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22 Oct 2013, 08:21 (Ref:3321498) | #1 | |
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Join Date: Oct 2013
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Building Hillclimb Car from Scratch...
I have been tossing up some ideas on building a Hill Climb car from scratch.
I was thinking of building a backbone chassis but instead of having a seat on each side, I was going to fit the Engine/Gearbox on the LHS of the Back Bone (where the passenger seat would normally reside( with the drivers seat on the RHS. I was going to use a Range Rover Gearbox and transfer case as both front and rear shafts are offset to the Left so the front and rear prop shafts can run alongside the central tunnel to the front and rear of the car. The idea was that all the weight and componentry would be centrally mounted within the wheelbase which would allow free reign on under car aero. I was going to have the radiator fitted within the central backbone and have cooling air intake at the front and the radiator mounted in the middle near the engine and have the hot air exiting above the diffuser at the rear as infill. I was thinking Alloy Chev V8 as they are powerful, common and easy to mount to a Range Rover box in Australia. I was hoping to remove the low range stuff from the range rover transfer case to shed some weight and then mount all other weight (fuel, water and oil tanks etc) on the RHS to try and corner balance the car as best I can. I was going to clothe the car in a simplified prototype body with the central tunnel dividing two underfloor tunnels. Has anyone seen a car layed out in such a way? Can anyone think of any disadvantages to this method? The closest I could find in principle was the turbine powered indy cars which had the turbine where the engine/gearbox would be on my car: |
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28 Oct 2013, 22:00 (Ref:3324461) | #2 | |
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I've just subscribed to this thread! Very interested.
How much would a Chevy V8 weigh in the spec you want to run? Are you thinking Lt77 or R380 box? |
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30 Oct 2013, 15:46 (Ref:3325161) | #3 | ||
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Join Date: Aug 2004
Posts: 300
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Build a hillclimb car from scratch
Hi Mistareno
This has already been done and it didn't work that well. The great Jim Sword built JASAG 2 with a Rover V8 etc in it but, for whatever reason, it didn't work that well. I owned JASAG 3[ a brilliant clubmans car which I should never have sold], also built by Jim Sword who also did some really good bike-engined single seaters that were essentially a JEDI/OMS clone. At the risk of insulting you, if you don't have an understanding of chassis and suspension design, as well as an appreciation of aerodynamics, you would be better buying an already built car and refining it. I bought the MATADOR clubmans car. This was a one off; it looked right but never handled properly. It currently has a ZX12 stuffed in it and is being used on the hills. It had pushrod front suspension but it needed re-designing to get it to work really well. Being close to retirement age and having competed in speed events and circuit racing for donkey's years, I have seen and driven a variety of one-off cars. John Oxborrow built a sports car as well as a FFord and he knew what he was doing. My JASAG was great; I loved my Terrapin. Even my LOCOST was fun. You have to make your own mind up. Good luck if you decide to go ahead. You won't go wrong by reading Alan Staniforth's book and the one on chassis design by Costin and Phipps. The principles of structural design haven't changed over the years ! |
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Life is more fun at 60 than when I was 18 ! Arrive at the great motor sport circuit in the sky with a big grin, shouting "that was fun! What's next?" |
2 Nov 2013, 13:16 (Ref:3326288) | #4 | |
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No insult.
I do have a reasonable knowledge of aero and mechanical design but am by no means Adrian Newey. The thought of buying a car, whilst infinitely easier and cheaper denies the challenge of trying something different. Do you have any photos/info of the JASAG 2? I'd love to see it. Regards, Richard |
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3 Nov 2013, 18:14 (Ref:3326637) | #5 | ||
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Richard
Please PM me with an e-mail address and I will send you a pdf of the Jim Sword article from Triple C Chris |
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Life is more fun at 60 than when I was 18 ! Arrive at the great motor sport circuit in the sky with a big grin, shouting "that was fun! What's next?" |
8 Nov 2013, 06:25 (Ref:3328769) | #6 | |
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9 Nov 2013, 07:27 (Ref:3329233) | #7 | |
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Thanks for that. That's sort of what I was planning except for the driver to be sitting in the same spot as the engine on the other side of the backbone.
I'll have to google that class. I assume it's oval racing and the idea is to get all the weight on one side? Looks like a solid front and presumably rear axle? Still, interesting. Thanks for that. |
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9 Nov 2013, 08:43 (Ref:3329268) | #8 | |
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This is a very rough cut and paste, so it's not to exact scale by any means, but this is the layout I was going to try.
Been looking around at other drivelines that are similar in layout and there is a similar transfer case attached to the Suzuki Vitara which has a very light weight 2.7L V6. The transfer case in the Suzi has one directly out the back of the box and the front is offset, but could probably fab a new rear housing for the transfer case to run 2 offset tailshafts as per a range rover box. It would be a lot lighter and more compact. |
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10 Nov 2013, 09:42 (Ref:3329566) | #9 | |
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Cool idea.
The only thing I would change straight up is to ditch the backbone chassis for a space frame. The torsional stiffness of a backbone is woeful for the equivalent weight / just woeful actually. Tubular space frames are just lighter and massively more rigid than anything you can do with a backbone chassis. It is also nice to have major chassis members between you and whatever you hit, not perfect not perfect, but nice anyway! I would also place an external sissy bar on your side of the car as per the super modified, but that's just me! Sounds a great idea though! |
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10 Nov 2013, 10:16 (Ref:3329583) | #10 | ||
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Quote:
The 'backbone' was actually going to be a hollow tubular spaceframe with the radiator mounted within the hollow section alongside the engine. The spaceframe would be covered internally with light alloy sheet to make a smooth tube inside. Basically I was thinking along the lines of a stretched out and inverted P51 Mustang cooling system in profile through the guts of the car and using the hot air as wake fill at the rear and inserting the exhaust gas into the tunnel behind the radiator to energize the air. This is what the central 'tunnel' (the chassis) would look like side on: Centrally mounting everything It also means I could run a long large venturi tunnels starting just behind the engine and either side of the 'backbone' as there is no engine or gearbox to foul things at the rear. The height of the chassis would be the tallest thing on the car (apart from rollover bar etc and I would triangulate to the sides to mount the engine and drivers seat and run side intrusion bars to link them. Not sure if that makes sense? |
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10 Nov 2013, 10:45 (Ref:3329590) | #11 | |
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10 Nov 2013, 22:45 (Ref:3329768) | #12 | |
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Mistereno, moving the vertical components of your central backbone out between the wheels greatly increases the sectional area and therefore the rigidity of your chassis. You could use the sides of the chassis to act as your ground effect venturi walls/ end fences. The central backbone concept with out riggers has a very small area in comparison and has to be made very heavy; comparatively; to have the same strength!
The central radiator duct, you could just make a duct, I would at that stage move the radiator to the outside of the car out of the duct; it generates a lot of heat which you don't really want in the car; and then use the duct as a clear tunnel to really generate a low pressure under the car. Look at the Locost / Lotus 7 type of chassis, modified to put the engine and gearbox in the passenger seat. You can then play about with the changes you wish to make. It looks a really interesting project! |
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11 Nov 2013, 00:31 (Ref:3329798) | #13 | ||
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Join Date: May 2004
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What are the cams rules on scratch built vehicles like these days?
Back in the day Jim Richards had a mid-engined Falcon or Mustang and it was fast. I will have to look up in his book sometime. NZ had the Algie Alfetta as a mid-engined car, is 160 mph quick enough for you? http://youtu.be/z31NiRMqFG8 (Algie - from 1.48) Are there any spaceframe sportscars around to modify? Rhys Millen modded a Palmer to 4-wd adding a inline transfer case http://www.autoblog.com/2011/06/16/h...ak-hill-climb/ Are the Skelta used in hillclimbs? |
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11 Nov 2013, 06:11 (Ref:3329845) | #14 | ||
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Join Date: May 2004
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Remember to cover the front wheels if you are hill climbing on gravel as the front tyres usually spray gravel.
Steve Riley had a space framed 4wd Hayabusa powered machine for race to the Sky. Brett Hayward's similar machine was also quick. This is another Riley machine. http://www.performancegarage.com.au/...wd-dirt-monaro |
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11 Nov 2013, 06:42 (Ref:3329856) | #15 | |||
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Quote:
Probably something fairly simple like a late 90's alms style car such as the Riley and Scott MkIII but with a few changes such as scalloping behind the front wheels to relieve any high pressure build. I should be able to have a large diffuser starting just behind the transfer case and I'll try and reduce and/or aerofoil any suspension intrusions. Quote:
By releasing the cooling into the turbulent low pressure air behind the car it also reduces the required size of the front air intake and the wake infill should reduce the drag. I can place the radiator behind the drivers seat in the tunnel which should prevent any huge heat problems and then inject the exhaust into the stream on the hot side of the radiator. F1 teams a few seasons back were spending mega bucks on trying to smooth the mechanical components seen by the air flowing through the engine covers so they could have a high velocity flow exiting behind the car. I won't have an engine in the way to worry about. |
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11 Nov 2013, 23:24 (Ref:3330185) | #16 | |
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Hi Mistareno, my thinking was that your duct would be awesome in a land speed record car, or a salt flats car.
In a hill climb car though it would be a pity not to use a duct like that to really try and evacuate the air under the car and generate masses of downforce! How much of the car's time will be spent going around corners as opposed to going flat out? Your reduction in drag will be really good, but could the tunnel be better used? You will also need to circulate some air over the engine and it may be better to use a small NACA type duct to get air into the engine and radiator, slow the air mass down to go over all the hot components and then speed all the hot air up in an exhaust duct and exit it behind the car. |
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21 Feb 2014, 20:35 (Ref:3370772) | #17 | |
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Quote:
Looking at this picture, I cant help but feel that before you do lots of fabrication moving a gearbox output, it may be worth having a look at some front wheel drive gearboxes. As in just turn the complete engine and box through 90 deg. Something with a big gearbox would hopefully give enough room to run an inline engine if not a V. Maybe worth looking at the old Volvo T5 850! |
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22 Feb 2014, 21:38 (Ref:3371123) | #18 | |
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You could go lightweight and use a bike engine turned through 90 deg. This could allow the car to be quite small and therefore lighter. Legends racing cars in the UK use this arrangement but the engine is in front but slightly offset from the driver.
http://www.legendsracingeurope.com/spec-and-info |
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22 Feb 2014, 23:00 (Ref:3371138) | #19 | ||
Racer
Join Date: May 2004
Posts: 301
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Star
The Star cars are similar to the legend cars, but have a gsxr 1100 engine and fibreglass scaled down Australian car body. 147 hp engine and 500 kg
http://starcars.co.nz/ |
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4 Dec 2015, 14:11 (Ref:3595471) | #20 | |||
OldRacingCars.com
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Quote:
Many thanks Allen allen@oldracingcars.com |
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