Does the dual clutch transmission rev match?

[Benfmd]

I have the DCT on my new M3. It does not seem to rev match when shifting the way I remember my old E46 M3 with SMG or even my old E60 M5 did.

Am I missing something?

[jc05e46m3]

Originally Posted by Benfmd

I have the DCT on my new M3. It does not seem to rev match when shifting the way I remember my old E46 M3 with SMG or even my old E60 M5 did.

Am I missing something?

Of course it does. What does it seem to be doing that makes you feel that it isnt operating correctly?

[mad chemist]

Originally Posted by Benfmd

I have the DCT on my new M3. It does not seem to rev match when shifting the way I remember my old E46 M3 with SMG or even my old E60 M5 did.

Am I missing something?

Mine does - sometimes at lower speeds/revs there does appear to be a little overlap on the down-shift to stop the gear-change slowing the car down, if that makes sense.

[williocom]

Yes it does. I believe it is more pronounced when you increase your transmission speed between comfort, sport and sport plus

[Benfmd]

I really do not notice the increased rev blip on downshifting that I remember from my older cars.

What should I be noticing to determine if the transmission is rev matching properly?

[farouke92]

I under stand what you mean cuz on the e92 it used to be a clear blip and you could hear it easily
Trust me this one does
The feel is different just look at the rpm when you downshift you'll see or do it a low speed you'll hear it more clearly

[E36toF30]

I haven't driven the new M3/M4, so I don't know how it behaves exactly, or if it does anything different in the three transmission modes. The E9X generation M3 only does rev matched downshifts in S4/S5/A4/A5 I believe, or if you're on throttle it will always rev match the downshifts. So maybe you need to switch your car from the default transmission mode to S2/S3 to get the rev matched downshifts? Really though, it seems like they should have made it rev match at all times.

If an automatic (or DCT) transmission is not rev matching on downshifts, that means it's using the momentum of the car to pull the engine rpm up, which will slow the car slightly. Also, doing downshifts that way is much slower generally, compared to rev matching. So if the downshifts seem to take a long time to execute, and during that time there seems to be more drag on the car, that problem means it's not rev matching. Otherwise, I'd probably say it is rev matching, especially if the downshifts are executed quickly. As another poster said, it's probably just more subtle than the older cars.

[04RC51]

Mine rev matches perfectly. Damn thing is a work of art!

[parky1215]

Downshifting is beautiful. Perfect rev match everytime.

[Wah]

It does revmatch, but it doesn't bark like my E92 did, so I can't scare the dude in the car next to me.

[GOLFFRR]

lets hope the downshift blurps will be more pronounce with the MPE or other aftermarket exhaust set ups. That was one of my favorite things about the e92's I had, loved the downshifts blurps

[CanAutM3]

The DCT on the F8X does rev match just fine.

The OP is comparing SMG with DCT. The entire downshift process on a single clutch SMG is a much longer process than a dual clutch DCT, the throttle blip needed is therefore more pronounced and noticeable on an SMG.

Further, the S55 is turbocharged, so the engine sound is much more muted than the S54, S85 or S65 and therefore has a much less pronounced "bark" while throttle blipping.

[Andrew115]

Put in sport plus mode d3 and break fairly hard from 40mph then report back.

[gthal]

I think you are confusing the lack of sound on downshift blips vs. not rev matching. It rev matches but the F8X is much quieter doing so than the E9X. This is the only thing I don't love about the car... lack of downshift exhaust bark.

[SakhirM4]

Originally Posted by gthal

I think you are confusing the lack of sound on downshift blips vs. not rev matching. It rev matches but the F8X is much quieter doing so than the E9X. This is the only thing I don't love about the car... lack of downshift exhaust bark.

The 6MT barks fairly well on downshift.

[CanAutM3]

Originally Posted by gmcconn535

The 6MT barks fairly well on downshift.

That's because it's slower to downshift

[gthal]

Originally Posted by gmcconn535

The 6MT barks fairly well on downshift.

I think rev matched downshifts are rev matched downshifts regardless of transmission

The DCT also does bark, depending on engine load, etc, etc... but it is quieter than the E92. I just prefer a nice, pronounced, deep, loud exhaust note on downshift.

[Powerslide]

Originally Posted by williocom

Yes it does. I believe it is more pronounced when you increase your transmission speed between comfort, sport and sport plus

+1 - change to the sportier transmission shift settings - especially S3...

[crashtestdummy81]

Still not had much chance do drive it yet (only 100 miles so far!) but pretty much all driven with engine in sport & D2, she certainly does make a lovely bark on the down shift, especially with the top down.

[dclowd9901]

Originally Posted by Benfmd

I really do not notice the increased rev blip on downshifting that I remember from my older cars.

What should I be noticing to determine if the transmission is rev matching properly?

If it wasn't rev matching and you were cruising at 3k RPM in 3rd, then dropped it to second, it would be a very hard shift if the engine had to absorb the wheel torque. So if you're downshifting and not flying through the windshield, it's blipping.

[vantagesc]

Originally Posted by CanAutM3

The DCT on the F8X does rev match just fine.

The OP is comparing SMG with DCT. The entire downshift process on a single clutch SMG is a much longer process than a dual clutch DCT, the throttle blip needed is therefore more pronounced and noticeable on an SMG.

Further, the S55 is turbocharged, so the engine sound is much more muted than the S54, S85 or S65 and therefore has a much less pronounced "bark" while throttle blipping.

+1. This is also why sometimes the manual downshifts sound better in slower shift modes.

[TheRealOrosie]

Originally Posted by GOLFFRR

lets hope the downshift blurps will be more pronounce with the MPE or other aftermarket exhaust set ups. That was one of my favorite things about the e92's I had, loved the downshifts blurps

^^^This^^^

Muscle cars would always think that I was revving on them when approaching a light and downshifting. I always got a good laugh out of them revving their engines after they heard the blurp....