garage19
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| posted on 3/11/03 at 04:04 PM |
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How fast will your car go??? In theory any way!
Found this great down load by a bloke called Peter Ogden (no relation to percy i hope).
Its called gearcalc and if you input your diff ratio, tyre sizes, and gearbox ratios it will tell you all sorts of info like top speed and which gear
you will reach sixty in for that all important dash!
It even has all the ratios for common gearboxes (type 9 is there) under the tools pull down.
http://locost7.info/gearcalc.php
Mine will do 143mph!
Ps sierra 4x4 LSDs are 3.62 ratio.
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Metal Hippy
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| posted on 3/11/03 at 04:20 PM |
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155 not taking into account wind resistance and the like....
More than fast enough for any Locost type methinks.
Rich.
Cock off or cock on. You choose.
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timf
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| posted on 3/11/03 at 04:49 PM |
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shit now i'm worried
Gear Mph per 1000 RPM Mph @6500 RPM Mph @7000 RPM
--------------------------------------------------------
1 6.30 41 44
2 10.41 68 73
3 15.38 100 108
4 20.60 134 144
5 30.30 197 212
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Browser
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| posted on 3/11/03 at 04:54 PM |
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Already done me own (much simpler and more basic) Excel-based version so I'll have to download this one and see if mine is close. If it is then
I'll be able to pull 60mph in second gear, which should be enough for anybody!
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blueshift
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| posted on 3/11/03 at 11:50 PM |
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Think with the rv8, lt77 and sierra lsd ours redlines at about 130mph, according to the quaife calculator.
assuming a standard rv8 redline (with solid lifters and other crazy potatoes you can get from 5500rpm redline to 8000 or something, I think.. nuts)
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Simon
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| posted on 6/11/03 at 04:29 PM |
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Like Blueshift, RV8/LT77 but with 3.82 diff:
117mph
Sad, but true!!
ATB
Simon
PS Ned - have you still got your 3.38?
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theconrodkid
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| posted on 6/11/03 at 04:52 PM |
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so how can you do your 0-60 time,my sundial aint that acurate
who cares who wins
pass the pork pies
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Hugh Paterson
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| posted on 6/11/03 at 06:50 PM |
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Har har 60 in second thats first in our beastie, but gawd it HOWLLLLLLLLs
Shug.
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Mark Allanson
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| posted on 8/11/03 at 12:23 PM |
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According to Andre Jute,
BHP =
Cd x Frontal Area in Sq Feet x Speed Squared
Divided by
146,000 x 0.7
which means
speed =
BHP x 102620
divided by
Cd x frontal area
all cube rooted
For my pinto, (assuming the Cd is the same as a caterham, 0.65), a frontal area of 3'x5' x 0.7 (0.6 for the fact that the car is not
completely 3'x5'
This gives a top speed of 109.45mph
Thats what I'm telling the SVA!
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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Surrey Dave
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| posted on 8/11/03 at 05:45 PM |
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Do You Agree?
If I've got it right , using your calculations it would take
95.4 bhp to get 100mph,
149.06 bhp to get 125mph
173.8 bhp to get 135mph
200.58 bhp to get 145mph
309.09 bhp to get 180mph
381.6 bhp to get 200mph
I'd be interested to know what top speed 'Hicost' has seen in his car , as it is quoted at 400+bhp
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Mark Allanson
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| posted on 8/11/03 at 09:54 PM |
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Like most of these formulae, they work well within normal (normal!?) parameters, but at the extreems, they get a bit fuzzy. The top speeds look very
believable and relatively normal BHP outputs - I don't think any locost would do 200mph without some pretty special aerodynamic aids which would
put up the Cd by an appeciable amount (I think an F1 car has a Cd of 1.15)
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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Alan B
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| posted on 8/11/03 at 10:18 PM |
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357mph....
Well, you lot started it.....
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Mark Allanson
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| posted on 8/11/03 at 10:56 PM |
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here we go again!!!
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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Surrey Dave
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| posted on 9/11/03 at 01:03 AM |
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I think it s food for thought when considering a trick motor just how much extra power you need for a modest improvement, I'd rather hit a speed
bump at 100 mph than 200mph
I find that when you get to 100mph in a 'Locost' you start wondering just how good your welding is!!!
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Mark Allanson
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| posted on 9/11/03 at 07:30 PM |
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No worries on the welding, but the aerodynamics worry me a bit at anything above 90mph, had a look at the new carerham in EVO magazine, they have an
F1 style front spoiler which looks good and may even make SVA easier on the front suspension lagging
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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Rob Lane
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| posted on 11/11/03 at 09:53 AM |
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Real figures from speed trap.
Toyota 4 age with matching 5 speed box. 3.89 diff, 15 inch wheels.
Windscreen fitted. (Air Dam !!)
5th gear 109mph.
4th gear 117mph.
I think when I did the calc last time I was truly excited as it quoted something like 135mph max. Yeah right!
The windscreen makes a huge difference.
You can see and definitely feel the pressure exerted upon it.
Haven't been able to try it with sidescreens fitted but they are supposed to help for about 3-4mph. Certainly more comfortable and I've
since seen 125mph indicated with them on, not on empty motorway officer.
Just to qualify this, when I had 3.54 diff fitted I'm sure it would reach 130 on the right road but i never found one long enough! The
acceleration was much slower with that diff so I changed to the 3.89.
0-60 is now 5.5 secs, which probably helps rob the top speed with 3.89 diff.
[Edited on 11/11/03 by Rob Lane]
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Alan B
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| posted on 11/11/03 at 02:22 PM |
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Is it just me?
The top speed thing has virtually no interest to me......(hence the p***take earlier)....
To me it's all about acceleration and handling......
Anyone else feel the same?
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pbura
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| posted on 11/11/03 at 02:35 PM |
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quote:
Originally posted by Alan B
Is it just me?
The top speed thing has virtually no interest to me......(hence the p***take earlier)....
To me it's all about acceleration and handling......
Anyone else feel the same?
I'd have to have a few beers in me to go for top speed on the road, in which case getting caught would be a double whammy. It's a long
way to Nevada and no speed limits... 
The aerodynamics issue is interesting, though, because a car that is limited to 120 mph by air friction is also going to have a lot of buffeting at
75-80.
Inboard shocks and a raked windscreen would help a bunch, I think.
Pete
Pete
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locoboy
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| posted on 11/11/03 at 03:34 PM |
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I think the shocks are of mminor importance when considering drag and aerodynamics of a locost, i agree with the windscreen rake / removal. the most
burning issue is the hole in the nose that creates the wind sock effect!
The shocks create as much aerodynamic "damage" as the roll bar!
All IMHO of course.
ATB
Locoboy
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Jasper
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| posted on 11/11/03 at 03:39 PM |
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I agree with Alan - top speed is rather unimportant - with the ZX9 and a 3.54 I only get 112mph, but I rarely go on a track with a long enough
straight to reach it (excpet Donnington), it's all about acceleration and handling
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Mark Allanson
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| posted on 11/11/03 at 09:22 PM |
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I am not really into top speed, more back lane bashing.
but this spoiler caught my eye, it could make the SVA alot easier, bit like the Dax 'front bumper'
 
Rescued attachment CaterhamFrontSpoiler.jpg
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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steve m
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| posted on 11/11/03 at 10:52 PM |
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Having passed the ton mark only last week (not on the road, of course??) the buffeting and eye watering effect detract from the fun element, and a s
for Daves wise comments
I find that when you get to 100mph in a 'Locost' you start wondering just how good your welding is!!!
I always think of the front wishbones for some reason,
they do look quite flimsy
steve
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Mark Allanson
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| posted on 11/11/03 at 11:01 PM |
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I would trust mine more than production car wishbones - especially Vauxhall. In my trade you see all the weak points of tintop cars
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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sgraber
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| posted on 12/11/03 at 03:15 AM |
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I'd have to go with the vocal majority about top speed not being as important as the "Squirt Factor". The ability to squirt through
traffic with ease. The 40-60MPH timing is important to me for passing on curvy 2 lane roads.
Of course, hitting your calculated top speed might induce a 'squirt factor' of a different nature. I made it to 130mph in my 250GTO
replica (once) and remember wondering how many pieces they would find my body in if a tire blew out... Talk about anal constriction!
Steve Graber
http://www.grabercars.com/
"Quickness through lightness"
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Rob Lane
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| posted on 12/11/03 at 11:19 AM |
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No, top speeds not my bag either. I just posted real world examples to show the huge discrepancy in the modeling software.
As you can tell from my post I have experimented in depth to achieve a fast accelerating, good handling car.
It's not perfect but whatever is!
On some tracks it's spot on but as a road going car it cannot match the cars with the availability to change gears and diff for each track.
Donington springs to mind as a good example, car matches it perfect. Croft, much too low geared, topped out third way down straight. Others just the
same, a compromise.
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