

thanks for the link 10:45

So, quite a list of differences in ancillaries really - most noticeable engine internals are Pistons/rings, I assume these are simply upgraded over standard to cope with the extra HP and increase engine life expectancy ?

[10:45PM]

Brabus do go to town when they get stuck in to a project and they know their subject after doing many much higher output projects , original owner is paying signicantly more for a proper brabus variant.

Have you seen their website ?

http://www.brabus.com/en/startpage.php

[Thrumbleux]

Pistons/rings, I assume these are simply upgraded over standard to cope with the extra HP and increase engine life expectancy ?

Kapt Q is the man who knows the differences. Pretty sure I read that the Roadster has more material around the gudgeon pin bosses - which becomes the weak point on a fortwo piston at high outputs. What difference(s) between Roadster and Brabus Roadster (if any) I do not know.

[Kapt. Q]

There is very little difference between the Brabus and standard roadster engine internals (contrary to what some say), and it's in the cylinder head; stronger springs (to compensate for slightly higher boost), stellite tipped exhaust valves and bigger injectors (that will not work with a standard roadster SAM). The turbo is a little different and its actuator has a stronger spring. The other ancillary difference is the charge cooler instead of the intercooler.

Cheers!

[sparkyman]

Thanks for the extra info Kapt Q - interesting to read that the Brabus has a charge cooler (Liquid cooled ?) rather than an intercooler. I assume it's also running higher boost pressures then ? What is standard & Brabus boost value ? (I have no gauge on my roadster...)

[Thrumbleux]

Boost for 45kW motor is 0.8bar, for the 55kW, 1.0bar (official smart figures).
A charge cooler and an intercooler are the same thing. A charge cooler is so named because it cools the air charge heading to be ingested by the engine, an inter cooler is so named because it cools the charge between (hence inter) compression stages - between turbo compression and final piston compression.
Coolers can employ either water or air as their cooling medium and the Brabus employs water. That is still no reason to refer to it as a charge cooler though as the air cooled one on my (non Brabus) car cools the charge so also can be described as a charge cooler.

[tolsen]

They should be called after coolers since fitted after the final and normally the only stage of intake air compression.

[Thrumbleux]

Is the charge not further compressed in the cylinder (as part of the thermodynamic cycle and by a considerably higher margin than any turbocharger can achieve)?

[tolsen]

Is the charge not further compressed in the cylinder (as part of the thermodynamic cycle and by a considerably higher margin than any turbocharger can achieve)?

Perhaps we then could simply do away with the after cooler and just increase cylinder compression accordingly?

[Thrumbleux]

Perhaps we then could simply do away with the after cooler and just increase cylinder compression accordingly?

Double the swept volume with the same clearance volume and you're there - but there are good reasons not to do that.

[sparkyman]

..so 1.0 Bar on my 80 BHP roadster ? I don't have a boost gauge, but could do with one just to monitor ....

[137699]

..so 1.0 Bar on my 80 BHP roadster ? I don't have a boost gauge, but could do with one just to monitor ....

1.0bar if running the earlier software.
0.9bar if running the later software.

[sparkyman]

Thanks for the extra detail - mine is 2004, so probably running 1.0 Bar .... must look for a pod set ...