MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGA - Matching revs, badly

I'm a bit embarrassed to confess never having learned to match revs reliably enough to downshift without benefit of the clutch. Sometimes I find the notch and other times not. I've papered over my deficit by learning to double clutch quickly, but this is really no help in dropping into first gear without synchromesh. The only time I gathered the courage to try this ended noisily. Is there any way to do this more-or-less safely? It would be occasionally quite useful to downshift into first, particularly turning into sharp switchbacks that ascend steeply. Any advice appreciated.

Ken
Ken Korey

Never did master double de-clutching so went the expensive way around the problem ( with some other benefits ) and fitted a 5 speed box. Loads of advice on Google on how to dde-c but still needs technique and courage on a steep corner.

Neil Ferguson

Ken,
I did the Skip Barber race school series. In their first 3 day school all cars are equipped with non-synchro gear boxes--for a reason. One of the first exercises they make you do it to master the "heel-toe" down shift. Heel-toe isn't necessary unless you are braking and downshifting at the same time, but the main point is to "blip" (big blip) the engine to match the engine rpm to the higher (lower gear) tranny input rpm. It takes practice. Better to use someone else's car for practice! You can get a course at Lime Rock CT. Oh yes, they don't allow the term "double clutch". That's only for truck drivers, not racers!
Cheers,
Gerry
G T Foster

Thanks much, Neil and Gerry! I would undoubtedly benefit considerably from the Lime Rock course; my skills in this regard are primitive. As a kid with a fast car I could once do the heel-toe downshift, but the larger paddle-style gas pedal of a '57 Chevy made control of blipping much surer than does the smaller MGA throttle pedal. I would be very reluctant to try this in my MGA now, although driving it like a truck I'll venture to double clutch, leaving the brake alone.

What I really want to do, however, doesn't involve the clutch at all. I want to match revs and downshift from second into first, WITHOUT depressing the clutch. With at least some success I could do a clutchless shift in the upper gears of my old all-synchromesh P1800S (without skipping gears), but I've no idea at all how it might go over in the MGA--especially trying to drop it into first gear. Is this entirely ill-advised, or am I simply not in on the secret?
Cheers, Ken
Ken Korey

Over the years, I have several times posted a lot on this subject. Check archives, on this and the TD/TF and MGB boards too.
It's not usually heel and toe, rather a twist of the ankle using the sides of your foot, esp with MG type gas pedals.
I can and sometimes do shift without clutch, but near a million miles in a 13 speed truck will teach you that - your clutch leg gets really tired after a day of driving through mountains! I taught my daughter to shift without clutch in a few hours on a trip, but that was an all synchro box.
First lesson is to get sensitive enough to slide it out of gear with fingertips and no upset of the car, then learn to get it back in. You can read the tach to help learning, but this is much to slow to use in real action. Start with the synchro gears before you try 1st. If you have a working clutch, I still suggest hitting the clutch quickly as you put it in first on a downshift, as it helps to prevent shelling teeth if you are not perfect. It is all a lot easier at higher rpm, since engine speed changes are quicker. Waiting for the engine causes you to lose track of the timing. The actual shift is quick to get between the teeth, but gentle enough that if you really missed it it can bounce back with a bad noise but no real damage.

FRM
FR Millmore

I believe my own teeth would be rattled out of their sockets before I could master that technique....all that crashing and grinding !!
Neil Ferguson

Matching the revs to next gear is the art. My driving instructor from back in 1964 taught me to change gears up and down without ever touching the clutch pedal. The only real difficulty was starting off from stationary. You had to switch off the engine, engage first gear, then hit the starter. Once you got over the first few bucking broncos, the engine fired and you were away. It was a good exercise in learning to listen to the engine revs. I can still do it.

Steve
Steve Gyles

Steve. There lies the rub...I must be artless. I have to say that I never think about changing gear..the foot has its own brain...and if the one on my shoulders tries to tell it something there is a rebellion and ......!!!! I am way past change now and all is cast in concrete. You were luckily, Steve, you got your foot brain disciplined at an early age.
Neil Ferguson

Ken,

I can't do it well even with the clutch. Downshifting, I de-clutch, rev the engine a bit, depress the clutch again and pray that I am not about to be embarrassed.

I have plans to rebuild the box this winter, but I swear I have probably done more damage than all the PO's combined...especially in the first two weeks after I got it running.

When we finally do get together, I want you to give me a lesson, professor!

JIM
AJ Mail

Thanks to all respondents. Your comments are valued, serving at least to reassure me that I'm not the single wallflower at the downshifters' ball. I always marveled at tractor drivers' mastery of their gearboxes, FRM. In fact, some time ago, when I first read your explanation of the proper ankle twist for blipping while braking, I went to the garage to practice just that maneuver with the gearshift in neutral. It made me aware of how much more practice would be needed before attempting it at speed. I could downshift my P1800 from 4th to 3rd without the clutch, but I had much more experience listening to its engine and feeling its gears than I've yet acquired with my MGA. If I ever become confident enough to try it again, I'll be sure to first perfect my technique in the upper gear range before attempting a downshift into first (hitting the clutch, of course!).

Starting off in first gear from stationary position without the clutch sounds quite daft, Steve, although there's good reason to believe in the effectiveness of an approach that taxes slow learners with a considerable investment in starter motors.

About all I can profess here, Jim, is a profound ignorance of the fine points of driving an MGA. I didn't expect that what I learned long ago would transfer intact to this car, but I'm a long way from feeling that it's a mechanical extension of me. More time in the seat and less time under the floorboards would surely help.

Cheers,
Ken
Ken Korey

Ken -
Part of this is survival. A few years ago there was somebody driving across the country to the Northwest coast for a big meet, and lost the clutch hydraulics in Idaho or some such. Ordered parts and waited (and paid!) in a Motel, finally got it fixed, missed the show, and drove all the way home to Alabama or someplace. I wouldn't have hesitated more than a minute to order the parts to be delivered to destination, then gotten there before they did - in that case it was a nest of MG guys.

I have dealt with raggedy cars enough that being able to figure out how to drive the lame is a real good idea! Saved myself and customers a lot of tow $$ at times. That's why I taught my daughter how to do these things.

To start in gear, it helps that the car is in tune. Start it up until warm, shutoff, and restart in gear. Planning ahead is good, stop only on downgrades and time your traffic lights, may have to shade Stop signs, but if you can downshift to low, it doesn't hardly count as walking speed.

Worst thing ever was driving a Porsche 356 with a 36hp VW engine and no throttle cable across Pittsburgh - no matter how far you screw the fast idle up, it is not real good on uphills, but downhill is exciting!

Did a couple of hundred miles on a Vincent Black Shadow without clutch - it had 11:1 pistons and was near impossible to start, so I planned ahead. Got gas at the top of a big hill pointed the wrong way, kicked the beast into life, pushed it down the hill, dropped it into gear, went two miles until I could make a big U turn. Planned the Turnpike tollbooths so I could grab the ticket on a roll, and hollered apologies to the toll taker when I rolled through and sort of threw the ticket and money at her - we didn't even drop the money as I yelled "can't stop, no clutch"! I had the about right $$ in my jacket pocket, but had to remove my left glove to get the zipper open, get the ticket and $$ out, hand it to her, all while downshifting to first and grabbing the brakes to slow it down without stalling the thing. Then get my glove on and go home another 20 miles and then through Pittsburgh city streets, fortunately late on a Sunday night.

This is called fun!

FRM
FR Millmore

I have modified the loud pedal to make blipping the throttle easier - sorry about the dirt inside, I haven't clean the mud out since the last OST competition.
Mike

Mike Ellsmore

Never, ever try to get it into first without a clutch. One single try can chip a gear and send a bit of tooth into the rest of the turning gears with very expensive results.

I have been forced to change gears a couple of times over my racing career, without using a clutch, simply because something went out on the clutch, so it was either pull over and stop or continue clutchless. As this sort of thing tends to happen in the last race of a series where you need the race credit, forging ahead was mandatory.

Racing gives you a pretty good feel for doing this.

Double clutching going down on the street will save your synchros a lot of wear, but like I said, NOT into first gear.
Bill Spohn

Is that a Paddy Hopkirk extender, Mike? I think Moss sells something of the sort. Does it work well? It looks as if it might fill in nicely for my shortcomings, rather like going back to training wheels.

I've given up all thought of looking for first without a clutch, Bill. If I need a synchro there I'll follow Neil's lead and put in a five-speed gearbox. I am glad that I asked you fellows for advice before setting off down the road with improvisation on my mind.

Ken
Ken Korey

ken..open up the gearbox ..,take out first meshing gears, machine off the awkward external protrusions ( teeth) and then super glue on some velcro on the remaining friction 'wheels'.....off you go!!
Neil Ferguson

Ken, that looks like a Paddy Hopkirk pedal to me. I've tried it in the past. It is very cheaply made and is held on with two super tiny screws that I would not trust. I placed two plastic ties around mine to ensure it stayed in place. In the end, I tossed it in my parts box.
D Quinn

Ken,
It is not a Paddy Hopkirk pedal - I tried one of those from Moss and it broke in half after about a month's use (diecast metal - very flimsy).
I made the one shown, the only similarity is that is foot shaped but is larger than the Paddy Hopkirk extension. The back portion is milled from a block of aluminium to fit in behind existing pedal and the front is made from a piece of aluminium angle (one side cut down to about 10 mm to give it some strength). The two pieces are bolted together with Unbrako countersunk bolts. Making it was a labour of love!
Mike
Mike Ellsmore

Double declutching is a mastered art and very beneficial when changing down to a lower ratio. Done properly it does indeed reduce wear on the synchro cones but over enthusiastically will actually increase wear. Now double declutch and select first gear if you wish this can be mastered within a few attempts at anything up to the maximum speed in that gear but NEVER attempt to select first without the clutch as this is the surest way to destroy this relatively fragile gearbox. As Bill says if you shed part of a tooth this can go through the rest of the gears with disastrous consequences.
Iain MacKintosh

The following website gives a good explanation of the heel and toe technique.
http://www.drivingfast.net/car-control/heel-toe-shifting.htm
Mike
Mike Ellsmore

This thread was discussed between 30/07/2011 and 04/08/2011

MG MGA index

This thread is from the archives. Join the live MG MGA BBS now