Fourlink wheel hop?

I would like to know what causes my right side to hop sometimes. It does not always do it. I tried different tire pressure up and down. I have the coilover shocks set real stiff.
I have a picture (I hope) attached so you can see the foot print.

http://picasaweb.google.com/63chevytoo/Wheelhop03/photo#5013893629037751250

Thanx
Don

You say you have a 4 link in it. What kind of car? What kind of 4 link? How much pinion angle are you running in it?

RM
I put a standard CE fourlink in my 63 sedan
I have about 3 deg. down on the pinion angle
I tried about the same deg up and I can't tell the difference.
I don't like to angle down any more because the farther you go the more the driveshaft yoke backs off of the transmission shaft. I want to maintain as much spline engagement as possible.

I just checked and the adjustable shocks are set to the stiffest setting. I think I will back them off about 3-4 clicks ant try that.

Don

Generally your pinion would be pointing slight up...if your engine & trans is pointing downward. You want to match your engine/trans angle only opposite i.e. if the eng trans is downward 3 degrees, your pinion should be pointing upward 2-4 degrees. Usually you want a degree or so of difference to ensure the U-joints work the grease a little.

Mike
It sounds like I should set the angle at about 7 deg. up?
If that sounds right I will give it a try.
I ran it about 3-4 deg. up before, but it may need more.

Don

Not to be an ***, but where did you get 7º from? You need +/- 1º or so from the angle of the transmission so that the u-joints are the wear points. so 3 +/- 1 is 2-4º.

Matt

Reading all these replies has me confused so I'll tell you what I do and you can do with that what you want. I check the angle of the driveshaft and the angle of the pinion. I want the pinion to be nose down a couple degrees more than the shaft is on a 4 link. I don't care what the front joint angle is or the trans angle because they are decided by their position and the cars ride height and non adjustable with the car already built. I never want the pinion to be above the shaft. If it is you get wheel hop and bust U joints too. On a stock suspension car with cal tracs or snapper bars I want more down pinion angle due to the pinion rotating up more than a 4 link at launch. Been doing it this way all my life and it works for me. Take this for what you think it's worth. Best wishes. RM

I just got done checking my pinion angle and it is about 2 deg. down
I don't know how accurate you can be checking pinion angle but I guess if you are + or - 1 degree that may not be too bad.

SuperNova69
The 7 deg. came from the trans shaft being 5 deg. down.
If the pinion is 5 deg. up they are parallel. 2 more degrees =7:confused:

Don

Yes, if your engine & trans is 5 degrees down, your pinion should be 3-4 degrees up which results in 1 or 2 degrees of pinion angle. Here's a nice powertrain setup guide from Inland Empire Driveline that should clear it up for you.

http://www.iedls.com/ptsetup.html

I set the pinion down about 2 degrees.
I do not believe the pinion rotates up much on a 4 link as RM mentioned already.
I just got back from trying it out and it still hops a little.
Could it be because the tires are cold.
They are BF Goodrich Drag Radials 345/55/R15
On the second burnout tires were warmer and it was a little smoother. So it may be the tire temp. and road temp. combination. I do not know. All I know is: I don't like it because it shakes the whole cage.
Here in PA it is about 40 deg. I may have to wait until the temp. is a little warmer.
I will keep you posted when I can eradicate the problem.

Don

Tire temperature wouldn't matter in my opinion so long as the pressure stays close to the same. Cold tires will be low on pressure compared to hot tires. Besides the rear frame and 4 link does the car have frame connectors and a roll cage or what? RM

RM
It has a cage and frame connectors. I am running it without the door bars but I don't think that would matter.

Don

OK so it has a main hoop two bars to the rear frame rail section and two diagionals from the main hoop to the frame connectors but no door bars? Is that it? If so why do you think the door bars aren't an issue? Also do you have the 4 link set up right or close to right? If so what is the instant center length and height off the ground? Last thing is how fast is this thing? Picture looked like it'll toast the hydes pretty good. RM

The answer you're looking for may be here. It seems bars need adjusting for anti squat to be at 100%. The car should neither rise or squat on acceleration.

http://www.pro-touring.com/forum/showthread.php?t=12696

RM
I am just getting this thing set up and trying to adjust the suspension. Putting on some street miles to get things broken in. (Or broken up)
It has a 12 point cage. I have 6 bars tied to the frame rails and 2 bars tied to the frame connectors. (no bars to the front clip)
I don't know how fast it is. But it's not a kid toy anymore:D
I do not have any experience with a 4-link so I am "tinkering" :eek: but not making drastic adjustments.
I appreciate everyone's feedback
The motor is a 383 with Crower mechanical roller set up
Dart Pro-1 200 cc heads
6in H-beam rods & forged crank
SRP flat top forged pistons
750 Demon carb
10.3:1 comp

Don

Don, Sounds like you do have a chassis that isn't an issue but as Shane65 says if the 4 link is not close that could rattle the car. I hate squatters and IMO most cars need to separate not squat. Pro Stocks and Pro Mods may need to but not a average car with a decent chassis. You should buy a chassis set up book, lots of them out there for about 50 bucks. A down and dirty method I use with some success is to install the bottom bar paralel to the ground with the car sitting on a level place. The top bar should run down ward from the rear to the front. If you can imagine a line from the bars angle forward there would be an imaginary intersection of the bars like a triangle. See if your bars intersect about 40 to 50 inches out from the rearend and if that intersection is about 8 inches high off the ground. Most Novas will be close at that setting. Buy a book! Chassis set up is a real deal and there is much to be done to make the car work to it's fullest potential. RM

Thanks guys for all the imput...
I thought about getting a book, looks like I will now.
This stuff is good stuff.
Thanks for the link Shane65.
I will keep you posted.

I not only use all the brains I have, but all that I can borrow...

Thanx
Don