'24 Ram Hemi less power than '17 Hemi?

[HSKR R/T]

At 80, the difference is 489 rpms. 3.92 is at 2700 rpms, 3.21 is at 2211.

The difference will be more if there are different diameter tires with each gear as well.

 

[dajogejr]

Again…. Math is one thing.
Variables is another.
One is worthless without having the other.

Throwing out more math without having the proper variable, like tire diameter, is just more incorrect information.
You are assuming tire diameter is 32” for both size rims/tires.
Clearly, it’s not. More data using that same variable clearly, isn’t correct.

Respectfully silver, you can’t tell me the difference if the variables aren’t correct.

 

[silver billet]

Again…. Math is one thing.
Variables is another.
One is worthless without having the other.

Throwing out more math without having the proper variable, like tire diameter, is just more incorrect information.
You are assuming tire diameter is 32” for both size rims/tires.
Clearly, it’s not. More data using that same variable clearly, isn’t correct.

Respectfully silver, you can’t tell me the difference if the variables aren’t correct.

I double checked and I was using 7th gear for comparisons in both trucks instead of 8th. That's my bad. Here are updated numbers, also using as much accurate information as I can find WRT tire sizes and transmission ratios.

TL;DR: you got pretty close to nailing the actual RPMs in both trucks, but being a little bit off in spots means the difference in RPMs between the 2 trucks is less than you think.


Tire sizes:
new truck: 285/45/22 = 32.1
old truck: 275/60/20 = 33

Transmission ratios (8th gear)
new truck: 0.64
old truck: 0.67

Axle ratios
new truck: 3.21
old truck: 3.92

new truck at 65 mph:
= (65 * 3.21 * 0.64 * 336) / 32.1
= 1397

old truck at 65 mph:
= (65 * 3.92 * 0.67 * 336) / 33
= 1738

Difference at 65 mph = 340
Difference at 70 mph = 366
Difference at 80 mph = 419

RPMs at 65 mph
new truck = 1397
old truck = 1738

RPMs at 80 mph
new truck = 1720
old truck = 2139

 

[SD Rebel]

As mentioned, it's not that it has less power, it's that other variables such as gear ratios, weight, transmission or throttle tuning, are the reasons why the truck is actually slower than your older one.

 

[dajogejr]

RPMs at 80 mph
new truck = 1720
old truck = 2139

That’s realistically a lot closer now that we’re in 8th gear….
I was less focused on the math, more focused on the actual RPM…and what you were putting out before simply wasn’t close.
8th gear math.. close enough, splitting hairs afterwards.
I think new truck is a tad low…I know it’s higher than 1720. There’s a mark every 250 RPM.
It’s between 1750 and 2K, and being frank, it’s a tick over the halfway between point.
Frankly, splitting hairs… but we’re playing the same game.

Haven’t seen the OP report back gear ratio or anything else, hopefully didn’t scare him off…

 

[DEG]

There is another thread on this issue and many have noticed the same thing. My 23 does not have nearly the same pep as my 2012 or my 2017. It's much closer to the 2003 Ram I had when the Hemi was only rated at about 345 HP.

 

[Dewey]

As mentioned, it's not that it has less power, it's that other variables such as gear ratios, weight, transmission or throttle tuning, are the reasons why the truck is actually slower than your older one.

My two 4th Gens were quite a bit faster. At least 1 second 0-60. Both were heavier Laramie’s with 6’4” boxes, fiberglass toppers and all 3 including my current Bighorn came with 3.21’s. My Bighorn with 5’7” box and no topper is much lighter. Transmission is exactly the same in all three cases. Throttle tuning is the only thing that makes sense. It’s been mostly poor on my 2022 since new. Like I mentioned earlier I just learned to live with it.

 

[Rebel2022]

I’ll go against the grain… previous Ram 2018 Sport with 20” wheels and 3.92 gears, current Ram 2022 Rebel 18” wheels with heavy 33” duratracs and 3.92 gears and my 22 Rebel seemed quicker from a dig and in highway passing.

 

[Alter Ego Trip]

Wheels are generally heavier than tires, so that's probably a wash.

 

[Willwork4truck]

Gramps storytime... Back in the late 90's I was getting my old workhorse 77 GMC 1 ton 400 rebuilt. The mechanic loaned me his 1996 C1500 shop truck, stock 350 and 350 turbo trans. No idea of gear ratio but the truck was bone stock.

That thing absolutely flew. Felt like triple the hp/speed/torque compared to my 400 ci, 4.10 axle 3 speed auto propane powered (appx 80% power of gas) pig. When I returned his truck I remarked about the phenominal power it had. He told me that he thought the same and said "in some engines everything just comes together". Now a builder would likely take issue with that statement but this guy raced and was a top mechanic, and that's what he said.

His engine stock specced at 255 hp, 330 tq at the crank. My dog 400 was appx 175 hp/290 tq, with a crappy 8.5 compression ratio. Plus my truck weighed maybe 1.5K more due to being a 4x crew cab 1 ton and his was a 2x shortbed std cab 1/2 ton.

Kinda' wish I had bought it off him but a standard cab 1/2 ton wasn't going to carry my family and pull the 28' TT.