B4 with wobbly back end ...

[BC Rog]

Folks,

this is a plea for help generating grip from the rear of a B4.

What have you tried? What worked? Just as importantly what didn't?

Any suggestion, well any serious ones, will be much appreciated!

Cheers,

Rog

[Doomanic]

How about replacing the rear wing with a house brick? ;D

[Doomanic]

Ooops, sorry, should have read the last line! :-[

[BC Rog]

Think I tried that one, well not a house brick but I'm sure I dragged a XXX of a rather large fellow around on the baclk of my car for a few corners @ Batley ........ did improve the handling of my car!!!

Rog

[BC Rog]

Has anybody tried REALLY soft suspension and a rear roll bar? That is my next move ... interested to see if anybody else has been down the same route!!!

Rog

[Craigs Cuuz]

I felt this with my B4 at first tried all sorts of stuff which only ever seemed to alter the way the back end stepped out. Rear roll bar made it turn in to fast, tried 25 oil and green spring on inside hole on wishbone but just meant you need to sling the car in to bend and bingo, same problem, out goes the arse!
Stiffening the front, oil and or spring, just seems to stop the car rolling and out goes the arse. i find the car needs to be quite soft at the front to generate consistant grip, to stop the front over gripping i run 2 or 3 internal limiters, I always run a short front link normally with only one washer and 30 deg caster blocks to stop car whipping in to quickly. I like to keep the rear link as short as possible, also to counteract the excess turn in usually one washer on outer hole std link plate and always middle hole on hub. Cells forward, same reason, slow down turn in.
fr assoc 35 #2 piston 2/3 limiters, inside mount on bone
Rr assoc 35 or 30 #1 NO limiters, outside mount on bone

Hope this is of some help Rog. :)

[BC Rog]

Craig ...

thank you for your response but I've been there, got the set-up sheet to prove it!!

Comments say

"better but still a bit like a freshly waxed jelly Badger on an ice-rink!"

I think I was pitty with Jake that day!!!

There is hope, I'm sure of that but I think it envolves getting the roll-centre below ground level ... not too easy to make it ride the bumps like that ... ;)

Rog

[BC Rog]

What I haven't tried is shortening the wheel base buy cutting down the rear whisbones ... now that might work!!! In theory it should push some more mass behind the axle line and make the effects of the shift in weight distribution less.

I prefer to run the caster blocks forward (even with the in-lines .. use the std. hole on the steering link!) to push the centre of mass back.

Rog

P.S. will let you know if the latest dremel fest works ..lol ;)

[Craigs Cuuz]

Ah well, i tried. I think i've just got used to the way it handles, i like all my cars to over steer now :D

[Richard Lowe]

What surface are you running on and with what tires? I ran my B4 for the first time at Batley last Sunday with Mick's setup on it (from the CML site) and the car was more-or-less perfect straight away, it does'nt quite feel sharp enough for me but thats prolly cos I'm used to the B3's 'knife-edge' handling ;)
I might try some inline axle's or 30deg caster on the front, just to give it a bit extra twitch ;D

[Craigs Cuuz]

Richard, I find the in lines only serve to make the car lap slower, they take off the huge mid corner grip the b4 has. 30 deg blocks on grass will give you less twitch but more overal steering. Try playing with the camber link position, washers and mounts. If the car is nearly right thgis is a great fine tune. If you want more twitch, shorten or lower the front. I recon the b4 is unbeatable on grass roll on the fact team :)

[BC Rog]

Rich,

I have the same problem on ALL surfaces!
Tried Neil's base set-up and it was undrivable for me ..... nothing at all, no front, no rear, nothing!!!! I think I was lappign something like 2.5 to 3 seconds a lap slower than guys I can normally bet with their B3's!!!

Craig,

what the in-lines are doing is balancing the car through the corner so the front grip level stays consistent! For me it's the "huge mid corner grip" that is catching the rear out!!!

Rog

[Dave G]

hmm i really dont understand why your b4 isnt gripping..mine is dialled on grass tracks and can be pushed/provoked quite hard without upsetting the car too much,i run the same setup at batley as i did at the f2's,car works well without having to make any real changes to any track...maybe somethings tweaked on yours?.

i did have a problem with mine at batley national,found out it was the plastic seal(the one that holds all the o rings in place) in one of the rear shocks had worked loose and was letting the rear right hand side collapse under hard cornering making the car undriveable when accelerating on loose surfaces,it wasnt noticable on the table,only on track,weird.

front: 35wt,blue springs,outside hole on wishbones,just below level,1 washer under camber ballstud on shock tower and 1 under ballstud on steering knuckle,no inner shock spacers.

rear: 25 or 30 wt,silver springs,outside hole on wishbones,long wheelbase,medium camber link,1 washer under inner ballstud,1 degree antisquat batteries fully forward,driveshafts level,no inner shock spacers.
yellow schumachers on rear,yellows on front with outer row off and every other one on the inside off.

hope you get it sorted because the car really is great to drive and very consistent.

dave

[Gaz_Stanton]

Rog
i did try going soft on the back end for Tiverton & i think it worked. Trouble is it was only 2 days after receiving the car & my first time on the sticks for quite a while so it's hard to judge.

I went to 20wt/black spring/losi orange piston with the shocks on the outer hole of the shock tower and put in a top 15 time in the last round of the National there.
The back end felt pretty planted but the only prob was the back end bottoming out on the jumps cos of not enough pack.

Never pursued that set-up though as Neil kicked arse there with a fairly standard set-up apart from going up to 4 degrees of anti-squat.

[jimmy]

i use neils batley setup everywhere and it just works, even indoors... i have hardly changed anything and it seems to suit all tracks...
the US guys do a mod with the rear wishbones or somethign to shorten the wheelbase and create more traction but its no use to me as mine grips..
get a kyosho ultima instead rog, you might start a new trend.. ;)

[BC Rog]

Jimmy, you must be able to read minds........

I've actually got a couple of sets of wishbones for the purpose of moving some more weight over the back end!!!!!

Also, when the latest Ultima was released (USA and Japan only .. boohoo) I looked into running one but with no support from the UK importer it was never going to work!!

Even tried to get Doom to import the bits direct ..... I can't remember exactly what he said but I seem to remember him mentioning a Miss Gough ... Not sure if she imports the bits, could never find her!! ;D

I've tried the "Craig" set-up and like his base set-up for the Yokomo it's just not got enough front end bite for me! I guess he doesn't need as much as I do as he doesn't have to rescuse the car from somewhere in a different postal district to the racing line quite as often as I do....;)

Boy do I need more practice!!

[Craigs Cuuz]

get a kyosho ultima instead rog, you might start a new trend.. ;)

Now your talking, any one want to buy a B4 :D

[trekkker]

hi rog,youre idea of making the wheelbase shorter by moving the rear wishbones,its on the rc10b4 website,apparently some team drivers use this on very loose surfaces,could be worth a go,im gonna try it on a new dirt track(3a raceway)very loose surface,ill let u know how it goes,trekkker

[BC Rog]

Trekker, cheers mate ... all feedback is greatfully recieved!

Doesn't change the fact that you shouldn't have to do it for a car running on grass!!!!

I'm really struggling with this car and the fact that most people aren't really suprises me!!!!

Rog

[super__dan]

God as much as it hurts me to admit this but I have a similair problem to Rodger, though not necesarily to the same extent.

Before I got my car I drove Millzy's and it was really planted, despite its unique setup which I've subsequently tried to replicate I simply can't get the stability. I just get understeer then breakaway. I can still lap respectably but I'm not happy with it. I'm looking forward to the controlled environment of running it indoors to try different things without those bumps getting in the way.

Dan

[Andy Taylor]

God as much as it hurts me to admit this but I have a similair problem to Rodger, though not necesarily to the same extent.

Before I got my car I drove Millzy's and it was really planted, despite its unique setup which I've subsequently tried to replicate I simply can't get the stability. I just get understeer then breakaway. I can still lap respectably but I'm not happy with it. I'm looking forward to the controlled environment of running it indoors to try different things without those bumps getting in the way.

Dan


Why not come to kidderminster and do some testing one day. the track will have bumps but they remain stable and ok so its not grass but its the best testing environment you will get in my opinion.

You could then try Lees car as that worked with the same set up at kidderminster, Telford Hot tracks, Worksop (juniors) Austria (massive bumps and holes) Telford Model car club (laguna seca) and Worcester F3's etc. TQ and A final win at juniors when we could not get XXX4 to go round quick enough and three 2nd in rounds at F3's must mean its not far away ...........I still think that Yok is awsome though Pity I never listened to Roger from the start of the season eh rog??? If it ever gets a slipper it WILL take some beating!

Let me know if you wanna come down one day!!

[super__dan]

God as much as it hurts me to admit this but I have a similair problem to Rodger, though not necesarily to the same extent.

Before I got my car I drove Millzy's and it was really planted, despite its unique setup which I've subsequently tried to replicate I simply can't get the stability. I just get understeer then breakaway. I can still lap respectably but I'm not happy with it. I'm looking forward to the controlled environment of running it indoors to try different things without those bumps getting in the way.

Dan


Why not come to kidderminster and do some testing one day. the track will have bumps but they remain stable and ok so its not grass but its the best testing environment you will get in my opinion.

You could then try Lees car as that worked with the same set up at kidderminster, Telford Hot tracks, Worksop (juniors) Austria (massive bumps and holes) Telford Model car club (laguna seca) and Worcester F3's etc. TQ and A final win at juniors when we could not get XXX4 to go round quick enough and three 2nd in rounds at F3's must mean its not far away ...........I still think that Yok is awsome though Pity I never listened to Roger from the start of the season eh rog??? If it ever gets a slipper it WILL take some beating!

Let me know if you wanna come down one day!!


Thanks for the kind offer Andy, unfortunatly I've just moved to York and so am about 160 miles away from kiddy, which is a shame as some quality time down there would be usefull.

Dan

PS Telford does have its own corkscrew doesn't it ;D

[Andy Taylor]

[Thanks for the kind offer Andy, unfortunatly I've just moved to York and so am about 160 miles away from kiddy, which is a shame as some quality time down there would be usefull.

Dan

PS Telford does have its own corkscrew doesn't it ;D


Hey you can have a bed as well if you need one :)

I sleep on the settee downstairs next to the wifes bed you are welcome to the double upstairs thats free...

[super__dan]

Thats a hell of a nice Offer Andy, maybe one time I'll take you up on it!

Cheers,

Dan

[millzy]

unique setup !!!!


Yea Baby, uniquely pased you in the finlas!!!

[Gaz_Stanton]

Rog,
Where do u run your cells? I started with the cells at the back when i first had the car and hated it with a passion. When i first tried it on grass it showed similar symptons to what i think you're describing - the steering response of an oil tanker going into the corner with the car swapping ends in the middle with no prior warning.
I tried the cells forward & it was a totally different car! And i've not moved them back all season. (even had the chassis machined for the forward cell position).
If i were you i'd try the car with the cells forward, longest wheelbase etc (i've been running this most of season) and see what you think, then take it from there.
I suspect that it the pendulum effect that is causing you probs which has been exaggerated by trying softer front suspension/inline axles etc in an effort to get more corner entry steering.

I think it would be best to try this once before you try the wishbone mod as I reckon it will just exagerate the route cause of your problem.
(also try smaller spur/smaller pinion combinations)
(I've found the best balance on my car this year has been found using an 8x2 motor! This was because the smaller pinion has brought the motor forward & reduced the pendulum effect even further.)

[DA_cookie_monstA]

This may sound daft, but have you ever thought that the back end is getting over worked with running a normal type setup, and that is causing it to step out mid-corner??

I mean, running LWB, cells furthest forward all reduces the weight the outside rear wheel has to cope with?

[millzy]

i run 5 (oz gram??? you know what i meen) on the back of the car over the cneter of the car.
an i allways run the 78 spr

[Gaz_Stanton]

This may sound daft, but have you ever thought that the back end is getting over worked with running a normal type setup, and that is causing it to step out mid-corner??

I mean, running LWB, cells furthest forward all reduces the weight the outside rear wheel has to cope with?


That's kinda what i mean by "pendulum effect". Too much weight too far behind the vertical axis of rotation.
Prob caused by combination of front end unloaded (relatively) and not giving enough lateral weight transfer to provide enough turn-in grip while the rear is overloaded giving too much lateral weight transfer and therefore too much grip resulting in corner entry understeer.
As the car goes through the turn the rear weight transfer continues until it reaches it's limit (end of shock movement etc) too early and then abruptly stops. This causes a sudden drop in rear end grip (sidebite).
While this happens there is also a a reaction from that stop in rear weight transfer (when rear becomes fully loaded) that causes a sudden weight transfer from the rear to the front. This then causes a sudden loading of the front tyres which in turn gives a sudden increase in front end grip.
The result of this is a scenario mid corner where the back suddenly loses grip and the front suddenly gains grip. This coupled with the fact that the driver has probably added more front lock to combat the corner entry understeer gives a sudden swapping of ends with no prior warning.

Hope that makes sense??? ???

Is that the problem you've been having Rog?

[BC Rog]

Gaz and DA'M .....

something to think about.......

As I said all sensible comments are appreciated ... I feel a days practicing coming on .....

Cheers,

Rog

[tyreman]

we could not get XXX4 to go round quick enough


The only reason that Lee couldn't get my car round quick enough at the juniors was because he kept hitting things, the setup was really good as it rode the bumps better than most of the other 4wd cars,
but he kept loosing his temper when someone gave him a gentle nudge on the first few corners!!!! ??? :-X

Thankfully he seems to gave gotten over that problem as the year has gone on, and had some really good results.

[Andy Taylor]

we could not get XXX4 to go round quick enough


The only reason that Lee couldn't get my car round quick enough at the juniors was because he kept hitting things, the setup was really good as it rode the bumps better than most of the other 4wd cars,
but he kept loosing his temper when someone gave him a gentle nudge on the first few corners!!!! ??? :-X

Thankfully he seems to gave gotten over that problem as the year has gone on, and had some really good results.


I would say it rode the bumps better than the other XXX4's yes. But it was always out of shape. My reason for the comment though brian was not Lees driving but the ease with which the set up transfered from kiddy to telford Hot tracks and then worksop and even to Austria.....4 very different tracks BUT he struggled with the XXX4 which was why we ran xx4 at the Euros. The XX4 that Adam T ran soaked up the bumps and looked way better just look how darren B fared also.

Yes he was fed up with being nudged /taken out without warnings being issued but he has never been in the position of being the best driver in a particular class and found the comments from other drivers that he should win easily quite hard to cope with BUT bearing in mind the state he drove the qualifier he got TQ in, moving down the rostrum while driving down the straight and with tears pouring down his face he can handle pressure he just needs to learn how.

The B4 set up so easy and he made few mistakes but those that he did make were easily caught. The 4 wheel drive was so different which means to me the B4 is an easy car to set up even I can do it :)


I do agree with your assesment though in general. I think to catch the XX4 both he and adam carter had to drive so hard that mistakes were inevitable whereas the B4 was so smooth even Tom Yardy went and brought one :) You might feel different but as you say since we stopped running it his results have been very good. Now if only associated would make a B4 X4 :) ;D 8) ::)

[BC Rog]

Andy,

If the B4 is so easy to set up fancy letting me drive Lee's car ... that would be interesting!!!!!

Seriously ... I'm trying all options at the moment as to my mind it is the single most difficult car I've ever had to deal with!!!!

Rog

[Doomanic]

What? Worse than a Cripple-X? :o

[BC Rog]

Yes dom, worse than a cripple X!!

The XXX wasn't too bad as it became apparent from fairly early on that it was never going to suit me and that the Associated car was going to be better.

The problem now is that there is no alternative to the B4!! The Losi is still as much of a pig as it always was (no matter who's I try!!) and if the B4 can't be made to suit me then I guess I am going to have to go back to the B3 which must be slower or why would they build a new car?????!!!!!?????

Before anybody says it I know it's my choice if I go back to the older car but if I can't get the new one to grip then I see no alternative!!

Maybe I should start trying to get Ripmax to import the Ultima RB Evo ;)

Rog

[DA_cookie_monstA]

It may be a new car, but that don't mean it is quicker, maybe easier for some to drive, but, if it don't go round corners for you properly, then, what can you do, B£, or, dare I say it, try a Blade!! ;D;D;D

[BC Rog]

The Blade was a fine car, I really like mine!

The only problem I had was that I couldn't get any help with set-ups!

I tried Mossy's .... help!!!!!! Not for me, too much bite!

Tried Yardy's ......no steering!

Went somewhere in the middle and the car worked well. At that time though I was not in a position where I could spend that much time on the cars, on track or on the workshop table, and the Blade need a lot of time!!! Something always seemed broken, worn out or just plain sloppy!

That is my main gripe about Schumacher cars ... as somebody keeps telling me .... they come factory knackered!

Rog

[DA_cookie_monstA]

Never had a problem with me Blade Rog, always there for me, and yeah, I could of done with a bit more steering and overall grip on Tivertons clay track, but on everything else, it was brill.

I couldn't get used to the way the B2 handled, and the XX, well, I tried EVERYTHING to stop the thing from breaking, and couldn't, got to a point where I actually bought a Blade at a RRCi meeting and built it between rounds, brought it out for round 3, and, well, managed to finish a heat!!! LOL

Maybe the B4 just isnt for you fella

[Andy Taylor]

Andy,

If the B4 is so easy to set up fancy letting me drive Lee's car ... that would be interesting!!!!!

Seriously ... I'm trying all options at the moment as to my mind it is the single most difficult car I've ever had to deal with!!!!

Rog


roger no problems. We were hoping to try it round Slough today but it took all day to get a set up on the hyper we were running and then the track kept changing on us....damn inconsiderate I felt :) Shame the lads who were going to the worlds did not manage to get there and practise it was so much like Austria.......I am sure it must be closer to the tracks in the states than our grass ones are. The B4 would love that track.

So its as it came of the track at Worcester three 2nds in round plus a 22nd so if you cant drive that there is no hope for you. BTW good job you did not take that EB4 to slough today if it took 3 weeks to get parts........you would have needed to reorder :)

rather a good job you have not had a XXX4 then :) ......................... ::)

[BC Rog]

Andy,

would like to try Lee's car, that's why I asked!!

I did have a XXX4 .... just not for long ... Yokomo soon scared it off!!

Rog

[Andy Taylor]

Andy,

would like to try Lee's car, that's why I asked!!

I did have a XXX4 .... just not for long ... Yokomo soon scared it off!!

Rog



I knew you had a XXX4 :)

But of course you can try his car. What grass meetings are coming up soon?? As you know we take most of the winter off to save money up for next year so have nothing planned yet. Its yours when you need it!

[burgie]

I converted an already great running B4 into a full carbon version. It only cost £ ??? from the US of A, so I thought it was a good buy. Then I drove the car, and initially, on a sandy/grass type surface, the car was absolutely spot on. A huge difference. Turned sharper, jumped better still and felt really lively. I then took it to my home track at Southport. It was superb over the bumps and I was generally made up with it. Then I noticed I was correcting the steering to try and bring the back end in line at the end of our straight every single time either power on entry or power off entry or "pulsing" the power throughout the corner. The good buy quickly became good bye and I went back to the original chassis. Its better now, but the handling isn't as sharp, and the bumps unsettle the car a little more (might be just me though). The carbon chassis is going back on for the indoor season though.

[millzy]

my b4 its totaly carbon'd nothing wrong with it, car has felt better with the new lighter bits.

[burgie]

what surface do you run on? If its predominatly grass, can you post your setup for it please?

[millzy]

Grass if its in wales

astro, clay and all types if its rrci and nats

[trekkker]

hi,ive just tested the rear arm mod on the b4,on a test day at a very dusty dirt track,on a single lap the b4 only lost out to the fastest 4wd cars by0.03 of a second,the setup i was using is kurt wengers 2.5,it can be found on rc10b4.com,i found the car excellent,hope this helps,trekkker

[BC Rog]

Thanks mate ... all helps!

Really going to get this one sorted this winter .. buging me now!!

Rog

[Chrislong]

Try running the back end as per kit, I know your car is slightly modified but I have few complaints about mine and see no need for any changes.

Did you say at Bury St.E's that you have a lot of camber change? this will loose grip won't it?

[BC Rog]

Chris,

I say the standard B4 has too much "effective" camber change at the front, that is why I prefer to work with the inline axles.

The reason I'm looking for the solution to the back end (mine has no grip at the back what so ever!!) is that the "standard" set-up is hateful!!!!

Whilst I'm glad that you all have found something that works for you I have not.

Well to say the back end is rubbish is wrong. What I should say is that there is no balance between the front and rear of the car (sure I've said all this before!!) and if I have the front set to give me anything like the steering I require then the back can not keep up with the pace. If I was prepair to drive it round like all the old grannies out for a sunday afternoon drive in there white Rovers then it would be fine. That is not my style. I need a car I can push as I know no other way of driving. The B4 isn't safe enough to push once you have got it steering nicely!

That is my opinion and my problem.

Still looking for the solution.

Rog

[Chrislong]

Have you considered drawing pins through the tyres? ;D

I remember now, got mixed up n thought you meant the rear of the car. How about more antisquat? would that help?

[burgie]

Rog - this thread has gone very quiet, does that mean that you have finally found a B4 setup that works?

[Richard Lowe]

I seem to have mine pretty much sorted now (I was having a similar problem to Rog), the solution I've found is to change driving styles. For me I can't push the car at all, granny driving all the way! :P
The speed is there even without pushing, it's just sooooooooo dull.

[Chrislong]

I can push mine to the limits and its soooooo forgiving everywhere without fail.

[trekkker]

hi chris,ive just tried my b4 on grass today for the first time,bit of a handfull,what setup are you running on yours,im sure a lot of people would be most gratefull,thanks trekkker

[BC Rog]

Yes I have found the cure!!!!

Been detailed before but I'll go through it again .... after dinner maybe .. just been told to get off the computer and eat it or the dog gets it!!!!

Not giving that dog anything ...lol

Rog

[shane.tidley]

:o damm the mrs as already given the dog my dinner after i bought the yokomo !!!!!!! ::) ::) ::) :- :-X

right warm the dog up i am eating him ! ;D

[BC Rog]

lol ....

Basically the main thing is to control the forward (towards the outside front wheel obviously) weight transfer.

To help with this I use #3 pistons in the front (30wt generally) and am running a slightly longer (home made) shock shaft in the rear shocks. This gives you about 4mm more extension. The effect of this is to keep the rear inside wheel on the ground.

You can get 80% of the way there by lengthening the rear shock by un-doing the shock bottom about 2mm, any more and you risk it pulling off. To Balance this I'd run about 2.5mm of spacing under the front pistons to limit droop. The car will feel similar like this but will loose out to a car with the longer rear shock shaft on rough surfaces.

Rog

[burgie]

I have not run my car on grass since falling out with the car in september/october time! now that we are on speaking terms once more, I am just going to change to 40wt oil in the rear shocks, as it feels overdamped as it is now. I might just alter the springs first though. I've not decided yet. Put as it is set up at the mo (I have previously posted the setup in this thread), with the addition of a full set of yellows and cut down front rims, the car is very pushable, and is basically rather quick. (even for someone with as little competitive edge in them as I currently have!)

[BC Rog]

As I originally stated in these hallowed pages I think the B4 can be any car you want it to be. Well that was before I'd realised that Associated had made a class A Fcuk up of the shock shaft lengths for high grip (grip and traction are two different things before any of you start!!).

Now I have changed to the shock shaft lengths that nice Mr Newton would approve of the car IS anything I want it to be.

I'm glad for all those people that have sorted the car out and am willing to share what I have learned with the rest.

If you find a set-up that suits you stick with it. Driving styles are like tastes in partners or sports cars ... what appeals to one may not appeal to another. You can't afford one of mine and the misses refuse to leave either!!! ;) ;D ;)

Can anybody with a set-up that works for them please post it in Danny's thread about B4 set-ups. If we work together then we'll all benifit in the long run and easily beat the Lousy jokers!!!!

Rog