Rev Hang in Manual Transmission

[Emirahep]

Some good info about rev hang in this video:

V interesting - does anyone know whether the Toyota V6 has Direct or Port fuel injection ?

 

[kitkat]

V interesting - does anyone know whether the Toyota V6 has Direct or Port fuel injection ?

Too old to be direct injected the 2GR-FSE added direct injection for twin injection.

 

[Emirahep]

Too old to be direct injected the 2GR-FSE added direct injection for twin injection.

thanks. I think that makes the Rev Hang issue for the Emira “worse” based on the earlier technical video.

 

[Emirahep]

Played with gear changes today in Tour and Sport and confirm no difference - noticeable rev hang in both modes. I couldn’t video myself so will ask a family member to hop in for a ride to try to capture what it looks and sounds like.

 

[Italiabrain]

From what I understand lifting off the throttle immediately causes the fuel mixture to becomes lean -- this increases NOx -- and comes across as an increase in emissions. Slowly reducing the throttle prevents this condition.



Touring and Sport both had it for me, didn't get a chance to try Track -- @Emirahep do you have any input here?

Other side of the curve. Throttle closure / tip-out cause the mix to become rich and increase unburnt or partially burnt hydrocarbon emissions. That's why the solution is to keep the throttle body open artificially long (add air). I agree there was no mode difference on my test drive and I would bet that since it's a regulatory / emissions thing you're not going to see it change meaningfully on drive modes on any modern car.

 

[Emirahep]

Other side of the curve. Throttle closure / tip-out cause the mix to become rich and increase unburnt or partially burnt hydrocarbon emissions. That's why the solution is to keep the throttle body open artificially long (add air). I agree there was no mode difference on my test drive and I would bet that since it's a regulatory / emissions thing you're not going to see it change meaningfully on drive modes on any modern car.

I hear what you say but it is a lot more noticeable/pronounced in the Emira than other modern manual cars that we own or have driven. For example there is slight rev hang in a GR Yaris but it dormant detract from the overall experience. For me, it does “intrude” in the Emira.

 

[Pugwash]

Interesting thread. From my first test drive I noted that the Emira seemed to rev more freely than my Evora and I speculated it had a lighter flywheel which would cause that. However a lighter flywheel would also cause the revs to come down more quickly too which it plainly doesn’t. Wasnt until I read this thread I realised there may be other things going on to cause that effect.

 

[Chobfreak]

I also feel that it only impacts the drive because the flywheel rushes through the rpms, so it feels off if it spins down at a slower rate.

That being said, my GT's racing flywheel drops revs so quickly that a short shifter has become a necessity in order to complete smooth upshifts.

I imagine some people would have a hard time managing the Emira's flywheel, if they aren't used to driving manual cars.

 

[haaaake]

Yeah I really don't understand whey the fuck rev hang is a thing. It just makes the engine feel super unresponsive.

 

[Finbarqs]

picked up my lotus a month ago, and I thought I was going crazy. My elise didn't have this crazy rev hang... It was incredibly difficult to drive the way I normally drive manually transmissions... I felt like I was over revving my engine each gear I go, (I'm only at 40 miles) yet it just feels like... weird...

 

[Bulls-Vivid-Red]

It's strange at first, but I was able to adjust rather quickly. After just a few drives with lots of shifting (I'm in Chicago) I was already shifting smoothly. Hell, at this point I've put on enough miles that I'd probably have issues jumping back into an old school manual.

 

[Finbarqs]

It's strange at first, but I was able to adjust rather quickly. After just a few drives with lots of shifting (I'm in Chicago) I was already shifting smoothly. Hell, at this point I've put on enough miles that I'd probably have issues jumping back into an old school manual.

also makes the car feel lazy...

 

[Finbarqs]

Weird just took the car out, and it’s not rev hanging anymore

 

[Speedy Emira]

Some good info about rev hang in this video:

Great video. I see it is worse on cars with port injection and from the diagram it appears the Emira V6 does have this. I suppose at least we are less likely to get the coke issue suffered by direct injection only cars.

Once suppliers like JUBU get their act together there may be a way to program the hang out. Certainly for Syvecs it is possible by having multiple maps and using the base map as the one with the rev hanging for emissions testing.

 

[B r I a n]

Some good info about rev hang in this video:

Great video! Thanks for sharing.