Do you 'blip' the gas?

[Flank]

Hi all, Lately I've been using my dad's 64 MGB as a daily driver, and I've noticed that when I shift gears, I like to 'blip' the gas as I'm moving the shift lever. I do it all the time, I don't know why. Today I drove the car and made a point not to 'blip' and it shifts just fine. Is this a reflex left over from the days of yore? Or am I 'show boating'? What do you do?

[stevepaa]

I do it on downshifts, not upshifts. I think it saves wear and tear on the synchros.

[David]

On downshifts it helps match gear rotational speeds, on upshifts it would make the rotational speed between gears even greater.

[VaSteve]

I do it on 1st and 2nd in the 911, makes it asier to coax into gear.

[stuartj]

Its counter productive on up shifts and will contribute to drive line wear.

[Vipergrün]

Yes, but are you letting the clutch out when the shifter is in neutral? You need to do this to be effective. This is required to get the rotating parts up to speed.

So, on a 1st -> 2nd shift you would;

Clutch in
Shift to neutral
Clutch out
Blip throttle
Clutch in
Shift to second

[Jeff Higgins]

I can't see any advantage on upshifts. I blip habitually on downshifts. Sounds like you might have it backwards, but then again, it is an MG. Don't you sit on the wrong side, too?

[88BlueTSiQuest]

Originally posted by bb80sc
Yes, but are you letting the clutch out when the shifter is in neutral? You need to do this to be effective. This is required to get the rotating parts up to speed.

So, on a 1st -> 2nd shift you would;

Clutch in
Shift to neutral
Clutch out
Blip throttle
Clutch in
Shift to second

That's the double clutching technique used on older cars that don't have synchros in the tranny. Totally useless on a synchronized tranny, unless you are a writer for the screenplay "The Fast and the Furious" and are looking for some somewhat technical line for your automotively impaired actors to speak outloud.

[stuartj]

Originally posted by 88BlueTSiQuest
That's the double clutching technique used on older cars that don't have synchros in the tranny. Totally useless on a synchronized tranny, unless you are a writer for the screenplay "The Fast and the Furious" and are looking for some somewhat technical line for your automotively impaired actors to speak outloud.

LOL, yes.

Except on the up shift, its desirable for the engine revs FALL to match road/engine speed, just as revs need to RISE when down shifting. Blipping on an upshift is actually precisley the wrong thing to do, unless revs have fallen so far during the shift they need to be raised to match road speed.

[Vipergrün]

Originally posted by 88BlueTSiQuest
That's the double clutching technique used on older cars that don't have synchros in the tranny. Totally useless on a synchronized tranny, unless you are a writer for the screenplay "The Fast and the Furious" and are looking for some somewhat technical line for your automotively impaired actors to speak outloud.

Not true at all. I guarantee, at least on a 915 Porsche tranny, you WILL save the synchros, especially the 1 -> 2nd gear stuff by using this method. Also, what about on the track? You're saying it's useless there as well? A hard down shift, without using this method can, and will temporarily lock the rear wheels and could cause a fish tail at a minimum, or a spin. However, yes, for Toyota's, Honda', and 911's >= 1987, your comment is at least partially accurate.

[88BlueTSiQuest]

Originally posted by bb80sc
A hard down shift, without using this method can, and will temporarily lock the rear wheels and could cause a fish tail at a minimum, or a spin. However, yes, for Toyota's, Honda', and 911's >= 1987, your comment is at least partially accurate.

My quote was on upshifts, not downshifts. But either way, I've never 'double clutched'.

Either way, it sounds like all that clutching would actually slow you down in lap times.

[yellowline]

Originally posted by 88BlueTSiQuest
Totally useless on a synchronized tranny, unless you are a writer for the screenplay "The Fast and the Furious" and are looking for some somewhat technical line for your automotively impaired actors to speak outloud.

Proper double-clutching (on downshifts) isn't useless. Anything to reduce wear on synchros is good. When making a turn off a main road, I double clutch before selecting 2nd. If I match it well, it slips right in; otherwise, I have to hold the gearshift against 2nd for a couple seconds until it goes in. On upshifts, my 944 shifts fairly nicely into 2nd when many other 944s would grind, so the synchros are still good. I'd like to keep it that way.

Skip Barber recommends double-clutch downshifting in his books. I haven't gone through his program, but I've browsed one of his books, and it mentioned the usefulness of double-clutching on downshifts.

Heel-and-toeing or clutchless shifting are probably useless and possibly dangerous techniques on the street, though.

Edit: Wow, a lot took place while I was typing this...Ignore this if you want...

[88BlueTSiQuest]

Originally posted by yellowline

Skip Barber recommends double-clutch downshifting in his books. I haven't gone through his program, but I've browsed one of his books, and it mentioned the usefulness of double-clutching on downshifts.

I am curious though... I rarely use my clutch to pull the car out of gear, I only use the clutch for this when on decel. But if you were planning a downshift, I find that I pull the car out of gear, then apply clutch to get the tranny into a lower gear.

I'm guessing the circumstances during a race would be different, to make the double clutch a more 'economical' means of hitting the downshift?

[stuartj]

Originally posted by yellowline
Proper double-clutching (on downshifts) isn't useless. Anything to reduce wear on synchros is good. When making a turn off a main road, I double clutch before selecting 2nd. If I match it well, it slips right in; otherwise, I have to hold the gearshift against 2nd for a couple seconds until it goes in. On upshifts, my 944 shifts fairly nicely into 2nd when many other 944s would grind, so the synchros are still good. I'd like to keep it that way.

Skip Barber recommends double-clutch downshifting in his books. I haven't gone through his program, but I've browsed one of his books, and it mentioned the usefulness of double-clutching on downshifts.

Heel-and-toeing or clutchless shifting are probably useless and possibly dangerous techniques on the street, though.

Edit: Wow, a lot took place while I was typing this...Ignore this if you want...

Double clutching is far too slow, useless and fraught with potenetial disaster driving on a track with a modern tranny. Too much to do. It may be of some value going 5 or 4>2, but proper heel/toe makes this unneccessary.

I used to D/C my 915 2>1 and it is of some use with that box, and other older boxes with poor synchro. The 915 was absiolutely fine in all other situations without D/C.

Flat shifting is a good way to shorten drive line life, true. Heel/toe however, is not useless on the street. Its kind to the car, its smooth, it keeps the car balanced and its good technique. Once you learn it, you will always drive that way.

Only in MHO ofcourse.

[yellowline]

In the Skip Barber book, he described and pictured heel-and-toeing as putting the right foot upright, having the left half on the brake, and right half on the gas, while pivoting your ankle to blip the throttle. Just claifying terms, that's how I understood heel-toe.

I do that on occasion, particularly on 5-2 downshifts, and I do a simple double clutch whenever the car's moving and I need to select 1st. It just seems like it would be possible for your foot to slip off the brake while heel-toeing, meaning you'd coast into another car, or someone's property...that's what I meant by heel-toeing being dangerous. When I do that, I'm really careful not to have my foot slip, but it does work well.

[stuartj]

Originally posted by yellowline
In the Skip Barber book, he described and pictured heel-and-toeing as putting the right foot upright, having the left half on the brake, and right half on the gas, while pivoting your ankle to blip the throttle. Just claifying terms, that's how I understood heel-toe.

I do that on occasion, particularly on 5-2 downshifts, and I do a simple double clutch whenever the car's moving and I need to select 1st. It just seems like it would be possible for your foot to slip off the brake while heel-toeing, meaning you'd coast into another car, or someone's property...that's what I meant by heel-toeing being dangerous. When I do that, I'm really careful not to have my foot slip, but it does work well.

What you describe is spot on. Your foot wont slip because what you are doing is, primarily, braking, and holding a controlled pressure on the brake while you roll your foot on the go pedal. Left foot braking takes some practice too.

Problem I found the otherday was opposite..full two feet in panic stop in traffic thanks to a moron- because I h/t all the time, I edged the acclerator as well as the brake. Clutch was in, so engine was revving its t1ts off. Lesson learnt.

Practice, practice, practice....

[campbellcj]

I blip and heel/toe many downshifts per day in the Audi. It's the only way to be relatively smooth, fast, and non-punishing in most manual trans cars.

I admit to double-clutching sometimes too, but really just for fun/practice. Although it does also seem to reduce stress on the driveline bits when they (and their trans fluid) are unusually cold.