Does the BRZ/FR-S suffer from rev hang?
 

I'm curious to know if anyone who has driven any of the GT 86 derivatives can comment on whether they noticed any rev-hang on throttle lift-off. For those unfamiliar with it, rev hang is when the engine speed does not drop immediately when your foot is removed from the throttle; it's VERY annoying and present on a lot of newer vehicles with manual transmissions.

From what I understand the hang is often programmed into the ECU for emissions reduction and/or mileage improvement. Given the type of car it is and where/how it has been tested so far I doubt this is an issue here, someone would have mentioned it. With all the effort they have put into making this a driver's car they are not surely going to make such a dumb mistake.

Not sure, but from the videos I've seen, it doesn't appear that it's an issue.

That's my feeling as well, but as bothered as I am by my current car's rev hang, I want to hear something definitive.

I always assumed it was to save the trans a clutch from shock during shifts, but a master tech from Honda told me it was emissions related. I believe you can minimize it with buddy club throttle controller, but I have not tried it myself (told it eliminated it by a tune). The 2010 SI I had had a horrible rev hang, and I agree it drove me crazy... so annoying

i'm 100% sure you can fix it by switching to a light crank pulley and lightweight flywheel.. Just remove all of the weight from the driveline and then you don't have anything to keep up the inertia.

It's an electronic throttle thing :/ it can be tuned out but it's annoying as hell on some cars.

Pardon my lack of knowledge, but what is rev hang exactly?

When it come to that, you can always reflash the ECU

i only notice rev hang in more economically driven vehicles in the last 15 years. Not so much on sport compact vehicles and hot hatches. I am assuming its the ECU tune that does this.

I am seriously doubting rev hang would be an issue in the Zx6, and it would surprise me a lot if this happened.

GTIs and civic si used to have horrific rev hang... Not rue on new GTIs and the si has gotten better.

I'd like to know the answer to the rev hang question, as well. I test drove a 2012 Civic Si, and the rev hang was extremely annoying. Not only did it make smooth shifting very difficult, it created an unnatural driving experience. I was so put off by rev hang in the Si, that I considered it a deal breaker -- and I'm partial to Hondas.

I test drove a 2012 VW Golf R, which did not have the rev hang problem, and it was very easy to shift smoothly. I see no reason why other manufacturers cannot avoid the rev hang problem and achieve the same smooth performance.

To me, the rev hang problem is not a trivial issue. If the BRZ has the rev hang problem to the degree that the Si has it, I'm not sure what I'm going to do. I hate to think about it, but backing out of the deal is not beyond the realm of possibilities.

I wish I could be more helpful, but being that I only drive older sports cars I have never encountered a rev hang unless it was due to heavy rotating mass. When driving the FRS I did not notice it, but I only made one or 2 quick downshifts and only used engine deceleration for a short distance. If there is a rev hang, its not incredibly intrusive.

That's good to hear.

All cars have it these days, it's to reduce HC emissions. When the engine decelerates quickly I'm guessing there's a bit of "ECU lag" because the sensors aren't picking up on the decreased airflow immediately, and you end up having excess fuel injected which comes out the tailpipe in the form of black smoke or a fireball + black smoke. I think that's the reason some cars have that fireball or puff of smoke come out when they shift gears.