anyone else’s 6MT feel slow?

Gear ratios affecting acceleration depends. Shifting takes time. Sometimes, a lot of time. For instance, that's why the first generation Ford GT was geared to hit 60MPH in first gear. It was faster to 60 with the taller ratio than having a shorter one that required a shift.

Regardless, that's more of a fun fact than anything. There's ways to tell if the tune is limited in the lower gears. It would seem to me that comparing the torque curves generated from dyno pulls in each gear and then normalizing the data for gear ratio would tell you that. As long as the wheels don't slip or you exceed the torque capacity of the dyno, the normalized curves should be the same in each gear unless it's pulling power in 1st and 2nd. I'm surprised this isn't something a tuner hasn't already done, honestly.

Informally, you could probably test this heavily load the truck, say with a trailer, and mat the throttle on a steep incline. Note what the boost pressure gets to. If it's higher in 3rd than in 2nd, it would indicate that's true.

As to why, other vehicles with lower power ratings for MT models than AT models usually came down to the fact that the manual transmission they used wasn't up to the higher torque output. I seem to recall reading someplace that your typical planetary gear automatic transmission tends to be "stronger" due to the way forces transmitted through them being more conducive to things staying where they're supposed to be. That is, the forces tend to be more "straight through" in a planetary gearbox where a constant mesh multishaft arrangement like a typical manual transmission uses wants to twist more, making it harder to keep everything in alignment. First and second gears would generate the biggest forces, so higher propensity for things to get out of shape. I can't help but wonder if the 310ft*lbs the MT tuned version of the engine makes is right at the upper end of what the RC60F transmission can handle. Google also volunteered that Sheldon Brown said that the rev limit on the MT tune was lowered to 5400 from the AT's 6300 because of "engine harmonics." I wonder if maybe that plays in, too. Maybe the combination of the T24A-FTS and the RC60F is just so that it conspires to rattle the poor transmission apart. I hope this doesn't manifest in people having issues with their manual transmissions long term. One of the reasons people get them is because they're simpler and tend to be reliable like stonework.

 

The solution to your acceleration problem is to get a transmission with two more gears that shifts automatically.

 

I wasn’t 100% on the chosen gear ratios during my first week of ownership. But by week two it felt fine. Worlds better compared to my old 3rd gen MT6 on 33’s.

But I can’t disagree that manuals from the 70s and 80s and 90s and 00s all felt effortless with the first drive. Well, not all of them. But in general.

 

I wouldn't want a manual on a modern truck. I'm guessing it feels like driving a 2000 International 4300 but with an additional forward gear. That might be great off road or any situation you need a low 1st gear.

 

That extra pedal and moving stick thing in the middle of the truck totally makes for cognitive overload. Super hard to update your Insta and Text and shift all at the same time.

 

Those cell phone user who um share the road with the people out there driving would hate it.

Edit Waymo don't look safe either pretty sure I've seen them burning in the streets on the evening news this week.

 

Boost by gear, the new auto Tacomas do it too.
You can pull up the boost gauge and watch it, it will not hit peak in 1st gear on the auto (I didn't look in the manual)

Probably to protect rear end gears and other driveline components from too much torque. I for one didn't notice it feeling slow, just the rev hang when I test drove a manual one.

 

I trust that boost gauge about as much as the oil pressure gauge on NB Miatas.

 

when logging with the JB4 I found boost to be underrepresented on the gauge at the lower levels. I consistently saw 3-4 psi in the logs when gauge indicated nothing yet. Strangely higher boost seemed dead on

The auto is definitely much quicker but I drive so much for work I need it to be engaging

 

5000 rpm is tractor engine speed. 4 bangers don't start singing until they're in the 7-8k neighborhood.

 

Since both the AT and MT have some boost limits applied in 1st and 2nd, I'm leaning toward the explanation that Toyota designed the stock tune to enhance "driveability" -- reducing output so the rear end doesn't step out when your average driver does a hard launch.

 

Not really. There's been plenty of I4 engines that were tuned for torque and had lower rev limits for any number of reasons. Honestly, production engines that are set up to rev in the 7k+ range are uncommon and ones that rev past 8k are downright rare.

 

So the manual gearbox is reporting each individual gear position to the pcm? I didnt know that was a thing

 

It knows what gear you’re in based on rpm + speed. It also now has the rev match input revolution sensor which tells the computer exactly how fast the transmission internals are spinning.

 

Cool

 

Not disagreeing but would think the 9.5" rear end standard on all manual Tacos should handle anything.

 

So the hybrids, which all have 9.5 rears, will get full power in every gear?

 

What kind of tractors you operating that rev to 5K?

 

Son, if you can't mow your lawn in 15 seconds or less, then you're wastin time.

 

OK kiddo, but most folk dont mow their lawn with tractors.
I certainly don't.
And I can achieve plenty of ground speed on my tractors with gearing, not RPM.
Just sayin.