BJ4WE and total lack of balance
 

Right then, before I make a choice between the for sale section or encasing the car in a block of concrete I want to make sure I am not missing a trick!!!

The BJ4WE seems to be a total piglet .... absolutely without balance in any way shape or form!!! The only place I have got it anywhere close to how I want it has been indoors on carpet and then it was passable at best!!!

The problem is a lack of balance, if you have front end grip you don't have rear and vice versa.

At kiddy I just couldn't get the nose into the corners without having the rear set so that you couldn't carry any throttle through the corners let alone adjust trottle mid corner.

At Coventry today I had absolutely no traction or sidebite at all and trying to set the car soft to help traction and sidebite it became really random (rolling about too much). I then stiffened the car back up and although it was much easier to drive it was a full second a lap SLOWER than when it was soft. Ok, it was consistently slow and much easier to drive but at least 1 second a lap slower than before (The top of the A went quicker than they had done all day so th track hadn't given out).

I've tried Richard Lowe's set-ups and working around those but they have FAR too much high speed understeer for my tastes.

I am convinced it is a combination of the rear inner link position not being outboard enough of the lower hinge pin and the fact the weight is too far back. Both of these will lead to the collapsing of the rear end.

My question is what have people done to deal with this this .... other than the S4 conversion obviously??

I have a couple more runs this year with the car and want to make sure I use them wisely. I don't mind rubbish placings due to constantly changing the car during the winter, all part of learning your way round a new car. The only problem is that I am going to have to do this with the 2wd too so have to move onto that in the new year.

If anybody can help I'd be greatful, if not I'm going to have to chance chassis.

what tyres AND insert did you use

Should point out I've been through .....

all rear link positions (1-3 washers as I can't get 4 in and rely on the nylock nuts)
both standard anti-squat settings .. and a bit of shimming
EVER Associated rear spring
Lots of oil changes

Smae at the front except I've not tried the longer link at the front as yet .... only so many runs in a day!

Whatever is most appropriate on tyres and always use the DC Racing light blue inserts (same as the snee ones)

Trust me, it's not a tyre issue as I've tried "interesting" choices too.

lifting the rear brace does help why i dont know but it does by placing two washer between chassis and block

fresh ballistic pinks or blues

sorry greens not blues

please read this
 

Fresh pinks today ... greens might have been a little more consistent but I had enough trouble with one set of tyres and glue in the cold.

I've seen that guide, it's very good.

Should point out that I've been racing since the mid 80's and car set-up generally isn't a problem.

I do however need a car that you can lean on and carry lots of corner speed that will stand throttle adjustment mid corner. Too many years running a Predator in RRCi stock class to change now!

ive been racing 20 years and newer cars dont seem as forgiving as older ones i must admit my favourite car of all time was the cat xls just awesome in its day

I'll offer more help tommorrow as right now im currently completely exhausted from today. But one thing i noticed you say:

I've tried richards car, and it is anything but how you have described. Infact richards car has the most steering i've ever experienced.. and very balanced. Something doesn't sound right..

the astro track at coventry is an absolute pig to drive in the wet it has no traction at all on the flipside its grippy as hell in the dry

Fairysnuff .... look forward to your input.
My car is pushing like a mother to be of quaduplets on Richard's Set-ups!!!!

How many washers are you running under the ball stud on the front camber link? reducing this makes the car more positive, as said above you must be missing something? are you running a 1 way?

I run the same as rich, give or take a shim here and there, the car is always positive.

Silver springs all round , 30 wt blue piston rear and red 35wt front.

3 shims under rear camber link, 1 at front, std squat, outside on all wishbones and middle of towers. Always run a 1 way!!;)

Front is 1 shim under and outer hole, rear is 3 under

I run a 1-way on the shaft .... never been a fan of them in the diff ... find having it on the shaft is much smoother to drive.

Interesting you say outside holes in the wishbones .... most of the set-ups I've seen have been using the inner hole on the front and all are inner on the rear. That might be the problem right there!!! Been thinking that there is a bit too much balance in the droop front to rear, usually prefer a car with less front droop than rear. My next step was going to be limiting the front by about 3-5mm in terms of the resultant droop.

Need to find somewhere to test over the next couple of weeks!!!!

In side holes on the front make it very random and snatchy and as you say increase droop which would give more lift on power and more weight transfer to the rear, and on power understeer;)

that is what I would ahve thought but so many people seem to be running that location I slavishly followed .... fool that I am!!!

Right then, first change!

I allways ran the inside holes on the xx4 but since going to the S4 have stayed on the outside hole on the front & inside on the rear on most tracks, it just seams to let you push much harder like that!

incoming spanner....

obviously my experience is from the S4 but I believe this option is universal between the 2.

front shock location on wishbone...

outside is safe and has mid-corner push.
inside keeps the car hooked up in the middle of the turn.

keeping the droop the same between these settings keeps similar on power steering, I find that letting the front droop more give you MORE on power response. (this is when using a one-way-diff. I never use anything different)

so I find if I want to make the car drive more from the front on-power I give it a slight bit more droop on the front than the rear.

typically I use axles level with chassis as a base setting for droop all round, a touch more on the front if I want the drive from the front feel.

also - if Lowe runs a one-way-diff and you don't thats where your heavy push comes from, especially on power.
you could try and tighten up your front diff, but you might loose turn-in

Q: how is all your electronics placed?

Thanks Chris, what your saying is true of my previous cars and makes perfect sense! That was part of the reason I kept the inner mounting point on the front as the car just seems to push like mad anyway so anything I can do to help with mid corner / corner exit steering is seen as a help.

As for the one-way diff ...... if it is absolutely required I'm probably going to move the car on and go for something else .... I dislike them that much. It's partly the way they drive and partly the fact that they seem to destroy everything around them!

KyoshoK, my electrics are all on one side .... servo, LRP Comp TC brushless then spectrum reciever .... I tried to get it all on one side to balance the motor weight as much as I could ... could probably do with a few extra grams to even it out further I agree.

I know that they are frowned upon by the 1/10th off-raod masses but I have always run anti-roll bars on everything from the Optima Mids through Preds to the car that I ran when I was last racing 1/10th O.R.

So .... question is ... how many people run them or have tried them and what do you think about the instalation of them on the BJ4WE???
I'm not worried if the standard bars are too thick or thin as afterall they are just a bent bit of piano wire .....

Most don't tend to run them unless on very high grip AND smooth tracks (both front and rear) or on smooth low grip dirt tracks (rear only to assist steering mid-corner).

HTH
Mark
I don't tend to run them at all tbh on any buggy.

I don't even run the on them Pred these days.

G

try a tighter front diff and slightly looser rear diff then Roger, this might give what your looking for.

one-ways give very much a 'drive front the front' feel to the car, I would have thought you would have liked it?

Can you post your exact setup Roger?

As Lee has said already we almost never run on the inside hole of the front wishbone unless desperate for steering, on the outside the car is very consistent.

I've only managed to get the centre one-way to feel right at one event, and that was Tiverton on dirt so generally the centre one-way is a no no.

Another thing to look for is how aggresivly you are driving, the car really likes you to be gentle and controlled - sit back, drive at 90% and let it do the work, 'ragging it' just doesn't work.

Something else I have found is the car always feels 'loose' and moves around more than most other cars, when it's set up correctly and is fast you are almost in a permanent state of drift.


Paul - I remember when you had a go with my car at Southport, you almost needed a change of underpants first time you turned into a corner haha :D

As an outsider to the BJ4;-

Firstly to echo Pauls comments, I too have never driven a car with so much on power(controlable) as Rich's. You say you're running Rich's setup but without a one way diff then surely you're not, and a pretty massive change it is too.

Other than that, Rich Coates car was consistantly a pig when he got it, no obvious reason. I think it was traced to a tweaked bit of blue on it somewhere and more importantly a mis functioning centre one way, but I forget what or why but when he went to full time 4wd, he was instantly a country mile faster. Now he likes the car he's on a one way diff and was second at Worksop yesterday I think.

Dan, Rich's centre one way was broken and wasn't getting drive half the time, we removed it and the car improved but was still rubbish. When I rebuilt the car for him the back end was tweaked for some reason, I put it back together using the same parts and it was fine again :confused:

I blame the origonal owner, wonder who that was :p

I am greatful for any help offered at the moment as I am currently of the opinion that nothing other than a re-engineering job to move a fair chunk of the weight forward is going to help. If that is the case I'd probably try a different chassis as I just don't have anywhere to test without driving for around 1.5 hours plus due to living in racing no-mans-land ... Cheltenham.

Any further suggestions (other than fitting a one way diff)????

Chris,

front diff is much tighter than the rear (but still working nicely if you knwo what I mean). Rear diff is just on the limit of slipping on high grip stuff!!!

I have never really got on with one-way diffs. They are probably managable if your in a heat where your not likely to have to drive around others but even when I was racing before as an F2 I always seemed to be seeded low (....think StuW was trying to tell me something :rolleyes:)

More than anything (other than the price) the fact that the S4 has to run a one-way diff or full time 4wd is what put me off going that route!!

I do like the drive from the front feel but it has to come from the chassis. I so nearly got the Pred again when coming back into the sport but the lack of support troubled me.

Thanks for the suggestions by the way.

You'll have somewhere to try it out soon Roger. We're building a 10th off road track at Ledbury, next to our rally cross track. And if you are getting rid of the BJ4, fire it in my direction!!

Sorry roger, one way`s are the future,

You can even use the brakes when using the 1 way in the BJ4, it is very consistant, lots of high and low speed turn in, its just so easy to drive.

Stick with it, possibly ask rich or myself for a go if were about and see how ours compare

Most people do run oneway diffs now Rog, the only people I can think of that dont are Yardy & Daz! It might be worth taking a look at Yardys D4 setup.

From past experiance when ive gone from a good setup with a oneway diff to the same setup with a diff in the front its understeer city :(
If I was you id try Rich's setup to the letter, it allways looks good

I'll have to put the final 'magic' setup up in the setups thread, it's almost as the Bury setup but with a few tweaks here and there that make it more consistent.

You also said you only had 3 washers under the rear camber link, try to get some longer Losi Ti ballstuds and get 4 under there, it makes a big difference!

Don't be scared of the one-way diff, if you have a go with either Lee's or my cars you will be amazed how consistent and balanced they are :D

Are you going to the indoor finals? If you are and still having trouble by then throw the car on my table on Sat and I'll give it a going over for the Sunday ;)

:::EDIT::: - I've just had a look back at the Bury setup, copy it exactly but goto the outside hole on the front wishbone and medium wheelbase ;)
Run the rear as wishbones level and the front slightly lower.

How about something like this to cure your handling probs Roger... :D :p
http://www.oople.com/rc/photos/mako/...es/mako10.html

Like what Gaz?

Still bar far the best handling car I have ever had the good fortune to own!!!! Don't think I would have held my F2 that last year with anything else!!!

She had so much front end grip you just didn't need the front one-way, ran quick even with permenant 4wd. You ran yours with a one-way diff didn't you (it's sitting on the desk in front of me as I type), must have been crazy!!!

Anyway back on topic!

My memories of one-way diffs are;

R1 broken front driveshaft
R2 broken other front driveshaft
R3 broken transmission
R4 broken everything as you drive like a donkey as you can't get anything with just one round anyway.

:(

On top of that there is the cost issue;

£60 for the one-way diff
£12.50 for the Shiny CVDs (so they stand some chance of lasting)
£5 for the springs to keep the outdrives in the one-way unit

£77.50 is a hell of a lot to throw at an 'upgrade' that may not suit me.

If the BJ4 does require a front one-way diff to make it work then I guess it's going to see big changes (or an Ebay listing).

Richard, thanks for the offer of help. If I am at the indoor finals with the BJ4 I'll take you up on that kind offer.

Time is running out however as I have to get a 2wd somewhere close before the start of teh season too.....

Somebody has the article code of the long Losi ball studs (I need them for the 4 washers under the rear camber link).

When you say "short camber link", what does this mean exactly? :confused: Still learning! :rolleyes:

Thanks!

roger, i only use the one way, i dont use the springs in it or the shiny CVD`s, my car is totally standard:D