Working out a BEC project, several questions so far.
Discussion
Toltec said:
Yeah, weird but fun nonetheless.Indeed the deltawing is a great technical feat, there is some info out therr about it, but i think resdesigning a complete frond end is a bit above my capacities
I have a ZZR1400 in a formula 27 (yellow one below). It's a fantastic engine, but my Achilles heal is the diff. Due to having an English Axle the best I can have is 3.54, which tops out around 125 with 195-50-15 wheels. The constant gear changes get a bit annoying... I used to have a 3.89 in it, which was horrendous. Ideally I'd like a 3.2 but 3.54 is the best I can get without changing the whole rear end. Good luck, sounds nuts!
Edited by ol on Tuesday 9th February 07:03
Nice ride. Was it converted later on to bike power ?
What RPM are you reaching at the 125 mph mark ?
Sounds like I do need to be above 3:1 with the small tyres i'll be having to use. Obviously i won't be reaching max speed but with a ZZR1400 there should be enough torque to get good acceleration and keep revs down a bit, even with a high ratio diff
My R1 bug with 2,78:1 I got to 120mph (GPS calibrated speedo healer) and i was around 10000 rpm
What RPM are you reaching at the 125 mph mark ?
Sounds like I do need to be above 3:1 with the small tyres i'll be having to use. Obviously i won't be reaching max speed but with a ZZR1400 there should be enough torque to get good acceleration and keep revs down a bit, even with a high ratio diff
My R1 bug with 2,78:1 I got to 120mph (GPS calibrated speedo healer) and i was around 10000 rpm
Edited by Reliant on Tuesday 9th February 16:56
Reliant, there has to be something wrong with those figures, even with the small wheels if you actually had a 2.78 diff I can't see any way you'd be doing 7000rpm at 80mph.
The gearing on an R1 wouldn't be more than around 10% lower Than the ZZR1400 (ignore the multiplier b4 the gearbox, for the purposes of these comparisons it is completely irrelevant), your tyres have a circumference of 1752mm, mine have 2049, so to compare the 2, IF your diff was a 2.78:1 then I would expect the rpm at 80mph to be somewhere around 4750 x 80/70 x 2.78/3.28 x 2049/1752 x 1.1 = 5919, so around 6000rpm would sound about right, to be doing 7000rpm your diff would be 3.3 or thereabouts
2.78 sounds very low (as in high geared) for a diff ratio, what axle was that diff from?
Either way to get something below or around 5000rpm at 80 mph you are going to need a diff ratio of around 2.5:1 by my reckoning, so one of the BMW diesel diffs you mentioned earlier in the thread would be about right, given the substantially lighter weight I can assure the ZZR1400 will pull that without any problem
The gearing on an R1 wouldn't be more than around 10% lower Than the ZZR1400 (ignore the multiplier b4 the gearbox, for the purposes of these comparisons it is completely irrelevant), your tyres have a circumference of 1752mm, mine have 2049, so to compare the 2, IF your diff was a 2.78:1 then I would expect the rpm at 80mph to be somewhere around 4750 x 80/70 x 2.78/3.28 x 2049/1752 x 1.1 = 5919, so around 6000rpm would sound about right, to be doing 7000rpm your diff would be 3.3 or thereabouts
2.78 sounds very low (as in high geared) for a diff ratio, what axle was that diff from?
Either way to get something below or around 5000rpm at 80 mph you are going to need a diff ratio of around 2.5:1 by my reckoning, so one of the BMW diesel diffs you mentioned earlier in the thread would be about right, given the substantially lighter weight I can assure the ZZR1400 will pull that without any problem
PM sent...
I have a an excel spreadsheet that you will find very helpful.
You key in the tyre size, differential ratio and engine gearing data and it shows speed vs rpm in each gear.
If anyone else wants it, feel free to contact me.
Reliant,
Bit of an extreme chance, but I passed a sorry looking bond bug on a trailer last year, going south bound on the A34 near Newbury (actually Tot Hill services).
If that was you, then
. I'm fairly sure you'd remember if it was you as I was in my trike at the time - there aren't many of us around who prefer three wheels to four.
I have a an excel spreadsheet that you will find very helpful.
You key in the tyre size, differential ratio and engine gearing data and it shows speed vs rpm in each gear.
If anyone else wants it, feel free to contact me.
Reliant,
Bit of an extreme chance, but I passed a sorry looking bond bug on a trailer last year, going south bound on the A34 near Newbury (actually Tot Hill services).
If that was you, then
. I'm fairly sure you'd remember if it was you as I was in my trike at the time - there aren't many of us around who prefer three wheels to four.Hi
Thank you both for your input.
I may have figures badly recorded in my head, maybe indeed it was lower @ 80mph
But the diff indeed was 2.78:1, the guy kept the Bond Bug specific half drives of the axle, and slipped them onto a diff casing from a 1984 Reliant Rialto "eco", that was fitted with a low torque tuned engine to pull the Reliant made 2,78:1 diff specific to this version.
I have no doubt the zzr1400 will pull a tall geared diff, seeing how the R1 performed. The compromise in my case, is to find the right balance between comfortable engine noise and acceleration.
With a higher diff, theoretical top speed will be higher, but it's not much of a concern if I can't reach it as long as acceleration is still in the near lethal zone
thanks for the excel sheet, i will look into it. And nope that wasn't my bug on the trailer.
Thank you both for your input.
I may have figures badly recorded in my head, maybe indeed it was lower @ 80mph
But the diff indeed was 2.78:1, the guy kept the Bond Bug specific half drives of the axle, and slipped them onto a diff casing from a 1984 Reliant Rialto "eco", that was fitted with a low torque tuned engine to pull the Reliant made 2,78:1 diff specific to this version.
I have no doubt the zzr1400 will pull a tall geared diff, seeing how the R1 performed. The compromise in my case, is to find the right balance between comfortable engine noise and acceleration.
With a higher diff, theoretical top speed will be higher, but it's not much of a concern if I can't reach it as long as acceleration is still in the near lethal zone
thanks for the excel sheet, i will look into it. And nope that wasn't my bug on the trailer.
Edited by Reliant on Friday 19th February 21:14
I use a 3.38:1 Sierra diff in my Fury R1, which is perfect in my view.
I can just get to 60mph in 1st and just get to 100mp in 3rd. Top speed is just over 130mph.
Lots of detail on the transmission design here:
http://www.robcollingridge.com/kitcar/design/trans...
Also includes a spreadsheet to work out speeds in given gears with other engines, etc.
http://www.robcollingridge.com/kitcar/design/trans...
Rob
I can just get to 60mph in 1st and just get to 100mp in 3rd. Top speed is just over 130mph.
Lots of detail on the transmission design here:
http://www.robcollingridge.com/kitcar/design/trans...
Also includes a spreadsheet to work out speeds in given gears with other engines, etc.
http://www.robcollingridge.com/kitcar/design/trans...
Rob
At the risk of sounding boring, why don't you use a lazier engine out of a touring bike, instead of an all out performance engine from a suberbike? This should help give you a more refined cruising speed.
Ive seen one or two bond bugs with k1100 engines in. Beauty with these is they are already shaft drive, so you can hook it straight up to a diff without too much messing around.
Ive seen one or two bond bugs with k1100 engines in. Beauty with these is they are already shaft drive, so you can hook it straight up to a diff without too much messing around.
I remember seeing a photo in progress of a bond bug with a boxer BMW engine, but no evidence of it finished. Was some years ago now.
Checking the specs, the K1100 is basically a 955i Tiger engine as far as output/torque/rpm goes.
But never having seen one, not sure how the flat 4 sits as far as engine bay clearance goes
I've seen a ZX12R with less than 5000 on the clock (full new engine exchange at the dealers, invoices etc to prove it). Price is good, so looks like i'll be using a smaller lump (although the torque/rpm is the same as the first ZZR1400).
I get what you mean by more subtle with a GT bike, but I would rather have a sportier engine seeing that I'll be massaging the chassis setup to make more out of the bike engine than my previous R1 bug
Checking the specs, the K1100 is basically a 955i Tiger engine as far as output/torque/rpm goes.
But never having seen one, not sure how the flat 4 sits as far as engine bay clearance goes
I've seen a ZX12R with less than 5000 on the clock (full new engine exchange at the dealers, invoices etc to prove it). Price is good, so looks like i'll be using a smaller lump (although the torque/rpm is the same as the first ZZR1400).
I get what you mean by more subtle with a GT bike, but I would rather have a sportier engine seeing that I'll be massaging the chassis setup to make more out of the bike engine than my previous R1 bug
Edited by Reliant on Friday 25th March 21:54
Edited by Reliant on Friday 25th March 22:02
Ah indeed, you must be talking about this one :
http://aasilencers.co.uk/blog/tag/reliant-robin
?
I found that car via a google search some time ago, description sounds promising in the blog but not much visual details of any setup.
Need to see if i can reach him directly. His front end setup sounds good, i think it would be good to have a look at thatw the factory setup is a bit flimsy
http://aasilencers.co.uk/blog/tag/reliant-robin
?
I found that car via a google search some time ago, description sounds promising in the blog but not much visual details of any setup.
Need to see if i can reach him directly. His front end setup sounds good, i think it would be good to have a look at thatw the factory setup is a bit flimsy
Hey
Small update, nothing fancy, but i have a few more questions.
Here is a photo of the BMW rear axle frame, as you can see, in itself it is much wider than the Bug chassis, but still easily useable, i think :
After several measures, it turns out the outer mounting point for the BMW A-arm clears (beyond) the chassis rail, and the arm member itself runs parallel outside the rail, thus clearing it (and avoiding having to chop up and rebuild the upper member where the shocks fit and body rests)
Full bmw setup :
With that in mind, i was thinking of :
- working out the tyre diameter i'll be planning to use, and making mockup wood blocks to mimick the tyre height, thus setting the hub (and therefore diff) height.
That would :
- allow me to work out the trailing arm angle in relation to the mounting points on the rear bmw frame.
I'm thinking of using the same angle as the OE bug trailing arms ? Should pretty much put me in the correct setup as far as diff/hub/shock travel (and therefore wheel travel) goes ?
My idea is to notch the top of the Bug rails in order to "sink" the BMW frame member into them, based on the wheel height, bug trailing arms angle, and OE wheelbase.
Any thoughts on my theory ?
Thanks !
Small update, nothing fancy, but i have a few more questions.
Here is a photo of the BMW rear axle frame, as you can see, in itself it is much wider than the Bug chassis, but still easily useable, i think :
After several measures, it turns out the outer mounting point for the BMW A-arm clears (beyond) the chassis rail, and the arm member itself runs parallel outside the rail, thus clearing it (and avoiding having to chop up and rebuild the upper member where the shocks fit and body rests)
Full bmw setup :
With that in mind, i was thinking of :
- working out the tyre diameter i'll be planning to use, and making mockup wood blocks to mimick the tyre height, thus setting the hub (and therefore diff) height.
That would :
- allow me to work out the trailing arm angle in relation to the mounting points on the rear bmw frame.
I'm thinking of using the same angle as the OE bug trailing arms ? Should pretty much put me in the correct setup as far as diff/hub/shock travel (and therefore wheel travel) goes ?
My idea is to notch the top of the Bug rails in order to "sink" the BMW frame member into them, based on the wheel height, bug trailing arms angle, and OE wheelbase.
Any thoughts on my theory ?
Thanks !
The BMW axle slipped in pretty well, as you can see the trailing arms are just right alongside the outer flank of the chassis rails
9 inch Gotti rims originally from a R5 Turbo2
Track is now 175 cm (originally 123)
Its almost an equal sided triangle
9 inch Gotti rims originally from a R5 Turbo2
Track is now 175 cm (originally 123)
Its almost an equal sided triangle
Edited by Reliant on Wednesday 25th July 11:29
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