I think this would knock my fillings loose


https://www.fleetforward.com/3...c_id=3914G4595089E5H



General Motors has confirmed that it will be bringing back the Hummer nameplate on an all-electric truck under its GMC brand.

The GMC Hummer EV truck will feature 1,000 hp, 11,500 lb.-ft. of torque, and go 0 to 60 mph in three seconds.

“GMC builds premium and capable trucks and SUVs and the GMC HUMMER EV takes this to new heights,” said Duncan Aldred, vice president of Global Buick and GMC. “We are excited to debut our revolutionary zero-emissions truck during the biggest night in TV advertising.”

The Hummer ad is scheduled to play during the second quarter of the Super Bowl. The ad will highlight anticipated performance of GMC’s EV Hummer as well as the fact that it will not generate any noise or emissions.

The GMC Hummer EV will be revealed on May 20, 2020. It will be built in Michigan at General Motors’ Detroit Hamtramck assembly plant. Initial availability is expected in Fall 2021.

GM recently announced that it will be investing $2.2 billion in this assembly plant to produce all-electric trucks and SUVs.

11,500 lb.-ft of torque?

That's more than a typical larger vessel marine or locomotive diesel. Something like a CAT C280 does around 9,000 ft. lbs.

Hope it's a typo or that drivetrain's life will be measured in seconds

Electric motors can be very powerful, and offer immediate high torque. Have you seen the electric dragsters?

quote:

Originally posted by arcwelder:
Electric motors can be very powerful, and offer immediate high torque. Have you seen the electric dragsters?

I sure have. And Formula E.

But 11,000+ pount feet of torque at the crank in an SUV is impossible. Teslas put out around 1,000 ft. lbs. Semi trucks put out about 2,000 ft. lbs.
Even if GM defied physics and created such an engine, the transmission, drive shaft, differential, and CV joints would almost instantly fail.

Either this is a typo or marketing BS (like reporting torque at the wheels versus at the crank).

It ain't a typo, cause I saw the same ridiculous number in a commercial during the Superbowl.

The torque number is probably a wheel torque in a crawler gear.

Think about this thing this way. GM can F-up just about anything, and this thing is likely to cost upwards of $70k+. How many ya think they'll sell? My bet, not enough to even count.

I thought the Chinese bought the Hummer brand.

quote:

Originally posted by caneau:
Either this is a typo or marketing BS (like reporting torque at the wheels versus at the crank).

I'm just taking a guess here, and I'll guess "marketing." Is it possible there's a motor for each wheel, each putting up a quarter of that 11K figure?

quote:

Originally posted by Scurvy:
The torque number is probably a wheel torque in a crawler gear.

If that's the case, that's the most disingenuous garbage I've heard.

Between a transmission and the differential it's not uncommon to have about 15x multiplication of torque from the crank. First gear is something like between 4 and 5 to 1 and your axle ratio is somewhere between 3 and 5 to 1. So a truck like the Ford F150 with a 4.69:1 first gear paired with a 3.55 gear ratio multiplying torque from the crank 16.65x. Multiply that by the 470 ft. lbs. of torque a 3.5L Ecoboost is outputting at the crank and you have 7825 ft. lbs. at the wheels. Which makes 11,000 ft. lbs. from an electric vehicle a lot less impressive.

quote:

Originally posted by vthoky:

quote:

Originally posted by caneau:
Either this is a typo or marketing BS (like reporting torque at the wheels versus at the crank).

Is it possible there's a motor for each wheel, each putting up a quarter of that 11K figure?

Maybe? But again, that's little different than a typical truck drivetrain when it comes to output at the wheels. And in that case, not all that impressive.

Hang on, first it's impossible, now it's not that impressive? Pick one and stick to it. How about we wait for the product?

Electric motors are not at all like combustion engines. If they're going to bother resurrecting the "Hummer" and make it electric, wouldn't you think they intend to deliver?

Combustion or electric, I want one with a ring mount .50.

Arc, 11,500 ft lbs.. of torque at the crank is impossible. There is nothing magical about electric motors. Torque is torque. But if you applied that much instantaneous torque to a drive train you'd instantly destroy the drive shaft of a typical SUV.

Transmissions, drive shafts, and differentials can only handle so much input torque. You can get 11,000 ft. lbs. of torque out of any motor. You just need a sufficiently low gearbox and enough patience cause you won't be moving very quickly.

Go attach a breaker bar to a torque wrench and see if you can max it out. Same thing. You're not any stronger, but your radius of motion is way bigger, hence more torque.

The whole purpose of a transmission or gearing ist to keep the total amount of work (energy) as constant as possible (accounting for friction) while brokering between force and velocity. Your engine outputs a certain amount of torque at a certain RPM, say 500 ft. lbs. at 5000 RPM. 500 ft. lbs. of torque at the wheels would barely get the car rolling, and a tire spinning at 5000 rotations per minute would disintegrate. Now reduce that same amount of work with 10:1 gearing and you have a much more reasonable 500 RPM for a tire (about how fast it spins at 35 mph) and 5,000 ft. lbs. of torque (well 2,500 ft. lbs. per wheel assuming two drive wheels).

Back to why I said "Maybe". Because you can absolutely take four small electrical motors, hook them up to reducer gears, and put it into the four corners of a car. And the RPM range of an electrical motor is much greater than that of an internal combustion engine so you don't need a transmission. Is that the same as those motors putting out 11,000 ft. lbs. of torque? Absolutely not. Because by that measure of torque at the wheels your average modern diesel pickup would be outputting something like 16,000 ft. lbs.

Lies, outright lies, and statistics. Oh yeah, then there is straight up fudging numbers. Using a nonsensical calculation to impress those who don’t understand the scenario. For those of us who prefer a discussion vs a rant it would be nice if GM said how they came up with their torque value and then used the same method to contrast their ICE version. Funny thing is, the torque number will still be very impressive. Just not ludicrous.

quote:

Originally posted by SigJacket:
I thought the Chinese bought the Hummer brand.

Well, don't forget that Obama (administration) bought GM.

Torque numbers in a EV aren't going to be measured at a "crankshaft" either, since one won't exist.

I'm not saying that's not still a lot of twist even if applied directly to the wheel/axle, but you have to get away from thinking of a crankshaft connected to a transmission and differential in these applications. Most have electric motors mounted directly at 2 or 4 corners of the car directly to that wheel. There's not traditional "drivetrain".


Still, that number is silly high. I'll be interested to see how they came up with it too.

quote:

Originally posted by caneau:

quote:

Originally posted by Scurvy:
The torque number is probably a wheel torque in a crawler gear.

If that's the case, that's the most disingenuous garbage I've heard.

Between a transmission and the differential it's not uncommon to have about 15x multiplication of torque from the crank. First gear is something like between 4 and 5 to 1 and your axle ratio is somewhere between 3 and 5 to 1. So a truck like the Ford F150 with a 4.69:1 first gear paired with a 3.55 gear ratio multiplying torque from the crank 16.65x. Multiply that by the 470 ft. lbs. of torque a 3.5L Ecoboost is outputting at the crank and you have 7825 ft. lbs. at the wheels. Which makes 11,000 ft. lbs. from an electric vehicle a lot less impressive.

Exactly.

Imagine a hummer with 4 electric motors putting out 500lbft of torque at each motor (2000lbft total) and then a 5.5:1 reduction for crawling.

Edit: looks like Tesla and BMW have both been reporting wheel torque numbers recently so maybe this is just going to be an EV thing...

Reminds me of when tv's went from 1080p to 4k. They used to measure the small length with 1080p and then decided to measure the long length to get 4k because it sounded more impressive. 4K is really 2160p based on the old method.

quote:

Originally posted by Georgeair:
Torque numbers in a EV aren't going to be measured at a "crankshaft" either, since one won't exist.

I'm not saying that's not still a lot of twist even if applied directly to the wheel/axle, but you have to get away from thinking of a crankshaft connected to a transmission and differential in these applications. Most have electric motors mounted directly at 2 or 4 corners of the car directly to that wheel. There's not traditional "drivetrain".


Still, that number is silly high. I'll be interested to see how they came up with it too.

Depends on the car. I believe Teslas have a motor per axle (so one motor if you get the 2WD version, 2 if your get the AWD).

Haters gonna hate