No Clutch Autox Shifting
For you autocrossers who don't use the clutch either up or down, any hints?
I've never been able to reliably make it work in autocross even though it was no problem in Road Race driver's school 20 years ago with the same car/transmission.
Do you even have time to match revs for downshifts in our typical very short braking zones?
Thanks,
Dick
CM 85
Dick,
I'm glad you started this thread. I was going to start it soon or later since I don't quite understand the mechanism of no-clutch shifting.
I read the article on Hewland's web site ( http://www.hewland.com/svga/advice.html ) several times but still don't quite get it. Especially the "Automated (semi automated)" and "Manual with engine cut" upshifting methods. Am I supposed to upshift without lifting in these methods? I was doing the "Manual" upshifting by lifting while shifting and it worked alright.
Down-shifting is a greater mistery to me. If no-clutch, how do you rev match when you down shift? I am guessing that you will pull it out from the gear, rev match while it is not engaged in a gear and put it in a lower gear with no clutch? Is this how it works??
Sho Torii
1985 Citation FF1600
I think most everyone lifts slightly when upshifting. Once you've done it a few times you'll never think about it again. It's really not an issue.
For downshifting, as Dick mentioned, our braking zones are really short. So I just wait until I'm near the apex when the revs are very low anyway and move the shift lever into the next gear. Once in awhile if the situation demanded, I'd make a very minor blip. This is a little easier for left foot brakers.
At a National Championship event at Forbes Field many years ago, a very fast section ended in a very tight corner. Most everyone in an FF was going directly from 3rd to 1st with no blipping at all.
I've read a column or two that endorses low blipping for road racers also. It's less abusive compared to the early and big blip to bring revs way up in order to match.
Jim
I wish I understood everything I know.
The key to a clutchless shift (IMO) is to get as close to zero torque load as possible. This means that you have to slightly lift on upshift, so that the output shaft is seeing neither drive nor drag (hope this makes sense - it's a feel thing). Same thing on the downshift - wait as late as possible, then very slightly blip to unload the drivetrain just as you flick the selector.
A perfect shift will be nearly instant, with almost no sense of "jolt" in the drivetrain - just a slightly audible "snick" as the dogs engage in the new gear. As noted in the Hewland article above, faster is actually better; I've found that if I get lazy and slow with my right hand, I am more likely to bounce off the dog rings and end up with a right foot connected to nothing but the volume control......
Marshall Mauney
Milwaukee Region
Haven't had the car for very long, and so I haven't really put much time into thinking about it. I just do it. Slight lift on up-shift and blip the throttle on the down-shift. Haven't had any real issues with it not going to gear since we tightened up everything in the linkage.
What Jim said
Everything Jim said is spot on, I even remember the turn he mentioned, my co-driver won that year and we had a conversation about that shift :-) One little thing to add: The traditional "brake, clutch in, move shifter, let out clutch and blip" takes a looooong time, so if you're doing that you're probably over-braking, slowing down too much. I think this can contribute to the "school of taller gears" instead of "short gearing and lots of shifting", because most people over brake when down shifting. ....not that I want to start that discussion again :-)
Barry
This has been a great thread. First practice is on Saturday at which point this will become all too real for me.
Can't wait.
Doug Wille
My car is back together (after a good amount of work on stuff I didn't imagine I'd be working on...) and Sunday looks dry, so I should be able to report back on Monday re: shifting a Hewland properly.
Thanks, Jim. You have made a lot of things clearer. I was lifting the throttle all the way when I upshifted but now I understand that I just need to lift just slightly instead. This should make shifting so much quicker.Originally Posted by Jim Garry
Now, when downshifting, if you need to blip, you will blip just before (or as) the lower gear is engaging, correct?. In my CSP Miata, I would blip the throttle while I was heel-and-toeing and letting out the clutch. The timing is the same without the clutch, right?
Sho Torii
1985 Citation FF1600
Thanks guys. Great info.
Did I understand correctly that for autocross downshifts w/o the clutch you don't take the time to blip? Just lift, brake, move lever when slow enough, and the dogs unload? (which is what I do with the clutch . . . i.e. no rev matching since no time.)
Considering I'm not rev matching anyway I'm not worried about more dog wear. Any minor "rear wheel drag" going into a slow corner just helps rotate the car . . .
I absolutely agree that a 3 -1 downshift does not need, or even have time for, going through 2nd.
Time for this old "dog" to learn a new trick . . . if I can train my brain to not automatically push the clutch.
FYI when autocrossing a street car I never used heel and toe downshifting. No time. Heel and toe was for the street to save the syncros for autocross.
Dick
CM 85
A day driving a shifter kart will open your eyes to the possibilities, and sharpen your upshift technique considerably. The major difference with a kart is that there is almost no flywheel inertia, so downshifts don't cause significant upsets.
Absolutely correct. No time. as stated above my with clutch downshifts involve one quick clutch depress combined with one shifter move. I don't even know if I could find neutral except when stopped . . or the screwed up 2-3 shift.Ditto for the upshifts. Pull lever as fast as possible while the clutch foot and throttle foot are also moving as fast as possible.
Dick
Hmmm. Finding a local kart track with rental shifter karts sounds like a priority.
Dick
I'm a little dissappointed that Neil didn't throw in a quote from his book about the "nonsense' of heel and toe downshifts. :-) I've been waiting for a good opportunity to plug his book and we finally got one! It is, by far, my favorite car book. Seems like every other book just talks about theories and equations, but Neil actually shares his wealth of experience to tell us what works. Invaluable! Thanks Neil! If you haven't bought his book yet, you should!
Barry Ott
I always upshift just the way the Hewland website suggests; light pressure on the lever, lift and re-floor the throttle as quickly as I can move my right foot. Only time it doesn't work quite right is when there's a tar strip right before my shift point, and that unloads the gears enough to cause an early upshift.
On downshifting, I use a little throttle blip to unload the gears and to get to neutral throttle in the lower gear (i.e. to avoid upsetting the car with too much engine braking). I never pause in neutral; in my experience that's a recipe for grinding them. I've also never gone back to 1st on course. But I run a 15 tooth 2nd gear. Some people avoid those because they sometimes break. I just put a fresh one in about every 5 seasons, and haven't broken one yet.
The other reason downshifting is way easier in the kart is because the 2-stroke has almost no engine braking.
I'll check out that book.
Don
Yeah, great book Don. I had Neil sign mine with a little note. Won't repeat it here because what I asked him to write was self-deprecating ... but true.
Sho, I guess I never thought about the timing of the blip. Must have been just before.
Jim
I wish I understood everything I know.
What pedal setup are you guys running? Do you just use a clutch/brake on the left and throttle on the right?
I've only driven a FF once and it was a long time ago. When you refer to blipping on downshift, you are blipping in neutral, correct?
In a kart, you just stick it in the lower gear without the clutch or blip.
I can now officially report back on clutchless shifting...easy peasy.
that about sums it up.
This. I was impressed, it was easy and happened super fast.I can now officially report back on clutchless shifting...easy peasy.
that about sums it up.
Definitely grin inducing
Dead pedal, clutch, brake, throttle all in a row. Steering shaft doesn't interfere in the Reynard due to the high rear mounted rack. Only time my right foot is on the brake is when I'm pulling up to the line and my left foot is on the clutch.
I never pause in neutral. I blip to unload the gears and somewhat match the revs, all in one motion if that makes sense. Don't need to blip in the kart because there's almost no engine braking to load the gears.
Don
do most FF's have a real dead pedal? None on my RF88. I was thinking it would be nice to have, but I can't see how there's room in the foot box...
The dead pedal in the Mondiale is almost 3/8" wide. Not very useful for my size 13's... Eric has little feet though so maybe it works for him?
A 3/8" wide dead pedal?? I would love to see that. Can you possibly post a pic?
I don't think there is any dead pedal or room for one in my Citation.
Sho Torii
1985 Citation FF1600
You need to start the blip just a hair before you push the selector - you want to unload the dogs as you are disengaging them. Obviously, you don't want to blip early or hard enough to load the dogs in the other direction....
Marshall Mauney
Milwaukee Region
Yeah, what he said!
Sho, I might have been exaggerating... a little. All I know is keeping my foot on the skinny dead pedal is nearly impossible.
You might be able to persuade Eric to go out to the trailer and take a pic. :-)
From my point of view at the National level you may get away with the shifting thing 98% of the time but what happen when; Your at the National's on your last run with .100 to .200 back from winning the National's and you do that non-clutch thing and there's a little hiccup on upshift or down shift. How far would you kick yourself.
So if you don't have another CM to play with and with Know times to see if it's working for you, I would be hard press to try the first year your trying the non-clutch thing at the National's, I would work on for a year or 2 to become proficient at it.
Just my .02
Ben
Ben, your suggestion about being conservative makes sense in a general way. However regarding the "no clutch" shifting on a Hewland, I'd hazard an educated guess and say that drivers probably experience less problems "no clutching" than using a clutch. Even inexperienced drivers.
Jim
I wish I understood everything I know.
Ben, true, but when you loose by .007 or less you wonder just where could I have gained that. The kicking yourself can go both ways. I have been beaten by that or less at some event somewhere.
I dunno...seems to me that if Hewland, himself, says that's the way to shift his transmission, that's the way I'm going to do it. I can't imagine, when your name is on the case, you want people either breaking gears or losing big events, based on your direction. I do find it hard to understand how the actual wear would be less shifting no clutch (on the gears, that is, I definitely can see how it saves clutch/throwout), but that's what Hewland says.
Ben, have you tried it on Mark's car? You may find it is a different deal than you might be thinking it is...it took me two shifts to get comfortable with the feel of upshifting. Downshifts are still to be explored, but based on the "feel", I think I know how they're going to go. Funny thing, it is more similar to no clutch shifting a motorcycle than I had imagined.
Dick R. & Jim
Valid points, my question to you is.. have you change your transmission gearing lately or are you shifting more at events you attend that shifting has become a problem or you feel your losing time?
I have found that when other people that had to shift there cars at a events, they lost time between .200 to .500, I won many events in my XR because I didn't have to shift passed 2nd. Now these are street cars and not real race cars but up shifting and down shifing you will lose time (in autocross trim), ask the F1 guys because if it dosen't make a difference they would not have transmission shifting in the milli seconds.
I hope it pans out for you guys and we will see at the National's how it works out. If I happen to be .200 back from winning at the National's and you beat me. I will be the first to offer up a big hand shake.
Ben
Ben, I agree, shifting has to take time. I also find Mark's car much easier to drive, with the taller 2nd gear. But, seems that all of our recent CM National champs appear to be using a 3 gear, if not 4 gear, set up and shifting a fair amount...of course, that's after having enough seat time to be able to make it work.
Lots of good discussion about gear ratios here:
http://www.apexspeed.com/forums/showthread.php?t=41197
Seems like this thread is "how to shift" not "how often". Personally, for upshifts, there's no doubt in my mind that clutchless is the way to go. From day one, when I test drove my soon-to-be Reynard, clutchless is easy, faster, recommended, no-more unreliable than a street-car clutched upshift. Downshifts? A little more interesting, I can certainly understand using the clutch to unload the drivetrain. If I were a right foot braker I think I'd probably use the clutch. But, being a left foot braker, clutchless is very natural for me.... I do think that clutchless is less involved so it takes less time and is therefore less prone to "overbraking"
Just my two cents.
Barry
Again I really appreciate the input as I'm sure the new CM guys do also. Thanks to the proven pros in our class for all your input.
FYI my biggest problems with clutchless and more shifting (since Ben and Barry have commented) is a combination of lack of the needed talent to reliably shift from 2 - 3 and to brake with my left foot in an autocross. Combine the talent shortage with the fact that when I've used say a 60 mph 2nd and a 70 or so 3rd the upshifts either came at the "wrong place" to really take advantage of the shorter gear or 3rd was actually taller than needed compared to say a "split the difference" 2nd. For actual fast straights then upshifting 2 -3 to a high 70's 3rd was easy to do. This left "overdrive" for the really fast local events.
FYI for anyone else who "just can't get clutchless and left foot braking to work for them it might make you (and me) feel better to read posts 19 and 24 in this thread from the road racing side of the situation.
http://apexspeed.com/forums/showthre...ghlight=clutch
I also talked with Craig Taylor many years ago and got the same info that Charles related.
FYI regarding dead pedal: See attached pic of the "heel dead pedal" in my Swift copy.
Dick
FYI regarding the importance of shift times in F1 I heard/read that the problem is the high speed drag is so high that the decel is amazing during shifts. Multiple g's in the upper gears I think. Even worse than a little bit of no forward acceleration during shifts. Obviously not a problem for us.
Dick
...and maybe one not so obvious thing about shifting. Is everyone's shifter easy to access? The first time I drove my VD, my shifts were marginal, especially downshifts. It dawned on me that my arm was cramped when moving the shifter, that I had to bend my wrist to move it. I adjusted my seating position so my arm could easily move the shifter without any flex in my wrist and voila: easy, consistent shifts. So, do your best to make sure you can access the controls properly.
Barry
Hey Dick R,
Thank you very much for the motivation, I will see at the National's, Yes?.
Ben
Also, make sure there is absolutely no play in any of the many joints, etc. in the linkage if the cockpit in your car is so tight that the available range of motion for the shift lever is very limited like mine is. Steering wheel on one side, bodywork on the other, frame brace above my arm, dash in front in my car greatly limit the available lever position. The bodywork is so close it has a bulge to make (some) room.
Dick
CM 85
Dick, The 2-3 shift should be exactly like the 1-2 and 3-4, except that instead of pulling straight back on the lever you are hooking your thumb around it and pushing to the right and forward, all in one motion. If it won't do that you should have somebody work on your transmission. Just don't carve away too much from the tip of the 'hockey stick' or you can wind up stuck in 2nd gear (if it can slip through the gate before the 1-2 fork is in neutral).
Don
Tight linkage = tight shifting. Last year I put AN taper pins in my linkage - since then, it shifts like butter.
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