evilution.co.uk/mod/gear-ratios.htm

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Gear Ratios

evilution.co.uk/mod/gear-ratios.htm · p. 1 · Applies to: 450, 453, 451, 452

Mod Description Overall gear ratios for Fortwo and Roadster. Thanks to Blackdog for the original ratios and thanks to Bettina from Getrag for supplying the new fortwo ratios and final drive info. Mod Details Premium No Difficulty Mod ID 304 Credit Blackdog/Getrag For Link https://evilution.co.uk/mod/gear-ratios.htm Copy to Clipboard ForTwo 450 Petrol Brabus Diesel 599cc 698cc 698cc pre-2006 2006 1st gear 14.203 13.230 13.230 12.375 12.375 2nd gear 10.310 9.604 9.604 8.983 8.983 3rd gear 7.407 6.899 7.350 6.453 6.875 4th gear 5.625 5.235 5.796 4.566 5.235 5th gear 4.083 3.800 4.208 3.315 3.800 6th gear 2.933 2.730 3.220 2.381 2.908 Reverse 12.888 12.005 12.005 11.229 11.569 Final Drive 1 4.208 3.920 3.920 3.667 3.667 Final Drive 2 1.667 1.551 1.717 1.353 1.551 Fortwo 451 999cc 800cc N/A Petrol Turbo Petrol Brabus Diesel 1st gear 13.912 13.909 14.982 13.755 2nd gear 8.664 8.664 8.664 7.954 3rd gear 5.697 5.697 5.697 5.231 4th gear 4.271 4.271 4.271 3.709 5th gear 3.456 3.202 3.456 2.674 Final Drive 4.529 4.529 4.529 4.158 Reverse 14.633 14.633 14.633 13.434 Roadster kW 45 60 & 74 1st gear 13.230 13.230 2nd gear 9.604 9.604 3rd gear 6.899 7.350 4th gear 5.235 5.796 5th gear 3.800 4.208 6th gear 2.730 3.220 Reverse 12.005 12.005 Final Drive 1 3.920 3.920 Final Drive 2 1.551 1.717 Crossblade 599cc 1st gear 14.203 2nd gear 10.310 3rd gear 7.407 4th gear 5.625 5th gear 4.083 6th gear 2.933 Reverse 12.888 Final Drive 1 4.208 Final Drive 2 1.167 Forfour 5 Speed Manual Petrol 1.1/75bhp 1.3/95bhp 1.5/109bhp 1.5/177bhp 1st gear 14.398 13.753 13.753 13.753 2nd gear 8.327 7.954 7.954 7.636 3rd gear 5.476 5.231 5.231 5.021 4th gear 4.104 3.92 3.92 3.838 5th gear 3.322 3.173 3.173 3.114 Reverse 14.063 13.433 13.433 12.545 Diesel 1.5/68bhp 1.5/95bhp 1st gear

2nd gear

3rd gear

4th gear

5th gear

Reverse

Forfour 6 Semi Auto Petrol Diesel 1st gear 3.071 3.308 2nd gear 1.913 1.913 3rd gear 1.258 1.219 4th gear 0.943 0.846 5th gear 0.763 0.651 6th gear 0.643 0.543 Reverse 3.231 3.357 Final Drive On The Five Speed 451 Gearbox Final drive is the fixed ratio that sits between the gearbox and the drive shafts. All of the figures above have been calculated with final drive already. For example, first gear of the Brabus 451 is 3.308, multiply this by the final drive ratio of 4.529. 3.308 x 4.529 = 14.981932 which is rounded up to 14.982 Therefore if you take the above pre-calculated figures and divide them by the final drive ratio you will arrive at the true gear ratio for each gear in the transmission. Final Drive On The Six Speed Gearbox The Fortwo and Roadster gearbox is unlike many other gearboxes as it had two final drives. Although it is a six speed gearbox, it only has three gears in it. This is doubled by the two final drives. Gear 1 = Gear 1 + FD1 Gear 2 = Gear 2 + FD1 Gear 3 = Gear 3 + FD1 Gear 4 = Gear 1 + FD2 Gear 5 = Gear 2 + FD2 Gear 6 = Gear 3 + FD2 This made the gearbox smaller but slowed it down as it had to change more cogs. Reverse Gear Reverse uses two gears and final drive 1. The engine obviously doesn’t spin backward in reverse which is why it uses two cogs before the final drive to reverse the rotation. The reverse gears are the same in all six speed gearboxes, from 599cc fortwo to Brabus Roadster. 1.5625 (25/16) x 1.960 (49/25) x FD1. Brabus 450 Gearbox In A Non Brabus 450 Smart It still isn’t widely known but you can’t just put a Brabus gearbox in a non Brabus smart. What happens is the car is usually happy to drive in gear 1, 2 and 3 but as it switches over to final drive 2, the gearbox speed is wrong so the ECU calls it up as a shifting fault and shows 3 bars on the speedo. You can’t just mix and match smart gearboxes. The gearbox ratios have to match what is coded in the ECU. Fitting A Gearbox From A Different Smart Obviously a 451 gearbox won’t fit on a Roadster or 450 fortwo. The fitment is different. A 450 gear box will fit a Roadster and vice versa but DON’T DO IT. Just because all Suprex engine gearboxes will fit all Suprex engines, it won’t work. The problem is that the ECU is expecting a certain speed coming out of the gearbox depending on the speed going in. If the speeds are different from expected (wrong ratios), you will get a transmission error. Usually it will fail as you shift between gear 3 and gear 4. Just To Be Sure… Just make sure you use the correct gearbox for your car. Is The 451 Gearbox Faster To Change? The biggest complaint on the original car (450) was the slow gear change. 6 gears was reduced to 5 so a single final drive could be used and speed up the change. The old system was controlled by the ECU, the new gearbox has a dedicated controller. Couple that with the new software and you have a gearchange that is faster than the original. Keith contacted me with the following information about the 451 gearbox. The gear change is faster due to it having two motors involved in the changing gear operation. One disengages while the other engages. This is the same set up as the smart forfour vehicle. Plus they took a sensor out due to a improvement in gear change. So… Is It Faster To Change Gear? No, unfortunately not. My remapped 450 changed gear faster than my remapped 451. So what smart have actually done is removed a gear which affect MPG when cruising at high speeds but haven’t improved the speed of the gear change to a point that can be felt. A Bit Of A Let Down Then? Yeah, it’s a backward’s step abortion of a gearbox compared to the 6 speed on the 450 and 452. Click if info helped 202 likes 112370 views Print