Do you need to rev match everytime you downshift?

[psteng19]

I've been told you have to rev match each time you downshift.

Lets say you're on local roads doing 30 mph and you approach a 90 degree turn.
I would slow down/brake to about 15-20 and downshift to 2nd before the turn.
But upon doing so, the car jerks forward. My friend says I have to rev match before downshifting because the revs are too low (in 3rd) before I downshift.

Or am I just release the clutch too quickly (which is what my dad says)?

 

I never "rev match". You're not on a damned race track.

Your clutch work is probably just subpar.

 

[Heisenberg]

I think the synchro's in modern tranny's make most rev-matching unneccessary. However, it's still probably not a good idea to drop it into 2nd gear at 80mph. You're probably just dropping the clutch a little fast and lugging the motor.

 

[MercenaryForHire]

Originally posted by: SammySon
Your clutch work is probably just subpar.

Yep. Just practice some more and you'll get there.

- M4H

 

[Beattie]

when I make turns, I downshift to second and tap the gas as I release the clutch. I guess that's what you mean by "rev matching"

 

[MercenaryForHire]

Originally posted by: Heisenberg
I think the synchro's in modern tranny's make most rev-matching unneccessary. However, it's still probably not a good idea to drop it into 2nd gear at 80mph.

Where's that video of the guy in the Accord who did the 5th-2nd misshift and owned his whole ride?

- M4H

 

[Aharami]

dang i feel silly askin this. what is rev-match? not familiar with the term

 

[Heisenberg]

Originally posted by: MercenaryForHire

Originally posted by: Heisenberg
I think the synchro's in modern tranny's make most rev-matching unneccessary. However, it's still probably not a good idea to drop it into 2nd gear at 80mph.

Where's that video of the guy in the Accord who did the 5th-2nd misshift and owned his whole ride?

- M4H

That video was classic. Unfortunately there's no level of technology that'll make up for being a dumbass.

 

[Brutuskend]

Only if your clutch is blown and you're "speed shifting".

 

[Electric Amish]

Originally posted by: Aharami
dang i feel silly askin this. what is rev-match? not familiar with the term

Approximating the revs of the engine to coincide with what the nominal revs should be in the gear you are shifting to.

 

[TheAudit]

I think you are thinking about it too much, it's not that hard.
You are doing 30 and you are slowing down. Unless you are in an econobox you can get away with leaving it in third. If you think it's revving too much when you drop it to second then leave it in third.

Give it a little time and you won't even think about shifting.

 

[NokiaDude]

Originally posted by: Heisenberg

Originally posted by: MercenaryForHire

Originally posted by: Heisenberg
I think the synchro's in modern tranny's make most rev-matching unneccessary. However, it's still probably not a good idea to drop it into 2nd gear at 80mph.

Where's that video of the guy in the Accord who did the 5th-2nd misshift and owned his whole ride?

- M4H

That video was classic. Unfortunately there's no level of technology that'll make up for being a dumbass.

Funny, my 99 Accord refuses to downshift to a gear lower than what car is speeding along. Meaning it won't goto 2nd if I'm doing 80mph.

 

[Vic]

Hell no.

Rev-matching is only for high-speed driving when you are either:
(1) Doing an accelerating downshift, say dropping from 5th to 3rd on the freeway. You need to rev-match to prevent the car from bucking or slowing down, when you actually want acceleration.
(2) Approaching a corner at a high speed (relative to the corner) and are planning on downshifting inside the turn radius. The sudden jerk could cause a loss of control, so you only options would be to release the clutch slowly (which provides less performance) or to rev-match to smooth it out.

Otherwise, modern synchros are more than capable of handling downshifts in normal driving. You just need to practice your clutch work like your dad says.

 

[Viper GTS]

Originally posted by: NokiaDude

Originally posted by: Heisenberg

Originally posted by: MercenaryForHire

Originally posted by: Heisenberg
I think the synchro's in modern tranny's make most rev-matching unneccessary. However, it's still probably not a good idea to drop it into 2nd gear at 80mph.

Where's that video of the guy in the Accord who did the 5th-2nd misshift and owned his whole ride?

- M4H

That video was classic. Unfortunately there's no level of technology that'll make up for being a dumbass.

Funny, my 99 Accord refuses to downshift to a gear lower than what car is speeding along. Meaning it won't goto 2nd if I'm doing 80mph.

If it's a manual you could force it into any gear but 1st and reverse (and even those if you tried hard enough).

Viper GTS

 

[Ferocious]

I'd like to see that video.

 

[psteng19]

Originally posted by: Beattie
when I make turns, I downshift to second and tap the gas as I release the clutch. I guess that's what you mean by "rev matching"

Pretty much that's how my friend described it.
Do you do this EVERY time you downshift?

 

[Vic]

I have the video in my main rig at home. He was in an newer Acura RSX shifting up from 3rd at redline, went for 4th and hit 2nd. That was amusing -- "Oh sh!t!" IIRC, that guy's engine didn't blow despite briefly hitting 12 grand.
I remember reading about the idiot shifting down from 5th at roughly 120mph to 4th and hit 2nd instead, but I don't believe there was a video of that guy, just pics of the aftermath (thrown and broken rods, holes in the block, etc.). IIRC, I figured in that thread that he went over 16k rpms. :Q

Honda makes great transmissions and apparently the RSX Type S 6 speed trans is too good for the idiots.

 

[MercenaryForHire]

Originally posted by: psteng19

Originally posted by: Beattie
when I make turns, I downshift to second and tap the gas as I release the clutch. I guess that's what you mean by "rev matching"

Pretty much that's how my friend described it.
Do you do this EVERY time you downshift?

If you're not putting any gas on as you downshift, then you might want to start with just a touch.

- M4H

 

[MercenaryForHire]

Originally posted by: Vic
I have the video in my main rig at home. He was in an newer Acura RSX shifting up from 3rd at redline, went for 4th and hit 2nd. That was amusing -- "Oh sh!t!" IIRC, that guy's engine didn't blow despite briefly hitting 12 grand.
I remember reading about the idiot shifting down from 5th at roughly 120mph to 4th and hit 2nd instead, but I don't believe there was a video of that guy, just pics of the aftermath (thrown and broken rods, holes in the block, etc.). IIRC, I figured in that thread that he went over 16k rpms. :Q

Honda makes great transmissions and apparently the RSX Type S 6 speed trans is too good for the idiots.

I think we're on different videos here.

There was two of the RSX misshift - the "during" and "aftermath" ones. With the kid with the nice coke nail on the highway.

And the Honda one was something else. Drag down a dirt road, then missed 5th-4th and got 2nd. Skid, slid, into cornfield.

- M4H

 

[StageLeft]

I agree with him that rev matching should always be done. Why not do it? It's simply good driving if you're driving a manual. Rev match on up and downshifts. It's easier on the occupants, and easier on the transmission.

And the Honda one was something else. Drag down a dirt road, then missed 5th-4th and got 2nd. Skid, slid, into cornfield.

And they whined like little bitches.

Anyway when are you buying that spec v? How much does the dealer want for it?

 

[Jzero]

YOu don't HAVE to rev match.
But you can. I almost always do just becuase it gives a smoother ride for the passengers.

 

[dirtboy]

You should always rev match. At the very least you make a nice, smooth shift and you will likely put less strain on your vehicle as it the syncros work to match things up.

 

[BCYL]

I always rev-match... it's much smoother that way... I dont want the car to jerk everytime I downshift...

 

[alkemyst]

unless I am trying not to upset balance in a turn I let the syncros handle the rev matching. Don't tell me you try to heel and toe into every corner too.

 

[Vic]

Rev matching in the common use of the phrase (blipping the throttle prior to gear selection to match expected revs for the next selected gear) on upshifts is completely unnecessary. The proper way to get a smooth shift on an upshift is with proper shift timing. Remember that when upshifting the revs come down to meet the next gear, not up. If you have to blip the throttle prior to shifting into the next gear up, then you are shifting too slowly. If the car jerks forward when you engage the next gear up, then you are shifting too quickly. Watch your tach if you need to. If you're still having trouble, try to remember that every gear should end on a high note when upshifting, meaning that the clutch should go in a millisecond before the gas comes off.

In regular braking downshifts during normal driving, rev matching is also unnecessary. First, modern cars have synchros and downshifting into the 2-4k range (depending on the vehicle) should not harm them at all. Just pause briefly before the synchro gate using light but steady pressure on the shifter and it will engage itself. Second, your foot should be on the brake at that time, not the gas. I don't want 18 year-old newbie manual trans drivers thinking they're cool doing unnecessary and possibly dangerous heel-and-toe maneuvers just because someone on the intarweb told them that they should... especially little 15-20 mph downshifts into 2nd that almost rev match at idle.

And yeah, M4H, we are thinking of 2 different videos. I recall the other one now... in an early 90s Accord IIRC. The driver was an idiot and they whined like little bitches.