[VaSteve]

Ever since learning to drive a manual transmission, I have downshifted when slowing and let the engine do some of the braking.

When I got the 911 I stopped after reading too many expert opinions on Pelican: "brakes are cheaper than the clutch" and have since tried to dow proper rev matching downshifts.

At the HPDC, the instructor discouraged downshift/engine braking I assume because people do it wrong: "down shift, dump clutch" rather than rev matching.

I drove a couple of those hybrid Hondas yesterday and found that they are designed for some amount of engine braking - it actaully helps to recharge the battery.

I'm curious, how do you all drive your manual cars 1) street and 2) track, with respect to downshifting either Porsches or non-Porsches.

[michael lang]

Steve

I have always used the engine to help slow down my cars. When I was @ a Mercedes Benz school they allowed us to take hot laps on the Jefferson Circuit, my instructor had turned off the BAS/ESP system in the E430 we were in. While we were going around the track, it was plain as day that he was downshifting to scrub off speed before entering his braking zones.

I have not been to any Porsche schools yet (should be this spring) so I don't know what to expect out of my 911 but I have gotten 117,000 on a clutch in a car that Shelly & I have owned since new just by doing that very practice. Don't get me wrong, I am by no means disclaiming your instructors but if I can get 117,000 out of a clutch on one vehicle and 107,000 and still going on another by driving the way that I drive there is no reason for me to stop using the engine to help slow the vehicle down.

BTW:both cars I have had since new, do not leak, nor have ever had to be opened up for any reason. The first car (117,000) was replaced this past June with a Toyota Sienna and the second veh. I still have and will probably hold onto it for another 9 years.


Mike

[Eli]

I'll second Mike's response. I've always downshifted and let the engine do the initial work before putting the foot on the brakes. Even going into turns the car feels more "controlled".
I had my last car for over 4 years and just over 60k miles (before I sold it) with no signs of clutch slipping.

[Mackpipes]

If you match revs while down shifting, it will minimize clutch ware. The classroom instructor during my HPDC told us the only reason to downshift was to get into the proper power band for optimal power.
Personally, I do it because I like the way it sounds.
Is it as effective as using the brakes: not a chance.
Will it cause additional clutch ware: yes, if compared to not engine braking.
The choice is yours, there is no right or wrong, one just lets your clutch live a little longer.

[Doug E]

After replacing my clutch last year I'm a member of the "brakes are cheaper then clutch" club

[jpinkert]

If you match revs, the clutch will see little wear from downshifting. But you are wearing the backside of the gears in the tranny and you're also making your synchros work unless you are double-clutching. A stoplight drag race will put lots more stress on your clutch than a 'proper' downshift.

What do I do? Double-clutch heel-toe downshifts. It is fun, great practice for the track, and entirely legal. I have yet to start using LFB on the street....

[Mackpipes]

Why's that Josh?

[Vicegrip]

(Caution my opinion to follow! Not the end all or even good info just one persons methods)

I never use the motor for braking street or track. On the street I will lift to match speed with someone in front of me or coast to the stop light but no downshifting. There is no need to. Coast in or feather in to a low RPM and then push in clutch and brake. Stop, select neutral and let clutch out while sitting at light to unload throw-out bearing and left foot. Downshifting is for increasing torque at the rear wheels, not slowing. It is not a mater of pads being less expensive than drive train it is a mater of what is made to do what. Drive train is for Go and brakes are for Stop.

In my opinion that at the track it is not the fast way around the track and that is enough for me right there. Don't matter if you can do it with finesse or if it hurts something or not it takes time and multiple inputs to engine brake. More time and unnecessary inputs = slower. Engine braking is inefficient as well it uses the unloaded wheels to scrub speed. Real braking uses all 4.

When coming into a corner that needs speed reduction I stay in the gas WOT and then threshold brake when it is time to slow. As the car slows I let the motor slow with it by leaving the clutch out. Just prior to turn it or just prior to the end of the braking cycle I push in the clutch and heel toe the throttle to match RPMs as I select the gear used in the turn. This lets me concentrate on good braking, turn in and power management through the turn rather than monkey motion activity with the hands and feet. If you can engine brake prior to real braking to scrub speed then you are braking too early. Keep the power on longer and brake more later. Faster longer is faster in total.

EDIT After thinking about it I do push the clutch in during the braking cycle for many turns but leave the gear the same. Not on turns that I might be left foot braking. Have not figured out how to heel toe the brake and clutch yet.

I agree with the HPDC instructor. Downshifting is for increasing torque at the rear wheels, not slowing.

[Chopper Dropper]

Mostly what Kurt says. Engine braking is extremely inefficient so why do it! If you are engine braking before putting the binders on, you just got passed by a bunch of hybrid Hondas. These I believe use the system to put some charge back in the battery for mild braking. Trucks will use engine braking because they have so much to stop and the brakes fade.No instructor would condone engine braking.
Dirk

[mroberts]

Maybe everyone already knows this, but there is one situation where engine braking is the "right" thing to do. It may be less of an issue for those of us with high performance pads, rotors, and fluid.

Descending a long hill on your brakes is a bad idea, and I think that's the only universally accepted "allowable" time. Coming down Pike's Peak, they stop everyone to check their front rotor temperature.

I agree you don't want to belt it into gear for sudden deceleration, but it is a good way to hold speed without riding the brakes.