Why do people down-shift to go faster on the highway, for example, when they switch lanes? Does it have something to do with getting the RPMs higher and faster?
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2005 Black GT Whipple HO | Oil Seperator | Steeda Tensioner | 93 dyno tune | Autometer Cobalt | GTAs
Yes, if you are maintaining a constant speed, and you shift to a lower gear, the lower gear is smaller and is therefor spinning faster and the throttle response will be better.
Yes, if you are maintaining a constant speed, and you shift to a lower gear, the lower gear is smaller and is therefor spinning faster and the throttle response will be better.
Acceleration in 5th is extremely slow in the Mustang.... tall gear - better mpg. My old car I didn't have to downshift as often.
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'05 Torch Red GT; medium graphite leather; 5sp Man.
Out of storage 3/25/06
back to storage 11/1/06
You want to accelerate "through" turns, not coast through them. Unless of coarse you are on an exit ramp behind trucks, vans, others. Or it's snowing!
The rear tires "grip" (or dig-in) under power; there is very little grip coasting through a turn. So you will see/hear cars down shifting (to second) and hitting the accelerator on turns. They are actually getting better traction than those coasting through the turn. A much better method of negotiating an exit ramp.
Take an elevated driving coarse.
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Chris Weber
05 GT
85 1/2 SVO
95 Explorer
00 Audi TT
My $.02 on this matter is a little different. You down shift to a lower gear to get the engine into a different (better) power range for the acceleration to pass. You can still pass in 5th gear but you don’t have as high of an HP/weight ratio as 4th gear does. Lets say it requires 100 HP in 5th gear to move our beloved Mustangs down the road at normal cruise speed. The gearing is setup to give us the best HP/weight and fuel economy at cruise speed. If you down shift, you put the engine transmission in a higher power ratio to more easily increase speed.
As for the downshifting and powering through the corner, I can only guess this is in reference to racing. By downshifting and letting the car idle into the corner as apposed to coasting which refers to tranny out of gear, the driver is using the engine to slow the car down to transition the corner with out using the brakes or to assist the brakes. It also puts the car (engine/tranny) in position to produce the best power to accelerate coming out of the corner.
I believe that the engine producing power to the tires has very little to do with how much traction the tires have going through the corner at a given speed. I think Newton can explain that a little better with momentum and lateral acceleration and other forces like that. You accelerate at the apex of the corner when the lateral forces are being reduced.
As for the downshifting and powering through the corner, I can only guess this is in reference to racing. By downshifting and letting the car idle into the corner as apposed to coasting which refers to tranny out of gear, the driver is using the engine to slow the car down to transition the corner with out using the brakes or to assist the brakes. It also puts the car (engine/tranny) in position to produce the best power to accelerate coming out of the corner.
You're part right. Downshifting in racing is only to put the car in the best gear to accellerate out of the corner and achieve highest corner exit speed. Generally the sequence is this:
Full throttle on the straight
Full braking as the corner approaches
Heel-toe downshift, sometimes 2 or 3 gears depending on the speed of the turn
Trailbraking to the apex
Throttle on at the apex - (here's where the downshift pays off)
Corner exit - He who has the highest exit speed gets the the next corner faster
While downshifting can aid in slowing the car, it's not the optimal way to slow the car, that's what brakes are for, and cheaper to replace too.
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"I was cured Alright"
1993 Mazda RX7 TT
1999 Toyota Tacoma
1996 Nissan Altima
Sonic Blue Premium GT - Order placed 5/7/05
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BTW, when downshifting and in the 2-3K RPM range my 5 Spd trans seems aweful loud and whinny. Any other 5 Spd GT's notice this also? I considered taking it in but thought better and will wait and see how it plays out. I'm probably still just getting used to the sounds of the car.
anyone else notice when upshifting at over 3500 or 4000 rpm, when I let off the gas, push in the clutch, the revs actually jump up about 250rpm or so, and are a bit slow to come down. I thought I was just timing the pedals poorly, but I slowed the foot movement down several times to make sure that was not the cause. weird. Is this "normal" behaviour for the '05s or should I get the shop to look into it?
Damn I hate that throttle by wire bs.
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'05 Torch Red GT; medium graphite leather; 5sp Man.
Out of storage 3/25/06
back to storage 11/1/06
anyone else notice when upshifting at over 3500 or 4000 rpm, when I let off the gas, push in the clutch, the revs actually jump up about 250rpm or so, and are a bit slow to come down.
Mine does the exact same thing and I noticed it the day I test drove one. At first I thought I just wasn't used to the new clutch but once I got one home and drove it for over 100 iles I realized it is the car! I've tried different techiniques too but same thing. Makes my shifting sound like some kinda newbie and I've driven a stick daily for the last 30 years. I wonder if any of the aftermarket tunes get rid if it?? It is annoying.
The aftermarket tunes do not get rid of it. It appears to be a "lag" in the fry by wire dealio. After you let off the gas to shift the rpms still climb a bit and then respond to the input.
At first I kinda didn't like it but, I am used to it and it makes the car "sound" agressive and helps keep rpm up when "jumping on it". Im good either way.
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C&L CAI with MAF, Steeda UP's, FR 4.10's, Predator "C&L-MAF" Tune, Borla 3" tip catbacks, Kooks LT/ Catted X-pipe, Nitto 255/45/18(F) 285/40/18(R), Steeda Springs, Tri-Ax, Adj Pan Hard, Camber plates, Cowel Hood, Tokico Adj Dampers.
dyno; 315 RWHP/ 320 RWTQ
That is true, it does help. Almost like power-shifting when you're really getting on it. However, when you're just going easy down a side street and trying to shift smoothly, you sound like a nub.
I would think that since it is throttle-by-wire, the gains in the computer could be changed so that the response is quicker and the lag between pedal and throttle plate reduced. Hmmmm.....
down-shifting...? 
Yepper, it's all about torque!
