Having raced a bike engined car for a few seasons I find the sequential box has a few big advantages for me; the first is the speed which you can go up and down the box, there is the ease of use (up or back) and the clutchless shifts freeing up the left foot.

For road racing braking with your left foot is an advantage but there is also the left foot braking (rally technique). I often get asked how I manage such high corner speeds. While trail braking accounts for most of the corner entry, the last bit comes from preloading the throttle (after I'm done with the heel and toe downshift) preloading the throttle ever so slightly gets the rear of the car to squat without unloading the front. I manage this now but it's a lot easier to do with one foot on the brake and one on the gas.

End of the day while I can do whole double declutch heel toe downshifts all day long, I'd rather have the faster and easier sequential/bike transmission.

Tom

Tom can this be a goer? heavy duty 1200cc BMW cruiser
http://www.ebay.com/itm/99-00-01-02-0 ... :~08AAOSw5VFWHRyq&vxp=mtr

http://www.motorcyclespecs.co.za/model/bmw/BMW_K1200LT%2099.htm

my old 1997-99 owned 1000 1966 model was 596kg at weigh bridge with no bumpers just alloy bumperettes, 5kg agm battery, stock A10 running gear, no tar, no spare wheel and doors gutted of winding mechanism using landrover window sliding glass kit. It went to a guy named Darren who doesnt get online but spotted on the hume hwy sometimes near Albury.
Stock B20 utes are confirmed under 600kg by another member Richard and myself and without
heavy tailgate probably another 20kg less again!

Now some race 1200s from NZ got down to 590ks so I figure with all alloy engine and similar weight gearbox as the A series 56a should get down another 20-25kg down in weight to 570kg.
Also removing front leaf replace with billet alloy coilovers -10kg and lexan glass another perhaps another 5kg but picking at straws now!

560kg is possible for a 1000 vs wet k1200LT 378kg wet plus loaded with panniers + 50-60kg
Theres only 150-200kg difference which is similar to locost and other lotus 7 copies with bike engines that far from struggle with bike boxes.

Maybe when one considers getting a base gearbox overhauling it and then modifying it and finding a Nismo gearset etc ect this would end up being a better option.http://www.saenztransmissioneurope.com/data.html
Saenz Transmissions are pretty good and cost effective because unlike the linked page which is the sales and service outlet the Transmissions can be more cost effective because they are made in Argentina, Argentina is not a backward place when it comes to some not well known but surprisingly good quality KIt one of their say TT3 series transmissions just may end up a cost effective option.

I didn't even know that there was a motorbike came with a reverse gear.

Pretty interesting find but what about the ratios.
Your link says the gear ratios are
1st 2.050 / 2nd 1.600 / 3rd 1.270 / 4th 0.960 / 5th 0.700:1

The engine torque is the same as a standard A15 but as you guys have said the extra weight could be the issue with the cluth and gearbox itself.

How have cars running the likes of hayabusa's handled the extra weight?

use 4.675 or 4.8 ratio and let the revvs do the rest :)

look at some vids of a 1200 coupe with busa
https://www.youtube.com/results?search_query=datsun+hayabusa

coxsteve, argentina is full of german engineers from ww2 so
quality control there is as good as it gets if not the best.

After looking at the ratios on wiki they are quite similar to the Competition Ultra Close Ratio box.
Will be quite tuff on the clutch off the mark because 1st is almost the same ratio as 2nd on a 56A 4 speed. Like you said the 4.8 will help though.

I do remember hearing a rumor that the Reg Cook Shellsport Cherry in NZ did run a motorbike box for some time. Whether that is true or not I'm not sure.

Just had a look at this video of replacing a clutch on one of these BMW's and it is a very different set up compared to what we are use to.
https://www.youtube.com/watch?v=BcXbHxSj3sI

any of my 76 bore A12, stock A14 and 15 through the years would take off without a hitch from 2nd gear and 4.11 rear. Using a 4.8 will make it even easier.

That clutch replacement is on the back of the engine not the gearbox, the gearbox bolts up to this with the input shaft but a stock A series clutch could be used with the deep male shaped spline to suit bmw input spline much like the T50 conversions.

spline from BMW to use on A series clutch
http://i165.photobucket.com/albums/u6 ... ods%20Apr-09/IMG_1486.jpg

The only issue is designing a bellhousing and this is interesting as the BMW input shaft and engine unitary bellhousing is very shallow, therefore only a shallow bellhousing would need to be made which will save on billet.

you can get a better idea on this link

http://www.bmwlt.com/forums/k1200lt/4 ... lacement-help-needed.html

also k1600 or 1.6 180hp engine with 129lbs of torque also uses the same kind of gearbox
thats alot of power and torque is astronomical more like a 2000cc modern engine.

It would look something like this



or in steel using 2 water/laser jets steel pieces and steel tubing



The starter could be incorporated as original not in the box like bmw uses
and original bmw starter and side mount angle grinded off :)
bmw box has mounts at the bottom so no probs about mounts but some mounts
on the custom bellhousing would also help

eg

Attach file:

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  bmw engine for seq gearbox output shaft.jpg (154.75 KB)

Steve I have looked at Saenz boxes before; used sequential boxes come up in the $3500 range from time to time.

D check the rotation direction on the BMW boxes I seem recall that being an issue, I just can't remember what the issue was though.

Tom

hope rotation is not an issue as that was usually a honda thing
and at worst can always flip the differential as done by many locost owners

for USD $500 for a strong sequential box that doesnt incorporate the clutch
mechanism and has reverse gear is worth further investigation.

Looks to me that the engine rotation is the same as the A Series (clockwise looking at the front) and the differential on the bike is the same as our Datsun diffs.

http://www.locostusa.com/forums/viewtopic.php?f=10&t=12439

Looking at the weights of Locosts being on average 600ish-kg and a lot of them getting larger motorcycle engine/gearbox combos. There are quite a few Toyota Starlets and other smaller cars in NZ running Hayabusa's in ralling cars but my friend seems to think a few of then are having problems with gearboxes.