The original throttle body has a fairly small opening, bigger is better. For the smart 450 and Roadster ONLY. NOT 451.
Smartmods
for all your modding needs, recommended by Evilution
News
Oil Sump Pan Change
The sump pan is in a very exposed area so they are prone to damage and rust
451 Coolant Drain
Draining Unless you like to be scalded, wait until the car is cold. Remove the front service panel and undo the cap to the coolant header tank. Look under the car at the engine over to the right. Just behind the long drive shaft, partially hidden by some...
Servicing The Clutch Actuator
It is becoming more and more common to hear of slower gear changes, increased revs before the clutch engages and smart being unable to adjust the clutch on their Star machine. Something new was shown to me.
The Camshaft
It's a multi-lobed shaft that rotates to open the inlet and outlet valves to the engine. The 600cc, 700cc and Roadster Camshafts are interchangable. Putting a roadster camshaft into a For2 increases the engine power.
451 Fortwo Speedo Cloning
Cloning The 451 Fortwo Speedo Cloning is a process where you take data from 1 item and copy it to another to make an exact replica. Why Would I Need To Do That? If your speedo has failed completely, has a hardware or PCB fault, you need to fit a new speedo. Can I Just...
451 Fuel Flap Solenoid
To remove the fuel flap solenoid, you have 2 options. You can take the rear panels off or leave them on. Rear Panels Removed If the panels are off, it makes it easy. Open the filler flap. On the back edge are 2 clips. They are very easy to push in by hand. Lever the...
451 Heater Fan Brushes
451 Heater Motor Brushes For some reason, it's mainly the American 451s that suffer with brush problems. Dunno why but it does affect non Americans as well. The standard brushes seem low quality and seem to wear very quickly. Probably because the commutator gets a...
452 Roadster Passenger Air Bag
If you are changing the passenger airbag on the Roadster, it probably means that it has exploded. If it has, you'll also have to change the top dash pad. Luckily, they are connected. First thing first. Disconnect the battery and leave the key in the house. If you look...
Hella 451 DRL Repair
The 5 per side Hella daytime running lights on the 451 where surprisingly poor quality and failed regularly.
451 DRL Options
Pre-Facelift DRLs The first type of daytime running lights available for the 451 was this type. They consist of a pair of Hella lights and surrounds. Smart part number A 451 820 00 61. However, if you buy them from smart, they'll be ridiculously expensive. So, do a...
Roadster Rear Light Faults
The biggest cause of rear lights not working on the Roadster is water damage and corrosion (surprise surprise). So, if a bulb isn't working, obviously 1st check that the bulb filament(s) are ok. Also check to make sure they are fitted correctly. Remove the bulb that...
Fitting A Better Horn
The Horn The standard horn fitted to all smarts isn't loud enough. It doesn't draw attention like it should. In fact, it's almost laughable and many people say it's like a scooter horn. There's a reason for that. That's exactly what it is. A single low wattage disc...
HID Headlight Interference
Radio Interference After HID Installation This is a fairly normal occurrence. The radio signal is fine until you turn on the headlights. But as soon as the headlights are on, you get loads of static interference over the music. What Is It? Radio stations are...
Roadster Indicator Faults
Roadster Indicator Faults It's surprisingly normal to hear Roadster owners come up against a strange issue along the lines of: 1 or both indicators come on and stay on when I indicate. 1 or both indicators come on and stay on when I turn the car on. 1 or both sides...
Roadster Speedo Dead
The speedo in the Roadster is beginning to suffer from a new common fault. Much like the rest of the Roadster, the speedo electrics are a weak point for a few reasons. Straight After A Battery Reconnect The story usually starts the same way. After reconnecting the...
453 Relay Layout
Relay Layout Main Fuse Box (Behind Dashboard) F2 Relay Number Function Specification K1 Heated rear window & mirrors (G Cartier) 20 241 077 35 Amp max K2 Electric windows (G Cartier) 20 241 077 35 Amp max K3 Sliding roof power Not sure, should be the same as K4 I...
Glow Plug Controller Fault
Symptoms I have had the same email once or twice a year from 450 and 451 CDI owners. "My glow plug light doesn't go out" Normally I recommend replacing the glow plugs and checking the engine earth lead. Normally this fixes it. However, sometimes I get another...
PAS Controller Waterproofing
Problems Another thing that dies due to water ingress in the Roadster is the power steering controller. However, it also happens in the fortwo 450 although it's much less likely. The reason for the issue is the placement in the cars. This unit sits low in the footwell...
453 Horn Upgrade
Like all previous smart models, the horn is an embarrassment. A single unit that's far too quiet. What we need is a pair of tone matched horns (high and low frequency). Remove the front panel to access the main horn. It's just below the offside headlight... ...hidden...