Driving a bike engined car
Discussion
Hi All,
a few questions... I hope this isnt going over old ground too much.
Having never driven a BEC, and having failed to persuade anyone to let me have a test drive, I have a few questions regarding the experience:
1) when do you and when dont you need to use the clutch?
2) how are they for creeping in say traffic?
3) how are they when parking and doing 3 point turns?
4) is there any need to heel and toe? is it as easy as with a car engine?
Much obliged
jaker
a few questions... I hope this isnt going over old ground too much.
Having never driven a BEC, and having failed to persuade anyone to let me have a test drive, I have a few questions regarding the experience:
1) when do you and when dont you need to use the clutch?
2) how are they for creeping in say traffic?
3) how are they when parking and doing 3 point turns?
4) is there any need to heel and toe? is it as easy as with a car engine?
Much obliged
jaker
jaker said:
Hi All,
a few questions... I hope this isnt going over old ground too much.
Having never driven a BEC, and having failed to persuade anyone to let me have a test drive, I have a few questions regarding the experience:
1) when do you and when dont you need to use the clutch?
2) how are they for creeping in say traffic?
3) how are they when parking and doing 3 point turns?
4) is there any need to heel and toe? is it as easy as with a car engine?
Much obliged
jaker
1) I use the clutch to pull off, change between 1st and second when going steady, and to change down.
2) fine, but the constant dragging of the clutch will wear it out quicker.
3) depends if you have a reverse box or not
if the car is light enough push it, my car is about 450kgs and is easy to manouver on my own. 4) if your driving style requires the use of heel and toe then try it, dont forget the bike engine is very revvy and has a very light flywheel and such has little engine inertia so matching gear speeds is less of a neccesity than a heavy car engine. when changing down i just snick it into gear and drop the clutch with the blink of an eye, so quick you would swear i didnt use the clutch!
Get one, or better still buy mine
Very good, only downside would be the cycle wing brackets but on a car like that it seems to be a problem area. I saw a Westfield system that looked stronger and neater but it wont fit my uprights.
Mine needs a little tidying before its sold (in progress) but chassis is strong and handling superb. Its essentially a track car but i have my fun on weekends
but the bike has taken over and it has to go
Mine needs a little tidying before its sold (in progress) but chassis is strong and handling superb. Its essentially a track car but i have my fun on weekends
but the bike has taken over and it has to go Mikey G said:I do the same.
QUESTION
1) when do you and when dont you need to use the clutch?
ANSWER
1) I use the clutch to pull off, change between 1st and second when going steady, and to change down.
But just be aware that, regardless of how smooth it sounds, if you haven't got a ProShift or similar you're shortening the life of the gearbox.
3) how are they when parking and doing 3 point turns?
A 3 point turn in a Westie XTR2 is a bit of a joke, and they have the turning circle of an aircraft carrier. However a little bit of right-foot gets you around much quicker.
Kiwi XTR2 said:
But just be aware that, regardless of how smooth it sounds, if you haven't got a ProShift or similar you're shortening the life of the gearbox.
Why do you think this? I'm still building my bec so haven't driven one yet but have been riding bikes for years and have been doing clutchless upshifts pretty much all that time (not every shift you understand but regularly on every bike including the 20k miles I've put on my blade).
All a pro-shift type thing does is cut the power shortly before shifting up and you can achieve exactly the same thing by putting light pressure on the shifter and then backing off on the throttle momentarily which unloads the box and the light pressure on the shifter moves it up a gear. Obviously timing is everything but you can get these changes pretty smooth and they shouldn't cause the box any particular stress or wear.
Caveats to that are that a bike has a rubber cushdrive in the back wheel and if you don't have the same thing in your driveline then you will cause more shocks to go through the system and secondly, if it sounds like a harsh change then it is.
Looking forward to trying these techniques out in my car.
Regards,
Mark
>> Edited by dern on Monday 1st August 10:09
dern said:Your technique might be much better than mine (which would not be too hard to do
But just be aware that, regardless of how smooth it sounds, if you haven't got a ProShift or similar you're shortening the life of the gearbox.
Why do you think this?
) Every graph I've seen of the loads comparing clutchless changes seems to tell the same story.
And there are quite a few stories of people "knocking their dogs off"
Regardless . . . clutchless changes are fun and I'll put up with the re-build cycle
Kiwi XTR2 said:
Your technique might be much better than mine (which would not be too hard to do
Every graph I've seen of the loads comparing clutchless changes seems to tell the same story.
And there are quite a few stories of people "knocking their dogs off"
Regardless . . . clutchless changes are fun and I'll put up with the re-build cycle
For future reference, is it relatively easy to get hold of the gearbox parts?
Another question I keep meaning to ask is that on a bike you have two throttle cables, one to open and one to close. It has a spring to close the throttle but by rolling the wrist sharply forward you can close the throttle much more quickly. Do you have the same on a bec (I'm still in the process of building my chassis so haven't got that far yet)? The reason I'm wondering is that maybe this is why clutchless changes are more difficult to get smooth in a bec rather than on a bike.
Regards,
Mark
>> Edited by dern on Tuesday 2nd August 09:35
I only have a single cable and a second, stronger spring to close the throttle.
Clutchless up shifts are pretty easy in a BEC but you need to make sure you have a trt or some other form of shock absorbing device in the prop shaft. They are much smoother when you're driving at least at 60%, if you're driving through town at modest speed then it's usually smoother and easier to use the clutch but different engines have different gearboxes.
You need also to make sure the throttle bodies are balanced and the engine is running well. This makes a big difference.
New gearbox parts are easily available, any bike dealer can get them for you but they are not cheap.
Clutchless up shifts are pretty easy in a BEC but you need to make sure you have a trt or some other form of shock absorbing device in the prop shaft. They are much smoother when you're driving at least at 60%, if you're driving through town at modest speed then it's usually smoother and easier to use the clutch but different engines have different gearboxes.
You need also to make sure the throttle bodies are balanced and the engine is running well. This makes a big difference.
New gearbox parts are easily available, any bike dealer can get them for you but they are not cheap.
busa_rush said:
I only have a single cable and a second, stronger spring to close the throttle.
Clutchless up shifts are pretty easy in a BEC but you need to make sure you have a trt or some other form of shock absorbing device in the prop
I've only been driving my car for about 2 months and I and still can't get the changes right but when I do its really smooth with the light pressure on the gearstick and backoff on the clutch method.The 1st to 2nd change is the biggest problem i've found,ive had some big nasty clunks on that one and also some high revving oops i've found neutral.
I also have only a single cable but use a standard spring (will this cause a problem). I'm also have a lot of noise (gear chatter) when running at a constant speed but i have a solid propshaft running to my reverse box (quaife) and then another solid prop to my axle.Is there something available that will fix(reduce) the noise (whats a trt [thick rubber thing?]). I was thinging of trying to make something up to fix it but I haven't spent any time trying to resolve it whilst the weathers good but any ideas would be good.
A trt is a torque resilient tube (can't remember the exact name, think that's right) but it's basically two tubes, one inserted into the other with a roll of rubber between them. One tube conencts to the engine and the other to the reverse box and the rubber absorbs some of the shock when you change gear.
You probably already have one as without it (or a rubber doughnut looking object, does a similar job) the shock will eventually danage the gearbox and the diff. The reverse box should be OK if it's a Quaife or similar.
They all clunk a bit because they are dog boxes without synchrmesh and any backlash or slippiness in the drive will make it worse. My LSD and the reverse box make the gearchange sound far worse and it does clunk a lot.
Enjoy it and fix it when it breaks !
You probably already have one as without it (or a rubber doughnut looking object, does a similar job) the shock will eventually danage the gearbox and the diff. The reverse box should be OK if it's a Quaife or similar.
They all clunk a bit because they are dog boxes without synchrmesh and any backlash or slippiness in the drive will make it worse. My LSD and the reverse box make the gearchange sound far worse and it does clunk a lot.
Enjoy it and fix it when it breaks !
jaker said:
I am getting DANGEROUSLY close to taking the plunge and speccing up my BEC... spending all the money I have and loads I dont have
Anyone got any recommendations (of any kind) for what I should/shouldn't go for?
ta...
Hayabusa engine in a fisher fury. They cut throught he air *much* better than a 7 although there are some interesting non-7's about, like the GT1 (GT 2 ??) that Jon is possibly pointing you towards.
What I would do if I did mine again is to buy a second hand car with a knackered x-flow or pinto engine, throw away the engine and fit a bike engine. You can ignore SVA as it won't need one, if it had a x-flow or old pinto you can probably ignore emissions testing for the MOT and you'll get all the bits you need for less than cost.
I'd look for a x-flow fury with a live rear axle and good quality gel coat, well built and swap the engine for an R1 or busa.
I was thinking more "indy" some great examples out there at reasonable costs 2nd hand or MK do offer turn key cars too. Worth a look that's all.
They have just built an "auto" 7, (turnnkey indy) with hand brake and throttle control for a disabled enthusiast, all the other manufacturers he contacted declined too build one for him, that's service for you.
They have just built an "auto" 7, (turnnkey indy) with hand brake and throttle control for a disabled enthusiast, all the other manufacturers he contacted declined too build one for him, that's service for you.
Some cheap Fury's here . . . couple are tax free too
http://ekmpowershop.com/ekmps/shops/GTIRMAN/index.asp?function=DISPLAYCAT&catid=1
I would think many kits would be difficult to adapt to an auto gearbox, mounting points, tunnel size etc. If I wanted an auto and couldn't do it myself I'd have a chat with somebody like the Kit Car Workshop.
http://ekmpowershop.com/ekmps/shops/GTIRMAN/index.asp?function=DISPLAYCAT&catid=1
I would think many kits would be difficult to adapt to an auto gearbox, mounting points, tunnel size etc. If I wanted an auto and couldn't do it myself I'd have a chat with somebody like the Kit Car Workshop.
cheers for the info guys, keep it coming...
The ground clearance on that MK looks about 3mm
, but I know it is cornering hard.
at the moment, the winner is:
www.stuart-taylor.co.uk/phoenix.html
with R1 power...
the spec I want (need??) is gonna make it £20k+ for a factory built car.
The ground clearance on that MK looks about 3mm
, but I know it is cornering hard. at the moment, the winner is:
www.stuart-taylor.co.uk/phoenix.html
with R1 power...
the spec I want (need??) is gonna make it £20k+ for a factory built car.
Kiwi XTR2 said:
But just be aware that, regardless of how smooth it sounds, if you haven't got a ProShift or similar you're shortening the life of the gearbox.
I'm also getting used to my new Honda CBR Powered Striker and finding a smooth gear change difficult. Under strong acceleration is real easy, but at anything less its rather clunky. Can't say I've had much expericance at using a bike engine, so maybe I just need to stick with it!
However your comment about the "Proshift" has got me thinking, as I've recently seen one advertised. How exactly do they work, and are they easiy to retrofit?
From what you are saying, they seem to be an essential purchase - correct?
Phil
pdw709 said:
From what you are saying, they seem to be an essential purchase - correct?
Phil
No, by ProShift I guess Kiwi means a device to change gear for you. Hardly anybody uses these in the UK and those that do are mainly on drag bikes. They are difficult to set up properly, often mean disconnecting the manual gear linkage and if (when) they go wrong or out of adjustment can ruin the gearbox/engine in double quick time.
They work by cutting the spark for a few milliseconds then banging the gearchange lever to make it change gear - your foot stays fully at 100% on the gas and when they work well you can't hear a gearchange, just a change in engine note.
Having said that, I quite fancy trying one.
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