beppesignori
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| posted on 29/9/13 at 09:25 PM |
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Scaling up chassis for midi build.
8 years ago I was pretty drunk and on ebay....which resulted in a winning bid for a Lexus LS400. It has served me well, even though it was never a car
I would have dreamt of buying in a sober state of mind. Now it has served out its purpose, but I have grown to love that beautiful lump under the
bonnet, and now playing around with the idea of using it in a midi build.
I currently have an Elise S1 111s which I love to bits, and will never(maybe) get rid of. Since I love the way it drives, I want my next project to
behave similarly.
Now to the big question.
I think I can create a chassis that has the required stiffness, and within 850 kg total weight. But I would not know where to start with suspension
geometry.
Would it in theory be possible to multiply the Elise dimensions by say 10% in all directions, and still have a similar result? i.e. use the elises
suspension pickup points, wishbone lenghts etc. multiplied by 1.1. By this i don't mean just lengthening and widening the chassis by 10%, but
also making wishbones 10% bigger etc.
10% would give me a 230mm longer wheelbase to accommodate the V8 transaxle.
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eddie99
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| posted on 29/9/13 at 09:32 PM |
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In theory it should work, however in practise, it means everything needs to be multiplied by say the 10% in X, Y and Z. This doesnt just mean pickup
points but also wheels, uprights etc.. which can be tricky if you intend to just use say Elise parts.
However you could argue that even with a few compromises to make it doable, you could still end up with something pretty decent.
[Edited on 29/9/13 by eddie99]
http://www.elitemotorsporteng.co.uk/
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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beppesignori
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| posted on 29/9/13 at 09:38 PM |
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I would not use any Elise parts, and would probably go up one wheel size from the Elises 15/16 setup anyway. Tires would have to be wider as well, to
cope with the planned 265bhp and torque from a 4 liter V8. Currently running 225 at the back, which would probably mean going up to 255/17.
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daniel mason
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| posted on 30/9/13 at 05:52 AM |
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i dont think it would drive badly in the front of a 7 type car! its not an overly heavy lump for a v8. any you could possibly use a few more of the
parts from the lexus!
others have put heavier motors than that in it them. and you could use smalller wheels which should make it ride even better
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beppesignori
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| posted on 30/9/13 at 08:30 AM |
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I have thought about the idea of using it in a Sevenesque chassis, which is probably an easier option, but I have already built one seven. I am also
of the opinion that a Seven is best suited for a light straight four N/A engine. Not a big fan of the dragster like creations out there. This time I
would like to build a car with a full bodyshell, which is why I also had a look at the AGM, which is basically a 7 in disguise. But I have made up my
mind, that i want it to be mid-engined. Not sure what type of bodyshell I want to go for, Lola T70 style, or more towards a modern LMP. All I know is
that it will be open, and simple. No big windscreen or complicated doors.
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40inches
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| posted on 30/9/13 at 09:40 AM |
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You can fit the Lexus V8 in a Spire. http://www.locostbuilders.co.uk/viewthread.php?tid=163580
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beppesignori
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| posted on 30/9/13 at 10:24 AM |
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Looking at the comments in before mentioned thread about the spire, it is pretty much why I am considering a scratch build. Using a chassis designed
for BEC or small inline fours, and trying to change it, stretch it, widen it, and strengthen it, seems like just as much work. There was someone on
the thread building a Haynes with the Lexus lump, but dont know how he is getting on. But the 7 is scary above 140mph, and with the Lexus engine you
would reach speeds well above that at the end of Long straits. Although thinking about it, the heavier Lexus engine might help push down on the nose
at higher speeds?
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mcerd1
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| posted on 30/9/13 at 10:56 AM |
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quote:
Originally posted by beppesignori
But the 7 is scary above 140mph, and with the Lexus engine you would reach speeds well above that at the end of Long straits
I doubt 265 hp will be enough to push any seven much past 150 mph - the aerodynamics are really bad and at that sort of speed your in the 4x the power
to got 2x the speed territory  (force from the wind is related to the square of its speed)
quote:
Originally posted by beppesignori
Although thinking about it, the heavier Lexus engine might help push down on the nose at higher speeds?
I doubt it would make enough difference at those speeds
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liam.mccaffrey
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| posted on 30/9/13 at 11:09 AM |
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get hold of Allan Staniforths "race and rally book", build a string computer, it will tell you exactly what difference it will make 
Build Blog
Build Photo Album
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blakep82
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| posted on 30/9/13 at 11:12 AM |
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Build this
http://www.locostbuilders.co.uk/viewthread.php?tid=183728
________________________
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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beppesignori
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| posted on 30/9/13 at 12:06 PM |
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Nice piece of kit...would be perfect, was it not for the price. Unfortunately they havent solved the problem that is always discussed when talking
Group-C LMP replicas, the perspex windscreen. But for track only...awesome.
Would still like some more input on implications of scaling up a chassis...
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ettore bugatti
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| posted on 30/9/13 at 06:54 PM |
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There have been v8s or v10s been put into Elises before.
http://www.pistonheads.com/gassing/topic.asp?t=1223266
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beppesignori
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| posted on 30/9/13 at 08:23 PM |
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No way I am cutting up my Elise. Love it too much. Just need a home for my Lexus V8....
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mcerd1
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| posted on 1/10/13 at 09:30 AM |
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from a practical point of view which 'off the shelf' transaxles fit the lexus V8 or can be made to fit with minimal work ?
(obviously they need to be able to handle the torque/power as well)
and here's a different lotus option for you:
http://www.motorgeek.com/viewtopic.php?t=9648
[Edited on 1/10/2013 by mcerd1]
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johnH20
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| posted on 1/10/13 at 10:49 AM |
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What you are proposing is not a million miles from the new V6 Exige. This has an extended wheelbase but as far as I know retains the same
suspension/track dimensions as the 4 cylinder cars and it obviously works pretty well. Might be worth reading up on the various press reports to find
out more.
In my less sober moments I have occasionally thought about using a sound S1 chassis from a car with tatty bodywork as the basis for something like
this, using a new rear subframe to suit. Would save a lot of work on such a project. Good luck!
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b14wrc
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| posted on 1/10/13 at 11:20 AM |
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Hi beppesignori
I'm am very interested in your idea, who would you build the 'Elise' style chassis? Tube or composite tub?
I had thought for my next car i would do something similar, id make a carbon tub and run a longitudinal engine in the rear with Elise style body
work.....
What is your S1 like, i went to view two on Saturday, S1 standard cars, both were purple with Cream leather, both high milers. One was
'average' - really nice straight original car let down by a few annoying points and lack of service evidence, would have been very tempted
if it had the paper work.... second one was a dog...
Interested to know more about your car, PM me if you like.
Rob
20vt powered rear engined locost
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beppesignori
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| posted on 1/10/13 at 11:29 AM |
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Thanks for the input. Have studied Hillys Esprit intensely over the years. Even contemplating doing the same, just with the Lexus engine. Looking to
use an Audi Transaxle, The 01X i believe has been used successfully.(hurts me to use any Audi part on my car). Interesting fact about the Exige. It
probably means that scaling up the S1 chassis is possible. Looking to fabricate uprights as well, so can even adjust the them to fit the 10%. Now just
have to clear the calendar for the next 3 years(yes, I am slow. The MK took me 4 years to finsih :-) )
http://youtu.be/Ba8sT2BQ4uc
[Edited on 1/10/13 by beppesignori]
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beppesignori
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| posted on 1/10/13 at 12:20 PM |
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Rob,
Regarding the Elise. They drink out of a magic well in Hethel. Have just completed my first trackday after rebuilding my S1. Complete makover with GAZ
suspension, new bushings, whishbone refurb, 111S engine plus plus. It just amazing how it drives. The feedback it gives you, the adjustability and the
grip levels are stunning.(setup advice from ES Motorsport)
I dont expect to get anywhere near with my build, but if some of that magic could rub off on the project by using some of the geometry from the Elise,
I would be happy.
Going low tech on this one. Tubes for the chassis. I know Colin would kill me for saying this, but as long as I get the chassis stiff enough, and
strong enough, I dont mind 50kgs extra.
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CNHSS1
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| posted on 1/10/13 at 02:21 PM |
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all seems a good idea, but will it realistically get finished? so many variables. 'building' a seven, can be as simplistic as assembly or
more involved, whereas a scratch build is loads of fabrication and all the maths etc as well and you still have to build the thing (I reckon similar
time needed as building 2-3 kits in reality)
why not buy a binned elise, ultilise the suspension and either create a tubular spaceframe that bolts to Lotuses tub to fit the lexus motor and audi
transaxle? at least most of it will work, and not as if 'just' creating a tubular back end is a months work. That way you get the
elecrics, wipers, pedal box, screen, all the odds and sods that aren't interesting but could drag the project down?
if you've watched the Elise story DVD, it was aimed at 750kg with a K series and it ended up 838kg (from memory), so the likelihood of scaling
up the dims by 10% and you getting it under 1000kg is marginal imho. Bigger wheels and tyres will instantly add 20-40kg for instance
great idea for a proj and not knocking you at all, just think you need to ensure that all the worst case scenarios are taken into account.
oh, and when its finished, can I have a go 
"Racing is life, everything else, before or after, is just waiting"---Steve McQueen
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johnH20
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| posted on 1/10/13 at 07:15 PM |
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Exactly my sentiments CNHSS1, and what I have in my day dreams. I think however the Elise ended up at a claimed 733 kg ( was that your typo ? ). My S2
135R with full tank, roof etc ready to go was 788 kg on calibrated scales, so a bare bones S1 at 733 kg is not impossible to believe. I have in mind a
Mazda KL V6 and Renault UN1 transaxle which should be doable on an S1 base at about 800kg. Wishful thinking?
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CNHSS1
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| posted on 1/10/13 at 07:38 PM |
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Ya dead right, was digging the weights from my poor memory lol
My point stands though, increasing the dims by 10% and going bigger wheels with fabricated parts will see it knocking on the door of 1000kg. The
suggested design is ball patk TVR, ally motor, fabricated chassis, grp body, 18-19" wheels and they tend to be just over 1000kg.
Even at that it would be great im sure, but the elises trump card is the light weight to give the sublime balance along witb some of the best chassis
techies in the world!
"Racing is life, everything else, before or after, is just waiting"---Steve McQueen
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iank
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| posted on 1/10/13 at 07:42 PM |
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carfolio.com (which is normally pretty good for weights and measures) has
K series ~714-756kg
Toyota ~ 852-876kg (!!)
Depending on the exact model.
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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b14wrc
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| posted on 1/10/13 at 08:08 PM |
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s1 was supposed to come in at 675kg, don't think they quite made it but it was close.
I can tell you with only 118bhp on tap in the standard car they drive very well and feel quick. Looking forward to getting the locost on the road!
20vt powered rear engined locost
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beppesignori
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| posted on 1/10/13 at 08:49 PM |
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Dry weight of my Elise is 699 according to my Certificate of Conformity. No doubt its a brilliant car.
However, this thread was about building a new chassis. No doubt the subframe idea is very doable. I even have access to a Speedster chassis, if I
wanted to go that route.
But i suffer from builderitis, and a severe case of starting new projecteritis. I built a seven, just finishing building my house(from scratch),
rebuild my Elise. I am going all in next time. Would like to have a go at a frame, and even designing a bodyshell.
Aim is to get the thing to weigh around 900 kg. But 1000 kg is no disaster. The 1UZFE will give an easy 300bhp with little modification and standard
torque is 380nm i believe. So it will be fast no matter what.
I also have no timeframe. Next year I will be racing the Elise in local series, and that should keep me going for a couple of years. But planning the
project is a big part of it, so just gathering information.
Hard part will be taking the Lexus apart...it has served me well.
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easytiger007
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 posted on 1/10/13 at 08:59 PM |
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http://www.super7thheaven.co.uk/blog/rover-v8-lexus-1uzfe-dimensions-a97.html
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