Saud2k, there are two ways to match the speed when downshifting. One is while braking the other is not.

Downshifting while braking involves manipulating all three pedals. This is the "heel-toe" technique. Basically you're braking, and you rotate your foot so that you can "blip" the gas.

Downshifting without braking is much simpler, since you can use a foot for the gas, and another for the clutch.

In both cases, the idea is to increase the engine rpm to match what you expect it to be when engaging the gear. This is known as "blipping" the throttle. If you push the clutch in, and then press the gas pedal (*lightly*), the engine will "rev". That is all there is to blipping the throttle.

The trick is to know how much to rev so that the engine doesn't "bog" when engaging the gear. That takes practice. A technique I've heard is to drive on a back road at, say, 40mph. Then try shifting up/down smoothly via rev matching. This way you can get a feel for the technique. If you're in 4th, try downshifting to 3rd. Put the clutch in, shift, blip the throttle, then put it into 3rd before the engine rpms drop back down. Once you've done it a few times you'll start to get the "knack" of it and can then start trying it out in different situations. After a while, you'll get a feel for how much to blip it.

If you downshift via clutch alone, you will probably notice yourself anticipating the "bog" of the engine, which you will probably avoid by "easing" the clutch in. This accelerates the engine via the wheels and the clutch (which is why the car feels like its slowing down when you do this). All blipping does is use gasoline to accelerate the engine rather than the car's motion.

I hope this helps!

 

Unless...... you double-clutch it. I assume your cause for concern about downshifting into 1st while rolling is wearing out the synchros?

 

Oh, to follow up, downshifting via clutch alone will put *far* more wear and tear on the clutch than rev-matching. When rev-matched, the two parts of the clutch are already close to their speed, therefore not much friction will occur (therefore not much wear). If you use the car's momentum to accelerate the engine, then the clutch acts as a mediator, controlling how fast the engine accelerates. This involves slipping, which *will* wear down your clutch somewhat. So if you want to downshift, rev match to reduce clutch wear.

 

We spent some time discussing this subject recently. For some reason, people start to get religious about this issue. I don't really get that. Anyway, here's a link:Ad Nauseum

 

Downshifting is just an opportunity to practice heel-toeing!

 

I remeber asking this question a few months ago and got an enormous reply. Well it is just a matter of driving style. However, I remeber one post that seemed to make a lot of sense to me, under certain conditions, downshifting teh car to slow down can cause in some casuses the tire to spin. So just be careful. Personally, I brake both ways...lol Under normal times, I just use the brake but whenI'm in a mood, I love to hear teh engine and nothing sounds quite as nice as a perfectly executed downshift

 

I usually double-clutch when slowing down, but never to 1st. I used to rev match but this does nothing to help the synchos out. I personally think you should always be in gear at speeds over 10 mph which includes braking in gear. I try to avoid the brakes as much as possible.

Don't you just hate is when the car in front of you is constantly braking or just riding the brakes. The brakes are meant to slow down, so if your not slowing down, don't use it. IMO

 

i only downshift to slow down if there is a cop around, so they dont' see me braking

 

[QUOTE]Originally posted by hoof
[B]Oh, to follow up, downshifting via clutch alone will put *far* more wear and tear on the clutch than rev-matching.

 

if im in 6th, i will downshift all the way down to 3rd or sometimes 2nd gear. downshifting to 1st gear is too much IMO. if you downshift correcty(rev matching), there will be no "additional" damage done. you just need to know what you're doing. whenever you downshift and you let go of the clutch, if you feel a jerking feeling, you are doing it wrong. when i downshift, it feels like im using an automatic transmission, thats how smooth it is.