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dan_kitty
08-03-2008, 11:58 AM
hi, I was having real problems jumping the b4 last night which ive never had before. Basically the car was nose diving off the jump real bad, even giving 100 percent throttle in the air would only bring the nose up a bit. Incidently crashing most times.

usually the car jumps really well so was wondering what could cause this, in hind sight i was running a loose slipper, could this be the cause. I know suspention setup affects jumping but i was using the common silver/blue combo.

any other suggestions would be a great help,

cheers
dan

Southwell
08-03-2008, 12:02 PM
If you are nose diving when u jump you need to come off the jump on power. I found this got worse when i went brushless.

bigred5765
08-03-2008, 12:02 PM
may have just been a dodgy ramp, or the way you hit the ramp.
the only thing that might have helped it seemed you tried
gyroing it, using the throttle

Lee
08-03-2008, 12:26 PM
Sounds like a dodgy ramp to me too, if its normally ok i wouldnt worry about it:)

dan_kitty
08-03-2008, 12:34 PM
the take off ramp is a good ramp, used many many times before. and other guys were getting big air keeping the car level in flight with ease. Maybe it was my take off speed but it didnt feel normal.

hmmm will take a close look at my b4 i think, check that there isnt problems with the drivetrain, it was a bit noisey.

cheers guys

Southwell
08-03-2008, 12:47 PM
Unless you were bottoming out the rear shocks and getting chassis slap on take off, that would cause it to push the back up.

dan_kitty
08-03-2008, 12:52 PM
now that could quite be what it was actually, i had the rear low and the front high, in my head this would make the nose raise more. Didnt occur to me that it could be bottoming out.

cheers:)

Danosborne6661
08-03-2008, 02:01 PM
What pistons are you running?
Cause if your running smaller hole in the back that front that could be why..

With a smaller hole piston it makes the car 'pop' out of jumps a bit more.

Seeing as you may only have the smaller piston in the rear it means only the back might get that 'Pop' which causes your car to nose dive. Its about balance so what i would do if i we're you is move to the smaller piston up front and drop the oil up front by 5w

c0sie
08-03-2008, 02:28 PM
Dan (Kitty),
I had the EXACT same problem last night at Caldicot.

What setup are you running fella?

I found that if I throttled up as I entered the ramp the car felt better than just hitting the ramp with a constant throttle...but its quite scary seeing a brand new B$ drop nose down whilst theres nothing you can do about lol

MK999
08-03-2008, 02:55 PM
Last time I had this problem I found it was a problem with the motor, and the time before that the mesh between pinion/spur had been pushed together. This effectively means you're running with a brake on all the time, if it was noisy and felt slow I'd look at that first. :)

dan_kitty
08-03-2008, 05:16 PM
because it was a slippy track last night and i had no decent tyres I tried to set up the car to have as much grip at the rear, so i lowered the back and used the inner hole on the towers. This leads me to believe it could have well been bottoming out on that high angle take off ramp like southwell suggested, cant remember what pistons are in, havent rebuilt for a while.

but you mention the motor thing, which could be the case because the car did have a drag-brake feel to it. Its good learning for me to hear all these tips:)

P.s Chris your b4 was going great on her maiden voyage, you enjoy 2wd?

cheers

Belsten
08-03-2008, 05:23 PM
Dan it was just the throttle control over that jump last night mate. Mine was going over it fine when my thumbs were working :woot:

Gaz_Stanton
08-03-2008, 05:26 PM
so i lowered the back

That's the problem.

c0sie
08-03-2008, 09:40 PM
because it was a slippy track last night and i had no decent tyres I tried to set up the car to have as much grip at the rear, so i lowered the back and used the inner hole on the towers. This leads me to believe it could have well been bottoming out on that high angle take off ramp like southwell suggested, cant remember what pistons are in, havent rebuilt for a while.

but you mention the motor thing, which could be the case because the car did have a drag-brake feel to it. Its good learning for me to hear all these tips:)

P.s Chris your b4 was going great on her maiden voyage, you enjoy 2wd?

cheers

Dan, are you dan with the tiger sprayed jobbed D4? Or another Dan?
Either way I didnt realise you were a Caldicot'ter sorry!

I LOOOOOVE 2WD! Ive never been so happy with a car like I was with the B4 last night. All bar the nose down jumping it was heaven to drive :)

Body Paint
09-03-2008, 12:18 AM
Dan, are you dan with the tiger sprayed jobbed D4? Or another Dan?


CRIS: Do the sums, Dan with the tiger spray job = Dan Kitty. Think about it..... Tiger / Kitty :thumbsup:

Sounds like there was slippy floor on the way to a steep ramp? If it was that would be the problem, you need traction to keep the momentum up the ramp otherwise you will be decelerating up the ramp and will inevetably drop the nose. Some more antisquat may have helped lift the car and doubtless the low rear end was killing your momentum on the up ramp even more.

c0sie
09-03-2008, 12:26 AM
Dude, I know you were all busy last night..but man..it was ace! The B4 is just brilliant :D

And yeah, I get it now lol! Hi Dan!

Danosborne6661
09-03-2008, 12:26 AM
Nawwp big stretch of carpet towards the jump!
I had ago on Cris' car n it was fine, its his thumbs ;)

But Dan it could well be if your running a smaller piston on the rear than front as Cris' back end was bucking up more than mine because of this. You may not of noticed the back end bucking up before because usually at Caldicot its a flat take off to the jump. The jump i'm assuming you had the back end kicking up that much more on was curved which does change the angle of the car quite alot. Pistons pistons pistons :D

rich_cree
09-03-2008, 01:08 AM
Jumping attitude:

Sudden kick of rear into air so car is pointing nose down shortly after leaving ramp = rear end bottoming out or binding in rear suspension. Check suspension is free first then try stiffer rear spring

Car jumping inconsistently, hard to judge correct speed to hit jumps = front too soft, grounding out on up ramps

Car tending to take off flat but ends up nose down before landing = too much anti squat

c0sie
09-03-2008, 12:44 PM
"Car tending to take off flat but ends up nose down before landing = too much anti squat"

Thats sounds about right for me on Friday.
Cheers Rich :)

dan_kitty
09-03-2008, 03:34 PM
lol, opened up a bit of a debate here, but its all good

If I remember rightly the car was jumping alright with my lipo in at practice and seemed to fly level on slow take-offs. I reckon the bad boy was bottoming out. Saying that, other points people have suggested probably added to it.

will have to make some adjustments and try again

ta