Kit car show Donnington - Views
Discussion
quote:
Hi all
Just for information I own a butchers shop and have just had a phone call saying some-one was slagging martin of MK off on the internet.Fraid as an MK indy owner I have to disagree with some of your comments.If you had spoken to any of the lads on the stand they would have told you they were hoping to get the car SVA'd by donnington but had a bad batch of head lamp pods that weren't upto standard.the chain drive might look fragile but my son was taken out in the car as a present prior to going in the R.E.M.E and was most impressed 11500 RPM.if you looked carefully at the drive set up you would have noticed the split rear sprocket which enables quickchanges of gearing.any way enough where all entitled to our opinion and really what the F~## do you want for 3500 quid.
tony
These opnions were all my own opinion stating that I was very disappointed in the MK. Which I still stand by. Saying it was just the lights that the car isn't SVA'd really just insults my intellegence. I presume you have seen the car as I have and theres a lot more work to be done than simply fitting lights to get that car through the SVA. (for example the instruments as they stand would fail)
The drive train does look fragile, it may work round the track for a few laps but IMO it wouldn't last for long on the public highway. A BEC has a lot of weight to pull from stationary and that puts a lot of strain on the chain and sprockets. Track cars spend very little time stationary but road cars do it all the time. I wouldn't be surprised with the sytem I saw if the chain or sprocket broke in the pulling away motion, this is very common with racing sidecar outfits. Of course as I stated in my first post this is IMHO.
£3500 is a lot of money for a basic chassis bodywork kit with suspension arms. May I suggest you look at Westfield, and Dax at their kit prices and what they contain for a similar price.
I believe that the post I did first was fair and reasonable. I never as you have implied actually insulted anyone (or slagged Martin off, as you put it)but made comments on the car I saw. Notice I also stated how good I thought their chassis for the other cars were and critised other manufacturers.
Hmm I think you're being a little harsh on a car that is essentially a prototype. It ain't going to be road legal for some time I suspect. But as with the XTR2, I see no reason why it could not be made legal. Quite why anyone would bother is another matter but then that's just my point of view on these types of car.
FWIW I am watching it's progress with great interest (as a track car, not a road car). At the moment it's a tad heavy as the chassis is way over engineered though I believe the MK guys are sorting this. Also it's only running a Fireblade engine though this is more down to cost than anything else. But even still it seems to be going quite well.
Chain drives may look fragile but they are incredibly strong (IIRC Radicals use them and I would be very suprised if the XTR2 wasn't driven this way also). They also offer significant advantages over a prop drive in a mid engined car. Firstly they allow the bike engine to be mounted the right way around which is better for weight distribution and the oil system. It also allows for quick changing of ratios for different circuits. Finally the Quaife LSD they use, IIRC is the same that is used in the Radicals so has been tried and tested in a racing environment (more proof that chain drive isn't fragile).
Give them a chance. This is an attempt at making a budget mid engined track car from scratch by a company who have not been building and racing very, very expensive cars of this format for ages like Radical have and do not have the cash to buy a design from someone else to work from as Westfield did. Personally I think it's very brave of them and if they can get the weight down low enough I think they might have a cracker on thier hands.
FWIW I am watching it's progress with great interest (as a track car, not a road car). At the moment it's a tad heavy as the chassis is way over engineered though I believe the MK guys are sorting this. Also it's only running a Fireblade engine though this is more down to cost than anything else. But even still it seems to be going quite well.
Chain drives may look fragile but they are incredibly strong (IIRC Radicals use them and I would be very suprised if the XTR2 wasn't driven this way also). They also offer significant advantages over a prop drive in a mid engined car. Firstly they allow the bike engine to be mounted the right way around which is better for weight distribution and the oil system. It also allows for quick changing of ratios for different circuits. Finally the Quaife LSD they use, IIRC is the same that is used in the Radicals so has been tried and tested in a racing environment (more proof that chain drive isn't fragile).
Give them a chance. This is an attempt at making a budget mid engined track car from scratch by a company who have not been building and racing very, very expensive cars of this format for ages like Radical have and do not have the cash to buy a design from someone else to work from as Westfield did. Personally I think it's very brave of them and if they can get the weight down low enough I think they might have a cracker on thier hands.
At the moment Radicals don't use chaindrive. They use the Powertec drive and dif system. I don't know what they used in the past.
At the moment Westfield's XTR2 uses a chaindrive.
I have some pictures but I don't know how to attach them to this message.
If somebody wants them I can mail them.
At the moment Westfield's XTR2 uses a chaindrive.
I have some pictures but I don't know how to attach them to this message.
If somebody wants them I can mail them.
quote:
Chain drives may look fragile but they are incredibly strong (IIRC Radicals use them and I would be very suprised if the XTR2 wasn't driven this way also). They also offer significant advantages over a prop drive in a mid engined car. Firstly they allow the bike engine to be mounted the right way around which is better for weight distribution and the oil system. It also allows for quick changing of ratios for different circuits. Finally the Quaife LSD they use, IIRC is the same that is used in the Radicals so has been tried and tested in a racing environment (more proof that chain drive isn't fragile).
Might be worth just posting it here!! 
On eth BEC oil front I would personally dry sump it no matter which way round the end is. On a bike it tilts into the corner so the oil stays level relative to the sump. (like water in a bucket swung round your head)
In the car the engine remains level whilst the oil goes from side to side. I believe a lot of the first BEC had problems of this type when testing for a long time.
Chain drive can be strong but the comment was more on how it was done on the MK, for example the t5 development car had chain drive but with a ratio of 1:1 going through a diff. The mk went from small gear to large gear (no I didn't count the teeth so I don't know the ratio). t5 pointed out that you would do 20 minutes track time in the morning adjust the tesion and then 20mins in the afternoon. That and the fact that most heavy bikes (eg honda goldwing, BMW K1300, etc.) are prop driven, is why I'm a little sceptical about chain drive.
I don't think I have been unfair on the MK. I was discussing the MK with someone via email and pointed out that it was a prototype then. Even considering that, theres still a lot of work to be done on what will be no doubt a good car eventually.
On eth BEC oil front I would personally dry sump it no matter which way round the end is. On a bike it tilts into the corner so the oil stays level relative to the sump. (like water in a bucket swung round your head)
In the car the engine remains level whilst the oil goes from side to side. I believe a lot of the first BEC had problems of this type when testing for a long time.
Chain drive can be strong but the comment was more on how it was done on the MK, for example the t5 development car had chain drive but with a ratio of 1:1 going through a diff. The mk went from small gear to large gear (no I didn't count the teeth so I don't know the ratio). t5 pointed out that you would do 20 minutes track time in the morning adjust the tesion and then 20mins in the afternoon. That and the fact that most heavy bikes (eg honda goldwing, BMW K1300, etc.) are prop driven, is why I'm a little sceptical about chain drive.
I don't think I have been unfair on the MK. I was discussing the MK with someone via email and pointed out that it was a prototype then. Even considering that, theres still a lot of work to be done on what will be no doubt a good car eventually.
Bike chains are very strong as if they break the rider dies!
they do however wear and need constant maintenance.
This is why large cruiser bikes end up with prop drives, they last longer and need less maintenance.
As the performance of the bike goes up so does the size of the chain, they arn't designed for the extra weight of a car but if looked after and correctly speced I would expect then to cope, just expect to replace the every 4000 miles!
they do however wear and need constant maintenance. This is why large cruiser bikes end up with prop drives, they last longer and need less maintenance.
As the performance of the bike goes up so does the size of the chain, they arn't designed for the extra weight of a car but if looked after and correctly speced I would expect then to cope, just expect to replace the every 4000 miles!
quote:
Bike chains are very strong as if they break the rider dies!
Bit OTT they lose drive thats all (equivalent to free wheeling on a pushbike). I have seen plenty of race sidecar outfits lose chains and race bikes for that matter losing drive (either through chain or gearbox) and rarely has it even caused an accident. Far worse is losing brakes or traction. I am a big fan of bike racing BTW and go regulary to Mallory or Donnington to watch the club racing. You can almost guarentee that someone in one of the races loses drive in some way. Usually ends up with hand up and coasting to the side.
quote:
This is why large cruiser bikes end up with prop drives, they last longer and need less maintenance.
As the performance of the bike goes up so does the size of the chain, they arn't designed for the extra weight of a car but if looked after and correctly speced I would expect then to cope, just expect to replace the every 4000 miles!
Exactly my thoughts except don't forget they are shorter than bikes chains meaning the chain is working harder (ie passes the through the system more than a long chain) making wear and tear even harder on the chain and sprocket. The equivalent torque to pull a BEC away would flip the bike (which riders don't try to do all the time, or at all
) again putting extra strain on the chain and sprockets. Most bike chains if looked after last 20,000 miles on a bike so I think you're probably right at 4000miles. I don't know how many miles you could do without needing to adjust it though!Smeagol is entirely right concerning the oil surge problem. The g-forces generated by a bike during cornering are centrifugal (water in bucket analogy), so the oil doesn't slop around in the sump - it is always pulled to the bottom of the sump. Those generated in a car during cornering - especially a high grip car - are horizontal. This means the oil is forced onto the side of the sump and away from the pick up, which is what causes all the problems.
There are numerous ways to combat this, but the most reliable seems to be dry sumping. This is the best guarantee that you will not have oil surge problems with BEC's.
Steve.
www.coram-automotive.com
There are numerous ways to combat this, but the most reliable seems to be dry sumping. This is the best guarantee that you will not have oil surge problems with BEC's.
Steve.
www.coram-automotive.com
quote:
Bit OTT they lose drive thats all (equivalent to free wheeling on a pushbike).
I was more thinking about the chain locking the rear wheel rather than free wheeling, race bikes aside its a consideration that a bike manufacturers have to think about.
Could be that they think a cush drive al-la bike would ruin the handling of a car?
Bike engined cars intest me but I would want to be able to do lots of worry free miles, my current understanding is "Fast but fragile"?
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