Hi All,

I was having a little think the other day while reading some thing on 4wd systems, I am planning my locost build around a mid engined chassis using a FWD donor car. This is a very simple way of doing it in my opinion as the complete drive train can be used from the donor car, I will use the same hubs, drive shafts and gear box, basically bolt it in…..

Now, looking at the ford twin cam 4x4 as an example, the gearbox houses a transfer box on the side which directs power forward to a front differential and front drive shafts.

If you look at my quick sketch – would any one suppose this concept would work? If not why? Has anyone tried it??




Try not to think of the space requirements, that could be an issue, the motor chosen will help or hinder the fitment into a standard(ish) locost.

Rob

I thought about this and it has been done with off-road trail vehicles but there is one essential problem that was pointed out.

The FWD set-up already has one diff with a 3.5:1(ish) reduction ratio, then the front and rear diffs will have another 3.5:1(ish) reduction ratio. so if the FWD car is geared to do 140mph its top speed with the extra diff and tiny 13" wheels will be about 40mph.

[Edited on 13/7/11 by Doctor Derek Doctors]

You will be going everywhere slowly.

You will be geared down with the tranverse gearbox and then gear yourself down agen with the final drive ratio diff.

Which is great for rock crawling 4x4 machines but no good for on the road

Its been covered before somewhere on here

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Originally posted by b14wrc
Hi All,

I was having a little think the other day while reading some thing on 4wd systems, I am planning my locost build around a mid engined chassis using a FWD donor car. This is a very simple way of doing it in my opinion as the complete drive train can be used from the donor car, I will use the same hubs, drive shafts and gear box, basically bolt it in…..

Now, looking at the ford twin cam 4x4 as an example, the gearbox houses a transfer box on the side which directs power forward to a front differential and front drive shafts.

If you look at my quick sketch – would any one suppose this concept would work? If not why? Has anyone tried it??




Try not to think of the space requirements, that could be an issue, the motor chosen will help or hinder the fitment into a standard(ish) locost.

Rob

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Hi mark has built one if you want to know how contact us we used 4x4 sierra 2.0 not to hard when you figure it out give me a ring if you like 07933787810
Cheers Ali

^^^ your not alone - there are quire a few '7 style' cars that have been made to use the sierra 4x4 setup (someone with a better memory will know who they all are on here) - dax even make an off the shelf kit for it
but all of these are a front-rear layout.....


as for the FWD to 4x4 the problems have been mentioned above

why the need for mid engine?

why not something like the 4x4 sierra engine with weight distributed better at the back with battery electrics etc behind the seat????

......

what about twin bike engine (busa) etc.....

As has also been covered before, why add the weight and complexity of any 4WD system to a 7 style car?

Why ??

is the biggest question, if you want a 4x4 by a landrover,

and as Tomgregory said, plus it will be another non finished car in 10 years
Sorry to be so negative, but out of the 10500 members on here, there is only a small percentage of completed road worthy cars

Steve

Hi,

Totally did not see the diff issue, correct, you would end up with a further reduction, not wanted! So unless the centre diff could be changed to 1:1, the car would be slow!

Emm…. Every one has their own views and preferences, but just for my two pence worth, I thought the whole idea of a locost was individuality and building something totally different to any thing you can buy? So that’s one reason for mid engined power as is the wide variety of FWD units for the mid engined purpose. Cost also can be reduced in finding less expensive donors (not in my case….)

4x4 has always interested me, and surly having four wheels griping the black stuff is better than two wheels?

For the extra weight added, just add a turbo and more power? I have not been in a nice 160BHP Zetec powered car, but I am sure it is rapid, but for people that want more than rapid - would 4x4 not help? There are limits to how much power can be effectively delivered to the road, I just wondered if anyone had gone down this route.

I agree that the diff is a non starter in my question – but can’t see that 4WD should be eliminated altogether. The japs seem to have mastered four wheel drive!

My car will end up being mid engined as that’s the engine and design I have gone for – hoping it does not take me 10 years to finish it, but if it does so what. It’s a hobby and other commitments come first.

Take your points about complexity of such a system, but as an engineer, I like trying new ways of doing things….. personally I don’t think the sierra 4x4 offers the best power package, and with the front shaft running through the sump you are fixed with this engine, I just wanted to think about alternatives and consider if the engine I have would work in a 4WD arrangement.

Thanks for the views – I will stick to mid engined power on this build – future builds (if by the time this one is done….) I do it again I would consider a big powered 4x4, just to show I could really.

Rob

if you were to start with a 4x4 donor, like subaru, sierra 4x4, or skyline gtr (oh my) so you take the transfer box that comes with the engine, then no reason why it can't be done!
don't let people that haven't tried it before put you off

[Edited on 13/7/11 by blakep82]

As above - the problem with your proposed layout is explained well enough.

The ford system is the only real option in something 7-shaped. Has 2/3 rear torque bias too which is another thing your idea would lack. That's what I'm using in mine. You're not stuck with the ford engine - you dont want the front axle going through the sump anyway. My engine is further back than most locosts (my chassis is not 'book' proportions either), finished weight including screen, etc will be around 650kg which isn't bad really for a V6 CEC (the 4x4 doesn't really add too much), and distribution almost bang on 50:50 - better than what you would get in a typical small lightweight middy CEC which will be heavily rear biased, arguably making a powered front axle of little benefit.

Have a look in my photo archive. Unfortunately after getting so close to completion I've done literally nothing for almost four years! Lot's of reasons including marriage, moving, renovating a house, moving more, career taking off, and now I've just started a year assignment in Norway so it wont be for at least another year! Still none of the reasons are to do with the added complexity of the 4WD, which isn't all that much to be honest.

Why? Cos I can Always preferred 4WD cars for fun and only really became dead set on building a locost (all those years ago ) after realising 4WD was a possibility.

Good luck and fire away with any questions. There have been a few builders of 4WDs over the years but I know of no finished on the road cars - would be interesting to hear more from ali 27.

[Edited on 13/7/11 by Liam]

Rob,

To add to what's been said....

Yes indeed that layout is often used, guys round my neck of the woods (central Florida, but I'm from Preston originally...)often take the common V6 FWD units from GMs (Chev, Buick, etc.) and use those to build swamp hunting buggies. The lack of top speed is not a problem so the layout works well.

Steve is right, a lot of cars do not get finished, but with enough time, money and focus there is no reason yours will be one of them.

Alan

For sale sierra 4x4 u2u me serious sale

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Originally posted by steve m
Why ??

is the biggest question, if you want a 4x4 by a landrover,

and as Tomgregory said, plus it will be another non finished car in 10 years
Sorry to be so negative, but out of the 10500 members on here, there is only a small percentage of completed road worthy cars

Steve

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ive started work on mine after a few years off , i was using a 3.9 rv8 but am now using a saab b234 mated to a v6 xr4x4 box with a big holset turbo . apart from having all the 4x4 bits i will be running over 450whp so need the extra traction .

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Originally posted by b14wrc
4x4 has always interested me, and surly having four wheels griping the black stuff is better than two wheels?

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quote:

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Originally posted by b14wrc
Emm…. Every one has their own views and preferences, but just for my two pence worth, I thought the whole idea of a locost was individuality and building something totally different to any thing you can buy?

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quote:

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Originally posted by froggy
ive started work on mine after a few years off , i was using a 3.9 rv8 but am now using a saab b234 mated to a v6 xr4x4 box with a big holset turbo . apart from having all the 4x4 bits i will be running over 450whp so need the extra traction .

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the only problem i see using sierra running gear is the front diff is in the sump which is behind the line of the front axle

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Originally posted by Gazeddy
the only problem i see using sierra running gear is the front diff is in the sump which is behind the line of the front axle

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quote:

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Originally posted by Gazeddy
the only problem i see using sierra running gear is the front diff is in the sump which is behind the line of the front axle

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front prop 2

Hi as you said on the sierra the shafts run through the sump we changed that and mounted the front diff in the front of the chassis allowing the engine to be mounted as far back as you want we used 2.0 i4 engine but cosworth would fit just as well.
Cheers Ali

Froggy - I like your style! Exactly the sort of monster I was talking about. 450bhp through the back wheels would be a 'handful' to say the least in a car of this nature. 4x4 is a def must! Look forward to updates.

Rob