Originally Posted by fishman1
Thanks for the reply.........i have another question when measuring ride hieght what do you use as a refernce point and also if the two back tires are at diffrent ride hieght will this affect the way it launchs making it go to the right.........
Pick 4 spots that you can find easy. Generally in the torque box area. Rear spots should be around your front mounting points of your suspension. The fronts should be about the same distance apart, usually before kick in by feet. This is measured on a level floor. Any tire pressure or tire diameter can enter into this also. Once you know how square your chassis and body is you can convert them measurement to wheel well spots. This makes it easier to measure.
i am kinda lost on chassy stuff never had to touch it before until i put more power in the car.........the car has 70 more horse and about 30 foot pounds of torque more.........but car only ran a little over a 1/10th faster as my 60 foots have went down from 1.40 to 1.45 i am guessing part of it is from going crooked and also my torque convertor is from my old motor and i looked at both motors dyno sheets and seen that my new motors torque is peaking later so it is affecting my stall which needs to somewhat higher..........old motor with no pill in 2 step with trans brake on would rev to 5300 rpm and new motor will only go to 5100 rpm new motor is peaking around 5200 rpm for torque........i have 32 inch tire and with the 5.14 gears i am at 7000 rpm probably 300 feet from finish line and car maybe gets to 7200-7300 rpm so it is laying down some so i am going to change the gears to 4.88 and see if maybe it will make the convertor work harder and pick up time and also not run out of gear on the top end.......my peak horse power is around 6600-6700 rpm........thanks sorry for being long winded
You have made a change in your combination. This leads you to believe that your torque cancellation (twisting or roll of chassis that adds bite to left rear and takes it from right rear).wasn't set quite right to start. This is probably your problem, if rear is square in the car and the tires was the same. There are several ways to counter act this torque. You have to remember that what is needed is more weight on the right rear tire contact patch. 1 You could get it by just moving weight to the area needing weight and re leveling car. (This stores extra energy in the right rear spring, so it has a head start on evening out with the left rear.)
2 option. Raise ride hight in right rear and left front. This stores energy in right rear and left front while removing it from the other two. It isn't quite as effective as plan one.
3 option. Preload ladder bars. This in effect raises the instant center on the right hand bars, putting more weight on right rear tire. It only does this when forward force is applied to car. It will raise the ride hight some on the right rear.
If you choose option 3, here is how I do it. Check axle tubes and ladder bars for being solid and no welds broken. remove right forward connecting bolt. Set wheel base and pinion angle with left ladder bar with chassis sitting level and driver weight in seat. Then with out moving chassis go to right side and adjust ladder to center up to bolt hole and same wheel base. When secure shorten the top left rear adjusting nut by no more than one flat of the hex headed adjusting bolt. You can always add more or take some away later. Most times a little goes a long ways. It is even something that can be done at the track. The coil over adjustments can be made at the track also. Always write down what you do so you can get backed up if you need to. To over simplify your just putting preasure on the right rear to even out the traction with the left.
I will add that Billy Shope has a traction dyno in his blog that sounds good to me, but I have never had the chance to use it. If anyone has used it, I'd like to hear results. I have to add you can mix and match these different ways. If you never mess with the chassis you will never know how it works or what tools you have to fix it. Knowledge is power.