Gravel/forest Setup

[lahondal 17]

Hi!

 

Im building a 205 Gti 1600 as a cheap project, and I have to set up a cheap suspension...I know some tips for tarmac, but no idea for gravel/forest....

 

The car is going to rally on very bumpy gravel roads, which will be a cheap OE parts to mix for this discipline?

 

Greetings....David.

[brumster 135 1 Cars]

I wouldn't consider running much OE to be honest. You really want to look at coil-over Bilsteins as your starting point, if you can. Mainly for durability, not necessarily performance. Some other manufacturer products might hold up to the abuse too (ASTs maybe?) but I've no first-hand experience of them.

 

Bad news is none of them are exactly 'cheap' but if you don't want to be replacing or rebuilding them every event, it's something you should consider. I know of someone who put some fast road units on a forest car and they were f*cked after the first stage!

[lahondal 17]

Hi all.

 

Well, yesterday i dont have too much time and the post was not the best writed ever...

 

The car will be used only in one or two events (here gravel rallyes are very rare) a year, and im building a tarmac spec 205 turbo 8v too, the car which receive the major part of the money, so cheapness is a must. If the gravel car can race 32km in a day (4 little stages), its all ok.

 

I have at home some pieces, a drum-type 309 beam, GTi subframe, and a lot of other parts to complete it.

 

I want to do this:

 

-309 Ream Beam, with a larger ET wheels for narrowing the rear track.

-Stiffer rear ARB.

-Simple 205 subframe, which will be converted to GTi type subframe. Im thinking on adding camber by pushing out the rear silentbloks.

-Strandard shocks with diesel springs.

-No front ARB.

-No LSD.

 

This is one option, the other is welding the diff, and stiffen the front ARB, and soften the rear. The theory says that with this configuration the front inner wheel tends to take air and aids to turn with a welded diff.

 

Anyone have tried this?

[welshpug 1,655]

I would discount the idea of a 309 beam for a gravel/forest car, you need as much wheel travel as you can get.

[lahondal 17]

Its a drum type beam, so the track is almost similar to the 205 Gti rear beam.

 

And Im going to use a larger ET rims, to compensate the wider track.

 

Whats the general setup for a gravel FWD car?

 

I think a big caster in conjuntion with a softer front ARB or no ARB, give me some more traction, isn´t it?

[Baz 421]

Its a drum type beam, so the track is almost similar to the 205 Gti rear beam.

 

And Im going to use a larger ET rims, to compensate the wider track.

 

Whats the general setup for a gravel FWD car?

 

I think a big caster in conjuntion with a softer front ARB or no ARB, give me some more traction, isn´t it?

 

Drum or disc, a 309 beam is wider than a 205 item.

 

PTS Gravel specs varied a bit, but many challenge cars, mine included runs tarmac spec inserts with gravel 180lb springs, standard rear beam with forest/tar dampers, no front ARB.

[lahondal 17]

Well, I will do that, front forest spec springs with no ARB, and narrowing the rear.

 

Anyone can say something to welding a FWD diff? I know some people use it for autocross, and I know too that they must use the handbrake for producing oversteering...

[brumster 135 1 Cars]

Not sure I'd be welding a diff closed, to be honest. A car trailered entirely to muddy fields and not doing anything else is one thing, but a stage rally car? No, I don't think so...

[lahondal 17]

More opinions?

 

The car is almost finished, but I still thinking if a welded diff works fine with a stiffer front ARB and no rear ARB, because in corners the front inside wheel tends to rise in the air, and this aids to turn

 

Here is the car, just tested....

 

 

 

 

Best regards, David.

[welshpug 1,655]

Not many gravel 205's run front arb at all, front lifts due to rear weight transfer.

 

No filter on gravel?!

[Tom Fenton 1,541]

I don't think a welded diff is a good idea at all. On a couple of occasions in the past when I have had planet wheels in diffs lock up on me the car becomes an utter pig to drive, you have pretty much no idea what it is going to do next. A plate LSD on the other hand is a MUST in my opinion.

I guess the standard diff is cheap and easy to lay your hands on, so if you do weld one and don't like it, it will be easy and cheap to change back.

[brumster 135 1 Cars]

Your service crew will thank you tens times over for fitting a stud kit but not for only putting it on the back!

Edited January 16, 2013 by brumster

[lahondal 17]

Not many gravel 205's run front arb at all, front lifts due to rear weight transfer.

 

No filter on gravel?!

 

That is the effect I want, the front inside lifts and lost grip because the stiffer ARB, (combined with the no rear ARB) and the outside tyre make the front to turn in. But Im starting to think that is a theory which need to try myself on practic.

 

I have to design a filter box, but I dont know how, is not any room enough to fit a filter.

 

I don't think a welded diff is a good idea at all. On a couple of occasions in the past when I have had planet wheels in diffs lock up on me the car becomes an utter pig to drive, you have pretty much no idea what it is going to do next. A plate LSD on the other hand is a MUST in my opinion.

I guess the standard diff is cheap and easy to lay your hands on, so if you do weld one and don't like it, it will be easy and cheap to change back.

 

I have a spare diff, i think with the same crown wheel, so if It dont like, can change without removing the box.

 

A plate diff is so much money for me, at least for this car. In the other car will be a must.

 

Your service crew will thank you tens times over for fitting a stud kit but not for only putting it on the back!

 

The cars is built with all spare parts I had at home. So the stud kit was already fitted on the rear axle, but the front hubs are from a 1.1 model. I have to dismantle the stud and fit the OE bolts.

Edited January 16, 2013 by lahondal

[lahondal 17]

Ah, and have changed the 309 beam, I fitted a 205Gti beam.

 

So now the specs are:

 

-Front: 1.1 Struts and hubs, "gravel" (diesel) springs, diesel driveshafts, no ARB, 205GTi wishbones. No LSD. 1.8 lock to lock steering, no PAS.

 

-Rear: Standard 205GTi beam, with an unknown "high spec red" dampers.....haha.

 

This are "s*it" specs, the car handles like it have shopping cart wheels at the rear, at least in tarmac. And likes me.

Edited January 16, 2013 by lahondal

[Rippthrough 98]

It's alright saying the inside wheel will lift and you can use power to help it around the corner....but you have to get it to turn in first.

I don't run a welded diff even in the buggy on mud because it makes it a nightmare in the tight stuff.

[lahondal 17]

Oh yes, I didn't think about that.

I think it would require to use the handbrake all the time...

Well, here many people use it for autocross races, some people says that is a total nightmare, some says its ok and use it for racing on gravel....and someone says he prefer the locked diff than a plate type...but maybe are total subjetive opinions....

Anyway, I need to try it by myself.

Edited January 16, 2013 by lahondal