By the way, I checked roll out. Passenger side tire is 9 5/8 inches at 7.5 lbs. Driver side tire is 8 7/8 inches at 7.5 lbs. I'm sure the difference is due to me having to replace the passenger tire. Not sure why the is toward the larger tire. Most likely due to me leaving with the front wheels on the ground. As mentioned I'm looking currently for somebody to correct the front end allignment and validate the chassis is square. I'll also replace the wheelie bars. Looks like another call to Jegs is in order. Again, thank you everybody.
You need too check overall circumference with a tape , Stagger for roundy round. They should be the same. Like ROOMAN said slicks are bought and replaced in pairs. ASK as many questions as you want .Racing is great.if the car goes straight.
So Rooman. you mentioned using unsprung or no springs in the wheelie bars. I need a set since i wacked my rails tailbone on the tarmack on this run http://www.youtube.com/watch?v=54mNrqkyLqM&feature=mfu_in_order&list=UL And although it was a month ago and despite the fact it doesnt look that bad in the video I am still hurting physcally. Help me understand why I should build them solid. it is on my to do list in the morning to put something on the car to stop the chassis from hitting the pavement on the Wheelie. I am asking now so i wont have to do the job twice. thanks Don
To do with new tires. I help crew on a car that match races with a bunch of guys with alcohol funny cars. One of the guys we ran with this year had bought new Goodyears and they were 3 inches different. Goodyear told him it's OK. THe car can't go down the track. He tried fixing with air pressure, but that was still not good enough. So even new tires anin't right unless you check them. and verify how close they are. BTW we run 5 1/4 psi with our deal and I'm adjusting the air right up til the time the engine gets started. This is 2400 lb 125 inch Blown alchohol. two wheelie bars. we ride the bars about 20 ft, the front end stays about 6 inches off the ground for 100 ft. We can 60 ft @ 1.0's
a simple question. Are you running slicks designed for a solid mounted rear end? There is a difference.
Don, my "solid" wheelie bars actually are not rigid as I make them long enough that they have some flex. That reduces the tendency to break the tires loose when the car comes up on the bar. We usually run a single wheel and adjust the height to control the launch. On a 200" car that generally works out to be around an inch or so. On your short wheelbase car there is not much (if any) chassis flex at the hit and a sprung bar may work better for you unless you have a bar that is almost as long as your car. Roo
Yes open or spool. A posi even a locker will always have one weak wheel or one that is slow to catch up with the other. Otherwise aside from making sure that everything is straight and true you are going to make adjustments by altering air pressure in your tires. IE one with a little less than the other. Its a fine tunning science that's whay racre teams have fellas that don't do anything but tires. But you can work it out. Remember an altered is a handfull. You will probably never make it point and shoot. its just the nature of the beast. You will have to get real aquainted with it and learn to drive it. After awhile you may decide just as I have that you are not a driver, be happy tunning and strap someone else in it. This is not to knock the wind out of your sails, just advice from an aging go fast junky.
The altered I bought (see my avatar) is "point, and shoot" even when it was running 8.20's in the 1/4. That was one of the reasons I bought it.
I ran 5 1/2 earlier this year until I saw the photo shots with the sidewall really wrapped up. Due the lack of HP with my car it runs better with more air .
My bad, I was thinking traditional altereds. No offense intended mind you it just never occures to me that anyone would be asking a question about a late model race car. Time continues to pass me by.
a 116" wheelbase would be considered short.Mine is 96".The point and shoot newer altereds are 125",and the motors are further to the front.This must make them handle great.I agree that tires should be considered first.Does the car always go the the right?Does this happen down track.Since you are leaving at such a low RPM,the tires could be growing futher down the track.if they are the same it will move the car.It has been suggested to swap the tires side to side,to see if it goes left
Not sure I understood your rollout measurement. It should be around 103-104inches. I would think one tire would have to be off by at least an inch to make a difference. Even at that the taller tire's only rolling 1" further every 8.5'. Not exactly a hard right turn. If it's an old car I'd be shocked if there wasn't some tweakage going on there someplace. We scaled the wheelie bars under load and adjusted the springs to compensate for it. It's still a moving target to get them right enough to manage the wheelie and keep the car straight. Those spring loaded bars take a beating and I believe the spring rates change over time too. At least in my case it's usually human error when the car gets goofy like that. Too much air, one tire hotter than the other even though the air pressure's the same, driver out of the groove, etc. That's why altered are so much fun
In the hardtails the rear follows the crankbolt. If tire rollout is the same and the frame isn't tweaked then check for equalaterial traingle, the axle ends to the crank bolt. Here's what i do, take the rear wheels off and clamp a laser beam to the rotor and shine it forward to the front tire and measure the distance to the front tire, then check the other side. That'll tell you whats up. That rotor should be dead nuts parallel to the chassis and the distance to each front tire better be the same (not distance from front to back tire, that is likely an 1" different from side to side). the distance to measure is the laser beam from the rear rotor to the front wheel rim. If one side is 6" and the other side 8" you'll need to figure out why - it won't be that much difference, you could see that without a ruler. Remember, the rear tires follow the crankbolt. oj (since everybody is bragging, T/S116P; .97 60' )
once you break in a set of drag slicks, you cannot switch them side for side. the sidewalls take a set based on the direction of rotation. they dont like to go the other way.
Ken Cox over-built his cars (which is good, and that's what makes them great cars), mine will still cert 6.0's! Don't let the nose peice that was built in 1986 fool you into thinking it's a "late model" car.
This method is contingent on the front axle being centered in the chassis and also is affected by the accuracy of the wheel alignment and the positioning of the wheels re centering the steering. Probably better to measure from the beam to the frame rail as far forward as possible (provided that the rails are not bent). It is also based on the rear axle being centered in the frame so that needs to be checked first. The triangulated measurement from the centerline of the rear hub or from the front face of the tire at the edge of the ""tread" to the centerline of the chassis at the front crossmember usually works best as having the rear tires slightly off center has less effect on the measurement as it is on the short side of the triangle. Roo
To check front tire alignment measure the front and rear edge of the wheel to the beam and it should have about 1/16" of toe-in on each side. That makes for an 1/8" total. This method aligns the front to the rear. I'd check the crank bolt to the beam, should be exact same on each side, and then find chassis centerline way up in front of the car and check to the beam. That will tell, you if the engine/rearend is out of whack with the chassis. We had same problem in a used funny car chassis, i fixed the problem messing with rearend alignment (holes were sloppy) and shimming the right front spindle, one guy we ran against told me he adjusted his with caster. I never really understood that but he swore by it. I exagerated a bit, got caught up in the moment, that .97 60' is questionable the clocks may have been a tad short. We were consistant .99, a 1.00 and i'd go looking for why.
shit, .99 is still something. We're normal at 1.06 but did have something go wrong with the car once and had put up a 1.03 Ours is with a dump truck engine (BBC) and taxi trans (glide)
oj Re " one guy we ran against told me he adjusted his with caster. I never really understood that but he swore by it." Sure that he was not confusing caster and camber? The big show floppers change their preload by cranking on the heim in the upper leg of the a-arm. Roo ps My ride only goes 1 teens in 60' (direct drive) but does run 4.0/193 at 660' and 6.2/222 in the quarter
When building a car like this or any car with a solid mount rear axle, how to make sure the rear axle is square with the chassis? More specifically, how do you cut the drill the brackets to insure the rear is square with the chassis? If you were going with suspended rear, then i suppose you could be a little off with brackets and make final adjustments at the rod ends (ladder bars) and i think most 4-links have some sort of threaded adjustment as well. But with solid mount, measuring to see if the rear is square doesn't seem so hard. It's the making of the brackets that seems the tough part to me.
Yup, Bootlegger is back with some new information. I have not been able to get to the track because of work and weather. However, Saturday (Jan 29) turned out to be a beautiful day and 57 degrees. Took the car to the track and had time to use the advise provided in the blog. Worked the tire presure and ended up with 5.5 lbs on the right side and 6.5 on the left. Set the wheelie bars at about 1 inch. Wheelie bar set up worked well. The tires were filmed and did not show excess wringle. I felt that we accomplished something and headed in the right direction. OK, here are the results. Keep in mind we are leaving at 3200 RPM vice 4500 (as we should). Reaction time = .002; 60 Ft = 1.3035; 330 Ft = 3.8298; 1/8 ET = 5.9048; MPH was 118.42. We will continue to work with the car and step it up. I expect low to mid 5's once we launch at a higher RPM. Thanks to everybody for the great information.
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