b14wrc
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| posted on 6/3/11 at 11:14 AM |
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Rear end design - track
Morning,
Does my rear track look right? Is it going to look right or maybe to wide or too narrow??
Rob
20vt powered rear engined locost
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Fred W B
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| posted on 6/3/11 at 11:44 AM |
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How wide is it over the outside of the wheel rims? Note this is diffent to "track" quoted in spec sheets, which is taken to wheel
centres.
Anything much over 1700 mm is heading to super car widths
examples, from my reading/calculation, don't take as gospel
Caterham R500 = 1520/1550 F/R
Radical SR3 = 1760 mm
Mclaren F1 = 1790/1800 F/R
Ferrari F40 = 1840/1945 F/R
Cheers
Fred W B
PS - is it the camera, or my eyes, or does that roll bar actually have a downwards bow to it in the centre?
[Edited on 6/3/11 by Fred W B]
You can do it quickly. You can do it cheap. You can do it right. – Pick any two.
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on_eighty_runner
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| posted on 6/3/11 at 11:50 AM |
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I had a look at different donors for a mid engined car and plan to re-use as much of the donor set up as possible, and most of what I looked at had a
track of ~1450 mm which is the same as most of the modern 7 type cars.
comparison here (cant vouch for the information though) http://wclocost.blogspot.com/2008/02/dimensions.html
sierra rear track is 1468mm
fiat coupe track is 1479mm
alfa 146, saab 9-5, Vecta, Astra, Clios etc are much the same but they do have a very useful subframe, that will "bolt on"!
How much have you shortened the front of the chassis by? Or what is your planned wheelbase? Want to know how much to take out of my own, current
thoughs are ~400mm
Best of luck with the build!
Steve
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b14wrc
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| posted on 7/3/11 at 12:52 PM |
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Hi Fred,
Yes, the roll bar is slightly saggy, it’s made from plastic. Thanks for the information.
Hi Steve,
Welcome to the club. I have just recently joined myself and really enjoy talking to people about different projects.
I am going to be using the entire coupe running gear as it was in the original car, so my rear track will end up at around 1480mm I expect. As for my
wheel base, I thought last time I checked it was about 2300mm, but my design changes all the time and it could have got slightly longer. I will have
to check to confirm the full length of my chassis, I will try and do tonight and let you know.
Where abouts are you based??
Keen to hear you are building something similar to me. Which Fiat are you planning to use? I think my car will end up being heavy, but saying that I
will have quite a bit of power, so the power to weight will still be good, 400bhp per ton!
[Edited on 7/3/11 by b14wrc]
20vt powered rear engined locost
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on_eighty_runner
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| posted on 9/3/11 at 08:44 PM |
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Hi Rob, am based in Cork
the Fiat connection is more of a means to an end.
Although there is no IVA or any checks here to register a "kit type"car, they treat them all as new (where the chassis is new) and they
new registrations
ie 11-C-666 for the 666th car registered in Cork in 2011.
The cost of registering and the road tax is based on the CO2 figure from the car the donor engine came from.
Registration is between 14% and 36% of whatever the car is worth when on the road.
Road tax is between €104 and €2,100/year (not a typo!)
If there is no CO2 figure for the engine you use or it does less than ~30 mpg (Petrol) you are in the €2,100/year road tax band. A Sierra donor will
probably put you here!
There are not many low CO2 rwd (petol) applications that anyway, so am looking at transverse units instead. The Fiat Punto 1.2 8v puts it in the 16%
band with roadtax of €156 /year. They are also cheap and easy to get.
Once registered, you can change the engine to whatever you like as the CO2 figure is fixed for life.
a bit silly but its the system in place!
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britishtrident
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| posted on 9/3/11 at 09:34 PM |
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Track has a lot less effect on handling than you might expect.
Relatively small changes in wheelbase have a much more noticeable effect.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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Neville Jones
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| posted on 13/3/11 at 08:52 PM |
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quote:
Originally posted by britishtrident
Track has a lot less effect on handling than you might expect.
Relatively small changes in wheelbase have a much more noticeable effect.
Now tell us why F1 and similar cars, LMP's and the like, are as wide as can be possibly achieved under their respective regulations. If max
track was of no great advantage, the cars would be as narrow as they were in the 50's, or moreso the 30's, when it appears you were born.
Mr. BT, go google this subject and come back and tell us why your first statement is so very wrong, yet again!
Track affects weight transfer, and weight carried on the respective corners of the car in cornering.
Cheers,
Nev.
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b14wrc
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| posted on 15/3/11 at 12:37 PM |
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Hi all,
Thanks for the info, there is another post up at the moment discussing this topic which has been interesting to read.
I reckon the magic 1.6 ratio will look right on my car. From advice on here my track is pretty much set, going from there i can work back to get the
optimum wheel base.
I think the main reason i asked was not from a technical point of view (although this is important - i want a serious track car), i want my car to
retain similar proportions to the locost. Just because i have always liked the look of them.
Steve,
It is very interesting to hear from you over in Ireland. You have a very different system over there, good luck with the build. I would be keen to see
how you get on. Let me know if i can help you with any thing.
For your info:
My track is 1440mm at the moment, but my wheels are directly on the hubs, so the discs will space them out slightly and i don't have the correct
wheels yet, so that may change the track slightly too. My wheelbase is 2335mm. I dont actually have a tape messure at my house at the moment - dont
ask!  so cant give you an exact figure for chassis shortening length.
Does any one have an opinion on differing track front to rear? I suppose this will help for tighter turn in at lower speeds?
Cheers, Rob
20vt powered rear engined locost
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blakep82
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| posted on 15/3/11 at 12:46 PM |
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quote:
Originally posted by b14wrc
Hi Fred,
Yes, the roll bar is slightly saggy, it’s made from plastic. Thanks for the information.
just before this starts any off topic discussions, its plastic because the chassis is made of wood to get the design done before making it in
steel!
could just see the way that was going to go already lol
________________________
IVA manual link http://www.businesslink.gov.uk/bdotg/action/detail?type=RESOURCES&itemId=1081997083
don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
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b14wrc
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| posted on 1/9/13 at 11:41 AM |
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Hi all,
I'm looking at starting the final detail design of the front end suspension now that the rear is almost completed.
Question is:
Should my front end be slightly wider, the same or narrower than my rear?
I have seen quite a few varying layouts and as the previous thread states track does not really effect handling as much as other factors. But I still
need to decide, so any ideas?
My rear is now set at around 1470mm.
Regards, Rob
20vt powered rear engined locost
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Jenko
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| posted on 2/9/13 at 03:32 PM |
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On my old Westfield, I changed from standard track to wide track which basically set the front wheels to the same as the rear........ I noticed a
differnce on track front end felt more planted, and also the turning circle was better. I had to adjust the damping on the shocks to suit.
MY BLOG - http://westfieldv8.blogspot.co.uk/
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beaver34
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| posted on 2/9/13 at 04:09 PM |
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quote:
Originally posted by Neville Jones
quote:
Originally posted by britishtrident
Track has a lot less effect on handling than you might expect.
Relatively small changes in wheelbase have a much more noticeable effect.
Now tell us why F1 and similar cars, LMP's and the like, are as wide as can be possibly achieved under their respective regulations. If max
track was of no great advantage, the cars would be as narrow as they were in the 50's, or moreso the 30's, when it appears you were born.
Mr. BT, go google this subject and come back and tell us why your first statement is so very wrong, yet again!
Track affects weight transfer, and weight carried on the respective corners of the car in cornering.
Cheers,
Nev.
what about the nissan delta wing?
or is that not true in terms of performace
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b14wrc
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| posted on 2/9/13 at 09:40 PM |
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Hi,
Been out tonight in the garage and the rear track is 1500mm exactly with the prorace 1.2's on.....
Going to try and set the front up to be the same.
Rob
20vt powered rear engined locost
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FERRARIST
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| posted on 10/9/13 at 05:36 PM |
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quote:
Originally posted by b14wrc
Hi,
Been out tonight in the garage and the rear track is 1500mm exactly with the prorace 1.2's on.....
Going to try and set the front up to be the same.
Rob
How did you measure track - center of the wheel, or from the inner or outer end?
My humble experience with mid-engined RWD Alfa 156 3.0V6 is that:
185rear track - 180 front - understeer - lot of understeer ....
185 rear - 185 front - hardly noticeably understeer it can be cured with other setups
185 rear - 189 front - very, very nice oversteer, just as i like it......maybe i must mention that rear was toed-OUT additionally 0.5mm........
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coyoteboy
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| posted on 10/9/13 at 11:11 PM |
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For any given suspension sysrem, a wider front track will tend to reduce understeer and a narrower one will encourage it. But that depends on your
starting point, they might all still understeer just to lesser extents as the front gets wider.
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b14wrc
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| posted on 11/9/13 at 11:21 AM |
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Having a big heavy 5 cylinder in the back may help unbalance my car, so from what’s been said I really need to consider the same or greater up
front.
Spent a bit of time thinking about it and expect I will start with the same, then later on if it needs changing I can always alter it.
I measured my track by measuring from the centre line of the car to the centre of the wheel bolted on, assuming my car is perfectly symmetrical I
doubled this. I didn’t think track could be measured any other way.....
A track of (assumed in cm) 185 seems wide, how have you measured your car?
My pro race 1.2s are ET38, I may look at changing the rears later on which may alter things, however, if I change the width, I can keep the same off
set and hence the track will not be effected.
I am looking at beginning the front suspension very soon. Watch this space.
Rob
20vt powered rear engined locost
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FERRARIST
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| posted on 11/9/13 at 04:03 PM |
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quote:
Originally posted by b14wrc
A track of (assumed in cm) 185 seems wide, how have you measured your car?
Outer end to outer end, i know that this is not the correct way, but using 2 sets of same wheel rims, for me it's way too easy to monitor my
changes.....
Don't know how possible is with your setup, but i have V6 166 3.0engine just in front of the rear wheels, and weight balance is 44 to 56 front
to rear......if you're able to fit your 20VT as much as possible between the rear and front wheels, you may achieve good balance as well.....
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b14wrc
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| posted on 11/9/13 at 06:51 PM |
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So take off the width of one wheel from the 185cm and you will have the actual track. 7" wheel?
20vt powered rear engined locost
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b14wrc
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| posted on 11/9/13 at 06:54 PM |
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My engine sits forward of the axel yes, most of the weight is in front of it. Not sure if I would get 44/56, but it should be reasonable. I should
work it out but it's hard when you haven't all the bits yet. ; (
Thanks for the info.
Rob
20vt powered rear engined locost
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FERRARIST
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| posted on 12/9/13 at 11:13 AM |
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quote:
Originally posted by b14wrc
So take off the width of one wheel from the 185cm and you will have the actual track. 7" wheel?
10" wheel, 250\64\18 slick - so i guess it's around 1600mm rear track.....
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b14wrc
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| posted on 12/9/13 at 11:36 AM |
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Hi Ferrarist,
So i am about the same as you in that sense, 1600mm.
From what you have said a nice ballanced setup will be gained from an equal track front to rear.
What power are you making??
Rob
20vt powered rear engined locost
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FERRARIST
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| posted on 12/9/13 at 11:44 AM |
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quote:
Originally posted by b14wrc
Hi Ferrarist,
So i am about the same as you in that sense, 1600mm.
From what you have said a nice ballanced setup will be gained from an equal track front to rear.
What power are you making??
Rob
Alfa 166 V6 3.0 engine with remap and 3.2GTA cams and intake runners.....let's say 240HP.....
I intend to rebuild my front suspension entirely, it should be 10-20mm wider than rear to suit my driving style and car setup.......Alfa 156 has awful
front suspension, heavy as hel*, A-wishbones will cure a lot......
[Edited on 12/9/13 by FERRARIST]
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b14wrc
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| posted on 12/9/13 at 01:21 PM |
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Sounds like my type of project.
Photos?? Keen to see how you do it.
I'm aiming for around 300bhp in my locost.
Rob
20vt powered rear engined locost
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FERRARIST
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| posted on 12/9/13 at 03:23 PM |
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http://guy-croft.com/viewtopic.php?f=5&t=3114
https://www.youtube.com/watch?v=ozcGHSsViqE
https://www.youtube.com/watch?v=4ErGozsG1x4
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