I keep seeing posts that mention rev matching and I am trying to figure out what that means. Is it automatic downshifting when the brakes are applied? I noticed going down a hill today with my foot on the brake that my G35 downshifted several times while maintaining high rpms throughout. On a flat surface, it doesn't do that. Does it have something to do with braking before going into a turn so you can accelerate out of it? Anyway, if someone could explain rev matching to me, I'd appreciate it.

Thanks,
Paul

 

im not sure but i think it match the gear with the engine rpm so that when you downshift it wont damage your engine.

 

its like HEAL & TOE, keeps the revs matched up when down shifting in to turns. i think it first appeared on a M3 SMG.and the euro cars pay a premium for this feature, but it comes stock for the Gs.

 

= tons of info
http://www.google.ca/search?q=rev+matching&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a

 

Thanks for the replies guys. I understand it now.

My G is an automatic which is why the concept of rev matching confused me. My car downshifts hard going downhill if my foot is on the brake, almost to the point where I don't need the brake. It does it on turns as well but not flat straight away stops. Somehow the car knows when to do it and when not to. Never had a car that does that before but I like it.

Thanks again

 

it's a very good feature for spirited driving / track use.

 

Yes it is...Step on the gas and the car is already in the proper gear to take off rather than trying to figure it out after you step on the gas. Very nice...

 

Not exactly. It is a bit easier on the drivetrain if the revs are matched to the gears as the shift engages, but it is more to create a smooth downshift than to protect the engine. The computer in your car will prevent you from downshifting to a gear that would cause the engine to over rev, so that isn't really a concern.


This isn't rev matching. This is simply the computer anticipating what gear you want and selecting it for you. Rev matching is just a way to make the actual shift smoother, but doesn't have anything to do with when the car's transmission performs a shift.

 

All "rev matching" means is that the engine speed matches the gearing speed during a shift. If you downshift the automatic transmission on a G35x, the computer revs the motor up to match the gearing so there isn't a sudden jerk of deceleration. Thus, it has automatic "rev matching".

It results in a smoother downshift than it would be if you dropped into a lower gear without this feature.

On a manual transmission, you would typically have to blip the throttle as you release the clutch, or it will result in a jerky downshift. In racing, this can cause a loss of traction to the drive wheels, and can be especially detrimental if you're braking and downshifting as you're coming into a corner where the rear wheels are struggling for traction already. Since most downshifts happen at the same time as braking, you have to operate all three pedals simultaneously to perform perfectly smooth "rev matched" downshift, so you can employ "heel toe" technique, which is a way to brake and hit the gas with one foot while the other operates the clutch pedal.

To break this down even further:

If you are in 3rd gear at 4000rpm and want to shift down to 2nd gear, the motor will need to be turning something like 7000rpm to maintain the same speed. So, as you shift, you must bring the engine speed up to 7000rpm before engaging second gear or the shift will not be smooth.

Infiniti G35's have "rev matching" software that takes care of this step automatically. If you shift down to 2nd, the computer will rev the motor for you.

 

Something to keep in mind:

This means that you cannot really use the 5AT's downshift to engine brake. If you switch over to DS-mode and then downshift, the computer rev-matches increasing the throttle automatically to hold at the new higher RPMs. It will continue to hold at that RPM until you blip throttle again (AFAIK).

If you are used to other Tiptronic automanuals without rev-matching, this can be a surprise if you were expecting to feel the lurch of an engine brake that doesn't come.

 

Ahm I use downshifting all the time to slow down. It actually slows the car down pretty damn quick.

 

Good info guys. Thanks for the replies. I read somewhere that the G has a gyro or something like that in it so it knows when the car is going downhill or in turns. Maybe that's the reason I feel the downshifts only in certain places?

Anyway. Thanks again.