rx7b13

lol right on brother but isnt that with all the threads

Wankels-Revenge

I downshift cuz i like the sound it makes...sue me :P

WVRx7

Actually, in this case you should have typed "You're really smart". Nonetheless, I appreciate the thought.

sliding_fox

Originally Posted by NZConvertible
Why is it that every discission on downshifting brings out the idiots? Using a combination of wheel braking and enigne braking is a normal part of driving and every car was designed to do it. Anybody who thinks rotaries is different in this regard is an idiot. Anybody who thinks it should only be done on racecars is an idiot. And all of this has nothing to do with emissions - that's a whole different level of idiocy.


^ Amen!

OC_

OMG!!! where do people come up with this stuff! Down shifting = bad??? HAHAHHAHA
Better not drive your car since thats 'bad' for it, too.

Dcrasta

Well if you like to drive in the rain/slippery conditions u better learn to rev-match or u will be doing a nice spin if u downshift. (personal experience) especially with LSD equipped car.

JoshRX7

iTrader: (5)

I do it all, everyday, and I'm the best at it... isn't that what we are all really trying to say? j/k end this thread.

Josh

RN's X-7

OK here I go, I have a CDL and when I was taking the driving part I got docked points because I put the clucth on during a stop, his explanation was if for some reason you have to make a quick jump and the clutch is depressed you have a chance of stalling i.e railroad tracks. So I have taken that to heart when I am turning a corner and or slowing down. When you down shift you have an out. By the way doesn't automatics downshift automaticly for breaking purposes? Correct me if I am wrong. One more point the driving schools that I have attended say to down shift to help slow your car.

88turbotime

Alls i got to say is i shift mad quick yo

rx7b13

ahh shiznit fo yo be phuckin up yo dravtrain dawg

drago86

Theoretically,

If you removed the OMP and ran nothing but premix

And found a 100+ mile VERY steep road,

and engine braked down the whole thing without touching the gas once

you could kill the motor, the car fuel cuts while engine braking.

JoshRX7

iTrader: (5)

Umm, you can use the clutch on your CDL coming to a stop... you should just try to minimize the distance you do this (less than 100 feet I'd say, try for much less). I always keep a rig in gear as long as possible... pushing the clutch in right before the truck wants to walk at idle in gear. I believe what your examiner was observing was obsessive "coasting", which is essentially "out of control" even if you think you are or not. A couple reasons for staying in gear in a vehicle such as a semi are a) the engine helps slow your heavy vehicle, b) staying in a proper gear helps you manage a 'workload' for situations such as turn setup, lane changes, etc, c) it conserves your momentum.

Your railroad example... usually vehicles requiring a CDL are either very long or "combination" vehicles... or both. If you roll over a railroad track out of gear at a low speed, there's a good chance a portion of your vehicle will remain on the tracks if it comes to a stop. This is why you should not shift while crossing a track. I guess you could also "stall" the truck with a quick dump of the clutch in too high of a gear like your examiner said... but that's not the main reason why you should keep it in gear.

Hope this helps you. Did you get your CDL?? If so, congrats... welcome to trucking!! Remember, you signed up for it.

Josh

EDIT: Typically examiners like to see a good bit of shifting on your checkride as well... it demonstrates that you have mastered the truck. Typically, from my experience, drivers that coast a lot are unsure of what gear they should be in at that particular speed/engine RPM, and have trouble recovering from missed shifts. You can bet your examiner thinks along these lines as well. Sorry I rambled. I love trucks. : )

Syonyk

In addition to recording the best fuel economy ever seen by an RX-7.

Now, show me where in the world you can do that. And, remember, engine braking with no throttle is the lightest load the engine sees. There's really not that much stress on the engine (no combustion pressure forcing the seals out). Given that it's possible to run a FC with *no* engine apex seal lubrication under normal driving for at least a while before it dies, I don't think that 100 miles of no load spinning would kill it.

That's a wonderful theoretical construct that has nothing to do with reality.

-=Russ=-

quickfast

And using your brakes on that same road wouldn't wear them out??

snowball

wrong rotors.

quickfast

My point is that example doesn't show much because while it might cause damage to your engine, using your brakes instead of engine braking would cause damage too.

janm

I took apart an engine that had been driven for at least 6 months with a broken OMP and no premix. Other than boned side seals it was surprisingly intact!

fcdrifter13

Wasnt double clutching used in transmissions before they had syncros pretty sure it dosnt need to used anymore because the only new transmission I can think of is just a POS alision used in coal trucks.

As for engine braking why would it matter. do you know what a jake brake is. An engine brake designed to be used quite often on long downhill grades where foot braking over heats the brakes. And like stated above only very very very slight wear to the clutch is caused.

Automatics engine brake. Had my corsica 10rs now and it still works fine. And they have more clutches than a manual.

Now if you downshift from lets say 2nd to first when your going pretty fast without matching one of two things is gonna happen the motor will rev high and the rear will lock up, or your motor will rev really high and then some damnage will be caused.

WVRX7 your like 5 minutes from my house. What do you drive. Wouldnt mind meeting someone else from WV.

gildardo

its even recomended on some owners manuels to engine brake when goin down a big hill. I agree with NZconvertible.


Gil

wishIhadanFC

absolutely, Every car owners manual i've ever seen says this. say whatever you want, but downshifting works and i'll keep doing it till I supposedly blow my motor.

rx7b13

if the car wasnt made to down shift then wouldnt there be lockouts in every gear. i know i cant down shift into first unless im under 10mph due to the lockout in first

WVRx7

I got a couple of very nasty PMs from some children in this thread. I can envision that a few of you are barely out of high school. Adults don't normally disagree on a subject and then immediately lash out about the other person's knowledge, education level and family heritage.

I can respect that opinions vary on subjects. I don't wish any misguided people ill-will.

I offered some information on proper driving technique and if you choose to drive differently, fine.

I'll try and explain my position again:

The act of moving down through the gears to slow a vehicle is not proper driving technique. Using the engine and driveline to slow a vehicle, instead of the brakes is not rightly recommended by any manufacturer.

BEFORE someone says I am wrong, yes, you can use a lower gear to keep your vehicle from accelerating down a steep incline. You can use lower gears to slow your vehicle when on slick surfaces. Yes, there are limited, special scenarios where engine braking can be used as a tool.

I am instead speaking about 99% of the driving that you do on public highways.

Proper driving technique states that you always have the vehicle in the proper gear for the speed you are traveling.

If you are going 50mph in 5th gear and you slow for a stop light you should use the brakes until the car stops. On the other hand, if while slowing, the light turns green and you need to accelerate, then select the proper gear and go.

If you are using the transmission and downshifting through 4th, 3rd, 2nd, then you are simply using a technique that is wholly unnecessary and silly. You are subjecting your clutch, syncronizers and other driveline components to double the wear and tear they should normally experience.

Why use all those expensive, consumable parts to slow a vehicle when you have cheap and replacable brakes installed on the vehicle to do that job?

The argument about not being in the proper gear for emergency acceleration is absurd. I guarantee I can get my car to a proper gear for acceleration and be on my way faster than an automatic transmission can kick down to get another vehicle moving.

Another scenario, you are driving on a curvy mountain road that constantly requires upshifts, braking and downshifts. In this situation, you aren't downshifting, you are simply selecting the proper gear.

You might be in 3rd gear and approaching a slow turn. By your experience with your car you know that you will need 2nd, well, you brake to the appropriate point and simply select the lower gear.

On the other hand, if you don't use the brakes, rev the engine and select 2nd to let the engine slow you down, sure it sounds cool, but you are upsetting the chassis, you are using the engine to slow the car instead of the brakes and you are generally showing that you don't know proper driving technique.

All of this transfers to driving on a race track, but in a competition or track driving situation every action is time compressed into a small braking or transition area. Rev-matching and balancing the car with the throttle and clutch is proper technique, but it is not something that rational drivers need to be doing on a public highway.

fcdrifter13

Where in Charleston are you located. If the car in your avatar is your I think I have seen it at a couple of Auto-x events in Riverside

WVRx7

That's me.

fcdrifter13

damn then Ive met you before. Lol. You were at my first one and I remeber just staring over your car friggin sweet car. I drove a corsica though no 7 for me back then. Its good to see another 7 from the mountain state lets see here that make 7 i believe.