This is the first manual vehicle I've owned...not driven just owned.

Do you downshift or just use the brakes? A combination maybe...basicly what are your driving habits?

Is it too much wear on the tranny downshifting all the time?

Depends on the situation. Back in the sixties the brakes on a lot of cars would fade pretty quickly, so downshifting was a necessity. One of the cars I owned when I was in high school was a '64 Barracuda with drum brakes. Pretty worthless drum brakes! Go through one major puddle and OOPS, no brakes!
These days I usually just downshift out of habit.

I own a 2002 Trans Am with the LS1 and M6. Personally, I feel more in control when the car is in a gear and it still has some response, so I "walk it down" as I slow down. Meaning, I brake to slow, then down shift, let out the clutch, then let off the brake letting the gear slow me down even further. I'm letting out the clutch/brake at a reasonable rev range (3k +/-), so it is still has some response if I need to accelerate. I would think that if you down shift and let out the clutch quickly within in a rev band intended for passing (4k +), that would be more wear on the tranny and drivetrain. I owned a '95 Grand Am GT with a M5 and drove this way for 6 years, 120k miles, never had problems with that tranny and only needed regular maintenance on the brakes. Of course that was all together a different vehicle, but I figured it was a good test for the future T/A. Besides, I was always taught being in Colorado and on snowy roads, that you downshift to slow, not apply brakes because brakes are more likely to cause a slide. I found this to be true real fast.

Yeah, I learned that very quickly when I lived in the Smokies back in the 70's. My 67 Beetle never let me down. I worked at a ski resort in Gatlinburg, and coming down Ski Mtn. Road could be a real adventure. The terrain down here is a lot flatter, so for me it just depends on the situation. If I'm in traffic, I want total control ( as you mentioned ), but if I'm alone and coming up on a light, I'll sometimes coast.

Originally posted by Foster'sguy@Dec 17 2004, 06:35 AM
Yeah, I learned that very quickly when I lived in the Smokies back in the 70's. My 67 Beetle never let me down. I worked at a ski resort in Gatlinburg, and coming down Ski Mtn. Road could be a real adventure. The terrain down here is a lot flatter, so for me it just depends on the situation. If I'm in traffic, I want total control ( as you mentioned ), but if I'm alone and coming up on a light, I'll sometimes coast.
Cool...Gatlinburg is so nice! My wife and I are going to stay there overnight on our way down to FL then on to TX in the Goat. :D I actually skiied there once back in '87. Parents used to have a timeshare up on Ski Mtn Rd. I remember my dads car overheating a couple times from going down that road using 1st gear too much.

Thanks for your input guys...anyone else?

I helped install a 5 1/2 acre astro turf ski slope there in '75. I skied almost every day for 2 years. Haven't been there in a long time though. Don't even know if the turf slope is still there.

Yeah I remember seeing it there during the summer. Only went that one winter when there was actual snow...well kind of slushy snow.

Hey, Gatlinburg is just a short hop away from me. :D

Regarding engine breaking, I've heard it's not good to do it excessively. I know I've heard where if the cats were bad, chunks of it would get sucked into the engine because the intake manifold turns into a vacuum chamber after people rev the engine up to 6k RPM and then let their foot out.
I have also heard from corvette articles that excessive engine braking is bad on the valves, though I'm not sure exactly why. Basically though the engine is meant to exert force, and not absorb it. The key word though is excessive, like gearing down to 5k RPM in order to slow down the car.

Originally posted by forestdweller@Dec 16 2004, 05:34 PM
Hey, Gatlinburg is just a short hop away from me. :D

Regarding engine breaking, I've heard it's not good to do it excessively. I know I've heard where if the cats were bad, chunks of it would get sucked into the engine because the intake manifold turns into a vacuum chamber after people rev the engine up to 6k RPM and then let their foot out.
I have also heard from corvette articles that excessive engine braking is bad on the valves, though I'm not sure exactly why. Basically though the engine is meant to exert force, and not absorb it. The key word though is excessive, like gearing down to 5k RPM in order to slow down the car.
Uhrm, theres no way bad parts of a cat (assuming catalatic convertor) could get sucked into an engine...it is physically impossible.

Originally posted by Nocturn@Dec 17 2004, 10:57 AM
Uhrm, theres no way bad parts of a cat (assuming catalatic convertor) could get sucked into an engine...it is physically impossible.
Maybe he ment a kitty cat that was trying to stay warm on the engine. :D

Originally posted by Nocturn@Dec 16 2004, 07:57 PM
Uhrm, theres no way bad parts of a cat (assuming catalatic convertor) could get sucked into an engine...it is physically impossible.
Sorry but yes, it can. I know from those who have had it happen. However don't take my word for it:

"The QR25, like many modern engines equipped with variable valve timing, has no exhaust gas recirculation (EGR) valve. Instead, it uses large valve overlap at cruise and under engine braking to suck exhaust gas back in from the exhaust manifold. If the cat has started to disintegrate, chunks of ceramic can be sucked back into the cylinders where they will score the cylinder walls. It's not clear how common this problem is, but when we removed our cat after 1,000 miles of relatively mild driving, a fine ceramic dust poured out the runners."

http://www.sportcompactcarweb.com/tech/030...c_projser_hold/ (http://www.sportcompactcarweb.com/tech/0307scc_projser_hold/)

also from another group of mine...
http://www.shotimes.com/SHO3catfailure.html

Well for one the LS1/2 dont have variable valve timing. This "larger" valve gap is supposedly supposed to suck gasses back in, but even while engine braking the engine is still putting out exhaust. The exhaust valve that would normally stay open longer would be redundant because the exhaust would push the cat residue towards the cat, and not suck it back in. It seems logical that other cylinders intake stroke would pull some in, but the cat is placed in the exhaust, not in the primary, so there is always preassure put on the cat towards the end of the exhaust, it doesnt make sence to me that somehow the cat residue is going to go against the exhaust preassure of all the cylinders and get sucked back into the cylinders. That I dont buy.

Now, for the EGR argument, that at least makes sence. But the EGR valve lets exhaust gases in, assuming some very fine parts got into the EGR valve, it still doesnt make sence as there is positive preassure comming to the cat, unless the EGR valve is near the cat (which last I checked it wasn't on the GTO), then even if the intake manifold did become a vacuume it wouldnt suck up cat parts as if anything it would simply neutralize the already positive preassure on the cat.

lastly, the intake manifold becomming a huge vacume? Its always a huge vacume. Unless your running forced induction there is no positive preassure in the intake manifold. When accelerating the engine RPM's increase and the engine sucks in more air and becomes a greater vacume, this is true. But as soon as you let off the throttle the throttle body/ECM or Carb cuts the amount of air/fuel entering and the engine speed slows. This causes the vacume to decrease from at its peak RPM, but it doesnt create a huge unordinary vacume that would suck in exhaust particles that wouldnt normally be. The vacume is caused by the pistons intake stroke, if that decreases so does the vacume.

Maybe I don't know what i'm talking about, but it seems logical to me.

Originally posted by Nocturn@Dec 17 2004, 04:54 AM
Maybe I don't know what i'm talking about, but it seems logical to me.
A car doesn't need to have VVT for this to happen, that was just the case in the first example...
What is required is for the cat to already be bad and pieces of the honeycomb material be loose. Saying that it can't happen because exhaust is always flowing outward is far too simplistic. That is the net effect overall, but during extremely short intervals there are other forces that take affect that aren't very obvious.

Of course it's possible it can't happen with the LS1, I don't know for sure. But nonetheless it does and HAS happened.

Another reason why cats are evil and LT's should be the norm for our cars (whether it's possible or not ;))...

I may be in the minority, but unless I am going down a long hill where I don't want to ride the brakes, I drive in whatever gear I'm in (typically 5th) until I have reached the point where the car would gently reach the stop sign/red light by coasting. Then I put in in neutral and coast, but i'm prepared to put the clutch down and get it in gear if need be. I don't begin the coast until I am very sure I'm coming to a complete stop; if there's a chance the light will turn I keep it in gear.

My reasoning:
- saves a little gas
- brake pads and rotors are easier and cheaper to replace than transmission syncros and clutches
- typically it results in a smoother, linear stopping feel. more comfortable on you and your passengers unless you are brilliant with rev matching and let the clutch out really slowly (once again, extra wear). i mean that in an comfort sense, not a performance one. applying brakes in neutral always has the same feel at a given speed, whereas braking feels differ in different gears, as well as depending somewhat on how long you have been off the throttle.

This is on a DOHC, my SVT Contour. Though when i test drove a GTO i drove it the same way. Car is at 62k and I have only done front pads once, rears are original, and tranny is 100% original.

brian

Regarding engine braking, I basically drive on the street as I do on the track, except for not being able to heel-toe downshift until I install a gas pedal extension on my new '04 M6.

I never downshift for a stop sign or stop light. I simply release the accelerator, and brake gently, without touching the clutch, until the revs are just above idle speed. I then clutch, shift to neutral, and release the clutch.

As the light is about to turn green, I select 1st and leave when the light turns. Less wear on the clutch, trans, brakes, and throwout bearing.

I do, of course, downshift for turns. Interestingly, the owner's manual recommends shifting down through each gear, to reduce the chance of making a mistake. After one day of driving, I have developed the muscle-memory to find the gear I want. So, if I'm in 5th and need 3rd, I brake until I get fairly close to the turn-in point, clutch, downshift, release the clutch, and then start my turn. You always want to get the shift completed before turning-in. That way, you're not screwing around with the shifter in the middle of the turn. You can concentrate on your turning. We teach this at our racing schools.

Carter
13 years of sports car racing and on-track instructing

great web site for pontiac gto info. i know there is the 1-4 shifter in the 6m transmission which requires you to shift form 1st to fourth under light acceleration. my 04 was built in june 04 and under light acceleration even at 10mph i can shift into 2nd,3rd, etc. is there any reason why this transmission allow this . it does not matter even if the car is cold and the indicator light has never come on and the car has about 100 miles on it. any input would be appreciated

Originally posted by DANSLS1@Dec 17 2004, 09:14 PM
Another reason why cats are evil and LT's should be the norm for our cars (whether it's possible or not ;))...
What are "LT's"? :unsure:

BTW...thanks guys for your techniques.

:huh: One can downshift or upshift the M6 tranny any number of ways, there is no right or wrong, as long as you follow these two guide lines.

1. It is imperative for the longest synchronizer life that the downshifts be double clutched and rev matched.

2. Never downshift to brake with the engine in the ice or snow. B)

Originally posted by forestdweller+Dec 17 2004, 06:10 AM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (forestdweller @ Dec 17 2004, 06:10 AM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-Nocturn@Dec 17 2004, 04:54 AM
Maybe I don't know what i'm talking about, but it seems logical to me.
A car doesn't need to have VVT for this to happen, that was just the case in the first example...
What is required is for the cat to already be bad and pieces of the honeycomb material be loose. Saying that it can't happen because exhaust is always flowing outward is far too simplistic. That is the net effect overall, but during extremely short intervals there are other forces that take affect that aren't very obvious.

Of course it's possible it can't happen with the LS1, I don't know for sure. But nonetheless it does and HAS happened. [/b][/quote]
Just happen to pick up on this thread and I would agree with Forrestdweller it has and can happen. I have heard of three different engines that this has happened on. The first was a ZR-1 Corvette, and the next, and most common was the 92-95 Ford Taurus SHO with the Yamaha V-6. The most common scenario with that car was the thermostat would stick open causing the car to run rich all the time, thus overheating the CATS and causing them to break down. Then, the way to make it actually happen, was to accelerate at WOT up to redline (7k) then let off the gas real quick, and poof, sucks the cat material back into the engine. That last one I have personal experience with was a regular old '03 Silverado with a 5.3. Came into the dealership with a check engine light. Found the converter on the passenger side bad. After replacement the check engine light was still on with a misfire. Looked into the cylinders with a bore scope and oops, cylinders all scored on the passenger side bank of the engine with some extra little pieces floating around in there.

The way this happens is the timing of how that valves open. If you think about, it under normal circumstances, air is pulled into the cylinder on the intake stroke, then pushed out on the exhaust stroke. Well, think about an engine turning 6000RPM with the throttle plate closed. On the intake stroke there is very little air to be pulled into the cylinder since the throttle plate won't let enough by to fill it. Them the intake valve closes and you have the compression stroke, then the piston comes down again on the power stroke and there is still the same small amount of air in there from the intake stroke, but again, not enough to fill the whole cylinder, so wal'la, as soon as the exhaust valve opens there is vacuum in the cylinder until the piston starts coming back up enough to start pushing the exhaust out again.

Thansk for the info, I had no clue I had to shift to 1st before shifting to R. This really helped, I kept fighting the shifter every morning.

That was dumb of me! <_<

Originally posted by mario04gto@Jan 31 2005, 11:32 AM
Thansk for the info, I had no clue I had to shift to 1st before shifting to R.
Yeah it's a real pain in the A$$! Has anyone found a fix for that problem? Even sometimes when I put it in 1st then R it still gives me a hard time. <_<

Originally posted by 04GOATGERM+Jan 31 2005, 11:45 AM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (04GOATGERM @ Jan 31 2005, 11:45 AM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-mario04gto@Jan 31 2005, 11:32 AM
Thansk for the info, I had no clue I had to shift to 1st before shifting to R.
Yeah it's a real pain in the A$$! Has anyone found a fix for that problem? Even sometimes when I put it in 1st then R it still gives me a hard time. <_< [/b][/quote]
Whenever I have a hard time getting the shifter into reverse, I just ease out the clutch as I lightly apply pressure to the shifter towards the reverse gate. It has always just slipped into gear without any grinding or other noises. I guess this method doesn't hurt the transmission as I used it on my TA which I owned for over 12 years without problems.

Originally posted by 04GOATGERM+Dec 27 2004, 05:06 PM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (04GOATGERM @ Dec 27 2004, 05:06 PM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-DANSLS1@Dec 17 2004, 09:14 PM
Another reason why cats are evil and LT's should be the norm for our cars (whether it's possible or not ;))...
What are "LT's"? :unsure:

BTW...thanks guys for your techniques. [/b][/quote]
Long Tube headers

If you have ever had a vacuum gauge on an engine, you learn a lot of things. I had a vacuum/boost guage on my 92 chevy truck for awhile for testing purposes. It idled at 17-18 psi of vacuum, which is where a stock fuel injected engine needs to idle. You need between 15-18 psi for your power brakes to work properly. Ever noticed a spongy pedal while coasting down and hard pedal at idle once pumped once or twice. Engines will develop around 22-24 psi intake vacuum while coasting down in gear from say 5000 to 6000 rpm. There is always positive pressure in you exhaust. Stand at you exhaust pipe with say a plain white sheet of paper over the pipe, have someone rev the motor, let off, and see if the paper is sucked to the exhaust pipe. This is a good test to find burnt valves also. At idle it will flutter a little on and off the pipe because of the 115+ degrees of overlap between intake and exhaust, but nothing substantial enough to suck anything into the engine. There has to be positive pressure in the exhaust or the egr system would not work because exhaust must travel into the intake and then back into the combustion chamber to be burned again (recirculation). Any vacuum in the exhaust side would pull air and fuel into the exhaust from the intake through the egr system and cause all kinds of problems. There will always be particles in the combustion chamber because burning gasoline makes carbon. That is why all companies make fuel injector/fuel system cleaners to clean carbon deposits in the combustion chamber.

Originally posted by QuicksilverGTO@Dec 22 2004, 11:20 PM
Regarding...
Your post, Carter, is a perfect description of what I do - braking, starting, downshifting, the whole thing. Maybe learning to drive on twisty-turny mountain backroads taught me some good habits???