B4 hooking on carpet

[Richard Lowe]

Originally Posted by stuey

Richard, what do you think about my ramblings on my last post?

I still think it's the front thats the problem

The B4 has a lower initial roll centre at the front than the rear, which will make it want to corner nose down. If the front is stiff enough to stop it rolling as it wants to then instead of the front end compressing on the outside it will try to lift the inside at the rear. Hooking like you describe is usually the inner rear wheel running out of droop and going light.

Am I right in guessing you also have lots of understeer mid corner on slippy parts of the track like wood floor?

[stuey]

I'm confused now! It seemed like the front of the car was rolling more than the rear, and it was then lifting the inside rear wheel. The rear seemed to have less roll, which was stopping the outside wheel compressing as much. I started on 35wt/2 hole/blue springs front, and went up to 40wt then 45wt to try and stop the front rolling as much. It did seem to improve a little. I am confused as you seem to be saying that the front is too stiff, and that I should soften it. Wont that make it worse? I have been out for a long time, and setup was never my strong point!
I appreciate the help btw!!

[elvo]

Thicker oil doesn't stop roll. It merely slows it down a bit.

[PaulRotheram]

wish i had this problem!

Im running at formby high school, carpet is med/high grip

Running the same set up as mr lowe but I have 30 weight front and rear, 35 lead weight around the front, 40 placed around the rear and short wheelbase. Running trakpower 3600's, have lead weight to use under the batt strap, will consider using/not using depending on advice given!

Problem i'm having is I want the rear to rotate more, or more initial and mid steering, exit steering is fine! Not sure which way to go to improove the problem, or what changes to make to fix it!

Entering the corner it seem the car doesnt want to dig in and pushes, as said exit steering is fine however!

[Richard Lowe]

Are you racing again Paul?

Try longer wheelbase, or shock to inner hole on the front arm.

Do you have the short wheelbase mod on the rear wishbones? If so get rid of it!

[PaulRotheram]

Indeed mr lowe

2nd race back yesterday! feels good to be on the sticks!

I do indeed have the short short mod, has that trend died out now?

will moving the front shocks in soften it up im assumeing?

I thought shorter wheelbase was used on smaller tracks, or am I wrong in this?

its been a while!!!

[Richard Lowe]

The super short wheelbase is rubbish on carpet, in fact I don't think anyone really uses it over here now

That should solve your problem, leave the shocks as-is for now

[stuey]

Originally Posted by stuey

I'm confused now! It seemed like the front of the car was rolling more than the rear, and it was then lifting the inside rear wheel. The rear seemed to have less roll, which was stopping the outside wheel compressing as much. I started on 35wt/2 hole/blue springs front, and went up to 40wt then 45wt to try and stop the front rolling as much. It did seem to improve a little. I am confused as you seem to be saying that the front is too stiff, and that I should soften it. Wont that make it worse? I have been out for a long time, and setup was never my strong point!
I appreciate the help btw!!

I'm still stuck!

[PaulRotheram]

cheers ill give it a go! much appreciated!

[Richard Lowe]

Originally Posted by stuey

I'm still stuck!

Try the setup I posted on the first page exactly

With the roll centres of the B4 it wants to drop the front as it corners - ie corner with the nose down. If you have some 45w maple syrup in there slowing the front ends weight transfer right down it will try to lift the rear of the car instead of compressing the front.

If you start with the posted setup you will have a balanced platform to work from. If you need to get rid of some steering the first thing to do is cut some rows from the front tyres, or even put some less grippy ones on. (Don't use staggers though, that'd be gay )

[stuey]

Thanks Richard, I will give it a go. I cant see that my original setup with the 35wt in the front is too far off, seeing as it was good on a bigger slightly less grippy track. It looks like I have the rear too stiff on damping, perhaps the extra front grip has tipped the rear past its limits. Appreciate the help

[sparrow.2]

I still say try gay staggers instead of tyres with all the pins cut off

[PaulRotheram]

or dont be gay and use all the pins, animal style

[sparrow.2]

Does using rib spikes (oldschool! YEAH!) make you a gay animal then?!?

[PaulRotheram]

Haha it definatly does! although dont be barking around my tree!!

[stuey]

Back again I'm afraid. I may have mis-diagnosed the problem a bit last time. On a fast sweeping corner, it looks like the front inside wheel is lifting as the back end is collapsing. The rear end then breaks away, which may have been why I thought it was hooking. It still has too much low speed steering, but I think i need to take the inner row of spikes off the front. I started on the following setup, which was similar to my first one I tried. (Sorry I didnt have a chance to try your one Richard).
Front:
middle on tower, outer wishbone, link 1A, 1 washer under ball
steering 30deg trailing
shock blue spring 35wt no.2 piston

Rear:
inner on tower, outer wishbone, link 1b, 1 washer under ball
2 deg anti squat, short wheelbase
shock silver spring 30wt no.1 piston

basically Lee Martins Petit carpet setup. except I didnt get a chance to change rear piston to no.2

yellow minipins outer row off

I tried removing the washer under the rear ball to stiffen the roll, no real help. Put it back, put 35wt oil in rear to try and stiffen a bit, no real help.
Added another washer to front link to try and equalise roll front to rear, and put blue springs on rear to try and stop it collapsing, helped a little but reduced rear grip a bit.
I have a feeling the car may have been diffing out from something I read on here, how much spin should it have if spinning a wheel by hand?
The carpet is very grippy, would a soft rear roll bar help keep the rear end flatter through the corner and stop it collapsing?
Thanks for looking

[sosidge]

The only thing I can suggest is going up to grey springs on the rear. That will give a setup very similar to what I run on carpet indoors - and my setup is harder than most people's!

I'm surprised you find that the car has too much steering - if find the balance of the blue/silver in the outer holes to be a bit understeery myself - so I wonder whether something is wrong mechanically on the car?

[stuey]

I think its just this carpet seems to grip so much, you really dont need much in the way of spike to get grip. I had no such issues at Newbury earlier this year, could have done with a tad more steering. I remember seeing some cars a few years ago (at this venue, DMS) with literally just a few rows of spikes in the middle of the front tyre on a B4. Most of the 4wd cars run on 2wd fronts as well. I think the small track needs a specific setup, the car cant be that wrong from the setup I tried surely! I could do with some advice on how tight the diff should be though, if that is causing an issue by diffing out.

[Darren Boyle]

Stu, I thought this was you when I read this thread previous, but until now you did not make reference to the track so I could not be sure.

Apart from stating the obvious you would expect me to (ie your motor is in the wrong place...LOL) have you in all seroiousness asked Kevin what he is running on the front of his X6 since the front end on the cars is the same.

His car is pretty stable with lots of steering, after all he was right with the quick 4wd's last night. Although the whole car is not the same the front end is and "might" be a good starting point for you to compare with and maybe try.

The carpet is grippy, but it is not THAT bad TBH, but less spike is always quicker around there (unless your name is Jack that is, he seems to LOVE new pins)

[sparrow.2]

Try some poofy european-style staggers

You'd really be surprised