Rev-matching

Hello everyone,

I am still a relatively new driver (3 years) and I am currently driving a 2012 Tacoma 2.7L 5 speed access cab.

I have been driving stick shifts from the beginning. But I have never been able to shift consistently smooth. Whenever I downshift, the truck lurches forward and it has never seemed right to me. Even though I took some lessons, downshifting without adding some gas just feels like it is bad for the truck.

A few days ago, I started doing what I think some of you call a single clutch rev match. I have only been doing it in situations where I need to downshift and then accelerate. Here is how I have been doing it:

1) While moving, I push the clutch in.
2) Select the next lower gear.
3) While still having the clutch to the floor, I gently and slowly push the gas until the engine is at least 500 rpm higher.
4) Then I slowly release the clutch.

Ever since I have started doing this, the ride has felt so much smoother than before. However, I am worried that I may be unintentionally damaging the clutch assembly doing this.

Does rev matching have to be done super fast, or will I be fine with the way I have been doing it?

Thanks!

 

Like you said you were doing, it's only worth doing if you need to accelerate quickly in a lower gear. The more you practice the faster you'll become with it. You can tap the gas quickly to get the rpms up faster instead of slowly. That way the whole shift process goes quicker. The longer you take to release the clutch the more the clutch wears down. You can get to the point where your rev matches the tranny speed and it will be a smooth transition. Practice makes perfect.

Otherwise no need to rev match.

 

When at a higher gear wanting to go lower and you want to match the synchros, the proper technique is this:
1. Push clutch in
2. Shift to neutral
3. Let go of clutch!!!
4. Blip throttle high enough to be a rev that matches the down shifted gear
5. Push clutch in
6. Shift into lower gear
7. Let clutch out

With practice it becomes buttery smooth. Then you move to toe-heel down shifting. It can be done in a truck.

 

I have attempted to double clutch several times. 95% of the time, I give it either too much gas or too little, and it results in the jerking from shock in the driveline. I stopped trying because I didn't want to ruin my truck.

I have considered the heel-toe method as well, but the pedals in the Tacos don't seem to be laid out to facilitate that.

All I want to do is make my shifts smoother. I am not Steve McQueen and I am not doing any racing. I appreciate the input though.

 

In my opinion you are way over thinking this. Everyday driving "rev matching" is not needed or worth one thought about it. That is why you are jerky, you are Thinking About It. Don't.

 

I don't even think about it when I drive a standard. I always just shift, roll off the clutch and back into the gas like I am taking off.

I'd say you are just disengaging the clutch too roughly.

 

The Toyota R series has a fairly wide ratio between gears which makes sense for a light truck application . I believe your only downfall is learning to drive with throttle hang . Once you have mastered the throttle hang , it should be smooth sailing .
If this was a close ratio transmission with gearing designed to carry heavy loads , double clutching and rev matching would be a benefit during deceleration .
You can read more about your actual ratios here.
Here are the gear ratios for your transmission http://en.wikipedia.org/wiki/Toyota_R_transmission

 

OK, so you are saying that after switching to a lower gear, you slowly let off the clutch while gently applying gas at the same time?

 

I'd say you need to go for a ride with someone that actually knows how to drive a manual. Like an instructor at a BMW club driver education event...

Now back on topic. Almost all modern manual transmissions have things called synchromesh gears. Most anything before the 1960's didn't. You had to double clutch to downshift. The technical term is double de-clutch. (clutch in, shift to neutral, clutch out, rev engine, clutch in, shift to lower gear, clutch out apply gas)

If you didn't, the lower gear in the transmission isn't spinning at the proper speed to allow the gear to be selected and you would grind the gears. With a sychromesh, the face of the current gear, speeds up the lower gear to the proper speed, allowing it to be selected. Most really well built boxes will allow you select ANY gear at speed, (true manuals, not a SMG or a DCT), so you could, in theory and practice, shift from 5th to 2nd. Whatever happens isn't going to be good...

Anyway. matching the revs of the engine to the anticipated speed of the wheels is only a driver aid. It does nothing about wear of the synchro's or tanny. On the other hand, a properly executed double declutch, eliminates all wear, and aids driver control. (but there are so few of us left that can properly do it...lol)

My first race car had straight cut gears and dogs, you had to DDC to drive it...Dancing on the pedals... Heal and toe double clutches....Sounds wonderful. But is completely unnecessary in a modern car. (still fun to do)