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Passed by another Fortwo 451 while going 78mph!

4K views 32 replies 19 participants last post by  OliverB 
#1 ·
So this morning, while commuting on the freeway, with my cruise control and maxed out speed of 78, another 451 Smart flew by me, at least 7-10 mph faster than I was going. How is this possible?? I thought the computer limited us to 80mph? I've never gotten above 78 by the way. I have a 2016 Smart Fortwo ED.
 
#3 ·
Petrol 451s: The limiter is supposed to kick in at 90 mph, though on a few occasions with my pedal to the floor I blasted past the limiter and pegged the speedometer at 100... verified by a GPS and the police officer that pulled me over! He was more amazed it could go that fast and let me off with a giggly warning.

*My speedo actually reads accurately because of my chunky tyres.

Petrol 453s will go 100 all day long. I think their limiters try to stop you at 95 mph.

Petrol 450s will top 85 and their limiters are really aggressive about making you stick to that speed.
 
#18 ·
Thank you,
All the Aero Kit was my own design, I modeled it in SolidWorks, ran tool paths with CamWorks and used my home garage CNC Mill to cut it out.

I wanted the "Bolt on" looks so all the Aero kit has bolts showing as well as the flare kit.
The H&R Lowering spring sure helped the front "Tuck"
It also took me 17x8 rims, 20mm adapters and 15mm spacers to get the rims out 1.75" past the body panels.
 

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#20 ·
I've got a 2015 (453) Passion ICE and I never take it faster than 75. The steering feels too light and crosswinds move the car significantly. I've been a speed demon with heavier cars in the past. Are you folks doing something to improve your suspension, aerodynamics, road stickiness, etc?
 
#23 ·
The speed error on my 451 speedometer varies. At 30mph you could be off a mile or two and by 70 be off 4 or 5. With 205/60/15's (and a Daystar lift) my speedometer is very accurate, but at 70 mph on the speedometer my phone GPS and the android radio GPS says I'm doing 71. When the speedometer reads 92 mph the GPS says 95. There are 2 limiters on the Fortwo. The first limits speed. Then second keeps you from over revving the engine. Sitting in Park or neutral mash the gas pedal to the floor and the engine will rev to exactly 3,000 and no further. When I had stock tires it was always an issue with the transmission in auto mode that it lugged the engine by trying to get me in fifth gear as soon as possible. I found with the taller tires the car senses the increased load and keeps the car in a lower gear a little longer. Now mileage suffers from larger tires but for me the improvement in handling and stability is well worth the tradeoff. The only 2 things that slows me down is strong crosswinds (like driving to this years April Fools Rally) or in a torrential downpour where the car will hydroplane at the bottom of a hill if the water is pooling acrossed your lane, but that's common sense for an 1,800 pound car. I've driven my brothers 2006 Chevy HHR and it hydroplanes worse than my Fortwo. And if it does begin to hydroplane stability control keeps you headed in the right direction. I know this to be a fact. The only 2 Fortwo's to outdo me on the interstate is Jetfuel and John Senka. John just recently reminded me of this right outside of Dayton....Ha ha.
 
#29 ·
When I bought my 2015 it had stock tires and my speedo was way off so I took these notes:

F 15x4.5 ET24 Tires 155/60 R15 [22.3" DIA, 6.1" W, 70.1" CIR, Revs/mile= 904]
R 15x5.5 ET22 Tires 175/55 R15 [22.6" DIA, 6.9" W, 70.9" CIR, Revs/mile= 894] AVG 22.45” tires
F-R Diff -1.1%
Speedo reads 5% over with stock tires.
Odometer reads 2.23% over with stock tires.
I was more interested in getting the odometer to read correctly 22.45" + 2.23% = 22.95" so 23” tires should be the closest fit.
This site has a great easy to use calculator TIRE SIZES: https://tiresize.com/calculator/
I ended up going with
195/40-17 front (23.1") and
205/40-17 rear (23.5") since I was limited by my wide stance conversion.
That put my Odometer under 1.04% but my speedo is very close now even though the math doesn't add up, at 50mph I'm going 51mph by GPS.
Go figure...
 
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