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Front Wheel Drive?
environ - 19/6/02 at 08:52 PM

Is is possible to make the locost with a front wheel drive engine say a golf/polo?? Has anyone done this and is it possible or can they only be rear whell driven.

cheers


Fatboy Dave - 19/6/02 at 08:55 PM

The only problem is the Locost would look silly with a FWD engine upfront. The chassis is also not wide enough. You could put a FWD setup out back, making it mid-engined, but that ain't exactly easy either.

You pays your money.........


Jon Ison - 19/6/02 at 08:57 PM

the choice is yours M8.........not seen one but there is no reason whatsoever why it can't be done, just be an odd shape at the front.......

Why not mount the FWD engine in the rear, just lock the track rod ends to the chassis with rose joints or bushed tubes, it is much more fun hanging the rear out than fighting terminal understeer.........everyone as a point of view, but having built several autograss cars mounting FWD engines in the rear my veiw would be it is actually quite easy.........no trans tunnel, no prop, no bellhousing worries, no clutch probs.....

what is it Nike say....."just do it"

happy building


interestedparty - 19/6/02 at 09:10 PM

Jon
Is there any particular engine/gearbox combo that you would reccommend for this? I'm thinking about the gear linkage, on a lot of fwd units it comes out the back of the box

John


stephen_gusterson - 19/6/02 at 09:10 PM

I have heard that using a fwd setup in the rear of a car gives problems with steering geometry. Apparently, the wheel will scribe strange angles as it moves up and down, with the normally steered hubs tied in a fixed position.

You can probably tell i know jack about it, its just I have heard this more than once on TOL.

However, I recon it could be a good idea. I originally considered using a mini front subframe complete, in the back, and it might work. However, you then have the gear change and hand brake to work out.

If you take a look at a locost chassis, you will soon see that the front tapers quite narrowly at the front. I cant see how you would fit any kind of fwd set up in there. Look at a real life chassis and its instantly a no go.


atb

steve


Fatboy Dave - 19/6/02 at 09:21 PM

quote:


I have heard that using a fwd setup in the rear of a car gives problems with steering geometry. Apparently, the wheel will scribe strange angles as it moves up and down, with the normally steered hubs tied in a fixed position.




I've heard this too. I suppose it's the equivalent of bump steer with fixed rods. You probably won't have a problem if you mount the tie rods in the same frame as the lower wishbone (i.e. the wishbone and tie rod scribe the same arc under suspension travel).

Well beyond me though. I'll stick to spannering......

And on the theme of the Mini, well, why not find a rusty mk1 MR2? all problems sorted for you then.


Jon Ison - 19/6/02 at 09:26 PM

here goes, the 1300 cc autograss class was dominated by rear engined "A series" engined cars till the bike came along, mounted both with or without there subframes, top n btm wishbones are fabricated, bit like the ones on the front of a locost, mounted paralell to stop any movement you remarked on above, the steering arm is mounted to the chassis with as long a rod as possible, ideal they meet in the middle, usually made adjustable so you can adjust rear toe (how many cars can do that) been able to adjust rear toe can have a dramatic effect on the handling of the car, induce, reduce oversteer, straight line stability, traction,
the 2000cc class is still dominated by the 16v Vauxhaul mounted in the rear much the same as above, if i could draw on a pc i would show you the gear linkage used but i can't, will try n get a sketch scanned n post it, but if you saw my linkage at newark it is along the same lines but simpler, it is best done using rose joints to cut the slack, but you end up with a very short gear lever aka what you used to see in F1 cars, probably in a locost i would mount it on the chassis rail by my right knee...
As for a paticular engine, for tunability 16v vauxhaul everytime, plus the fact its a tried n tested route, if you do go Mini, you MUST fit a center oil pick up pipe, or the bottom end will go on the 1st corner, you have been warned.......there think that covers most of it


Jon Ison - 19/6/02 at 09:42 PM

ah, just thought, next time you get the chance have a look at the rear of a "Formula 1st Race car" you will find FWD engine rear mounted in there....cant remember if there CVH or 1600 Vauxhaul....
oh and one last point, the susspension travel used on grass is "As much as you can get" i guess i have 3/4" max, so any "bump steer" movements if present are minute.


stephen_gusterson - 19/6/02 at 10:26 PM

quote:
ah, just thought, next time you get the chance have a look at the rear of a "Formula 1st Race car" you will find FWD engine rear mounted in there....cant remember if there CVH or 1600 Vauxhaul....
oh and one last point, the susspension travel used on grass is "As much as you can get" i guess i have 3/4" max, so any "bump steer" movements if present are minute.



I have actually driven a formula first car around silverstone!

Its one of those half day racing experience days.

We were told that the engines were out of 1600 fiestas, so its gotta be the CVH then - or at least the cars at the john watson school at silverstone have them.

atb

steve


Simon - 19/6/02 at 10:36 PM

Hi all,

My thoughts for this poser!

How about a normal front engine/rear drive engine/box combo, turn 180 degrees and drive the front diff of a Sierra 4x4. Suggest checking input rotation of diff or you may have a rear drive car that goes very well - backwards!!!!

Alternatively, put typical FWD engine/box combo in the "boot" and up front have mobile burger bar, bbq or an 80 gallon fuel tank

Just my thoughts

ATB

Simon


Liam - 20/6/02 at 03:32 PM

quote:
How about a normal front engine/rear drive engine/box combo, turn 180 degrees and drive the front diff of a Sierra 4x4.


Eh? Dont quite get what you mean. Sierra 4x4 front diff is pretty much like any other diff. Smaller than most rear diffs, mind you.

Liam


Alan B - 20/6/02 at 07:54 PM

quote:
Is is possible to make the locost with a front wheel drive engine say a golf/polo?? Has anyone done this and is it possible or can they only be rear whell driven.



The wide availibility of FWD cars was my main motivation.

http://www.desicodesign.com/meerkat/


OK, so I used an MR2, but as someone mentioned a lot of the problems (gear change, handbrake etc.) are already sorted.

quote:
How about a normal front engine/rear drive engine/box combo, turn 180 degrees and drive the front diff of a Sierra 4x4. Suggest checking input rotation of diff or you may have a rear drive car that goes very well - backwards!!!!



Don't you mean turning it 90 degrees and having front and rear driveshafts? If you do, I've seen it done before, and the main problem (if it is a problem) is you get two lots of final drive reduction and consequently a very low final drive ratio.
If you didn't mean that, then sorry.


Alan B - 20/6/02 at 08:05 PM

quote:
quote:
--------------------------------------------------------------------------------


I have heard that using a fwd setup in the rear of a car gives problems with steering geometry. Apparently, the wheel will scribe strange angles as it moves up and down, with the normally steered hubs tied in a fixed position.

--------------------------------------------------------------------------------




I've heard this too. I suppose it's the equivalent of bump steer with fixed rods. You probably won't have a problem if you mount the tie rods in the same frame as the lower wishbone (i.e. the wishbone and tie rod scribe the same arc under suspension travel).



It IS bump steer, but just as you do at the front it has be designed out of it. It is no different from any rear suspension design really in terms of design goals.

If the FWD unit had little bump steer when installed originally then it will be OK to duplicate the rack inner pivot point as an anti-steer link mounting point. However, it is my understanding that many FWD units did NOT have little bumpsteer for whatever reason and that must be allowed for in the design.


Simon - 21/6/02 at 08:41 AM

Liam / Alan B

It was actually a bit of a wind up.

My opinion is that this type of car should be front engine / rear wheel drive (but that's MY opinion), so thought I'd put in a stoopid idea - ie front wheel drive using normal front engine/RWD engine. Given the Sierra engine/box combo is getting on for 5 (ish) feet long, you'd have trouble turning it 90 deg. That's why I suggested turning it 180 deg, to drive the front diff of a 4X4 Sierra.

Like I said, that's my opinion. As for my suggestion, you were supposed to laugh. Didn't work apparently. Oh Well

ATB guys

Simon


Liam - 22/6/02 at 04:20 PM

Ooooh, right. It all makes sense now. I thought you were still talking about making it RWD. But a FWD locost - truly AWESOME .

Unfortunately it seems that even though most of us are british, you still occasionally need these things ( ) for people to be able to see sarcasm in text. Or maybe it's just me...

Liam


Simon - 23/6/02 at 10:08 PM

Liam,

If I had figured out how to use those faces you (and others) put on your posting, I would have done. Sorry, I'm a bit stoopid in that respect - don't even know what they're called (1st forum I've belonged to - and a bit ignorant of such things. Also, bit of a traditionalist too. So you get things like:-)

As for the rear wheel drive bit - if the diff input shaft rotation was wrong for the g/box output, you would indeed have a rear wheel drive car. It would also be rear wheel steering, and have brake lights at the front. Reversing lights would be pretty good though. You would also, I suspect, get the most monumental neckache

Hope that's all clear now, and apologies for any confusion:-)

All the best

Simon


David Jenkins - 24/6/02 at 07:50 AM

quote:
If I had figured out how to use those faces you (and others) put on your posting, I would have done. Sorry, I'm a bit stoopid in that respect - don't even know what they're called.


'emoticons' is the trendy name - 'smileys' to most people!


jbmcsorley - 25/6/02 at 09:28 PM

In fact, you're already using the emoticons in the form of ;-) ...

pull of the nose (the dash) and the forum will automatically convert the emoticon to a graphic. For instance, ":)" will be converted to a standard smile (if I hadn't disabled the feature to demonstrate my point)

;)

-jim m.