Exactly the point my truck doesnāt go 130 and I doubt anyone elseās currently does either. My top speed is a indicated 115 or 116.
I'm sure it is "programming" that limits the PWM at both the maximum torque and maximum power ends. At the low end the computers sense slip and as soon as the break point is sensed no more current is allowed. More current won't get you more thrust beyond that point so why apply it only to waste tyres. At the high end power is probably being limited out of consideration for the battery and motor longevity.
That's also a function of a permanent magnet DC Motor. Granted, we don't know much about the motor hardware or how the software is controlling the power to the motor. But we know it is a permanent magnet DC motor so some basic principles must apply. As the curves below show, torque decreases as RPM increases.
Permanent magnet, yes. DC, no.
That would be great indeed.
Exactly.
I have an X5M and I would say the acceleration from a standstill is pretty violent. It would be nice if the Rivian had the OPTION of being more aggressive based on drive modes.
Probably a stupid question, but are you trying to launch in sport mode? The video/interview with RJ and Munro, RJ indicated you get 20% more torque in sport mode and the throttle mapping is much more aggressive. One of the recent software updates, maybe 2022.11.2, definitely made the truck launch harder than before. As for the top speed...electric motors are usually limited by back EMF, though it does sound like pre-production models had a much higher top speed.
More and more EVs are becoming fast. Lucid has motors pulling hard all the way. The iX also has a nice flat power curve up to top speed. Curious to see if this will hold true for the iX M60 that should have a 155 mph speed limit.
I guess I'm getting old ?.Surprised in 5 years, you don't hit high speeds often. I hit 120 daily for very short bursts. For quick/fast cars, this can happen in a few seconds. And maybe I'm different than most but because of how "quick" modern cars are, I'm a little disappointed in the ~115mph top speed of the Rivian. If you want to do a short burst/pull on the freeway, you're at 115 in mere seconds. A lot of folks new to quick/fast cars don't realize this and automatically think anything above 80mph is "unsafe". Some sports cars can go from 60-130 in 5 seconds.
But I get this forum is a lot different than the others I frequent. This one is mixed with enthusiasts and people who like EVs/want to know more about them. So there's a big mix of "Why the heck would you want to go faster than 100mph?!" and "115mph is way too low for a top speed!" lols.
Not sure what that set of curves is supposed to represent but it isn't a PMSM motor in a BEV. In that application torque is constant at the maximum allowable level (breakpoint slip) from 0 rpm up to 60 mph (the "torque limited region" giving best 0 - 60 acceleration) and then declines linearly with speed above that (the "power limited region") holding the power at the motor's maximum rating above that.
Haha! I'm getting old too, but I guess that can be relative. I've definitely calmed down over the years with my driving habits.
"But we know it is a permanent magnet DC motor so some basic principles must apply."
Having mentioned how fast and fun our track day was, it did take place on a closed course. While it makes me feel much more secure when driving my R1T around in the open world, it is a reminder that safety, and red and blue lights are to be respected. As crazy as the acceleration is in these things, I'm always aware that Electrons, Protons, and Morons don't mix well. And, while alcohol technically is a solution, it doesn't help with that mix.
Highly doubt it's a warranty issue of the motors and just that they're putting a limiter on it for safety, and stock tire limits.
22's are an H rating, which is a 130 mph rating. (so are the 20's and 21's)
