Difference between: Diff, front one-way and centre one-way and when to use them?

[jrs]

Hi,

Just wondering if people have tried the various options of front diff, front one-way and centre one-way on their D4's.

What are the handling differences for the D4?
What's the difference between the front and centre one-ways?
What sort of track surfaces suit each option?

The tracks I'm running on here are quite slippery. I tend to get a bit of understeer going into a corner, specifically the tighter ones, so am wondering if a one-way will help to solve that.

Regards,
Jason,

[cmgreen]

Quite intresting 92 people have read the post and no replys.

I willl try to give a reason why I use one.

I tend to find that with a front diff in the car will give me off power understeer in a corner, also over a jump make the car nose dive while in the air, plus with a one way you can do a handbrake turn in the middle of a corner where poss. For me the car feels quicker with a oneway in.

[jrs]

Hi cmgreen,

Are you talking about a front one-way or a centre one-way ? I can see why it would be better in the situation you speak of and that's why I'm looking at fitting one, however I've read elsewhere that you only get the benefit from a one-way if you're running on high traction surfaces - which I'm not. The tracks here as pretty slippery.

I was thinking of loosening the front-diff slightly to see if the extra diff action would give better turn-in. Most forum thread talking about the D4's diffs seem to advice having them as tight as possible, but I reckon that defeats the point of having a diff in the first place - they may as well have a solid axle ;-)

[cmgreen]

Yeah full one way, I tend to use one every where regardless. Just feel its better for me. Try running them back to back.

At batley regional i started off running a diff up front, i had just got the JC bj4we, so built it as per book, in the last round i switched to a oneway and was at least a second a lap quicker, wish i had started with it in.

[chris68nufc]

Well CMGreen. I did tell you to do it and you didnt listen to me and still didnt finish higher up than me without a one way!! Sorry Chris had to!

[mark christopher]

its not just down to turn in

a front one way will give you less control in the air on big jumps when you want to change nose up or down

it also allow more power to be applied out of a corner, as the diff will not diff out (which will happen if you loosen the front diff.) this will give you more forward traction out of a corner

[Arn0]

I can't answer the question as I don't use a 4wd car but you will find some there - top left picture.
Call reading this document and it was more for TC but that may be apply to Off-Road in some way.

[cmgreen]

Originally Posted by chris68nufc

Well CMGreen. I did tell you to do it and you didnt listen to me and still didnt finish higher up than me without a one way!! Sorry Chris had to!

At least i bought the right one LOL, Sorry Chris had to!

[ifuonlyknew]

Front one-way vs. Center one-way vs. Front diff.

Some of this stuff may be a little different for you guys as I am explaining for the conditions I have raced under in America, they might be different for you guys due to your vastly different track conditions.

A front one-way acts like a solid axle (Spool) on throttle (no diff action), this is going to make a car push on throttle as the wheels have to go the same speed but travel different distances, therefore the front wheels are not going to want to turn (push). That is why touring cars can get away with running a Spool one-way, because they are on a high traction surface.

The center one-way is what will work the best as it gives you the best of both worlds. You can use the brakes to swing the rear end around if necessary (tight 180 degree corner), or drive through the corner because you still have a front diff (all other corners).

A front diff would act much like the center one-way except it will give you front brakes as well so if the track your at has any 180 degree turns and your running the front diff, if you don't slow down early (which is going to set you up to get passed) and drive through the corner, you will do one of two things: A. You will hit the brakes and try to turn at the same time, causing your car to push worse than snowplow, or B. You will end up going into the corner with too much speed and taking a wide line (also setting yourself up to get passed).

Personally I would recommend the center one-way, it will work the best in most situations. Not to mention the designers over at Hot Bodies were smart and designed the center one-way so that you can install a pin to change it back to a solid shaft, giving you the ability to go from center one-way with a front diff, to a solid shaft with a front diff, in a matter of seconds, basically giving you two completely different handling cars with one adjustment that takes a second to change and a second to change back.

Good Luck,
Chris

[super__dan]

Interesting as that's quite different to my exerience.

Front diff vs full one way, one way has more steering into and out of the corner i.e. on and off power.

Off power you get more turn in because the inertia of the drivetrain (inc motor) isn't pushing the front wheels out. You get more weight transfer to the front and the front is now only doing the steering like a 2wd car so you get more steering.

On power I think of it as the axle literally hauling the front of the car round. There is no diff action so it's harder on the front tyres but for me 99% of the time it is faster.

None of this is based on a D4, my limited experience of centre one ways is that they are a bit of a half way house but 'safer' than a full one way.

[markwilliamson2001]

Yeah agree with you Dan...

In the XX4, you could run a centre clicker (essentially a centre one-way that is adjustable). I find indoors on carpet/polished floor, that this still gives good turn in (on the carpet), and you have some 'swing' on the rear of the car on the polished floor. The only downside is that you lose some on-power steering on tight turns on higher traction surfaces, but it is very easy to drive.

HTH
Mark