Rev Matching to second gear

[stugray]

Originally Posted by murdoc

I feel like if the RPM gap was always the same, shifting from third to second at 10 MPH would take you from ~800 RPM to around 2700 RPM, since doing it at 60 MPH will increase RPM by about 2000.

You are right, I am wrong.
I was picturing the engine RPM vs drivshaft RPM graph having all of hte lines parallel.
However all 6 gear plots have y-intercepts of zero, so the lines are not parallel.
So transitioning from one gear to another when low in the RPM range is a smaller jump than doing it at high RPM.

Sorry bout that.

[mav1178]

Originally Posted by krayzie

Why don't you just double clutch downshift from 3 to 2?

Originally Posted by Jfheisenberg

Yeah, im not very familiar with double clutch and i haven't try the hill and toe method yet.

Because double clutching is a method used in trucks (and sometimes cars) without synchros.

If you have a modern transmission with a synchro, there would be zero need to double clutch unless you are doing it wrong or hesitate too much between shifts.

-alex

[ryoma]

I found it hard to rev match in this car when I first got it. I think it's due to the DBW and I feel that the pedal response is sluggish. I definitely notice a little dead zone area when I push the pedal down about 1 cm. Maybe I was spoiled by my old MR2 that uses a throttle cable. loved the response with an actual cable instead of this new electronic crap. that and the clutch pedal is one of the things I still haven't gotten real used to in this car yet.

[krayzie]

Originally Posted by mav1178

Because double clutching is a method used in trucks (and sometimes cars) without synchros.

If you have a modern transmission with a synchro, there would be zero need to double clutch unless you are doing it wrong or hesitate too much between shifts.

-alex

This is correct there is no need to double clutch due to synchros (triple cone synchros too for the first 3 gears in this car) but it's just another skill to have, very useful when the gearbox tends to hesitate 2nd gear in very cold winter mornings.

Yes DBW and dare I say electric steering also, no matter how good they get just can't replicate the responsiveness and feel of old skool cable throttle and hydraulic power steering.

[JS + BRZ]

Clutch in, Blip the throttle, Downshift.

This doesn't work for 2nd gear??

No need for double clutching.

[D_Thissen]

I think going in to 2nd needs a slightly bigger blip then the other gears. I'll have to see when I drive it.

[ajaxthebetter]

I have a question to ask on a related topic.

When peformance driving, is there a general RPM which, once you drop below, you downshift so as to remain on power? IE, Revs drop below 4.5k you downshift. Drop below 5k. Etc.

I ask because I put myself in a dangerous situation, both mechanically and mortally, by under revving on a downshift when going around a corner.

The situation: Navigating a diminishing radius corner, third gear but decelerating gradually as the corner got tighter. Next their comes a pretty sharp kink--I was going around 50-55, can't be sure. Revs at/around five. I go for it, initiating a quick heel/toe which I didn't match properly. Think I needed to hit near 6.5 or so, which I didn't. Don't know how much I missed by, but the rears locked as I was turning in (still on the sweeping part) and as a result my rear kicked out alarmingly quick. Thankfully I caught it. Dangerous situation I put myself in; my nose was angled directly toward the ditch. Desolate road so there were no oncoming cars ( I could see through corner.)

Anyways, haven't driven that hard since then, which was a couple weeks ago, nor have I returned to that road.

So you downshift when you dip below what RPMs when performance driving? I'd like to find out if there is a sweet spot most people adhere to.

[Crestwood1001]

For whatever reason when you blip the throttle going from third to second the rpm's don't rise as fast as going to other gears. Next time watch your tach as you downshift through gears and you will see the difference. Iv had good luck just giving it a split second more on the throttle going into second

[DocWalt]

Originally Posted by ajaxthebetter

I have a question to ask on a related topic.

When peformance driving, is there a general RPM which, once you drop below, you downshift so as to remain on power? IE, Revs drop below 4.5k you downshift. Drop below 5k. Etc.

I ask because I put myself in a dangerous situation, both mechanically and mortally, by under revving on a downshift when going around a corner.

The situation: Navigating a diminishing radius corner, third gear but decelerating gradually as the corner got tighter. Next their comes a pretty sharp kink--I was going around 50-55, can't be sure. Revs at/around five. I go for it, initiating a quick heel/toe which I didn't match properly. Think I needed to hit near 6.5 or so, which I didn't. Don't know how much I missed by, but the rears locked as I was turning in (still on the sweeping part) and as a result my rear kicked out alarmingly quick. Thankfully I caught it. Dangerous situation I put myself in; my nose was angled directly toward the ditch. Desolate road so there were no oncoming cars ( I could see through corner.)

Anyways, haven't driven that hard since then, which was a couple weeks ago, nor have I returned to that road.

So you downshift when you dip below what RPMs when performance driving? I'd like to find out if there is a sweet spot most people adhere to.

If I'm not on the track I'll let the revs drop pretty low. I'd probably try to stay above at least 4k in hard street driving, that way you're not in the torque dip.

[Vroomin86]

Blip twice that's what I do works every time

[Andrew025]

Originally Posted by Vroomin86

Blip twice that's what I do works every time

Why not just give it a bit more throttle?

[SR5]

Originally Posted by ARTBRZ

This is my first manual so I have a simple question that I haven't been able to find through search. So I've been able to rev match well going to 5th, 4th and 3rd well but not to 2nd gear. I'd say I blip it about 700 rpm to get a smooth downshift without lunging forward in the other gears. I've tried a few times rev matching to second and it's a horrible feeling. I want to get a reference how much to blip because I feel that I'm going to wear down my clutch or mess up something before I figure it out.

So how much do you guys blip the throttle when going to 2nd gear (with or without A/C on)?

good observation for this being your first manual car. 2nd gear is a bit more difficult to downshift to.

First off, the stock Electronic Drive-by-Wire doesn't make it any easier.
It's a bit miss leading as far as throttle, speed, & gear.
My DC2 (cable throttle) felt easier to downshift into 2nd, using the same amount of throttle in any gear.

Secondly, 2.188 gear ratio and 4.100 final is fairly short when you compare it to other gears.

So, you have to give it more throttle than if you were downshifting from 4th-to-3rd.

just as an example downshifting from 3rd-to-2nd:
while in 3rd gear at 25mph give it to about 3100rpm then shift. It should go right in! However, notice it feels like you have to give it more throttle than if you were downshifting from 4th-to-3rd.

[Vroomin86]

Originally Posted by Andrew025

Why not just give it a bit more throttle?

I find it more controllable and smoother shifts when I blip once, it climbs a few hundred rpms which puts the second blip already on a head start in higher rpm, then again I also tend to mostly engage 2nd on the coming down of the second blip when downshifting. If I was driving through a very spirited course or track I'd probably just give it a bit more throttle like you mentioned.

I am referring more to daily driving for blipping twice.

[humdizzle]

like everyone else said. clutch in -> blip throttle -> throw it into lower gear -> let clutch out. eventually you will get good at it and do it one fluid motion.

however with hard driving you will want to heel-toe. same as above except you are using your toes to brake and your heel to blip throttle

practice, practice, practice... thats the only way you will get good. I found the BRZ to be very easy to heel-toe.