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Gating the Shifter

Posted: Thu Nov 01, 2018 2:59 pm
by Loren
Background: An unfortunate missed shift (1st instead of 3rd at 54 mph) caused the early demise of the engine in my Mirage. We learned that it is very much an interference engine, it has very weak valve springs, and simply doesn't tolerate over-revving. While it wasn't TOO expensive as far as replacing an engine goes, I'd like to avoid this happening again.

Hat tip to Nate for instigating the idea of implementing some sort of first-gear lockout device! That's where this started, and could ultimately be where it goes. But, I want to start with a gated shifter. Partly because I've always thought they were cool, and wanted to do one, anyway. And partly because I wonder if it would make it more obvious when you're headed for 3rd vs 1st. If it does, then we're good. No further action required. If it's still easy to grab 1st rather than 3rd, then I can work on some sort of spring-loaded 1st gear lockout that would block that gate after you shift to 2nd.

First thing I noticed when I tried to mock this up is that if I simply remove the shift boot and put a gate plate on top of the shifter pedestal, the gates are too close! The shift lever is prety fat at 13mm, and center-to-center on each gate is about 15mm. So, 1-2mm max width for the "fingers" on the metal gate plate. Not gonna work!

Thinking on it further, if I were to raise the pedestal, obscuring more of the shift lever, the throws get wider up there. So, I started playing with that today. First 3/4", then an inch, and lastly 1.25". Mocked it up with some foam and cardboard.

This could work! Doesn't get in the way. (maybe the cupholders behind the shifter will be slightly harder to reach, but those cupholders aren't deep enough and drinks like to flop out of them, anyway!) And doesn't look too bad, if I build it in a relatively neat fashion.

Image

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Gating the Shifter

Posted: Thu Nov 01, 2018 3:07 pm
by Loren
Thoughts? Anybody done this before?

My initial thought is that it could be clunky, rattly and I might hate it. If it were in something like a Miata, this would almost certainly be the case, as the shifter is part of the transmission, and the transmission can move separtely from the body of the car. A recipe for shifter movement and clanking against the shifter plate. But, the Mirage has a cable-operated shifter, so the whole shifter assembly is rigidly attached to the body. Unless the shifter mechanism breaks, or the shift lever bends (at 13mm diameter, it ain't gonna bend), everything should stay in place. As long as I've got enough clearance in the horizontal gate to allow for a little fishing without interference, it should be good.

Only way to find out is to build it, I suppose. Need to decide what materials to build it with, and what the easiest method will be. I'm almost thinking wood would be the easy solution for the pedestal part. Not overly heavy, and easy to work with. Then, probably a 1/4" brushed aluminum plate for the top... or maybe 3/16" steel.

Gating the Shifter

Posted: Thu Nov 01, 2018 3:10 pm
by Magooiii
White cutting board material it will be slicker less drag then wood

Gating the Shifter

Posted: Thu Nov 01, 2018 3:19 pm
by Loren
I was just going to use wood for the upright part to get that 1.25" of height. Plastic for the top plate isn't a terrible idea.

If I was more motivated and into working wood, I could just take out the stock center console and build a new one. But, I'm trying to keep it as simple as possible, and not stray too far from stock appearance. (being easily removable to return to the stock boot is also a happy thought)

Gating the Shifter

Posted: Thu Nov 01, 2018 3:43 pm
by twistedwankel
If you still had your 3oz stock shifter knob it might not have enough stored energy to go back into first with a palm whack? I drove a Ferrari with a gated shifter and it was irritating - nearly impossible to do a quickie shift to 3rd as had to pause for it - but it looked fancy. Maybe why they don't make sticks anymore? Like with my Mazdae must develop a limp wrist with finger tip shifts to 3rd to avoid 5th:) Tea anyone?

A shorter shifter arm would also reduce the available force. If you still have one of those bent valves it would make an awesome shifter/reminder.

Gating the Shifter

Posted: Thu Nov 01, 2018 4:04 pm
by SlowMiataDrew
If it's hard to get into 3rd from 2nd with the gate, would it be worth exploring having the finger between 1st and 3rd be angled toward first, opening up the gate for 3rd? That way, you only go into first with the shifter pushed all the way to the left and it makes the 2-3 shift easier. Just a thought. The bright side is that this wouldn't require any mechanisms, just a "guide" towards 3rd.

Gating the Shifter

Posted: Thu Nov 01, 2018 4:09 pm
by Loren
Yeah, best I can do right now is a mockup. Until I've got the transmission back in, I can't get into to details of where the detents are, and how to angle hates and stuff. I do like that line of thinking, though.

Doug, the car shifts like crap with the light knob on it... But, yeah, it might not go places or is shouldn't so easily with the stock knob.

Gating the Shifter

Posted: Thu Nov 01, 2018 6:45 pm
by twistedwankel
Dan probably has a heck of a time reaching across his lap with his left hand to shift your car without looking. I have driven a number of RHD cars and no way can I throw a proper power shift with weak left arm and wrist. So that's why they build them that way in UK and Japan so they last? Everyone needs a "shifty" passenger from UK to make them last?

Anyhow hope you come up with something that is bulletproof and easy. Doubt you'll find a billet short shifter for a Mirage? But overseas guys do trick out even their Mopeds pulling wheelies. I've seen them.

Gating the Shifter

Posted: Thu Nov 01, 2018 8:32 pm
by JasonS
I've never driven a car with a gated shifter so this may be a dumb question but here it goes.

I dont look at my shifter when shifting. Im not sure I understand how this will make it harder to get into first without some sort of block. Would this change the feel enough to accomplish what your after?

Gating the Shifter

Posted: Thu Nov 01, 2018 9:11 pm
by Loren
I've never driven with one, either. I suspect you're right. If the gates are properly designed to not interfere... probably wont' make much difference.

But, along the lines of whe Andrew was saying, I can probably tweak that first gear gate to make it hard to accidentally get into. Perhaps not a deliberate lock-out, but just make it harder to get into 1st without realizing it. Maybe just offset it slightly to the left so that you REALLY have to pull the stick to the left to get into first? If you're even remotely shooting for 3rd, you'll either hit 3rd or clunk metal at which point you'll know you did it wrong and you won't force it or let the clutch out.

Unfortunately, I'll have to delay this detail work and experimentation until I've got the car back together!

Gating the Shifter

Posted: Thu Nov 15, 2018 7:38 pm
by Loren
Time for an update.

First, the shift gate template that I drafted won't work. I based it on the full range-of-motion of the shifter mechanism. Once we put the transmission back in, it was obvious that the transmission doesn't use that much of the range. Not even close. It's actually a VERY tight shift pattern.

What does that mean? Well, the shift gates are narrower than the thickness of the shifter shaft. So, a gated shifter is impossible. At least at the height that I had planned to do it. I could go taller with the platform, but it would have to be at least twice as tall... and it's already 1.5" above the console. I may experiment with that yet, but at first thought... I don't like the idea.

Played a little bit today with the notion of just doing a "first gear lockout tab". Nothing fancy, just a little finger from the front side of the console to go between first and third. Bend it a little to the left so that you have to really WANT to get over into first.

Something like this:
Shift Lockout.png
Shift Lockout.png (6.78 KiB) Viewed 16470 times
And I tried it. And it sort of works. But, what I found is that the forces at work are enough to really move the console around quite a bit. It's not the sturdiest piece of plastic. I expect that if I built something that was going to see constant lateral forces from shifting in and out of first gear, it would eventually start breaking the plastic. It's also not going to be as effective if it's that easy to move out of alignment.

So, I'm left with: Completely build a new, sturdier (and heavier) console; Hack something together and hope it doesn't fall apart; or just leave it alone and be mindful of 3rd gear shifts.

For the moment, I'm going with the last option. I'm just going to leave it alone. If you palm the shifter from 2nd, it hits third EVERY time. The only way to hit first is to try to "find" 3rd... and you don't have to be off by very much.

Hmmm... someone else suggested stiffer centering springs. I guess that could also be an option. But, too stiff and it could cause 2nd gear shifts to go toward 4th. I might look at that option, though.

Gating the Shifter

Posted: Thu Nov 15, 2018 8:50 pm
by Native
If that finger over the first gear slot was a switch, or powered such that when the stick hits it there's a warning buzzer? :dunno:

Gating the Shifter

Posted: Thu Nov 15, 2018 8:52 pm
by Loren
Yeah, that's certainly possible. I think the tactile feel would be more effective than a buzzer, though.

I did a little looking a bit ago and found that stiffer shifter centering springs are "a thing". Pretty common in the Honda world. Might have to dig more into it.

Gating the Shifter

Posted: Thu Nov 15, 2018 11:08 pm
by ImpostorDan
You cold just have swaped in an autobox in and avoided the whole driving issue already.

:snicker:

Gating the Shifter

Posted: Thu Nov 15, 2018 11:45 pm
by lddavis91
ImpostorDan wrote:You cold just have swaped in an autobox in and avoided the whole driving issue already.

:snicker:
Way to think outside the box Dan, bravo! :)

Gating the Shifter

Posted: Fri Nov 16, 2018 9:22 am
by Jamie
ImpostorDan wrote:You cold just have swaped in an autobox in and avoided the whole driving issue already.
Better than that: just go to one, maybe two gears. Lighter transmission, too, which fits Loren's whole philosophy for the car.

Gating the Shifter

Posted: Fri Nov 16, 2018 10:35 am
by Loren
If I could get a tall enough second gear, I could do without 3rd and 4th. :geek: :headscratch:

Gating the Shifter

Posted: Fri Nov 16, 2018 11:30 am
by twistedwankel
Did your new driver student have any issues going into 3rd with a power shift? You teach that to all your students right? Along with heel toe downshifts?

Gating the Shifter

Posted: Fri Nov 16, 2018 1:34 pm
by Loren
I teach them whatever they are ready to learn. That student was ready to learn to slow down and feel the friction point of the clutch to quit stalling the engine.

Gating the Shifter

Posted: Fri Nov 16, 2018 3:41 pm
by Jamie
Loren wrote:If I could get a tall enough second gear, I could do without 3rd and 4th. :geek: :headscratch:
Hey - it worked for the old Indy roadsters!