Hey Bonehead - I don't mean that in a negative way Yes, I blip some times when I'm getting geared up for the track. But day to day there's no need. I've never had my car lurch / buck when down shifting and can't even imagine how you could get your car to react that way. If coasting to a red light, just leave it in neutral and use the brakes (much cheaper wear item than clutch). If coasting and it turns green, pick the correct gear, feed in enough gas to rev match, and go. If slowing into a turn, down shift and release the clutch at the appropriate revs. I'm not sure I'm explaining it right, it's something I do naturally and realy don't think about it - but I know I don't blip the throttle all day long.

 

I love to blip the throttle for downshifts on the street.

 

Uh yeah, this.

What PSDS seems to be teaching is just plain old non-H/T downshifting. It should be the standard way that people downshift on the street. I presume they are teaching it because H/T is too difficult for most students to do right, and it's more important to focus on the correct line and correct speeds to drive fast than it is to get a perfect H/T.

Lately I've been double-clutching every downshift just for laughs. It's the only way to get a perfect silky smooth downshift and provides something for me to play with in boring street driving.

Clutch in
select neutral
clutch out
press throttle
clutch in
select new gear
modulate throttle and clutch out

try to do it as fast as possible and so smooth that a passenger doesn't even know you shifted.

 

Hi Ron,
When you say "completely braking before engaging your lower gear", do you mean engage but releasing cluth, or shifting to lower gear (which clutch still disengaged/clutch in)... I assume you say thing to reduce wear on synchros?

Is it ok to hit brakes, clutch in, shift lower gear, finish braking, blip throttle, release clutch?

 

but where's the fun in that?

might as well drive a pdk..

although i rarely HT in the streets,

i DCHT more than 50% of the time because its a thrill to match the rev perfectly. (actually not a real HT.. more like the big-toe and the pinky-toe )

 

I do a rev matching almost every downshift, it isn't needed on the street, but it was a great way to practice, and now has become something that happens without really thinking about it. Under normal braking the brake pedal and gas pedal are at about the same height, and with the Rennline extensions I added it is really easy.

 

Maybe I'm misreading what you wrote and am missing something here. But, the whole purpose of the H/T downshift with rev matching is so that you WON't use engine braking. Engine braking is a disadvantage, not advantage. It's hard on the motor and the higher your revs are when you downshift WITHOUT a rev match, the more engine braking that willl occur when you engage the next lowest gear and release the clutch. I've seen people actually make their rear tires lock up and skid on the track from NOT rev-matching and using "engine braking".


Dan

 

Me too!
You don't cause any wear on the clutch if you do it right - you could actually do it without the clutch if you perfectly matched the revs (can't say anyone would recommend!) When I double clutch, I literally drop the clutch into the lower gear and the car just continues to decellerate in the lower gear. If you miss it though, the car will jerk! I think the syncros these days are so good that double clutching is probably unnecessary and much harder to learn than the simple rev matching downshifting used in the school. I agree, it is probably used because both because double clutching isn't really necessary and it is way to hard for someone to learn over a weekend.

 

HT downshifting allows you to employ smooth engine braking without upsetting the car.

Imagine you're on the brakes at the start of the deceleration zone. When the revs have dropped to the point where it's safe to switch to a lower gear, you press the clutch, shift to the lower gear, blip the gas with your right heel and release the clutch in one motion. You've been on the brakes the whole time, and most of the time the clutch was up so you also had engine braking.

When you release the clutch after the downshift, the engine revs have to increase in speed by around 2k - 3k. The energy to do this has to come from somewhere. So if you don't blip the gas, the engine will take the energy from the driven wheels. Depending on what you're asking the car to do, this could apply so much sudden braking force that the tires lose adhesion.

The technique the original poster described it a safe and smooth downshift without having to learn how to HT. The downside is that you have to be off the brakes first, and there are some corners where I like to turn in while still feathering the brakes. I can't perform a smooth 4>3>2 HT downshift in sequence, so there's one particular corner where I shift after braking and go from 4 straight to 2 and follow the OPs technique.

 

I think I used the wrong term there. What I meant to say was that when the engine is in higher RPM it is much easier to slow the car down compared to a high gear and low RPM.

 

"Engine braking" is not dropping the clutch with engine at too slow a speed for that gear. Engine braking is using the engine to slow the car by getting off the gas while the car is in gear. IF you don't know how to rev match the downshift and lock up the rears, THEN you really throw off the car in a corner.
Half of engine braking is getting the engine in the right gear to exit a corner. You DO downshift to assist slowing the car down. I've never heard of anyone putting a car into neutral and then selecting the gear only on the exit. At the track, you need to take full advantage of the whole car's ability to slow it down. On the street, it doesn't really matter, other than the joy of driving.

 

Little bit of a subject change but I usually rev match my downshifts on the street to minimize clutch/synchro wear. However, I do this by clutching in, selecting lower gear, blipping, and then clutch out. Read on my an Elise forum that it is better to double clutch downshifts as far as clutch/synchro life is concerned. Is this really necessary in modern cars? Is this substantially better than just rev matching downshifts without the double clutch?

 

You still perform the downshift before the corner. You brake as normal in the deceleration zone with the clutch up so you still have some engine braking. Once you're done with braking, you release the brake and perform a rev-matched downshift, then enter the corner with your foot ready over the gas.

 

Supposedly better on the synchros to double clutch, but I've heard synchros these days can easily take it and I totally believe it. I've never seen a post about someone losing a tranny or synchro in a 997. Plenty of burnt clutches though! Certainly a lot cheaper to just use the brakes! I love downshifting, otherwise I would have just bought a PDK.

 

My bad...I didn't realize that the above description was the proper definition of "Enginge Braking". You are indeed correct and I use engine braking as well in the same manner as described above. The only thing I do different is that I go ahead and H/T in sequence from 4>3>2 or as in the case of turn 1 at VIR...5>4>3. I like the way it sounds! Thanks for the education!


Dan