QuestionThanks Dan, I'll give it a try and will keep you posted, by the way thank you
so much for your time and expertise. Sincerely Jim
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-----Question-----
Dan, Thanks for the hot tip and in fact I do have an adjustable top link at
both ends and have tried playing with this with no success, although I have
not tried the torsion link I guess I dont have anything to lose. Is there any one
torque absorber that you like ie. with or without shock and also it looks like
the spring rates vary from 400 to 1500 lbs. thanks Jim
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-----Question-----
Hi Dan, I've been racing late models on circle tracks for a number of years
and
consistently have the same problem every year, when exiting the corner the
rear
wheels just start spinning. I have a port city chassis with a 3-link suspension,
using a solid top link. I'm wondering if maybe I have too much engine, is that
a
possibility? I've also been told that moving the axle forward on the right side
will
increase bite coming off. Any ideas would surely be appreciated, thanks Jim
-----Answer-----
Ahem- - -well the first thing I would do would be to put the spring and shock
arrangement in that third link. Then after trying that, I would add ,( if it's not
already there) a way to raise and lower the pick up point on the chassis for
the third link. Please don't do both at once.
Now here's what happens. When you add poweer comming off, the link
compresses, absorbing a notable amount of the initial torque, and softening
your acceleration just a tiny bit. It can't slow you down, cuz you're already
losing a lot with the wheel spin. It works as a shock absorber (which it is !)
allowing the tires an instant to grip.
Once that's done and you have noted the results, add the adjustable pick up
point with about 5 choices. This will be a "U" shaped bracket welded vertically
to the chassis where the link attaches, with several holes to locate the heim
joint at various levels. This will give you a finer adjustment of the action of
the link and also allow you some adjustment of the stiffness of the rear
suspension.
Of course it will be stiffest when the link is horizontal when the car is at ride
height.
With these two changes, you need to go to the track and do a few hot laps.
Run races if you have to , but carefully note what effects the changes have.
Again, don't change anything else at this point.
You should find that the soft link serves to reduce the wheel spin you are
suffering. At least a little bit. It should go without saying that you should be
sure the rest of the car is squared up before you take it out. Don't do the
asymetrical rear end just yet. That's some pretty kinky stuff, and can have
disasterous results. However if you can use a cambered diff like the Cup guys,
go for it- - -take your wallet to that party !
One final thought, while you're trying this new link arrangement, please keep
accurate records of your tire temps, Outside, middle and inside on each tire,
starting on the two right side tires, and then going around to the left.
Write me back when you have some results, your problem interests me .
Thanks for writing !!
Dan Liddy
Sarasota, Florida
-----Answer-----
Hi again Jim:
Here's the set up I had in mind- - - the shock is mounted separately so not
only can you move the link up and down, you can try it with, and without the
shock. Relatively cheap too. This from Performance Bodies.
My little road racers are all equipped with indepenent rear suspension, and
I'm not having to hold back 700 horsepower.
If youre wheel spin is that bad I would go with a softer spring to start, and
move up in increments. When you stop hearing a bang on acceleration, you
have enough spring.
The shock will stop it from bouncing back and forth which would probably
give you some really strange handling problems, the stuff of nightmares. As
you add power, you want the diff to rotate enough to absorb the first blast of
torque, and stay in that positon gradually returning to it's natural state as you
reach the end of the straight. As long as all your other heim joints are in good
shape, there shouldn't be any slop to cause you concern.
At this point I would suggest that you contact Performance Bodies at
800-722-4661 and ask for some tech help regarding the torque link. They
sell all this stuff and can give you better advice that I can. They're in Iowa and
have a good reputation as a supplier.
Finally , get a copy of the book "HOw to Make Your Car Handle" by Fred Puhn
, bookostores either have it or can ordert for you - - it's about $16.00 and
will shave a half second off your lap times. Seriously I picked up a full 3
seconds on a fairly short road course- - with about 120 swaybacked old nags
struggling away.
Let me know what happens, as I said, the problem interests me.
Thanks again
Dan Liddy
AnswerHi again Jim:
I checked with two people I know who are more experienced with the high horsepower late models and both suggested you start with about 700 Lbs. of spring in the torque link. If you still have the wheel spin, lower the amount of spring until you hear it bottom coming off. Go up a notch, and you should be right there.
Both also said don't EVER misalign the rear end, keep it square and check it often. If you want to run a little lead in the RF it should turn in a little better but won't affect your loose rear. After that try more or less stagger, check your tire temps and make sure they aren't hot in the middle (too much pressure) or cold (not enough ) The RR should be a little hotter on the outside , but even on the center and inside. The reverse is true for the LR.
Performance Bodies also has a dual action link that works both with acceleration and deceleration, A little too kinky for my limited knowledge, but it's s'posed to help the car settle better under hard braking- - - can you say Martinville ?
By the way, you didn't tell me what the car weighs, and what kind of rear end you're running, Posi, or a spool, and tell me about the rest of your set up. Save it til you've tried the torque link though- - Then we'll look at the whole package. I've got a couple of wise old roundy round guys around here whose brains I pick regularly. One of them used to work on Cup cars.
Good luck, keep the greasy side down.
Dan
