Ok, i have a question regarding shifting in 2005+ mustangs. When the RPMs are too high to shift into a lower gear the literaly wont let me. keep in mind im not ever letting off the clutch (doing so would obviously F*** up the car and its transmission) but even when the clutch is fully depressed it wont let me shift into a gear that the car thinks the speed is too high for. If i try to force it it just grinds. it sounds like it would sound if the clutch werent in at all and i was trying to shift, even though its fully depressed. Is this normal? I assume its some kinda of electronic saftey feature, but do you guys have this on your cars (mine is a 07 gt btw, in case that matters)? If so is there a way to turn it off with a tuner or something? thanks.PS. like i said im not actually letting off the clutch at all when down shifting into too low of gears, i am aware doin so would only jack up the rpms so high that it would hurt the car, i am just curious as to why it does this.

 

I think you answered your own question. It would hurt the car, so it won't let you. Why would you want to shift into a gear that is too high anyway? Just the act of putting the shifter into that gear, even without letting out the clutch, is very VERY hard on the syncros in the tranny. You do NOT want to screw up your syncros, that is expensive.

 

I'm not aware of any safeguards programmed into the computer on Mustangs to prevent over revving on downshifts... not to say they aren't there.

Since I haven't done any open course style driving with this new S-197, I haven't experienced the situation you are discribing..

In my experience in road racing, it has always been standard procedure when downshifting from high RPM to a lower gear to blip the throttle just as the clutch is depressed and while the trans is being shifted to the desired gear. Some only blip once, others do two quick blips. This helps the syncros and gears get lined up.

If I were shifting from 4th or 5th to 2nd that's the way I would do the downshift and braking at the same time to scrub off speed and let the RPM drop some to assist in the gear change. As a matter of fact, I even do it on the street if I want to drop a couple of gears to listen to that beautiful exhaust sound.

Bobby M.

 

When you down shift, as you move the shifter into the lower gear, you can hear a whine from the synchro's spooling up.
i generally try not to shift till the pitch of the whine is about right ( you tend to get used to what's right for the RPM range you're shifting at )

never jam the gear in if the RPM is too high for it.. you'll fry your syncrhos in no time.

assuming everything is right, your clutch is fine, your transmission is fine, and your speed is fine for the lower gear, try bliping the throttle a bit to raise your RPM a bit to help the synchronizers get up to speed.
this usually helps with downshifting

if it still doesn't go, don't push it.. you're probably going too fast for the lower gear..

 

This thread seems silly to me. Why even discuss why your tranny tries to protect itself from being destroyed by doing something foolish like that? What would happen if it let you do such a thing and then your foot slipped off of the clutch pedal? The last time I did crazy things to break cars was when I was five years old and I broke my hot wheels cars on purpose.

 

I found the thread quite informative. I was always curious why it was sooo difficult to shift from 5th to 3rd when I was only doing 70 and now it makes a little more sense.

 

Good thread. I'm going to have to check this out, don't worry, I know how to drive a stick shift car and won't break anything.

Anywho - I still can't figure out why I get locked out going 1-2 at high RPM's. I see a new shifter in my future.

 

There is no such thing as a silly or stupid question... I grant you it is not recommended to downshift to a lower gear from a high rpm without doing some things in the process. Otherwise, you'll end up with a busted Hot Wheels like Derek..

If there is ever a need to downshift to a lower gear, it never hurts to know how to do it without busting your Hot Wheels.

Bobby M.

 

I've never noticed any downshift issues when its done to some sane rpm 5th-3rd is easy at highway speeds, I do it all the time. 5th to 2nd, 4th to 2nd, even at 50mph, whatever.

Never tried to blow the engine up trying to shift into 2nd at 80mph though, I guess you could blow it up if you tried hard enough...

 

Are you trying to downshift into first?

 

Downshifting into 1st gear is kind of iffy and I wouldn't recommend it unless you are at very slow speeds.

For anything between and including 2nd gear to 4th gear, blipping the throttle or double clutch downshifting works very well for me. If you are below 1000 RPM, rev matching/double clutching isn't necessary but can be done.

When I ask other manual operators, they usually tell me that they have no problems downshifting without revmatching or double clutching. One woman gave me a WTF look when I asked her about double clutching.

 

I can't go into first gear unless I'm going under about 5 MPH or so, and that is a saftey feature built into the tranny, as far as I know. Same type of thing with reverse.

You ever try matching RPM w/ your MPH?

 

If take your foot off the gas after the shift the engine won't blow.
The tires chirp and you do slow down wicked fast and the rear end gets real squirrely.
I did it by accident (looking for 4th).
I wouldn't recommend it, especially for people that haven't done that sort of thing on purpose before with other cars.

 

I had a heavy duty clutch and flywheel in my 00' along with a ton of other mods, I used to chirp downshifting into 2nd for entertainment purposes all the time.

But downshift at 80 and let out the clutch and you are at 8000 rpm.

 

Nope...
You would be at over 7000rpm anyway if you didn't lay down a patch of rubber until you get to under 70.
My car does over 65 in 2nd, I think all the new GTs can.
Like I said I wouldn't recommend it.
It is a little tricky to drive at over 70 with the rear wheels doin' 60 and climbing. You ever see those TV shows with a car comin' off a trailer?

 

Since were are asking silly questions, is double clutching pressing it in twice before you switch gears? TIA

 

If you are in 5th gear and want to do a double clutch downshift into 4th gear, you would hit the clutch pedal, shift into Neutral, let out the clutch, rev the engine (blip throttle), hit the clutch pedal, and downshift into 4th gear.

Revmatching can accomplish the same thing and is usually much faster to do.

 

K.I.T.T. used to do it all the time

 

Yea, that is usually reserved for 1965 Brockway tractor trailers

 

Engine Braking - Breaks Engines
Ok once and awhile... but i wouldn'[t make it a habit.