Alez
|
| posted on 26/3/12 at 10:06 PM |
|
|
Bike engine next to driver single seater Locost?
As per the thread title. Could this be done?
My reasoning is:
Q: Why not classic Locost BEC?
A: I'd like the engine to sit closer to the rear axle.
Q: But the classic Locost BEC has a really good weight distribution
A: I'd like a low moment of inertia with respect to the rear axle. 50%-50% weight distribution must be good in order to achieve good lateral
acceleration during corners, once your steering wheel is still at a certain angle. But when you are turning the steering wheel, having weight away
from the rear axle is bad. Basically because you will be trying to change the direction of this weight somewhat as you turn the front wheels. This
doesn't apply to weight placed on the rear axle simply because the rear axle goes always goes in the same direction: forward.
Q: Why not build a [link-->] MEV Atomic?
A: I don't like the [pic-->] E-W assimetry on its weight distribution. I
understand that the engine position helps placing the CoG close to the middle of the car but I think this car must brake assimetrically and it must
accelerate assimetrically (I'd like an open diff to help keep the car really light, btw).
Q: OK, then simply change the engine mounts to place the engine more to the rear
A: Because I think they got it fundamentally wrong in the first place, I think it's safer to use a proven chassis such as a Locost chassis or a
chassis designed by Jeremy Philips (Fury, Riot).
Q: Since you are ok with having one seat only, and you don't want 4wd like on the [link-->] DP Cars D series, why
not use a classic mid engine layout and get slightly better weight distribution plus central driving position?
A: I don't like the transmission solutions available for bike engined single seaters / mid engined cars. Chains need too much servicing and
other solutions are expensive and / or use too much space.
So, could this be done using a Locost / Fury chassis? After all, Fisher once put a bike engine between the seats and the rear axle of a Fury (much
bigger of a change I think), called it a [link-->] Fury Menace and said it worked
good. Or maybe a mid engine chassis like the Riot would be better? Either the case, would I be able to use the original bodywork? Or should I make the
distance between the axles shorter or move the driver position with respect to the axles, calling for major bodywork redesing?
Opinions, please 
|
|
|
|
|
jeffw
|
| posted on 27/3/12 at 04:15 AM |
|
|
The Menace had the engine alongside the driver in the passenger seat effectively.
|
|
|
iank
|
| posted on 27/3/12 at 06:51 AM |
|
|
For the Atomic the E-W weight distribution will be pretty good (person on E, engine on W) are roughly comparable. It will certainly be much better
than a 7 without a passenger.
The advantage (to my mind) is the extremely low polar inertia of that layout and the minimal weight of the thing.
Downside is one seat (obviously) and the noise in your left ear.
T66's Fiat BEC was going to use a range rover box which would be a cheap option if it works out.
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
|
|
|
Slimy38
|
| posted on 27/3/12 at 07:21 AM |
|
|
quote:
Originally posted by iankDownside is one seat (obviously) and the noise in your left ear.
Bikers have had a bike engine between their legs since the dark ages, with very few complaints! The engines themselves are quite quiet, it's
the exhaust and wind noise that are much louder. As long as you can route the exhaust to somewhere behind the driver (which I believe is an IVA thing
anyway) you should be fine.
You're right about the E-W distribution though, a bike engine weighs about the same as an average person. And from memory, for the N-S
distribution MEV put the engine slightly more forward and the driver slightly back. But moving the engine forward and backwards is quite an easy task
to be honest.
|
|
|
adithorp
|
| posted on 27/3/12 at 07:32 AM |
|
|
quote:
Originally posted by jeffw
The Menace had the engine alongside the driver in the passenger seat effectively.
...and I think, the drivers seat, pedal box and scuttle moved forward a bit. That'd mean adaptng the bodywork a bit.
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
|
|
|
matt_gsxr
|
| posted on 27/3/12 at 08:47 AM |
|
|
some examples here, mostly single seaters
http://www.dpcars.net/
|
|
|
Alez
|
| posted on 27/3/12 at 10:38 AM |
|
|
quote:
Originally posted by jeffw
The Menace had the engine alongside the driver in the passenger seat effectively.
quote:
Originally posted by adithorp
...and I think, the drivers seat, pedal box and scuttle moved forward a bit. That'd mean adaptng the bodywork a bit.
Oh, did it? Was the engine mounted N-S with a propshaft or E-W and chain driven?
quote:
Originally posted by iank
For the Atomic the E-W weight distribution will be pretty good (person on E, engine on W) are roughly comparable. It will certainly be much better
than a 7 without a passenger.
The engine is a lot more to the front than the driver's CoG. I agree (from experience) that a Seven without a passenger is pretty poor.
quote:
Originally posted by iank
The advantage (to my mind) is the extremely low polar inertia of that layout and the minimal weight of the thing.
Downside is one seat (obviously) and the noise in your left ear.
The manufacturer quotes 335 kg total weight but I fail to understand how they got it SO light compared to a Riot or similar. Also a shorter car (I
don't know wether that's the case) is both a good and a bad thing I guess.
I think the noise coming from the engine is probably negligible even at that distance from the driver, compared to exhaust noise and wind, which are
pretty loud.
quote:
Originally posted by iank
T66's Fiat BEC was going to use a range rover box which would be a cheap option if it works out.
I didn't know about this one, I shall check it out and learn the details of its layout.
quote:
Originally posted by Slimy38
Bikers have had a bike engine between their legs since the dark ages, with very few complaints! The engines themselves are quite quiet, it's
the exhaust and wind noise that are much louder. As long as you can route the exhaust to somewhere behind the driver (which I believe is an IVA thing
anyway) you should be fine.
I would think so.
quote:
Originally posted by Slimy38You're right about the E-W distribution though, a bike engine weighs about the same as an average
person. And from memory, for the N-S distribution MEV put the engine slightly more forward and the driver slightly back. But moving the engine forward
and backwards is quite an easy task to be honest.
Have a look to the pic I posted a link for yesterday, I think they put the engine a lot more forward, not slightly, which I don't like. I think
that's the wrong way to balance weight distribution.
quote:
Originally posted by matt_gsxr
some examples here, mostly single seaters
http://www.dpcars.net/
Yes, those are on my original post. Years ago the guy was designing the DP1 with conventional bike power and at some point he switched to V8 Hayabusa
from Hartley Enterprises because he thinks the one from Powertec (as used by Radical) is not ideal.
|
|
|
Alez
|
| posted on 27/3/12 at 10:40 AM |
|
|
I mean this picture:
|
|
|
MK9R
|
| posted on 27/3/12 at 11:22 AM |
|
|
I have a new car build plan that will be doing something along these lines, but still fit in the RGB class f regs ...... Watch this space
[Edited on 27/3/12 by MK9R]
Cheers Austen
RGB car number 9
www.austengreenway.co.uk
www.automatedtechnologygroup.co.uk
www.trackace.co.uk
|
|
|
BobM
|
| posted on 27/3/12 at 11:45 AM |
|
|
quote:
Originally posted by MK9R
I have a new car build plan that will be doing something along these lines, but still fit in the RGB class f regs ...... Watch this space
Not very Locost but very BEC
|
|
|
BobM
|
| posted on 27/3/12 at 11:49 AM |
|
|
quote:
Originally posted by AlezI think the noise coming from the engine is probably negligible even at that distance from the driver, compared
to exhaust noise and wind, which are pretty loud.
I disagree. There are 2 issues, induction noise and the mechanical engine noise.
The former is loud enough in my mid-engined car that I wear earplugs when racing/tracking as it's a very harsh and painful noise once the engine
is under load at high rpm (and the air intake is close to my left ear).
Don't underestimate mechanical engine noise either - my car initially failed IVA but I reduced it from 103 to 99 dBA by adding sound deadening
material to the engine bay. Some of the noise was panel resonance but at high rpm there's quite a lot of mechanical noise and it will be
noticeable when the engine's right next to you.
Not very Locost but very BEC
|
|
|
Slimy38
|
| posted on 27/3/12 at 12:04 PM |
|
|
I see what you mean about the engine positioning, that top view really demonstrates how far forward it is. The pictures I've seen don't
make it so obvious.
BobM, having ridden a few bikes I've never noticed that much mechanical noise. I can understand your thoughts on induction noise, especially
with the intake being so close and having to be exposed. But the only appreciable sound from the engine is the straight cut boxes and the
characteristic whine that they give off. Are you sure your engines are healthy?  
|
|
|
BobM
|
| posted on 27/3/12 at 12:28 PM |
|
|
quote:
Originally posted by Slimy38BobM, having ridden a few bikes I've never noticed that much mechanical noise.
Yeah, I've
ridden bikes too but you've got a nice big airbox and fuel tank between the engine and your ears on a bike. Also 3-4 feet of vertical
separation, added to this is the fact that at 12k rpm in top you're doing near 180mph on the bike so massively more wind noise and no way
you'll hear the engine!
quote:
Originally posted by Slimy38But the only appreciable sound from the engine is the straight cut boxes and the characteristic whine that
they give off. Are you sure your engines are healthy?
Yes, pretty confident my engines have been healthy You get quite a lot of top
end and cam chain noise.
Not very Locost but very BEC
|
|
|
Stott
|
| posted on 27/3/12 at 02:54 PM |
|
|
I agree with Bob, mech and induction noise are incredible when it's sat next to you.
Having owned bikes too I can definitely say they are not comparable.
|
|
|
Alez
|
| posted on 27/3/12 at 04:07 PM |
|
|
OK, so noise is an issue.
Right, here's the best pic of a Menace I've been able to find:
Longitudinally mounted engine, to me it looks very similar to the Atomic concept-wise. I wonder why they placed the engine there instead of next to
the driver, may that have to do with the transmission arrangement? Is that still a propshaft?
|
|
|
maccmike
|
| posted on 27/3/12 at 05:06 PM |
|
|
http://www.dpcars.net/
very cool looking car
|
|
|
Alez
|
| posted on 28/3/12 at 02:55 PM |
|
|
quote:
Originally posted by iank
T66's Fiat BEC was going to use a range rover box which would be a cheap option if it works out.
Here it is:
http://www.retropower.co.uk/projects_126_Blackbird.htm
This must be this box:
http://www.locostbuilders.co.uk/viewthread.php?tid=146963
However I've also found this:
http://www.locostbuilders.co.uk/viewthread.php?tid=162229
Does anyone know what happened to this project? Is T66 still active on this forum? As I understand it, the transmission idea changed, but I
don't understand well, I really like this stuff but my knowledge on these things is very poor and so it is my English, also I don't know
what a "transfer box" is. I've seen mentions of different approaches: this range rover box, chain drive and something else from
Powertec too.
|
|
|
Volvorsport
|
| posted on 1/4/12 at 04:58 PM |
|
|
look at a clubmans car , a mallock or something
www.dbsmotorsport.co.uk
getting dirty under a bus
|
|
|
JoelP
|
| posted on 1/4/12 at 06:07 PM |
|
|
I half built a bec with the engine in the passanger footwell. Was planning on still getting a seat in, just with minimal leg room - knees up to chin!
You would have good balance all round, and a low polar moment. You could also have longer front wishbones if you wanted, and a better aero profile.
Scrapped mine in the end, because i realised i should have started with a scratch build, rather than modifying an existing locost chassis.
4wd isnt really needed for a single bike engine.
Transfer box is just the middle box on an offroader, that splits drive front to back.
|
|
|
iank
|
| posted on 1/4/12 at 08:38 PM |
|
|
quote:
Originally posted by Alez
...
Does anyone know what happened to this project? Is T66 still active on this forum? ...
Still being built, and yes he's still active, try a u2u
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
|
|
|
Alez
|
| posted on 6/4/12 at 09:11 PM |
|
|
Thanks, guys
[Edited on 6/4/12 by Alez]
|
|
|
