B4 raced in anger for first time......

[scott_davis]

Yesterday at Bury I got to race my B4 in the summer series round two for the first time....

As some of you may know I have only just done the transition from B3 to B4 so istaking some getting used too.

First impression were not good - the back end was constantly pushing wide in tight corners - it would turn into the corner nicely then the back would snap out.

Chris Long helped (thanks again mate) me get it sorted out so it was at least consistent - I removed one of the washers on the back shock tower, and dropped the back end lower... I was then able to actually drive it and was surprised just how aggressive I could be with it and yet get away with it compared to the B3 :D - well happy.

The back end still does snap out a little but no where as near as when I first started out yesterday... anyone got any suggestions for me to try? - Do I need to run the clutch really loose?

Oh and considering my first race in it - I qualified 7/10th's of a second from the A final just behind little Tom Moore (you really have to watch this young lad - he came 4th in the A final yesterday against a couple of drivers who were in the National A final at Bury last weekend I believe......!!!!)

Cheers

Scott.

[Doomanic]

Hi Scott, glad you like your B4.

You could try increasing the droop on the rear of your car.
You can do this in two ways;
1. Unscrew the shock rod end about 1.5mm.
I don't like this method as it increases the chances of the rod end pulling off the shaft
2. Use Losi/MIP 1" shock shafts.
These are slightly longer than the AE 1.02 shafts so have the same effect as unscrewing the rod end with no problematic side effects.

[DA_cookie_monstA]

I have used basically Dave Baileys setup from the CML site on my B4 and the car is just awesome, on grass I los the outer and inner row of minispikes on the front, and cut the outer row on the rear at 45' to stop it from snatching, and thats it. Lowering the back just makes the car slap on the floor over small bumps, and cuased other nasty handling habits.

[scott_davis]

Thanks Guys.

I had Chris Long have a couple of drives and even he said somethings not right.... it looses traction 3/4 of way through the corner and doesnt suffer from lack of grip at all!!!

I currently have this setup:

Front:
Blue Springs
35wt oil
1.5 deg camber
1 washer

Rear:
Silver Springs
30wt Oil
1.5 deg camber
1 washer

Medium Wheelbase
Cells forward
Clutch set reasonably loose

Sch Yellow Mini spikes all round
Front outside edge taken off....but thats it.

No weight in back

I am racing in Southport next weekend so really do want to get this problem sorted....

Cheers

Scott

[mr4man]

like dom said rebuild with losi shafts as this corrects the front and rear droop
difference.
have done this on mine and it makes a world of difference :D
richard

[Chrislong]

Its a weird handling characteristic Scotts car has, as you turn it turns nice, then 3/4 way through the bend the back end just come around like a pendulam. I have read about Chris Burgess having same kind of troubles hence he switched to the BK2.

I cannot see any obvious factors which could cause this, camber links all in kit positions, 1.5 degree camber all around, 1 washer under ball on rear camber link. Tyres were brand new too with outer row cut off the front (Yellow Minispikes front and rear on Bury Metro).

I have suggested taking all droop limiters out of the front (as he still has some in) and using 30wt oil front and rear, start from there. Also removing any additional weight he has put on and using the HD servo saver spring. Trimming spikes off rear will make his problem a lot worse than it is.

He is also using a tranny with no EPA, so full lock reached too early in stick motion.

IDEALLY, he should have started with the car 100% as per kit setup, and slowly tweeeeked it from there.


Chris

[scott_davis]

Ok then - I will try adjusting the shafts as per Doms first method - if it works I will order the shafts (although I have just bought MIP Gold shock shafts!!! :( )

Dan did mention that I can increase the rear droop by loosening off the rear shock screws a bit???

Scott

[scott_davis]

Cheers Chris..... new transmitter is on my wish list.... but I know what I want which means saving as mucho cost unless someone has a second hand KO for sale :D but for the time being I will have to wait.... didnt have any problem with the B3 though....

I will be removing the remaining washers from front shocks tonight and changing to 30wt oil front and rear (should I change front to silver spring too?)

I will be phoning Dom today for the HD servo spring and a few other bits.

Cheers

Scott

[DA_cookie_monstA]

Adding weight to the rear should help keep the rear a little more planted mid corner, also, just chamfering the outside row of spikes on the rear makes the progression from decent turn ing to break away a lot easier to feel and correct. Also, are there limiters in the rear shocks too, as I found removing them made a lot of difference to the back end, especially it stepping out?

[Chrislong]

My B4 was great out of the box, I built it exactly how the manual said to. I don't see why you felt it neccessary to not do this for your first run...

Before you buy anything such as longer shafts, take it back to manual set up, springs and oils and everything. Then that should cure the weird handling it had yesterday, and then begin to tweek it to suit your style, you'll also learn what each single mod does this way and learn for yourself a lot quicker.

Id still recomend the HD servo saver spring though.

Chris

[scott_davis]

I removed the rear limiters when I built the kit as everyone said it will be pants with them in :p

A few people have mentioned adding weight to the rear also....


Scott

[scott_davis]

My B4 was great out of the box, I built it exactly how the manual said to. I don't see why you felt it neccessary to not do this for your first run...

Before you buy anything such as longer shafts, take it back to manual set up, springs and oils and everything. Then that should cure the weird handling it had yesterday, and then begin to tweek it to suit your style, you'll also learn what each single mod does this way and learn for yourself a lot quicker.

Id still recomend the HD servo saver spring though.

Chris

Seems like the best idea otherwise will be going round in circles!!!

Trouble is kit setup says green springs on front :eek: :eek:

Cheers

Scott

[DA_cookie_monstA]

I built mine to factory settings and didn't find it too my liking, but then Dave Baileys is only a tweak of that isn't it. And the HD servo saver spring is a must, most disconcerting watching your front wheels flapping around mid corner/

[burgie]

Its a weird handling characteristic Scotts car has, as you turn it turns nice, then 3/4 way through the bend the back end just come around like a pendulam. I have read about Chris Burgess having same kind of troubles hence he switched to the BK2.

Chris

that is very true, mo. My B4 was awful to drive, and every rear component was changed to see if they were at fault, and the car never handled well, the back end did just as yours is doing Scott.

I rebuilt the car to kit spec, and it just didn't handle. BCrog had the same problem with his too, i think. The biggest improvement came when I ran trinity rear hubs, with different camber locations, but by the time i got these, I hated the car!

Just make sure you don't loose confidence in the car, Scott, I did, and i almost gave up completely.

[scott_davis]

True - have been looking at Dave Baileys setup and other than front droop washers and rear shock oil its basically the same!!! :eek:

[scott_davis]

that is very true, mo. My B4 was awful to drive, and every rear component was changed to see if they were at fault, and the car never handled well, the back end did just as yours is doing Scott.

I rebuilt the car to kit spec, and it just didn't handle. BCrog had the same problem with his too, i think. The biggest improvement came when I ran trinity rear hubs, with different camber locations, but by the time i got these, I hated the car!

Just make sure you don't loose confidence in the car, Scott, I did, and i almost gave up completely.

Its not actually that bad at moment - the fine tuning Chris helped me with made a massive improvement - its still not 100% right though.... I have a few ideas of what to do before I start ripping my hair out :D

[scott_davis]

These are the ideas I have been given from a few people - I thought it might be worth mentioning these to help other people should they have similar problems....

- Increase Camber links to longest settings
- Increase Rear droop by unwinding shock bottoms two full turns
- Run cells towards back
- Cut inside and outside rows of front tyres off
- Add weight to back end to help stabilse it through bends - as much as 40g if necessary
- Run short wheelbase

Failing all that return to kit setup and start again.... (which is pretty much what I am going to do!!!)

Cheers

Scott

[rich_p]

Mine doesnt seem to have that problem at all, it does however suffer from bad on power under steer. Could this be caaused by the 30 degree caster blocks it has on it?

[scott_davis]

Mine doesnt seem to have that problem at all, it does however suffer from bad on power under steer. Could this be caaused by the 30 degree caster blocks it has on it?

I think most people run 30 degree caster blocks so would look at other tuning first.... what setup do you run?

[DA_cookie_monstA]

Try the weight in the back first, and trimming the front tyres of like you said, that should help things greatly.

As for Caster, I Am still on 25, gives more turn in, less steering out of the corner, the 30 should give you more, tried turning the torque down a little??

[Doughty]

moved into associated section, this is very car specific

[DA_cookie_monstA]

cheers me dear

[scott_davis]

Try the weight in the back first, and trimming the front tyres of like you said, that should help things greatly.

As for Caster, I Am still on 25, gives more turn in, less steering out of the corner, the 30 should give you more, tried turning the torque down a little??

Yeah I have a few things I want to try first before starting over again with the kit setup like Chris says... I am planning on doing some practice after work during week which hopefully will give me time to sort it. But first thing I want to try is removing the droop washers in front so same all round and adding droop to rear with weight in back ....

What is the kit caster?

Turn down torque? how? :o

[scott_davis]

moved into associated section, this is very car specific

cheers mate

[DA_cookie_monstA]

Kit is 25, optional caster is 20 or 30. Adding the weight in the back don't increase droop, but keeps the car more secure around the corner, and I have found dropping the back end on the B4 don't help mid corner either.

You could try this setup DAVE BAILEY - Southport (http://www.cmldistribution.co.uk/docs/B4baileynasouth.jpg) I find it is close to kit, but enough away from it to get away from the traites the car has.

[Chrislong]

Scott has listened to a variety of peoples advice and ended up with a strange setup combining many peoples tips, so we can't explain where the handling has come from since there is so many changes done at once.

I am hoping with kit setup it will be pretty safe and predictable like mine was and it is a good starting point to put the mods back on as and when he feels like it is neccessary... learning what the changes do at the same time. He has got the right idea filling out and saving setup sheets with comments.

[Doomanic]

Make sure the rear chassis brace is flat, both on and off the car. They can become tweaked if overtightened.

[scott_davis]

Cheers guys :D

Dom: Which is the rear chassis brace? - I dont over tighten anything these days as worried about stripping threads... I also tighten every bolt the same on the car.... tighten until feel resistance then half a turn ;) - I learnt the hard way by stripping the threads in an aluminium car cylinder head a few years ago.....with my skills I should have known better :o :( lol

I am going to check a couple of things tonight and try and if no luck then I will be returning it to pretty much kit setup (excluding front springs Chris ;) ) then hopefully I will be able to fettle it to something am happy with...

Cheers

Scott.

[mr4man]

hi just to let you know i ran my b4 last night for the first time with the losi rear shock shaft mods.
the car is awersome with far more grip than before and seems to turn in better due to rear wheels staying on the ground.
stops the car GTI ing (for all you youngsters golf gti`s used to pick up the inside rear wheel on hard cornering)
superb mods.
richard

[old_thumbs]

Scott - Sunday at Bury was not only my first time out with the B4, but also my first race meeting in about a decade, :eek: so I was quite happy to qualify (and finish) second in the A, despite my old Tekin speedo having some thermal shutdown problems. :D That said, there were a few of the faster guys missing or running in another class...

Just looking at your setup and mine was exactly the same, with the sole exception of the rear camber links which I made shorter at the inner end to stop it rolling so much in the corners.

With such little difference in our setups it seems you may have a 'tweaked' piece somewhere affecting the geometry. There are lots of good suggestions on this thread, remember to only change one thing at a time and keep practicing until you nail it.

THIS (http://home.tiscali.be/be067749/58/bug/print.htm) is a handy page for setup tuning.

[scott_davis]

Thanks for all the advice people!!!

Thought would give you guys an update.

I have now stripped the car down and although I found nothing to be of concern other than some screws that could have been just that little tighter I stripped the whole lot down anyway. I checked everything including the chassis brace and found nothing until I removed the rear shocks - one of them felt a little iffy so removed the spring and bingo - little damping and no rebound at all!!! :eek:

What happened? - I honestly dont know... brand new shock with MIP shock shaft and it seems it has leaked quite badly... I have rebuilt ALL the shocks to be on safe side as I needed to remove the limiters anyway to balance the car.

So hopefully I have fixed the problem with tail happy back end.

I have also returned the car to standard other than the front springs (kit says green and I say too soft - plus I love my blue springs :p - sorry Chris!) so I will try the car out and report back how it goes. If the tail happy back end is corrected then I will begin fine tuning it with some of the suggestions given.

Thanks People!

Scott

[DA_cookie_monstA]

your welcome Scott, but running a buggy on three shocks and a pogo stick NEVER helps :D:D:D

[Richard Lowe]

Been there, done that.... :p

I suffered from the same problem when I got mine, I solved the problem eventually with quite a few setup changes, but the main one was the front toplinks.
Kit is 1-b with one washer under the inner ball, I'm currently on 1-a with no washers and a low profile ballstud on the inside. It stops the front end colapsing mid corner and causing the aweful front end bite.
Word of warning, with the low profile ball the joint is right on the limit of it's movement with the suspention fully compressed, I've been running mine like this for a couple of months though and it has'nt popped off yet.... /crosses fingers

[scott_davis]

your welcome Scott, but running a buggy on three shocks and a pogo stick NEVER helps :D:D:D

Tell me about it.... was really shocked ( :rolleyes: ) about the state of it .... its supposed to be brand new!

Seems that I might not have pushed the square clip down enough to compress the seals enough so fluid seeping through... I will see how it goes.

Scott.

[scott_davis]

I have now returned the car to standard kit setup with the following changes:

- Blue Front Springs with 35wt oil
- Medium Wheelbase
- Rear Shock eyelets un screwed two turns (0.60)
- No limiters in rear shocks
- 1 limiter in front shocks

It seems to handle well and is very consistent - the rear is pretty well glued to the track although I feel I could use some more exit steering.... any suggestions?

I also feel it might be rolling just a little tad too much...

Cheers

Scott

[Richard Lowe]

If you want more exit steering you can either:-

Move the battery forward,
Go to long wheelbase,
Add antisquat.

To stop the car rolling about try what I suggested with the toplinks a couple of posts ago...

[scott_davis]

Battery is already forward....as per kit and am already running 3 degrees anti squat :(

I might try running long wheelbase though although never heard of anyone using it....

Will experiment with top links

Cheers

Scott

[MattW]

30 deg caster may help.