2nd Gear Manual Transmission question.

First off; let me ensure you by any means am I bitching about my truck. I freaking love it. Just one particular thing I've noticed and wondering if it's normal. And yes I've searched and can't find the answer..

After I've shifted into 2nd gear and decide to "punch the throttle" I noticed it accelerates but seems to bog down for like 1-2 secs at around 3500 rpms, before the engine "let's it go"... and then the power comes? Truck has just over 1000 miles on it..so I'm not sure this has to do with the engine break in period and in hopes the engine "wakes up" after more miles are added. Anyway whether it's temporary or permanent, I'll drive the piss outta this thing either way. Hope to hear any insight on the matter. Thanks everyone!

 

Mine did this when new a little bit but mine was around 1900rpms. It has gone away though with 20000 miles on it.

 

Looks like I have 19,000 miles to go lol!

 

Likely just ECU Learning as the truck figures out your driving style.

 

The bump in power at 3500 rpm is due to the variable valve timing. Basically makes it feel like the power band in a 2 stroke dirt bike. There is much more technical stuff to it. But I am no technician so I'll leave that explanation to the pros.

 

Yeah, mine does the same thing, I think it may be the variable timing change from Atkinson to Otto cycle that causes the delay.

 

While not specific to the Tacoma platform my last car there was a notable deminishmemt to the available power till the ECU had recorded almost 5k miles on the odometer.

 

Thanks all for the input, relieved to know that this is all pretty normal then, gotta get used to this atkinson-cycle, I remember driving my mom's old trans am and boy when I threw that bad boy in 2nd it would take off like a bat outta hell. Guess that's a long comparison.. haha.

 

Mine just did it again tonight, 2436 miles on it.

 

Have you looked at a dyno graph for our trucks? Pretty wild looking and matches what I "feel" in regards to inconsistent (or non-linear) power delivery.

 

the power bump at 3500 is the variable valve timing.
the atkinson cycle i believe is only at cruising light throttle times.

 

That ^^^^ VVTi - variable valve timing.... kicks in on hard excel, Atkinson is at idle speeds.

 

Info on what these dynos are referring to?

 

The "bog down" or dip around 3500 RPM

 

Any other input?

 

There was some discussion about it here:

Things such as VVT, Otto/Atkinson switch, switch from direct & port to direct injectors only, to backing off timing to prevent knocking. For one dyno graph, the tech thought the timing was being backed off (ECU) as well.

"In terms of the wavyness, talking to my buddy who runs the dyno was saying that those dips are probably due to knock correction from the hot day when I had it on the dyno. Also generally I drive like a grandpa so the computer wasn't ready for the full throttle runs I think. When I go next I'll drive a bit more aggressively to see if it makes a big difference"


Haven't tried a higher octane myself. Sounds like it is pretty hard to hack and tune the ECU