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-   -   Chassis for a dino (http://www.madabout-kitcars.com/forum/showthread.php?t=6224)

thecarbuilder246 4th January 2017 15:20

Chassis for a dino
 
Hi

I'm looking to build a chassis with more up to date components for a dino build.
I currently have a rolling chassis built up with a dino 206 body fitted to it. (Deon GT)It's fitted with a cosworth v6 engine mated to the ford rs turbo box as per the dino build.
My reasons are that I want to remove the high cill sections present at the door openings, and remove the massive centre tunnel/backbone section. I also wish to upgrade the gearbox to either a ford focus mk2 st225/rs gearbox or toyota mr2 turbo one, to give me a better gearbox but also give me a cable change which will enable a better looking centre tunnel. My plan is then to fit a 246gt bodyshell.
Any input greatly recieved.

ian

redratbike 4th January 2017 17:44

Can the one you have be modified to get where you need to be?

thecarbuilder246 5th January 2017 09:26

chassis
 
Hi

I don't really want to cut and shut the one I have. The 246 dino has a slightly longer wheel base than the 206. I intend to use it as a starting point for a new chassis and alter it as I need. My plan being to sell on the deon at a later date.

ian

thecarbuilder246 6th January 2017 17:15

chassis
 
Hi

My current plan is to use a double wishbone front suspension set up similar to the deon, but using a modern billet alloy front upright with correct 5x108 bolt pattern so enabling the use of the correct cromadora wheels.These will be fitted with a 300mm vented disc and four pot calipers.I may use the mini rack as used on the deon as these are still available new.
At the rear is where the real work is needed. As stated by ross in another post on this forum fitting a V6 engine with the gearbox mounted end on, space issues mean that top wishbones end up very small.I know it's not strictly dino replication, but I'm looking at a macpherson strut arrangement on the rear with a bottom wishbone. This will allow me more room for the engine. Similar to the set up that is used on the Lancia stratos replica. Again using a billet upright with correct 5x108 hub,300mm vented disc and four pot calipers, along with a pair of brembo hand brake calipers.
My idea is to build a front chassis section with all suspension fitted,a rear section with engine/gearbox and suspension and join the two with the centre floor pan section. I intend to use 75mmx50mm out riggers with a smaller section to join the two.
What do others think?

ian

thecarbuilder246 10th January 2017 09:18

chassis
 
1 Attachment(s)
hi

just a quick pencil sketch but something like this. 50x50mm box section front and rear sections, 75 or 100mm x 50mm box section for perimeter of floor pan. I plan to have a bolt on structure to support the boot floor with bumper mounts at the rear,and a similar front structure for bumper and radiator mounts that bolts on at the front.

ian

redratbike 10th January 2017 21:56

Looks good to me

rossnzwpi 17th January 2017 18:49

Good start Ian. A couple of points:
the 30mm brakes may not fit in cromodora wheels. Alfa 166 hubs are the right size (5x108mm and correct centre bore, unlike Ford 108 hubs)
Mazda Mx5 front, fitted with Alfa 166 hubs, is almost ideal.
Chassis triangulation is essential. If you think of a triangulated box you get the picture - it is rigid any way you look at it. Take away one face or one triangulation and you have a problem. Racing cars built around road cars have big diagonals across the doorways. If you want unrestricted cabin doorways and no centre tunnel then you are left with the original Ferrari-type design of an overly heavy floor (platform) that actually is not very stiff. Stiffness is needed for modern tyres and suspension geometry. In the good old days chassis twist was actually accepted and used as part of the geometry and the skinny tyres would give way long before the grip imposed too much force on the chassis. Now days it is different.....

rossnzwpi 19th January 2017 00:04

http://roa.h-cdn.co/assets/cm/14/47/...r_1r1p1-lg.jpgThe Factory Five 818 is a good example of an interesting chassis. It isn't a replica though and sacrifices access in favour of rigidity:
http://www.roadandtrack.com/car-cult...rive/?zoomable

http://roa.h-cdn.co/assets/cm/14/47/...r_1r1p1-lg.jpg

I hope this picture link works - I'm not having much luck inserting them!
cheers
Ross

thecarbuilder246 19th January 2017 09:20

chassis
 
2 Attachment(s)
Hi
I'm looking to build a back end something like this. This is a stratos replica built using an alfa engine.
The front suspension would be along the lines of the old deon but using modern mechanicals.

thecarbuilder246 19th January 2017 09:32

chassis
 
1 Attachment(s)
Hi
Although this is an old picture, this is the front end of the deon. My plan is to shorten the front overhang and have a bolt on section to carry the radiator, bonnet hinges and front bumpers. This way the chassis around the suspension mounts/steering rack can have a larger build material than the bolt on section giving a stiffer structure.
Something else has come to mind regarding the large outer chassis rails.These could be swapped out for a double smaller rail using a triangulated arrangement that sits behind the dino's cill.

redratbike 19th January 2017 19:05

Is your chassis a copy of an original or specific to the kit it's fitted to

If you wanted a different style chassis I believe the "cascu" chassis Is better suited

thecarbuilder246 20th January 2017 17:16

chassis
 
Hi
The cascu chassis is an exact copy of the original dino and as such requires dino suspension components. These can come from a 308dino or an original 246dino.
Nobody would scrap an original 246dino to build a recreation 246, with the price they fetch it would be restored. Similar story with the 308dino/gt4. These are rapidly going up in price and it wouldn't be worth it to scrap one justt to source the components needed.
There are other problems too, the main one being the engine bay, It's designed around the ferrari engine and gearbox-with the gearbox being underneath the engine, not for an end on gearbox fitment.
I want a more bespoke chassis built with more up to date mechanicals,not with an aging 30 year plus donor. I have a new crate V6 engine and I'm hoping to mate it to a modern Ford Focus RS gearbox. The engine cradle/bay is to be my starting point.

rossnzwpi 21st January 2017 04:18

Hi Ian, the Stratos replicas are very interesting - Lister Bell's in particular. This link is to a Lotus Europa scratch built chassis project which I find interesting for its smaller tube triangulation and use of Mazda MX5 components:
http://fortinimillwork.com/car.htm
cheers
Ross

rossnzwpi 22nd January 2017 20:26

I just found this website. It has very useful info on designing a sports car (or racing car) from scratch, including links to free software:
http://www.buildyourownracecar.com/r...esign-process/
cheers
Ross

rossnzwpi 22nd January 2017 20:34

I learned something about triangulation - the difference in strength between compression and tension - in the first paragraph of reading this! http://www.buildyourownracecar.com/r...cs-and-design/
cheers
Ross

thecarbuilder246 28th January 2017 08:55

chassis
 
Hi

Funny I had been reading these pages myself recently! It was actually the guys at LB who suggested the macpherson strut arrangement at the back. They use it in heir stratos replica to very good effect. It'll give you more room for an end on transmission too.Front steering and suspension is very similar to the deon just modern donor parts but all purchased new. He has invited me up with my 16" cromadora wheels to see if they fit his set set up using 300mm discs, so I could possibly use his mechanicals in my build.Also looking at an engine cradle similar to his as a starting point to.

ian

rossnzwpi 29th January 2017 08:54

Stratos vs Dino 246. Before getting too excited about the Stratos and chapman strut type suspension do a quick measurement of the available space in a Dino body. I once thought a Toyota MR2 rear strut would work before I discovered it was over two inches too high for the bodywork. It'd be a great solution if it fits!

thecarbuilder246 29th January 2017 13:47

chassis
 
Hi
Funny that! I was thinking the same thing about height issues. LB have all their suspension components made to measure, so to speak, so I'm guessing the struts and springs could be made shorter? The top mount could be lowered to fit under the dino's body.
I know with the Toyota MR2 they fit lowering struts and springs thus lowering the whole car to the ground. I'm guessing if you lowered the top mounting points and fitted the lowered suspension the car would keep the normal ride height?
Alternately there must be some cars out there riding on mcpherson struts with a lower bonnet line? the MX5 springs to mind? I myself do think it would be a better solution to an end on transmission fitment.
ian

rossnzwpi 31st January 2017 08:33

strut rear suspension
 
The DGT/Deon is a strut front suspension but with the actual strut replaced with wishbones and coilover. You could try the actual suspension from the car you've sourced your engine/transaxle from. This will require complete rethink of geometry though which is way beyond me! Or you could look at MGF. Someone on here already went down that route with an Alfa 166 hub adapted to it.

Modern suspensions tend to have different offsets to the cromodora wheel though.

rossnzwpi 31st January 2017 08:38

like this:
http://pictures.topspeed.com/IMG/cro...-22_600x0w.jpg


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