Board logo

Crazy idea...
sprouts-car - 20/5/09 at 04:55 PM

Basically the idea is this:

Put the engine and gearbox in the middle, no driveshaft (or very short) then the diff. The driver then sits in front of the engine.
The gear selection is sorted out with some rods/pulleys/cables (or maybe an auto box).

Now i know where are better ways to get this layout:
transaxel,
bike engine,
etc... but this is hard to beat for the cost
But what do people think of this idea?

And because everyone loves pictures here you go:
(My first attempt at 3D modelling like this, i basically took apart a model of a caterham and rearranged everything, the wheel base and track are the same though)
Description
Description

Description
Description

Description
Description

Description
Description


Right, now that's out of my system I'll get back to revising for my finals.

Cheers all,
Chris


scotlad - 20/5/09 at 04:59 PM

Fab pictures! Wouldn't the driver need to be around 2'6'' tall to fit though?


CraigJ - 20/5/09 at 05:00 PM

looks good but as you say it would be a lot easer to use a transaxel.


AdamR - 20/5/09 at 05:00 PM

It'd probably work OK from a mechanical point of view but why would you do it? Most 7s end up with pretty close to 50-50 weight distribution.

Also I think you'd really struggle to fit a driver (definitely no passenger) in the gap that is left at the front.


sprouts-car - 20/5/09 at 05:05 PM

quote:
Originally posted by CraigJ
looks good but as you say it would be a lot easer to use a transaxel.


I was thinking the sierra is pretty long, so maybe move the front forward in my pictures, to fit the driver.


sprouts-car - 20/5/09 at 05:07 PM

quote:
Originally posted by AdamR
It'd probably work OK from a mechanical point of view but why would you do it? Most 7s end up with pretty close to 50-50 weight distribution.

Also I think you'd really struggle to fit a driver (definitely no passenger) in the gap that is left at the front.



Not a real plan, just something to distract me from revising.


oldtimer - 20/5/09 at 05:08 PM

I don't fancy my feet sticking out the front of the nose cone. Just not enough room by the look of it.


cd.thomson - 20/5/09 at 05:09 PM

you would then end up with a very very light front end. I think the proportions youve given in the original pictures would be the only way to get an *almost* sensible weight distribution - but you couldnt fit a driver in.

Thatll be why its never been done


Memphis Twin - 20/5/09 at 05:15 PM

Been done before! (even with a live axle). F750 "Darvi 877"
You'd be better using a shorter gearbox.
If you used a shortened case gearbox from a Clubmans (like a Mallock) car you'd gain an extra 40cm or so.

But I'd spend £1500 or so and stick a Hewland LD200 or Type9 F3 (5speed) box up it's chuff...


iank - 20/5/09 at 05:27 PM

The 750 Formula guys do similar to that with a live axle. Only reason for it is if the regs say you aren't allowed a transaxle, otherwise you're just making a very heavy and long transaxle out of a sierra gearbox and diff.

Edit: shouldn't go and have dinner before pressing post.

[Edited on 20/5/09 by iank]


BenB - 20/5/09 at 05:32 PM

Your meat + 2 veg would be right next to the flywheel if it ever fragmented and exploded the bell(end)housing


mccsp - 20/5/09 at 05:42 PM

why not a front wheel drive set-up in the rear, would be more compact. Weight distribution issues, but could put the fuel tank at the fron and have a huge "boot"


blakep82 - 20/5/09 at 05:44 PM

or maybe if you made a different chassis, full bodied car (if you can within regs?)
make the chassis like a normal car, and you sit next to the engine, but not as far back as the flywheel


Guinness - 20/5/09 at 05:44 PM

Why not shorten the chassis, have the engine centrally and sit the driver one side and the passenger on the other side?? Sort of 3 wide.

The traditional layout of a 7 leaves the wheels sticking out and the body plan quite a bit narrower than the track.

Radiator could go in front of the front suspension, fuel tank above gearbox

Mike


MikeRJ - 20/5/09 at 05:52 PM

quote:
Originally posted by BenB
Your meat + 2 veg would be right next to the flywheel if it ever fragmented and exploded the bell(end)housing


Not if you are sitting in front of the engine??


blakep82 - 20/5/09 at 05:53 PM

something along these lines

Description
Description


blue is seats, black is pedal box, green is fuel tank, and around the engine build up like a huge transmission tunnel to enclose the engine

[Edited on 20/5/09 by blakep82]


tilly819 - 20/5/09 at 07:07 PM

you also need a short length of propshaft since if you dont have the 2 Ujs between the gearbox/engine and the diff the vibrations off the engine and gearbox on the rubber mounts will transmit down to the hard mounted sierra diff and shake the car to bits since the is not pro shaft and Ujs to take up the movement of the engine

sorry
Tilly


JoelP - 20/5/09 at 07:14 PM

having the car wide with the driver beside the engine would leave the car very unbalanced if there was no passanger. Far nicer to have a bike engine in the passanger seat, then the driver and the engine balance each other.


adithorp - 20/5/09 at 07:33 PM

If you used a bike engine then you don't have as much length issue and the engine sits on the n/s leaving room for the driver to only move forward a little bit.
The Fury Menace was done this way as is the new MEV.

adrian


sprouts-car - 20/5/09 at 08:54 PM

quote:
Originally posted by Memphis Twin
Been done before! (even with a live axle). F750 "Darvi 877"
You'd be better using a shorter gearbox.
If you used a shortened case gearbox from a Clubmans (like a Mallock) car you'd gain an extra 40cm or so.

But I'd spend £1500 or so and stick a Hewland LD200 or Type9 F3 (5speed) box up it's chuff...



Does anyone have any pics of this F750 "Darvi 877". Just out of interest


belgian2b - 20/5/09 at 09:46 PM

Why don't you use a gearbox with integrated output shaft .
You will have rear mid engine like the xtr4

http://images.google.be/imgres?imgurl=http://www.roadster.se/xtr4/Engine%2520Bay%2520XTR4%25201.jpg&imgrefurl=http://www.roadster.se/xtr4.html& ;usg=__HoKmZ4vo6dMHg1UtmxL2sOvpQk8=&h=750&w=1000&sz=134&hl=fr&start=1&um=1&tbnid=lqOzwkbMxSunhM:&tbnh=112&tbnw=149 &prev=/images%3Fq%3Dxtr4%26hl%3Dfr%26rlz%3D1B3GGGL_frBE313BE313%26sa%3DN%26um%3D1


see picture in the list .


Gerardo

[Edited on 20/5/09 by belgian2b]


mark chandler - 20/5/09 at 09:58 PM

Thats an audi transaxle in the XTR pictured above, cost £50 from a breakers, get one from an old 100gt and its take take loads of power.

You could also track down the rear axle from an alfa, soem have a dedion rear with integrated gearbox and diff.


Liam - 20/5/09 at 10:37 PM

Ridiculous idea with the layout, but where did you get those CAD models?


mr henderson - 21/5/09 at 06:56 AM

quote:
Originally posted by sprouts-car


I was thinking the sierra is pretty long, so maybe move the front forward in my pictures, to fit the driver.


I like your ability to use CAD, but usually people who are designing cars aren't quite so vague about the dimensions of their starting points

John

[Edited on 21/5/09 by mr henderson]