2024 Sport Premium Manual transmission frustration

"Ordered" a 2024 Tacoma Sport Premium Package Manual Transmission June, 2023. Got it last Friday (7/12/24). So, waited over a year. Test drove it a bit, but just around town. Liked it. Bought it. Getting on the highway I kept hitting the rev limiter and was confused as to why. I bought my 2007 Tacoma Sport Manual Transmission brand new and still have it. Its V6 revs to 5,500 RPM. Very natural and fun feel/performance. As most manual transmission owners know, the horsepower pulls and then tapers off and you can "feel" when to shift if you're accelerating to highway speeds. This 2024 is a 4 cylinder starts pulling around 4,000 and right when the engine seems to "come alive" it slams the rev limiter. Come to find out the Manual Transmissions are rev-limited on a 4 cylinder (normal engine expectations are around 6,500 RPM) to 5,300 RPM. The Automatics - 6,300 RPM. Looking at the horsepower curve it doesn't appear Toyota "lowered the horsepower" for Manual transmissions, but they in fact lowered the Rev Limiter which prevents it from getting max horsepower. I don't feel their engineers have driven a manual to understand how this upward slope to a dead end feels very awkward while shifting. Wanted to post this so others that like "actual driving" where you're making decisions instead of the car, you like having more control over how the vehicle behaves, so you buy a manual, will have an aneurism when you find out it won't let you drive "normally", it's neutered in a very frustrating way. Will be looking at how to up this limit as my assumption is they did it to protect the truck from "full rev clutch dumps" which I have never done as I don't want to fix what I'd tear up.

 

Welcome to TW!

 

Welcome to TW. Redline is seriously only 5300rpm? That doesn't sound right. That's old small block chevy territory not a 4cyl turbo. It should easily be revving to 6500.

Edit: Looks like the manual revs to 5400, auto goes to 6300. Insane - that's a nonstarter for me. You'll need to look into a tune OP. Sheldon Brown claims it's due to "crankshaft hammering" fyi.

 

Thanks for the reply! Yeah, it never blipped on my radar that an OEM would do this, so I didn't even think to check on that kind of spec. When thinking of the variables of the impact of a manual transmission versus an automatic on the crank I guess there is an argument that pushing the clutch adds normal directional force onto the crank bearings, but if it's running at 1500 RPM or 6300 RPM the force would be the same as it's contributed to constant spring force from the pressure plate. In addition, in the range from 5400 RPM to 6300 RPM the duration of normal force on the bearings versus engaged clutch duration (therefore no additional force) is theoretically minimal as most clutch disengagement duration is in low RPM situations of in traffic or starting/stopping. "Hammering" implies rhythmatic impulses opposed to a constant force contributory degredation. So, if clutch forces aren't dependent on RPM, and constant clutch force wouldn't constitute "hammering" I'm more inclined to think the failure mechanism is high horsepower being applied to the crankshaft by the pistons and a sudden anti-rotational force applied by the clutch/driveline. The pistons' action on the crank would be rhythmatic impulse forces that could be constituted as "hammering" and the sudden strain of engaging such rotational momentum/force to a stopped transmission would make sense that it'd tear things up. So, it really makes more sense to me that what they're trying to avoid is a 6300 RPM rev-limit bouncing full turbo spooled engine getting a clutch suddenly engaged by someone wanting to spin 35" tires and shearing a crank. If that's the case, I can "understand" the reason, but instead of ruining the driving experience, they should find alternative solutions like a slip clutch that starts slipping at X ft/lbs of torque or whatever to protect itself. Just my opinion. If my hunch is correct about the root cause of the decision, upping the rev limiter and driving like I care about my truck will not only be non-problematic, but will make me a much happier owner.

 

I think you're spot on. Toyota is designing their truck to withstand a 16 year old monkey learning stick shift on it, not somebody that understands how to drive a manual transmission with mechanical sympathy. This is the article I was reading btw if you're curious
https://www.theautopian.com/2024-toyota-tacoma-review/