Free power upgrade petrol W168 A class

[Copiertech]

You can gain a little top end power on the w168 A class by replacing the hose from the airbox to the grille snorkel with one with a larger diameter, you can feel an improvement from 3000 rpm upwards, the only side effect i`ve noticed is the sound of the engine has changed slightly at full throttle, it doesnt sound any louder, just a slight bit deeper. I like the sound, it might not be to your crannys taste though (not that your granny yould use full throttle much.

Also if the 2 brass pipes on the front of the throttle body are connected to the coolant circuit disconnect the pipes and bridge then with a bit of copper pipe, the throttle body heater is not needed in our climate and reduces power by making the inlet air less dense.
Another free mod you can do to any merc is remove the throttle spindle and very carefully cut out part of the spindle. you have to be quite careful doing this one to avoid binding and thinner spindles can snap so only do it if you are confident at engineering and dont blame me if it goes wrong

 

[spannerman]

I 'get' the bit about bypassing/bridging the heating pipes to the throttle body, but not having an A168 to hand, don't get the benefit of cutting out part of the spindle?? I'm curious .

 

[Copiertech]

its a mod that can be applied to a lot of cars, removing part of the spindle increases the effective area through the throttle. I havent actually done it to the A class yet but have done it to many other vehicles with varied results. some vehicles respond well with more top end, others less so but never any bad results. i have heard of one guy whose spindle broken but his throttle switch was adjusted incorrectly and he had also modified his throttle linkage doing away with most of it so at full throttle the cable was trying to twist the spindle. the mod works on the same principle as fitting a larger throttle butterfly, more air can flow due to the increased surface area. halving the spindle thickness gives aproximately 6-7% more surface area for airflow