[Edited on 1/7/08 by garage19]
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?
I think the longer the wheel base the more stable cars tend to be at high speed
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.
As ^^^^. Could be very twitchy if the wheelbase is very short. Whats a typical se7en's wheelbase anyway??
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)
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]
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.
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.
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?
DP1 is
1727 mm track
2006 mm wheel base.
Hmmm, maybe i should add some length?
A ratio of roughly 1:1.61803 is a pretty good start!
Steve
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.
If you mean centre of wheel (width) to center for track then mine is 1475mm.
I thought it was outside of wheel to outside?
The above figures give me a ration of 1:1.17
[Edited on 1/7/08 by garage19]
Agreed
Steve
quote:
Originally posted by Alan B
To the best of my knowledge track is measured centre to centre, as is wheelbase of course.
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]
How come it's so short? Are you sure you are not forgetting something? (Like the occupants' legs for instance)
John
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.
As your aim is to build the smallest package possible, narrow the track by 200mm to get a reasonable ratio..Ians
Good point Ian....only downside is that would mean custom driveshafts.
PS. did you get my email with loads more questions as normal
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.
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
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.
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
My recollection is 1:1.61.
In my experience handling will really suffer under hard braking, expect the rear to try and come around.
Regards Mark
quote:
Originally posted by garage19
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?
Oddly enough, the ideal ratio seems to be that 'human ratio' thing, which is 1:1.6+.
Someone mentioned LMP cars. You can't use the obvious figures for these, because they are designed to maximum body widths, and also the wide
tyres make things a little different to the accepted norms.
Cheers,
Syd.
[Edited on 2/7/08 by Syd Bridge]