Tigger
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posted on 29/1/08 at 11:37 PM |
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Sequential gearbox flatshift
Guys,
Anybody had any experience with a Sequential gearbox flatshift system for a CAR not bike.
I've found plenty that do bike engines but the few for cars are REAL expensive.
Need a cheaper solution that is known to work?
Cheers
Tigger
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lsdweb
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posted on 30/1/08 at 08:34 AM |
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Tigger
What's stopping you using a bike one? Can't the parameters be adjusted for the different rev ranges?
I know it's drastic but you could use a different ECU that has a built in flat shift facility!
Wyn
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novacaine
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posted on 30/1/08 at 08:36 AM |
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sequential dog engagement gearbox avaliable from quaife but are definitley not cheap, (over £2k)
IIRC bike gearboxes are sequential dog engagement as standard to you can get away with flat shifting them
basicaly synchromeshes dont like to like to work fast
And you run and you run to catch up with the sun but its sinking, Racing around to come up behind you again, the sun is the same in a relative way but
your older, shorter of breath and one day closer to death
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coozer
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posted on 30/1/08 at 08:44 AM |
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Bike boxes are non sequential and normally have straight cut gears, with the gear reduction from the clutch drum they get a bit easier life.
1972 V8 Jago
1980 Z750
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novacaine
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posted on 30/1/08 at 08:51 AM |
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quote: Originally posted by coozer
Bike boxes are non sequential and normally have straight cut gears, with the gear reduction from the clutch drum they get a bit easier life.
surely bikes are sequential? you dont get a H-Gate gearlever on a bike, i might be wrong thought...
And you run and you run to catch up with the sun but its sinking, Racing around to come up behind you again, the sun is the same in a relative way but
your older, shorter of breath and one day closer to death
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sucksqueezebangblow
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posted on 30/1/08 at 09:26 AM |
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Yes, bike 'boxes are sequential. Hence you can do clutchless gearchanges if they are not under load. For example when going for it at full chat
on my 'Busa the exceleration forces are so great that I cannot release my grip in the bar to grab the clutch however by snapping the throttle
off then on again while applying pressure to the gear lever I can get a really quick change and stay 'on it'.
Same principle for car sequentials so long as the linkage allows you to apply sufficient force to make the change. Flappy paddles are probably a bit
more of an issue as you probably need powered actuators to make the change otherwise the paddles will probably be to stiff.
Better to Burnout than to Fade Away JET METAL ~ AndySparrow ©
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Jubal
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posted on 30/1/08 at 10:26 AM |
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I drove a mate's ex Clio Cup race car last week. It has a sequential box with ignition cut for clutchless flat shfting. On the downshift it
needs the clutch. However, it's not cheap. Made by Sadev if I remember correctly. There's a company that sells/refurbs them:
http://www.swrmotorsport.com/main/6_speed_sequential.htm
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bimbleuk
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posted on 30/1/08 at 11:12 AM |
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OMEX ECUs have the feature at least the 600 and 710 do. Not clutchless though just keep your foot planted and when you de-clutch a sensor on the pedal
signals the ECU to back off the timing. I've not used it on my car but I have driven the OMEX CEC Striker with it enabled.
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lsdweb
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posted on 30/1/08 at 12:43 PM |
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quote:
OMEX ECUs have the feature at least the 600 and 710 do. Not clutchless though just keep your foot planted and when you de-clutch a sensor on the pedal
signals the ECU to back off the timing.
And the Emerald K3 ECU - I'm going to use it on my single seater (BEC though).
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jono_misfit
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posted on 30/1/08 at 03:12 PM |
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A power break to unload the dogs is the key bit otherwise you stand a good chance of knakering the retention tip and it'll stop holding the gear
in.
On upshift cutting the spark or dipping the clutch breaks provides the unload.
On downshifts you can do the same with a throttle blip applied when shifting (actuated shifting).
If you want a really cheap and home made version of a spark cut for a non-actuated shift, you could always fit a sensor on the shift lever through an
on latched micro timer and a solid state relay for spark cutting.
Work out how long your slowest shift takes and set the timer to say 20ms longer than this. When you pull the lever the timer circuit will cut the
spark and connected it back after you've released the lever and made the gear.
I wont be lightest or foolproof though.
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coozer
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posted on 30/1/08 at 04:46 PM |
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Sorry chaps was looking at a blonde in the office and had a moment.... Doh!
What I meant was syncromesh! No syncromesh on bike!
Bugger!
1972 V8 Jago
1980 Z750
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grazo
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posted on 25/6/14 at 01:41 PM |
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Very old thread i know, Flatshifter in the uk do clutchless up and down gearshift systems for any vehicle using a sequential gearbox ie Hewland Sadev,
Elite, Quaife etc etc as well as bike engines.www.flatshifter.com
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