Twisting

NaughtyAlan · Post by **NaughtyAlan** » Tue Nov 18, 08 6:14 pm

Since fitting the Detroit locker the car seems to quiver when i launch hard.
Even when i hoof it on the motor way it seems to dive to the right for a split second. Just feels like the car is twisting?
I now i could do with call tracks but scint. Am taking it for an MOT tomorrow, is there anything that i can check while on the ramp.

JohnR · Post by **JohnR** » Tue Nov 18, 08 6:54 pm

Probably is !! have you got frame connectors on mate??? you might need some if you aint

NaughtyAlan · Post by **NaughtyAlan** » Tue Nov 18, 08 7:00 pm

JohnR wrote:Probably is !! have you got frame connectors on mate??? you might need some if you aint

Yes John, welded in.

mopar_mark · Post by **mopar_mark** » Tue Nov 18, 08 7:11 pm

Al, Can't remember how your axle is mounted, is it still leaf spring, I assume so by your Cal tracs comment.

When you launch, does the car squat evenly ?

I would get some one to stand behind, while you do a few launches, if they had a video camera even better.

Did you change the whole axle or just the centre section ?

Are shocks adjustable ? how old ? Do they seem ok, even rebound, etc

Does body show twist when you load up on the verter, I know they all twist some what, but more now than you remember before the changes.

Had a mate with a high revvin small block in a 57, twisted so hard, it popped/cracked the screen

Dave-R · Post by **Dave-R** » Tue Nov 18, 08 7:23 pm

You need to stiffen the right rear spring.

You don't want the car to squat down at the rear a lot either. The back end dropping is the same as the axle lifting. You loose traction. The more weight transfer you can get without the back end dropping - the more force you plant onto the ground.

So the rear springs need to be stiff.
The right rear needs to be stiffer than the left.
You can drop the front eye of the right rear a little too.
You need at the very least a pinion snubber that actually does something.
Clamp the front half of the springs.
Fit a rear sway bar.

NaughtyAlan · Post by **NaughtyAlan** » Tue Nov 18, 08 7:26 pm

Got Rancheros adjustable witch are on hard set at the moment.
Its just strange that its become more apparent since going detroit?
My mates 55 Chevy with a Detroit quivers when you put it in to drive but goes in a straight line.
The car seems to load up OK when holding it.

mopar_mark · Post by **mopar_mark** » Tue Nov 18, 08 7:28 pm

As Dave said

Put more weight that side, which is why when relocating battery to the rear, they recommend that side

NaughtyAlan · Post by **NaughtyAlan** » Tue Nov 18, 08 7:28 pm

Had the springs upgraded and extra leaves put on the passenger side with more clamps.

NaughtyAlan · Post by **NaughtyAlan** » Tue Nov 18, 08 7:29 pm

Battery is on that side.

Dave-R · Post by **Dave-R** » Tue Nov 18, 08 7:33 pm

What about a rear sway bar then?

mopar_mark · Post by **mopar_mark** » Tue Nov 18, 08 7:33 pm

Maybe the locker is magnifying a problem that was previously there ? If it wasn't a Locker before then power wasn't being planted evenly as it is now.

If you have the right shock on hard, try reducing the one on the left

NaughtyAlan · Post by **NaughtyAlan** » Tue Nov 18, 08 7:47 pm

Will try that Mark.
Always had a locker Dave but kept breaking them. Think a sway bar is for cornering? Snubber is modified and about inch clearance.
I will have to ask Adam what it looks like from the rear as he is always following me.

Dave-R · Post by **Dave-R** » Tue Nov 18, 08 8:14 pm

NaughtyAlan wrote:Think a sway bar is for cornering?

Think again. Sway bars control body roll by applying a force to the side of the axle that is trying to lift. Remove the front bar if you want but use a rear bar for axle control. Just don't try taking corners like that.

Snubber is modified and about inch clearance.

Then it is not doing anything. By the time the snubber has rotated that far you are into major axle wind-up. Adjust your snubber at the track to a quarter inch clearance. This will apply forces to the axle and also increase weight transfer.

NaughtyAlan · Post by **NaughtyAlan** » Tue Nov 18, 08 8:22 pm

Was thinking of fitting one Dave along time ago but didn't think it would make that much difference as it is a rubber mounted thin bar with link bars to the chassis.
Still quite a few mopars street and strip with stock set up on the rear with no problems?

Dave-R · Post by **Dave-R** » Tue Nov 18, 08 9:22 pm

How thick are your front torsion bars? They hold up the full weight of the front of your car don't they?

A 3/4 thick bar at the rear (trying to twist in opposite directions) will go a long way to keeping body and axle in line with each other.

Every little helps!