I know exactly what you mean. If you try shifting to 2nd too early, it seems to "lock you out" of the gear if you don't double-clutch.

It's probably a safety thing for the engine, so that if you down shift by accident (ie-intending to go into 4th, but choose 2nd instead), it keeps you from hurting the engine.

This happens to me a lot, because my neighborhood is off a 55mph road. So, as I'm slowing down to make the turn into the 25mph zone, I try moving into 2nd gear (still on the clutch, but the shifter in 2nd), and it seems to not let me do unless I'm below a certain speed (that it predetermines as it feels).

I think we're on the same page with what's going on. That, and like you said, the gas pedal requires more effort for rev-matching that what it "should"...considering where the gas pedal is for cruising. And as we stated before, it's more than likely due to the throttle by wire, and probably another engine safety too.

 

Getting professional instruction prior to my first manual 05+ was one of the best things I did.

Knowing the sweet spots of your car with regards to rpm range for the driving style will help enable smoother shifts, eliminate the u-joints clunking and be much easier on the syncroes.

City traffic driving and slow acceleration; the range is at 1400-1800 in the Roush and 1200-1500 in the GT500. Over revving the engine beyond the given sweet spot to shift is not necessary. Although, these modulars like to revv more than the previous generation, the more power and matching torque, does not require the car to work as hard to get speed. Combining this with steeper gearing and this helps explain the lower required revvs.

Extending the sweet spot rpm technique with very slow acceleration, while "guiding" the shifter into place without the clutch, is a lot like "floating" the gears in the trucks. This is one old school trick for when the cars had bad syncroes and missing some gears.

"Bliping" the gas in between shifting to a higher gear and prior to engaging the clutch, will allow the syncroes to advance to a closer match and also mesh better when the clutch is let out.

Heel and Toe driving is used mostly in road racing to save wear on the brake pads and enable higher speeds while accelerating out of the apex of a turn.

Double clutching is best for launching high torque cars to help eliminate the sideways launch that is typical of them with not enough hook up. Also, keeps them at a more sensible accleration in heavy traffic.

Powershifting is not good as it encourages slipping of the clutch and the e.t. advantage can be made up by use of aftermarket driving equipment like a short shifter, speed handle, racing pedals, clutch adjustment closer to the floor, etc.

 

eh.... I don't want a tune... I haven't replaced the fuel pump yet, so.... perhaps I'll consider it if it still does it then, but... my question is what would have changed after I bought my car?.... The tune certainly wouldn't have... and it was fine for months. Anyways, I don't like the idea of my motor hangin' right on the edge of predetonation because the fuel pump has the mixture so leaned out... simply because it's cavitating and can't keep up.
I read the stories about cars shutting down, going into safe mode because their tune is doing something funny. Sometimes the problem goes away and never comes back, and they never figure it out, other times, the ghost in the machine keeps on haunting.... I don't want to even put myself in that position. So, for me.... a tune is out. Unless, of course, I have a 2.6L huffer on top, and have a couple of fuel pumps and, therefore NEED a tune.... but I'll cross that bridge the next time a $10K turd drops outta my a**.

 

Good luck on that bowel movement!

 

I think the stock shifter is fine and have no issues shifting ever with them. Of course it will clunk a bit if you load/unload the drivetrain tooling around in 1st/2nd at slow speeds. I've always been good with manuals, a lot of people like to ride in their own cars with me giving it a go for them. Too hard to be specific though, I probably have about 500 slightly different ways to shift a car depending on the situation.

 

I agree that people generally drive their cars differently. Other than the weird downshifting in my 3650, it's an otherwise smooth shifting gearbox. I have no problems with the stock shifter.

 

Stangette

Not to be picky, but the drive line clunk is actually not the u-joints. If it were, they would already be shot and needing replacement. What you are hearing and feeling is the sum of the all gear back lash from the transmission to the differential. There is also a tiny bit of free play in the axle splines, the tail shaft and the clutch splines.

The syncro blocker rings only get hurt or wear heavily is when one tries to jam it unwillingly into gear. Once the blocker rings are shot, you have no synchromesh and the slider and gear you are shifting into grind at their mechanical interface and point of engagement.

I think all your other points were spot on and well put.

mike rx

There is no speed sensor locking you out when down shifting at higher speeds (for the gear). What is happening is the blocker ring is trying to speed the input shaft up and the speed differential is so much that its takes it longer than usual to drag it up to match the output gear you are trying to engage. Its also tougher on the blocker ring and will promote accelerated wear. A blip of the throttle between the shift will help alleviate that as there is some clutch drag and the input shaft will spin up. This is a lot quicker than double clutching. You should keep your down shifts below 2500 or even 2000 IMO unless you are in a race. Normal street driving my down shifts are below 2000. This is NOT a close ratio trans by any stretch of the imagination so RPM differential between any two gears is quite a bit.

 

A downshift below 2000. That's not even possible if you are on the highway and want to pass someone, as you are turning more rpm than that just cruising. Besides, even if it was possible, it wouldn't matter, because your going into the lower gear, so your revs are going to be higher than that as soon as you downshift anyway.

And, there's nothing wrong with being "high up" on the rpm range, assuming you aren't doing it consistently. Theoretically, hitting the rev limiter isn't "bad", because that's what it's there to do...prevent you from over-revving the engine, which would be fatal. Now, even though theoretically it's not bad to do, I almost never drive it that high on the rev range. But, considering that our "supposed" redline is about 6K, 5K is nothing to worry about [once again, assuming you aren't maintaining that rpm]. The only thing that is affected at this rpm would be the fact that you are out of the optimal power range for the car.

And, I don't think that blipping the throttle helps as much with "meshing" everything together, as the drivetrain is still in "stress". Double clutching disengages everything for a brief moment, taking the stress off the drivetrain and allowing everything to be in equilibrium.

Finally, if one knows what they're doing, they could double clutch as fast as someone can just blip the throttle. It's easy (and fast) once you learn how to do it right.

 

Hmmm ... 2000 RPM in 5th is over 65 ... impossible to downshift ... Whoooa ... I must be doing something I am not supposed to be able to do?

I guess you must speed everywhere you go?

Well if you can push the pedal to the floor, push trans to neutral, let the pedal up, blip the throttle, push the pedal to the floor, slide into gear, let the pedal up again (double clutching) rather than push the pedal to the floor, blip the throttle, pull trans into gear and let the pedal up again you are some super human ...

When you double clutch, you are blipping the throttle with clutch released and trans in neutral. This spins up the input shaft (its also slows it down if you don't declutch fast enough). The output shaft directly coupled to the rear wheels effectively stays at the same RPM it was. When you are down shifting the input shaft has to speed up in order to allow the slider to engage the gear. Speed not matched ... it grinds or won't slide in. Double clutching does this, but this a poor boy band aide for bad synchro's, not for superior shifting technique. The job of the blocker ring during up or down shift is to the make the input shaft match the RPM of the output shaft. The blocker ring is effectively a clutch in this mode. When you are up shifting the input shaft has to slow down hence you let the engine slow down ... just the opposite of down shifting. Blipping the throttle in the downshift will speed the input shaft up as there is some drag on the clutch. If its not working for you its more likely the technique rather than the process.

Anyway, this is all in response to the complaint / observation the trans does not want to down shift easily. If you want to down shift at 5,000 RPM, knock yourself out.

Attached is a curve showing rear wheel torque vs. speed for each gear. This curve is based on no driveline losses and on one of the 'stock' dyno curves I pulled down that was posted. The lowest data point starts at 2500 RPM and each subsequent one at +250 RPM. Enjoy.

 

I was talking about downshifting at 1500-2500 RPM max.

 

We must not be on the same page AT ALL!!!!

If you are in 5th, going 65 mph, you are running about 2000 rpm. So, based of what you said before, I take that as meaning that you wouldn't downshift, because it's over 2000 rpm.

I'm not talking about downshifting at 5000 at all, as that would be idiotic. I'm talking about downshifting at about 2500-3000K, and then running it to about 5K (if so desired)

So, like I said, I don't think we're on the same page at all.

Also, what you're saying about double clutching sounds fine, but then you say that this is a "band aid". Uh, no its not. In your discussion, you say yourself that it speeds up the input shaft. Well, if it does this, and your technique of just blipping the throttle does this, they they are pretty much the same, which is what I've been saying from the get-go. They help the synchros, not hurt. Think about it...if you used to have to use this method back in the day, when there weren't any synchros, then doing it now would save them from doing the work, thus prolonging their life.

 

Mike

I'm assuming by your initial statement (#61 above) you are down shifting to slow down. i.e. into 2nd (from 3rd?) and your perception the trans was somehow automatically locking you out.

Double clutching is very tedious and your claim was you could double clutch shift as fast or faster (#68 above) than just bliping the throttle with a conventional shift.

Yeah, if your synchros are toast, you need to learn how to double clutch or get the trans fixed.

The only way to un load/stress the trans is declutch and/or go to neutral.

And when you are shifting, the input shaft, clustergear and the free spinning gears on the output shaft have to spin up or down to to match the output shaft RPM to successfully engage in the gear of choice.

 

If I am doing about 2000 RPM in 5th gear, the trans won't let me downshift into 4th gear w/o revmatching. The drive by wire makes it very weird to revmatch or double-clutch.

 

http://www.youtube.com/watch?v=RUbe125ege0

I know this video was re-mixed with the Ferrari engine sounds, but it sounds like the spike in RPM right before the downshift might be the throttle blip.

 

Then you have something wrong with your transmission.

 

Sorry for the vague statement. No...that's not what I meant. What I meant in the middle of slowing down, I try just placing the shifter in gear (vs. putting the shifter into a gear after I'm slowed down), and that it sometimes locks me out when attempting this.

I do NOT downshift to slow down, as I think that's dumb. Some people do use the clutch/downshift to slow down, but brake pads are a lot cheaper than a new clutch, so I stick with conventional braking.

That's what double clutching does, and that's the exact point of it. Just blipping the throttle doesn't unload the stress, which has been my point from the beginning.

BTW, it isn't tedious at all once you learn how to do it, and do it correctly. It becomes a part of you when driving a manual, just like all the other habits people have when driving a manual.

 

I just want to downshift so I'm in the right gear to enter and exit the turn.

 

5th-2nd, 3rd, or 4th should be no issue It can be a little clunky from the shift mechanisim, but not from the transmission itself. Typically 5th to 3rd is much more effective then 5th to 4th though.

Since it is typically a pretty casual downshift from 5th to 4th for a somewhat lazy highway pass, you probably are subconsiously not pushing the clutch all the way in and shifting slower or with less authority then normal or have the timing a bit off, unlike say a 1st to 2nd spirited shift.

god, not double clutching again. Double clutching is what a Brockway 1960's tractor trailer needs, From first to second= Clutch in(at the 2900rpm redline)/shift to neutral and let the motor slow for a split second/clutch fully out-depress clutch again and re-rev motor slightly and shift into second repeat and rinse 5 or so more times and you are doing 40mph. It has nothing to do with a modern(or pretty much any) passenger car post WWII.

I also don't press the clutch in coming to a stop untill I am at about 2mph and always downshift into 3rd/2nd. You should always be in some gear(preferably a matched gear for the speed-but by no means screaming RPMs-your GF should not be 1' leaned off the seatback) so you are not just a rolling cart, you can move if you need to if you are in gear. I have never noticed any clutch wear from it and always get at least 50k out of a clutch, including a lot of hard driving. Its actually been about 18 years since I replaced a clutch from anything other then adding mods that required it-and that old car was one I bought with a wasted clutch....

 

Since only a couple of people are acutally on the same page with what's being talked about, I say let's just forget it.

Metroplex...+1. I know exactly what you're talking about. I'd rather be in the gear before exiting the turn, so that I just slip off the clutch and go. And, this was the issue that you first brought up: that doing that sometimes isn't possible, because you get "locked out".

 

Dropping a gear from 5th at 2000 RPM into 4th means non mandatory blipping to about 3,000 RPM (in fact you should be able to raise the RPM slowly 2 - 3 sec) and it should drop right into 4th. You are not just missing the gate in anticipation are you? Clutch pedal completely to the floor ... these diaphram clutches require full travel for a clean disengagement.

Not sure why your fly by wire would make it that difficult. One usually has more smoothness trouble on the upshift because of the throttle hang. On the down shift it works to your advantage (though not near enough RPM rise to make a difference)

You have not put any magic trans fluid in your car have you? Trans fluid that is too slick will reduce the effectiveness of the blocker rings as they truely act as a clutch to get the input side matched with the out put (shifting up or down). Stick with the Mercon.