garage19
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| posted on 1/7/08 at 11:32 AM |
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Track Vs Wheelbase?
Looks like the track and wheel base figures for my middy will be:
1660 mm track
1730 wheel base
Are there any potential problems with having such a square layout?
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Mr Whippy
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| posted on 1/7/08 at 11:37 AM |
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I think the longer the wheel base the more stable cars tend to be at high speed
Fame is when your old car is plastered all over the internet
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Alan B
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| posted on 1/7/08 at 11:38 AM |
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Don't know if problem is the right word or not but there will definitely be quite specific handling characteristics with such a square layout.
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Paul TigerB6
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| posted on 1/7/08 at 11:39 AM |
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As ^^^^. Could be very twitchy if the wheelbase is very short. Whats a typical se7en's wheelbase anyway??
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alistairolsen
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| posted on 1/7/08 at 11:39 AM |
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as above, the greater the ratio of wheelbase to width the more stable the car, the shorter it is the more twitchy it will be. (all for a given width)
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Paul TigerB6
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| posted on 1/7/08 at 11:44 AM |
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To answer my own question a quick search gave approx 2365mm for a locost so guess yours is pretty short at about 2ft less!! What are other
middy's wheelbase (R1ot etc)
[Edited on 1/7/08 by Paul TigerB6]
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garage19
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| posted on 1/7/08 at 11:46 AM |
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quote:
Originally posted by Alan B
Don't know if problem is the right word or not but there will definitely be quite specific handling characteristics with such a square layout.
Alan, out of interest, what are the figures for you car?
And does anyone know the figues for a typical locost?
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smart51
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| posted on 1/7/08 at 12:01 PM |
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I believe that track is measured between the centre of the tyres. A 1660mm track would give a vehcile width of about 2 metres. I don't think
you mean this.
On the other hand. If your car measures 1660 from outside edge of tyre to outside edge of tyre, then your track is going to be nearer 1470mm, giving
you a longer wheelbase to track ratio.
I seem to recall reading a 1.6:1 ratio is best, but I guess that depends on what you call best. Longer ratios are more stable in a straight line but
don't turn so well. Shorter ratios turn in like figher planes but are more twitchy at speed.
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Alan B
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| posted on 1/7/08 at 12:01 PM |
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Mine is 96" 2438mm WB x 59.25" 1505mm Track which gives a W/T ratio of 1.62:1
Alan
quote:
Originally posted by garage19
quote:
Originally posted by Alan B
Don't know if problem is the right word or not but there will definitely be quite specific handling characteristics with such a square layout.
Alan, out of interest, what are the figures for you car?
And does anyone know the figues for a typical locost?
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garage19
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| posted on 1/7/08 at 12:01 PM |
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DP1 is
1727 mm track
2006 mm wheel base.
Hmmm, maybe i should add some length?
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worX
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| posted on 1/7/08 at 12:02 PM |
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A ratio of roughly 1:1.61803 is a pretty good start!
Steve
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Alan B
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| posted on 1/7/08 at 12:03 PM |
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To the best of my knowledge track is measured centre to centre, as is wheelbase of course.
quote:
Originally posted by smart51
I believe that track is measured between the centre of the tyres. A 1660mm track would give a vehcile width of about 2 metres. I don't think
you mean this.
On the other hand. If your car measures 1660 from outside edge of tyre to outside edge of tyre, then your track is going to be nearer 1470mm, giving
you a longer wheelbase to track ratio.
I seem to recall reading a 1.6:1 ratio is best, but I guess that depends on what you call best. Longer ratios are more stable in a straight line but
don't turn so well. Shorter ratios turn in like figher planes but are more twitchy at speed.
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garage19
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| posted on 1/7/08 at 12:07 PM |
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If you mean centre of wheel (width) to center for track then mine is 1475mm.
I thought it was outside of wheel to outside?
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garage19
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| posted on 1/7/08 at 12:11 PM |
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The above figures give me a ration of 1:1.17
[Edited on 1/7/08 by garage19]
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worX
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| posted on 1/7/08 at 12:15 PM |
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Agreed
Stevequote:
Originally posted by Alan B
To the best of my knowledge track is measured centre to centre, as is wheelbase of course.
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iank
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| posted on 1/7/08 at 12:25 PM |
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Some information in this thread http://www.locostbuilders.co.uk/viewthread.php?tid=68259
I suspect it will be a little twitchy on the straight but very quick to corner, but weight distribution, tyre choice, steering wheel size etc. etc.
will all make a big difference to the final feel.
[Edited on 1/7/08 by iank]
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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mr henderson
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| posted on 1/7/08 at 12:43 PM |
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How come it's so short? Are you sure you are not forgetting something? (Like the occupants' legs for instance)
John
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garage19
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| posted on 1/7/08 at 12:50 PM |
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No, same size cabin as my Indy.
Engine is mounted on other side of spine chassis to driver. Very much like DP1 but with out the 4wd.
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Ians
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| posted on 1/7/08 at 02:38 PM |
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T vs W
As your aim is to build the smallest package possible, narrow the track by 200mm to get a reasonable ratio..Ians
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garage19
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| posted on 1/7/08 at 02:52 PM |
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Good point Ian....only downside is that would mean custom driveshafts.
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garage19
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| posted on 1/7/08 at 02:53 PM |
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PS. did you get my email with loads more questions as normal
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Doug68
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| posted on 1/7/08 at 02:59 PM |
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1660 does seem a bit wide on the track, where is that measured too?
Mine will have a wheelbase of ~2570mm and a track of 1620mm at the rear that gives an overall width just under 2m.
Track and overall width are the same as the Ford GT wheel base has ended up a bit shorter.
Thats a ratio of 1.59:1 as opposed to the Ford GT's 1.67:1
With a bit of guess work the Peugeot 908 LMP has a wheelbase of 2950 and a 1632 rear track so thats 1.81:1.
I doubt it'd work very well as a rally car though so whats appropriate depends on the task you put it too I guess.
Doug. 1TG
Sports Car Builders WA
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Alan B
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| posted on 1/7/08 at 04:26 PM |
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quote:
Originally posted by chris mason........btw don't be put off by having to have custom driveshafts made, a pair will cost well
under £200 so there's no reason to compromise the project.
Chris
I've got to agree with this... some things will dictate the final sizes and specs of the project, but I wouldn't let driveshafts be one of
them..
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James
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| posted on 1/7/08 at 05:07 PM |
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quote:
Originally posted by smart51
I seem to recall reading a 1.6:1 ratio is best, but I guess that depends on what you call best. Longer ratios are more stable in a straight line but
don't turn so well. Shorter ratios turn in like figher planes but are more twitchy at speed.
Yeah, I'm sure I read an article by Gordon Murray where he said that.
May well have been in the big Mclaren F1 book.
Cheers,
James
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"The fight is won or lost far away from witnesses, behind the lines, in the gym and out there on the road, long before I dance under those lights."
- Muhammad Ali
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garage19
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| posted on 1/7/08 at 07:20 PM |
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quote:
Originally posted by chris mason
yep mine's a similar length with a wb of 1890mm but my track is only 1175mm
that gives me a ratio of approx 1.6ish 
yours sounds a little square almost kart like, btw don't be put off by having to have custom driveshafts made, a pair will cost well under £200
so there's no reason to compromise the project.
Chris
That is much cheaper than i thought. Any links to suppliers?
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