1st and 2nd don't do this. However in 3rd (drive, not paddle-shifting), my bone-stock a/t Fit, pedal to the metal at ~6000 rpms drops back down to 5800 and then climbs back through 6000 before shifting to 4th. However, the speedo does not drop but is constantly climbing, and there is no sense of any deceleration either. You can here the motor dip, and I grabbed the rpms from the scangauge (and you can see the tach dip). It's like the transmission decides to grab onto the wheels a little harder and drags down the motor for a second. Another good way to describe it is that it acts like a CVT for 2 seconds -- speed is increasing while the rpms drop. wtf is that? Does anyone else's a/t do that?

 

VTEC, whatever little it is?

 

I vote for electronics causing the 'hitch'.
My automatic acts like a CVT. As the terrain changes in cruise the rpm will vary by as much as 600 rpm without changing speed.
Does Honda have secret CVT's?

 

wow.
that's weird.

 

probably the rev limiter.

 

weird i dont think i ever noticed that. not sure what it could be either

 

My guess is the locking torque converter. Maybe when it was 6000, the TC wasn't locked yet. then when it locks, the RPM drops to 5800, due to "gripping" the wheels harder.

 

Yah but doesn't the locking mechanism basically let go when you stomp on it? I was under the impression lock-up basically only worked for cruising or light acceleration. Having anything related to that dancing around 6k rpms sounds a bit weird...

 

i've seen that dip to...when i had my intake and exhaust i saw it went away a lil....but also that happens when using paddle shifters...

 

Mine does that too. What's happening is when u acclerate quickly, the rpm's will pretent to "shift" or so it seems. Actually, what's happening is that the alternator is increasing in speed which then sends a quick voltage of electricity through the car, making all sensors respond quickly. This then makes ur tach jump quickly about 100-200rpm's. It's normal, nothing 2 worry about. My EK does the exact same thing.

 

okay that explains it....thanxs koolkev

 

Eh? Does my engine also pretend to sound differently? The rpms actually drop. You can hear it drop. If your theory were true, it would be happening in 1st and 2nd too, methinks...

And I seriously doubt that the ECU starts miscounting rpms at any point in time, that would be a major boo-boo.

 

Its the electronic lock-up mechanism in the torque converter... There's nothing "magically delicious" going on... Even after the engine RPMs overcome the stall speed of the torque converter, there is still a calculated ammount of slip between the engine and transmission... Once you reach cruising speed in top gear, the the electronic lock-up mechanism will engage and the engine and transmission will be spinning 1:1.

My educated guess is that 1st and 2nd are fairly short and don't create enough load for the TC to lock-up.

 

Please read the first post of this thread before sending it around in circles... the discussion is about WOT behavior...

 

Why should he, hes right, lol. The torque converter always lets the engine flex a couple hundred RPM, the reason why its called a slush box. When the torque converter locks up it performs like a clutch, no flex. Like if you drive it a certain way it will appear to shift 1 more time than you actually have gears.

There is a min and max speed on torque converter lockup. Min speed is the lowest point it'll lock and its prob around 30 MPH under low throttle. The max speed is the max speed will stay unlocked until it locks and is prob at 6000 rpm in 3rd (w/e speed that is) so when the engine hits 6000 RPM in 3rd, the transmission is only spinning 5800ish and then the torque converter locks and brings the engine down to 5800.

 

Hmm, I was under the impression lockup didn't happen under full WOT. Seems kinda odd to kick in 250 rpms before it's gonna shift at 6250 or so in drive mode... then again maybe it's the car's last little oomph before 4th hits...

 

Sounds right. At 90 MPH I noticed I was at 4000 rpm's. Someone pointed out that mathematically, that didn't agree with the gearing, considering that 80MPH = 3,000 rpm. (AT Fit.) Turns out it was cuz I had just blasted up to 90MPH, and the TC was not yet locked.

 

I can't verify that on the fit since mine is 5MT, but as far as EG and EJ civics go, dropping it into D3 and going WOT, the TC will lockup around 100mph which gives you breathing room to take 3rd gear all the way to about 115ish mph before hitting the stock rev limiter.