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  Topic Review (Newest First)
05-08-2019 08:01 AM
data883 sounds like a fun swap.good luck
07-09-2018 10:01 AM
Miss Mercedes Most likely no. US border customs usually are not fond of Roadsters. I reckon the few that have leaked through were cars that overstayed their visas or brought over by members of the military and again, overstayed their visas.
07-09-2018 09:35 AM
SLEI65 Did Roadster diesel come alive in America?
Roadster 800 diesel don't have to be slow, tiny engine has been beaten a long way past 100hp.
01-13-2013 02:55 PM
cdi engine swap into 452 Roadster

Thanks Gentlemen for your valuable insights and opinions. In my experience, any engine swap can be done and is just a lot of hard work. (That plus sufficient money and dogged determination of course).

I have seen some amazing conversions come out of the least likely backyard garages. Ever been to India and witnessed what those self-taught, but extremely talented and creative folks do there with Diesel conversions? They make things happen!
01-13-2013 01:15 PM
Leroy It would be no problem to put the CDI in the Roadster. If you use the Roadster fuel tank you would not have to put the fuel cooler in the car. The 2009 smart diesels have the bigger fuel tank and they did away with the fuel cooler. You would also need to change the fuel pump and modify it to fit into the gas tank. Use the 4X2 diesel wiring harness minis the Canadian add on stuff. The Roadster will work if you take out the catalytic converter inside of the muffler. Now the dash could be a different story as with the air bags and anti lock brakes. The problem is the VIN numbers on all the parts have to match to keep the check engine lights from coming on. It can be done if you use new parts and then program them to match the SAM and ECU VIN numbers.

01-12-2013 09:52 PM
Mike T Aside from weighing more, the roadster is less aerodynamic than the fortwo 450. The Cd of the roadster is 0.41 and the 450 is 0.37. However, the roadster has slightly less frontal area. That body would be working the engine really hard!

The roadster-coupe had a better aero rating, 0.39 IIRC.

You would need to design a new exhaust or at least heavily modify the regular one. You would need to find room for a fuel cooler, which on the fortwo cdi, sits under the passenger seat. The roadster is too low to have room there for that. w/o a fuel cooler, the injection system would suffer and eventually fail prematurely.
01-12-2013 01:10 PM
Yes of course - diesel fuel economy

Yea, I am after the unbelievable fuel economy that only the cdi can provide. I drive a cdi now (commute at least 105 miles per business day) and yes the performance is modest......but adequate......for me anyway. We have some pretty good elevations here and the cdi scoots right up them. The cdi has noticeably more torque and maintains a reasonable road speed in sixth gear, hills or no hills.

The Roadster 452 model is soooooo pretty, combine that with the fuel efficiency of the cdi engine and wow I think that would be a very superior combination. True........ slow but getting there is also half the fun! The 450 model certainly won't win any beauty contests!

Anyway that is my plan. My Roadster 452 Champagne remix will hopefully get my Canadian cdi diesel engine implant. And then I will have a drop dead pretty daily driver that gets crazy fuel economy.
01-12-2013 12:30 PM
Miss Mercedes Maybe he wants that crazy MPG?

His 0-60mph would be so slow a semi could outrun him!
01-12-2013 09:25 AM
Mike T The roadster weighs 130 pounds more than the fortwo. So putting a 40 HP engine into a roadster chassis would be a bizarre project. The fortwo cdi is dog slow to begin with! Far better would be to use an original roadster engine, with either 82 or 101 HP. Those original engines are superficially similar to the G&K smart 450 gas engines, which of course G&K did certify for the USA.
01-12-2013 08:46 AM
Originally Posted by robssmart View Post

I have Canadian cdi engine, drivetrain, SAM, ECU, wiring harness. Anyone ever hear of a successful swap of a cdi into the pretty little model 452 Roadster??
Probably an automotive project that is not for the shade tree mechanic?

Getting a gray market CDI conversion titled and registered in NM may be your biggest hurdle?

But then again, anything is possible if you have several of these;
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