Just about to start a build, need some advice!
Discussion
Right chaps, im just about to start a build, not a "kit car" by deffinition, but will require an IVA, so close.
Ok the plan -
I have a classic mini, i am going to remove the floor-pan, and create a spaceframe chassis to go under it, which will hold the engine (Rover V8) and drive train.
(dont worry ive done the measurements!) the body will basically drop over the chassis.
First question is:
What grade of steel tube would be best for the main chassis? 1", 28mm etc, and what thickness? 2mm?
Square section or round?
Next is chassis design, i have some ideas, but at the same time no ideas!
Peter
Ok the plan -
I have a classic mini, i am going to remove the floor-pan, and create a spaceframe chassis to go under it, which will hold the engine (Rover V8) and drive train.
(dont worry ive done the measurements!) the body will basically drop over the chassis.
First question is:
What grade of steel tube would be best for the main chassis? 1", 28mm etc, and what thickness? 2mm?
Square section or round?
Next is chassis design, i have some ideas, but at the same time no ideas!
Peter
Edited by darkcat on Tuesday 27th July 16:26
darkcat said:
Next is chassis design, i have some ideas, but at the same time no ideas!
Are you sure you are starting from the right place?There are so many questions that lead from your intoduction to this thread that one barely knows where to start. Perhaps by asking you-
where is the engine and gearbox going?
what sort of suspension do you plan to use?
what do you hope to achieve?
do you realise that the RV8 is somewhat passe?
Yes true i didnt really explain very well, was a coffee break message..!!
Ok, it is going to be front engined, RV8 up front, Borg warner T5 or SD1 gearbox, to a fixed rear diff (MX5 LSD), to some sort of independent rear suspension, not yet decided.
possibly MX5 again.
Front will be custom wishbones to coil over shocks, though i may just nick something off a fiesta or similar, depending on the space, and uprate the springs.
its very much at a planning stage at the mo.
its a project road car, not for the track, so basically for fun, nothing more, though obviously it needs to be reasonably safe!.
Yes i know the RV8 is rather old now, but im using it for 3 reasons: I have a spare! the parts are very cheap, and its got one of the all time great sounds.
Ok, it is going to be front engined, RV8 up front, Borg warner T5 or SD1 gearbox, to a fixed rear diff (MX5 LSD), to some sort of independent rear suspension, not yet decided.
possibly MX5 again.
Front will be custom wishbones to coil over shocks, though i may just nick something off a fiesta or similar, depending on the space, and uprate the springs.
its very much at a planning stage at the mo.
its a project road car, not for the track, so basically for fun, nothing more, though obviously it needs to be reasonably safe!.
Yes i know the RV8 is rather old now, but im using it for 3 reasons: I have a spare! the parts are very cheap, and its got one of the all time great sounds.
Just had a quick measure of an RV8 LT77 I have here, and it's about 1400 from front pulley to propshaft flange. The Mini's wheelbase is 2036 so that's going to be a very short propshaft and I daresay you will lose some cabin space too.
This means the engine will have to straddle the front axle (unlike TVRs, 7s etc) so the design will need to provide for taking the weight of the front end at two points (the upper spring mounting points) that can't have a chassis rail passing between them to stop them moving towards each other.
If I fancied dong somthing like this I would probably think along the lines of a TVR chassis and running gear, with a body stretch where the scuttle meets the bonnet, and big wheel arches.
Interesting project, though, I've often thought about doing something with a spaceframe chassis and a body from something classis on top (not a MIni, though, as I am a person of the tall persuasion)
This means the engine will have to straddle the front axle (unlike TVRs, 7s etc) so the design will need to provide for taking the weight of the front end at two points (the upper spring mounting points) that can't have a chassis rail passing between them to stop them moving towards each other.
If I fancied dong somthing like this I would probably think along the lines of a TVR chassis and running gear, with a body stretch where the scuttle meets the bonnet, and big wheel arches.
Interesting project, though, I've often thought about doing something with a spaceframe chassis and a body from something classis on top (not a MIni, though, as I am a person of the tall persuasion)
singlecoil said:
Just had a quick measure of an RV8 LT77 I have here, and it's about 1400 from front pulley to propshaft flange. The Mini's wheelbase is 2036 so that's going to be a very short propshaft and I daresay you will lose some cabin space too.
This means the engine will have to straddle the front axle (unlike TVRs, 7s etc) so the design will need to provide for taking the weight of the front end at two points (the upper spring mounting points) that can't have a chassis rail passing between them to stop them moving towards each other.
If I fancied dong somthing like this I would probably think along the lines of a TVR chassis and running gear, with a body stretch where the scuttle meets the bonnet, and big wheel arches.
Interesting project, though, I've often thought about doing something with a spaceframe chassis and a body from something classis on top (not a MIni, though, as I am a person of the tall persuasion)
Ah thanks for measuring up (Doesnt the LT77 have a low/high box on there too?) , yes it'll be a short prop shaft, but thats no problem as far as i can see, neither is cabin space. I intend to mostly remove the bulkhead if needed and will most likely have to move the seating position back a way. This means the engine will have to straddle the front axle (unlike TVRs, 7s etc) so the design will need to provide for taking the weight of the front end at two points (the upper spring mounting points) that can't have a chassis rail passing between them to stop them moving towards each other.
If I fancied dong somthing like this I would probably think along the lines of a TVR chassis and running gear, with a body stretch where the scuttle meets the bonnet, and big wheel arches.
Interesting project, though, I've often thought about doing something with a spaceframe chassis and a body from something classis on top (not a MIni, though, as I am a person of the tall persuasion)
Luckily i have a TVR to inspire me and have spent many "great" hours under the bonet. I could do as the TVR and build an engine cage from large square section and mount the suspension directly to that. then off the back of that build the transmission tunnel, finally constructing a floor pan.
infact the tvr runs 2 large square sections as a sort of back bone. sounds like a plan to me.
I MAY need a slight bonet-lump to accomodate the plenum chamber. or i could run a bit higher.. depends how it fits when i start to mock up. next thing to think about is cooling, of course....
Im getting the Mini tomorrow, so will start stripping the subframes etc off.
Edited by darkcat on Tuesday 27th July 17:37
You may want to check out this book: http://www.kimini.com/book_info/ seems quite similar to what you want to do.
Be worth a check on the locostbuilders chassis section for tube sizes and stuff - a few engineering types hang out there.
http://www.locostbuilders.co.uk/forum/2/
http://www.locostbuilders.co.uk/forum/2/
I feel the need to throw in the plea for caution.
If a CAD design system were employed along with its stress calculation functions I would be reasonably confident the new chassis was going to cope with this big engine.
Failing that if the builder/designer had some years of experience in engineering and could just look at the design and materials and know it will work then again a level of confidence would exist.
In this case neither of these fundamentals appear to be evident so I am deeply concerned for the safety of the finished article.
I have huge respect for someone who wants to 'have a go' and on a project that seems to have no other purpose than to scratch and itch or do something because it's there. Just be very careful and err on the side of 'Brick $hithouse' rather than 'light weight' with your design.
Steve
If a CAD design system were employed along with its stress calculation functions I would be reasonably confident the new chassis was going to cope with this big engine.
Failing that if the builder/designer had some years of experience in engineering and could just look at the design and materials and know it will work then again a level of confidence would exist.
In this case neither of these fundamentals appear to be evident so I am deeply concerned for the safety of the finished article.
I have huge respect for someone who wants to 'have a go' and on a project that seems to have no other purpose than to scratch and itch or do something because it's there. Just be very careful and err on the side of 'Brick $hithouse' rather than 'light weight' with your design.
Steve
Steve_D said:
I feel the need to throw in the plea for caution.
If a CAD design system were employed along with its stress calculation functions I would be reasonably confident the new chassis was going to cope with this big engine.
Failing that if the builder/designer had some years of experience in engineering and could just look at the design and materials and know it will work then again a level of confidence would exist.
In this case neither of these fundamentals appear to be evident so I am deeply concerned for the safety of the finished article.
I have huge respect for someone who wants to 'have a go' and on a project that seems to have no other purpose than to scratch and itch or do something because it's there. Just be very careful and err on the side of 'Brick $hithouse' rather than 'light weight' with your design.
Steve
Hi Steve!If a CAD design system were employed along with its stress calculation functions I would be reasonably confident the new chassis was going to cope with this big engine.
Failing that if the builder/designer had some years of experience in engineering and could just look at the design and materials and know it will work then again a level of confidence would exist.
In this case neither of these fundamentals appear to be evident so I am deeply concerned for the safety of the finished article.
I have huge respect for someone who wants to 'have a go' and on a project that seems to have no other purpose than to scratch and itch or do something because it's there. Just be very careful and err on the side of 'Brick $hithouse' rather than 'light weight' with your design.
Steve
Yes i fully understand and agree with what you are saying! I do have a good knowledge of stress/material design, and fully intend to, as you say, over-build. This is not goin to be a speed machine or a race car, purely a project / go to the pub / show car.
id love to CAD it, but there are so many unknowns that its impossible to plan like that.
So, for the actual chassis, i have been doing some research, and have come to this basic design:
approx 1.5x3" square section front to rear ladder frame, with frame up front to hold the engine and suspension, very much like the TVR chassis.
with 25/28mm square section to create the floor pan and transmission tunnel.
not 100% on the exact design yet, but does this sound about right?
If so, what thickness of steel square section should i be going for? 2mm?
Im going to have a play around with solid works later and see what it looks like, now i need a solidworks Mini mesh...
approx 1.5x3" square section front to rear ladder frame, with frame up front to hold the engine and suspension, very much like the TVR chassis.
with 25/28mm square section to create the floor pan and transmission tunnel.
not 100% on the exact design yet, but does this sound about right?
If so, what thickness of steel square section should i be going for? 2mm?
Im going to have a play around with solid works later and see what it looks like, now i need a solidworks Mini mesh...
NiceCupOfTea said:
darkcat said:
yazza54 said:
Won't the mx5 diff just have a prolapse with all the torque?
not necasarily, the light weight + small tyres will put less torque on the diff.Sounds good though, try it, break it, fix and beef it up! Only way to develop!
Gassing Station | Kit Cars | Top of Page | What's New | My Stuff