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I'd be rather inclined to say that an auto gearbox with a clutch would be the best of both worlds - the torque converter is the hydraulic pump to power the auto gearbox, but at the same it's also a "fluid clutch", of sorts - this is a VERY rough comparison, but think of a tube - a turbine at one end, a turbine at the other - the turbine on one end is forcing fluid down the tube, forcing the other one to spin. If you hold the other turbine still (or slow it down forcefully - i.e. when the auto gearbox shifts) the torque on it increases (hence, torque converter), but it doesn't stop the turbine at the other end completely. However, as you can imagine, if the unpowered turbine has a load put on it, it'll never spin as fast as the turbine on the other end, no matter how efficient the turbine is. This is the major drawback of the auto gearbox setup, and why it's slower than a manual - nothing to do with gears, they still use the normal cogs - it's just the torque converter. Anyhoodles, I know this paddle-shift idea is pointless, but it's not very often you have fun doing something that does have a point, is it? :-D At the moment I just want to do it to basically shift gears - i.e. fully depress clutch as fast as possible, move gearlever, release clutch (Can do automatic throttle release later, but I'll get to that later). However, this "smooth shift" idea has got me thinking - if I can find out the exact gear ratios, I can dynamically calculate what speed the engine will spin at what road speed - so I can make it change gear, and keep the clutch depressed until exactly the right moment, when the engine is coming close to the speed it will be spinning when the clutch is let out, and then release the clutch - not suddenly though, sort of like a slow-ish let-out. Later on, if automatic throttle control can be managed, the throttle can be released when the shifting starts, and slowly regained as the clutch is left out. which brings me to something else - if the synchros on the gearbox go bust it can be programmed to double-clutch :burnout: Some good ideas floating around here... though I'm afraid this project will be in the planning stage for a while yet - one of my close friends is hopefully coming to visit from the other side of the world, and the obligatory tour of the country might turn out to be, well, expensive Now I have a problem though - got to find some kind of high-speed pneumatic-or-otherwise actuators that can be controlled by digital electronics. If I can find those, this battle is half won!

True, true... I've been wondering though, what about pneumatics, possibly powered off the exhaust? As for the interface, good point... some more thinking to do! maybe the paddles, but with a seperate 1-5 selection? alternatively just manually move the gear lever for a first concept i'd like to automate the movement of the gear lever, maybe later do the clutch...

You'll still have the clutch pedal and the gearlever, they'll just move by themselves ;-) But you're right, electronic servos (most of them anyway) don't shift very fast at all. Allright for model planes, and maybe generic driving, but not spirited driving that's why i'm either trying to look for electronic servos with high amounts of torque that can shift very fast (200ms for a 60-degree rotation with 10kg/cm of torque is the best I found so far.....), or go for something else, like pneumatics. It'll suck quite badly having your arm broken by the gearlever though

True The idea isn't to completely replace the shifter though - it's only to add an automatic control to it - as soon as you move the gearlever the computer will be able to detect this (by means of contacts on the cables moving the shifter) and stop pulsing the servos, so they can turn freely. I thought of doing this as I was driving from uni in the GL, in the stop-and-go traffic flicking through gears, wishing at that time to have an auto, but as soon as the road opened up I was thankful for having a manual again.. so this idea popped up

True - I had a thought of using a tunable two-way ratchet type mechanism to move the gearlever, so it can be calibrated to move the right amounts to get in gear. As for the clutch, switching from neutral to 1st would signal a takeoff in this scenario (or a seperate clutch paddle...?), when the controller would take the RPM's at which you chose to "release" the clutch (or take off), and choose a specific engine speed, at which point it starts releasing the clutch if the RPMs drop too much below that engine speed - could even use fuzzy logic. The whole idea behind this is to combine the best of both worlds (auto/manual) - the comfort of being able to let the gearbox automatically handle shifts (auto) while still having efficiency, and total control if/when you want it (manual). Getting pretty excited... just got to scrape enough money together to get the parts!

Sup folks, I'm having a lot of really crazy ideas lately The latest one is "robotizing" the gearbox on my 89 GL (EA82) using heavy duty servos or pneumatic drive, and a PIC16F84A microcontroller. Basically, connecting some "servos" (let's call them that for now) up to the shifter, or its linkage along some point, the servos being controlled by said microcontroller, linked to two microswitched paddles mounted on the steering column. None of this will be too hard to make - I've done gearlever-related microcontroller exercises before, including building an H-style gearlever for PC racing games using the same microcontroller. Basically, the idea for now is just to make this system control the gearlever - I don't know where to find actuators strong enough to manipulate the clutch - so it goes sort of like, depress clutch, pull paddle, let go of clutch. Maybe later when I find some kind of actuator I'll be able to do an automatic clutch as well - hook up a torque/rev sensor and make it automatically do the clutch for takeoffs. I'm budgeting on less than NZ$500 for this system. If I can get it going, I'll put some plans up for those that are interested - some tips will be very much appreciated!

Don't light a match

Oh yes, and never ever ever ever turn a carb or sections of a carb upside-down to have a look at it....

could be a bad jet or a bad needle and seat valve. Take the top of the carb off (SLOWLY... these damn things fly apart sometimes, then you're screwed ) and have a look close to the float, there should be a little valve (screw-in?) between the chamber and where the fuel line reaches the carb. This valve is designed to cut off the fuel flow into the carb if the fuel level in the chamber reaches a certain level, pushing the float up and closing the valve. However, if the valve has gunk in it, it won't close fully, so the pressure from the fuel pump will force fuel past the valve and up & out of the jet. Take this valve out (Once again, carefully...) and either give it a good wash out, or replace it...

May also be warped brake rotors. My car (Nissan) also vibrated above ~50mph, and I checked everything (wheel rebalance, suspension free play etc), nothing helped, so I had the brake discs machined - instant smooth ride.

I really miss my metalworking days. If I got my Subie when I was still at school and doing metalwork, I woulda had an ER27 in there LONG ago :horse:

Or if you're crazy, take the timing belt off of the side that's doing it and see if it goes away

Eh, oldskool works :D

That sounds pretty bad... I don't think it's a lifter tick, unless your heads are made of wood sounds as if something's impacting the block from the inside... something with the conrods? worn bearing somewhere....? Definately from the engine, and not the transmission? (take a broomhandle and firmly press it against various parts of the engine, press your ear to the other end, and figure out what part the sound originates from the loudest)

COUGH EJ22 COUGH :cool: