Manual Transmission

[JRBRUIN7@aol.com]

I have had the tC since April and I love this car and can't wait to do more to it, I have a manual transmission and its my first car thats a manual, I have the basics down pretty good, like starting from a dead stop and what not but I would really appreciate some feedback on the correct way to downshift and rev match and all that and if one is better than the other and how to make my clutch last as long as possible? Like I said any feedback will help.

[claytongozoom]

good boy, rev-matching is always a good idea to make sure you get the most life out of your clutch. the best way i can explain it is keep an eye on the rpm your car is running at in whatever gear you are currently in, then when down shifting(while you have the clutch in) make sure to rev the engine to at least that rpm the previous gear was in, now the tricky part is to let go of the clutch as close to that rpm as possible to get a smooth transition between gears, if it's released over the rpm it'll rev up and be a little harder on the engine, but generally that's not too bad, it's letting go when the engine is BELOW the rpm you want to hit that makes the car jerk and is harder on your car overall. after a while you'll get the feel of it, it's a lot easier to rev-match by ear and feel then to look at your gauge, my advise would be to start down shifting from 5th to 4th, as the difference in the rpm of the engine isn't going to as great so less of a margin for error, then as you get better to can bring it from 5th all the way down to 1st and really save your brakes gauging stopping distance as far as coming up to traffic lights and stop signs will take some getting used to as well, rev-matching is no good if you still have to slam on your brakes because you timed the distance wrong. hope this helps a little, i'm sure you'll get a post or two better explaining it. good luck man.

[SPARTAN]

Firstly, I have an automatic, so I don't have much experience with manual transmissions. However, according to Car and Driver, attempting to rev match on downshifts is ill advised at best. Even if you manage to match rpms perfectly, you're still likely to wear out the synchromesh gear faster.

[claytongozoom]

ha, car and driver...well i happen to know someone who races for langston subaru out of PA and he's the one who taught me how to rev-match, also, according to sport compact there isn't any strain on your clutch what-so-ever unless you horribly screw up the timing, all the pressure is on your engine, and the tc has the camry block in it which is pretty much bullet-proof, so it would take A LOT to jeopardize it.

[SPARTAN]

That's fine. I'll choose to listen to my engineering bretheren.

[navylife59]

Why the need to downshift; racing, hard stops, or just force of habit? For everyday driving, you really don't need to downshift. Just leave it in gear till the RPM's get low (dont' bog) around 1.8K then either go to neutral or downshift. This puts very little strain on your drivetrain. If you are racing, then you should not be concerned with the longevity of your clutch. You need max performance for the win. Hard stops, then I say just do it and don't worry about anything else. If you need to stop, then hard downshifting (correctly), along with progressively harder breaking is the name of the game. The key here is to not downshift at too high an RPM or you risk breaking the tires loose, killing your chances of stopping quickly.

Be that as it may, claytongozoom is CORRECT about the undue strain that is put on a transmission when downshifting hard at high RPM's. Sudden pressure and heat buildup of the clutch impounding the speeding flywheel could creat stress fractures on the flywheel mating surface. At the least it grabs an extra layer of wear on the clutch pad. If you do this habitually for every stop, then yes, you could be putting undue stress and wear on your drive train. On boosted apps, the sudden increase in cylinder head pressures could lead to failed gaskets/seals or worse; cylinder wall fractures. Of course, that would be the case if we were sporting a domestic iron block built prior to the turn of the century. You would have to be a heavy downshifter and popping the clutch at high RPM's to cause that kind of damage. Don't misunderstand me. You can destroy, even a 2AZ-FE by abusing it daily. I am at 43K with the stock brake, tires, and clutch that Scion sent with the car. I do downshift and/or brake hard at times. I am amazed at how tough this motor is stock.

[Sciolyslvr]

down shifting saves lives!!!

[Tony G]

does it waste more gas?

[Azn Chief]

i'd say it does only if you downshift and cause the engine to rev above what is needed. Say you downshift from 3rd to 2nd going 30........ in 3rd you'll be dong about 2000rpm. and in 2nd you'll be around 3500rpm. (that is until you slow down even more.) So if you were to downshift at improper times. you'll use a small amount gas because of the higher rpm's. If you downshift correctly there shouldn't be any problems with gas.

That amount of the other hand may not even be noticable, unless you maintain speed and do not slow down as you should. Although this also depends on how frequent you do this. Daily= it'll eat at your gas Once in a while= shouldn't bother you Just saying my opinion. *Correct if needed.*

[TBITB]

first time reading this thread and... well i've been rev matching since i got my car july 06. i have also messed up the syncro from 4 to 3 and 3 to 2. i thought it was cuz i was always missing those gears while upshifting. but it doesnt make sense why it crunches when i downshift and not upshifting. me missing gears has nothing to do with it? is it the downshift rev matching?

is this a clutch issue or a transmission problem?

[hotrice]

Originally Posted by navylife59

Why the need to downshift; racing, hard stops, or just force of habit? For everyday driving, you really don't need to downshift. Just leave it in gear till the RPM's get low (dont' bog) around 1.8K then either go to neutral or downshift. This puts very little strain on your drivetrain. If you are racing, then you should not be concerned with the longevity of your clutch. You need max performance for the win. Hard stops, then I say just do it and don't worry about anything else. If you need to stop, then hard downshifting (correctly), along with progressively harder breaking is the name of the game. The key here is to not downshift at too high an RPM or you risk breaking the tires loose, killing your chances of stopping quickly.

Be that as it may, claytongozoom is CORRECT about the undue strain that is put on a transmission when downshifting hard at high RPM's. Sudden pressure and heat buildup of the clutch impounding the speeding flywheel could creat stress fractures on the flywheel mating surface. At the least it grabs an extra layer of wear on the clutch pad. If you do this habitually for every stop, then yes, you could be putting undue stress and wear on your drive train. On boosted apps, the sudden increase in cylinder head pressures could lead to failed gaskets/seals or worse; cylinder wall fractures. Of course, that would be the case if we were sporting a domestic iron block built prior to the turn of the century. You would have to be a heavy downshifter and popping the clutch at high RPM's to cause that kind of damage. Don't misunderstand me. You can destroy, even a 2AZ-FE by abusing it daily. I am at 43K with the stock brake, tires, and clutch that Scion sent with the car. I do downshift and/or brake hard at times. I am amazed at how tough this motor is stock.

navy i know i will be looked at funny for asking you this but are you saying that it would be ok to down shift hard to help slow down???

[Vmix06]

the only time that i think is ok to downshift hard like that is when its an emergency other than that its ok to leave it in the same gear while you are slowing down but you do eventually have to down shift

[TBITB]

i started doin it cuz i liked the way it sounds especially with an exhaust - timing a red light stop from 1/4 mile away downshifting from 5th or 4th to a stop.

[ac3 b00gi3]

i definetly need new syncro's .. 2nd and 3rd are chewwwd .. gotta start rev matching again .. anyone know where i can order new syncro's .. better yet a stronger tranny ??

[TBITB]

syncros are something you can just order? are they expensive? what about the install? can i do that? please say yes!!! i feel like everyone can hear the crunch when i go from 4 to 3 and 3 to 2!

[ac3 b00gi3]

i hav no clue .. i may jus buy a newer tranny

[hotrice]

that would suck

[ac3 b00gi3]

it would but its not too expensive .. one with 18k miles is about $800

[TBITB]

ugh - gotta add that to my list now - it gets longer every week! but that's worth it considering im at 43K miles in less than two yrs

[ac3 b00gi3]

lol .. might as well right
while im at it .. since the tranny'z dropped i may change my short shifer from this Megan trash .. to either B&M or Perrin