I have a buddy that is having trouble with his t-bucket. When he gets on it from dead stop or slow roll the rear end wheel hops like crazy. It is setup with hair pins and coil overs in rear. Pinion angle is 2 degrees down. All mounting points are tight and not worn. Any suggestions on what we should do or look for?
Wheel hop
- Thread starter wedgehead
- Start date
Help Support Rat Rods Rule:
donsrods
Well-known member
Are you saying pinion angle of the rear end is 2 down ? If so, that is backwards, you generally put the pinion of the rear end UP about 3 degrees and the transmission down a corresponding amount.
Pictures of your buddies setup would help.
Don
Pictures of your buddies setup would help.
Don
I do know for a fact that you DO NOT put pinion angle up at ALL. The rotational force want to drive the pinion up already. What i am asking is that the bars on both ends are solid on the hair pins. Clevis on rear Heim joint on front. Both bars are same length adjusted 2 degrees down. Should we play with downward angle or add some preload to the bars? Shocks are not adjustable.http://www.baselinesuspensions.com/info/pinionangle.htm
dmw56
Busted and Rusted on Route 66
If transmission angle is down set Pinion angle is up!
donsrods
Well-known member
Generally, you only do downward pinion angle on a drag car, for obvious reasons. But on a street driven car there is no reason to do it that way.
We can lead you to water but we can't make you drink. You asked for advice, and the best advice we can give you is to do the pinion angle the way everyone else does it. It could be other issues, like your hairpins are too thin, allowing wrap up, but a good place to start is the pinion angle.
Don
We can lead you to water but we can't make you drink. You asked for advice, and the best advice we can give you is to do the pinion angle the way everyone else does it. It could be other issues, like your hairpins are too thin, allowing wrap up, but a good place to start is the pinion angle.
Don
Last edited:
Dr Crankenstein
Rocket Surgeon
What Don said.
Are we talking race car or street car?
A street car should have a pinion angle equal to and opposite of the trans whether it's up, down or sideways.
Intentionally placing the pinion down is an attempt to reach 0 degrees under hard acceleration. Race car.
I suspect you have also have problem with Instant Center. More info and pictures will help alot.
Are we talking race car or street car?
A street car should have a pinion angle equal to and opposite of the trans whether it's up, down or sideways.
Intentionally placing the pinion down is an attempt to reach 0 degrees under hard acceleration. Race car.
I suspect you have also have problem with Instant Center. More info and pictures will help alot.
Dirtyrat
Got Fins?
Yea I was scratching my head reading the link showing like 18 degrees overall....
Street car stuff is like 3-5 degrees between pinion and driveshaft no?
Street car stuff is like 3-5 degrees between pinion and driveshaft no?
donsrods
Well-known member
Yep. Generally 3 down on the transmission tailshaft and 3 up on the rear axle yoke.
Don
Torch
Extremely dangerous with a torch!!!
- Joined
- Jul 18, 2008
- Messages
- 1,627
No pictures yet for all we know he built the car from holy moly menards metal and zip ties
wheel hop under acceleration is a geometry or a flex problem. shocks just dampen the problem...slow it down and absorb it.
the wheels are either hopping because the suspension under power is negative and is compressing the suspension ie the torque is pulling the tires away from the pavement>
or the suspension geometry is either neutral or positive and flexing of the suspension parts is allowing the power to reach the tires intermittently
for example... if you have a 4 link setup...where the upper and lower links intersect on an imaginary line is your dynamic center of gravity under power. the farther foreward this is the more the engine power will lift the nose...the farther back the more the torque will try to push the tail of the car in the air... both of these will not cause wheel hop but if the upper and lower planes do not intersect and are parallell it might be a source. perfecty paralell upper and lower bars will result in zero torque converted into downward pressure.
Also if they intersect behind the rear axle then the axle torque will be trying to compress the suspension pulling the tires away from the road.
One downside of the mustang II front suspension is they have no upper a arm inclination.
The upper and lower a arms are paralell.
On GM cars the front of the upper A arm sits higher than it's rear.
Tilting the upper a arms back causes the torque of braking as it tries to rotate the top of the spindle foreward to push downward on the suspension.. This is called dynamic anti-dive
When driving a 1967-1981 f body into the corner a slight application of brake going in will tighten up the front suspension and loosen up the rear a little which is why you brake going in, coast through and at perigee begin to apply the throttle to loosen up the front and tighten up the rear.
every suspension is different and responds differently.
Too much brake going in or staying on the brake and you end up with oversteer
not accellerating out of the hole halfway through the turn and you'll end up putting the car into the inside corner and will have to countersteer coming out... you'll be diving in loose and fishtailing out of the corners
do it the right way and you glide through... slight brake...tighten up the front to get into the turn tighter and faster. power up at perigee and as the front end lifts and the rear tightens up you come out like a bullet. too much gas and you spin out
Drifting is for guys who can't keep their car from skidding if you drive right you'll take corners faster than any drifter.
wheel hop under acceleration is a geometry or a flex problem. shocks just dampen the problem...slow it down and absorb it.
the wheels are either hopping because the suspension under power is negative and is compressing the suspension ie the torque is pulling the tires away from the pavement>
or the suspension geometry is either neutral or positive and flexing of the suspension parts is allowing the power to reach the tires intermittently
for example... if you have a 4 link setup...where the upper and lower links intersect on an imaginary line is your dynamic center of gravity under power. the farther foreward this is the more the engine power will lift the nose...the farther back the more the torque will try to push the tail of the car in the air... both of these will not cause wheel hop but if the upper and lower planes do not intersect and are parallell it might be a source. perfecty paralell upper and lower bars will result in zero torque converted into downward pressure.
Also if they intersect behind the rear axle then the axle torque will be trying to compress the suspension pulling the tires away from the road.
One downside of the mustang II front suspension is they have no upper a arm inclination.
The upper and lower a arms are paralell.
On GM cars the front of the upper A arm sits higher than it's rear.
Tilting the upper a arms back causes the torque of braking as it tries to rotate the top of the spindle foreward to push downward on the suspension.. This is called dynamic anti-dive
When driving a 1967-1981 f body into the corner a slight application of brake going in will tighten up the front suspension and loosen up the rear a little which is why you brake going in, coast through and at perigee begin to apply the throttle to loosen up the front and tighten up the rear.
every suspension is different and responds differently.
Too much brake going in or staying on the brake and you end up with oversteer
not accellerating out of the hole halfway through the turn and you'll end up putting the car into the inside corner and will have to countersteer coming out... you'll be diving in loose and fishtailing out of the corners
do it the right way and you glide through... slight brake...tighten up the front to get into the turn tighter and faster. power up at perigee and as the front end lifts and the rear tightens up you come out like a bullet. too much gas and you spin out
Drifting is for guys who can't keep their car from skidding if you drive right you'll take corners faster than any drifter.
