I was reading your article in GMHTP and noticed you guys centered the rear end (PHB adjustment) by measuring off the tire in relation to the 1/4 panel. Isn't that highly inaccurate? I mean, these cars are NOT square. I tried doing that and afterward put my car on an actual alignment rack and was off a little past factory spec. I'd rather the car go straight then "look" square. Something like that might work on a vehicle with tighter production tolerances, but F bodies ain't one of them. I guess I was just suprised you guys didn't use a modern alignment rack to set things.

 

Because Madman is and he does what he wants. Questioning Madman is like playing with fire .






















J/K I'm sure he'll chime in soon enough.

 

He's a redneck Miller boy, doing it liek that insures he messed up somewhere and it will come out right

 

Chuck Norris has madman set up his suspension..

In a modern car the 1/4s are pretty close, way less room for error then a DIY with a tape measure on an axle that the mounting points arent necessarily equal side to side IMO. I have used the thumb between the wheelwell and slick method and on a 4wheel rack it was a lot closer then I expected. Of course there is no replacement for a 4 wheel alighnment machine unless the tires stick out and you can string it.

 

thats because on a drag car, the panhard rod adjustment is not to "center" the rear exactly in the car.

its to get the rear centered with the body clearance so your tires dont rub the inner fenderwell.

 

oops, for some reason I seen LCA instead of PHB Only thing I worry about with the PHB is the tires rubbing on the inside, more then the outside anyway on these, same difference depending what is closer.

 

Mr Dude is correct the PHR is for side to side. As to the alignment rack, I only use one for the front. The rear I use plumb bobs and tape measures to get the rear square front to rear and then go off the rear tires to set the front.

 

Interesting tidbit for you: After MadMan set the rear end up in my car, we took it for a front end alignment. They put the car on the four wheel alignment machine and the rear end was perfect per the computer.

 

im also willing to bet that madman took the time to measure everything out first.
someone (that knows what they're doing) with a measuring tape can actually set a car up more accurately then the "green light" clearances given by a machine.
technially the machine COULD BE more accurate, as what it does measure, it measures more accurately...
but its designed to be "close enough" for the hamfisted mechanic to set a street car...
no one wants to spend 2 hours getting a toyota corolla to within .1* when you cant tell a .5 diff.

 

tue, if you are building a whole car in a shop you can easily measure everything out and get it perfect. But for me in my garage at home when I put a rear in the car its easier to eyeball it and it put it on a 4 wheel myself. I havent had anyone else align one of my cars in 25 years, right after I had one of first cars aligned. A 100K machine only as good as the person using it.

Thrust angle on a drag car is important but so many guys never measure the rollout of ther slicks so all that perfection can easily go to waste

 

in the article TA angle was mentioned. Is that nose up or nose down?

 

Very true KP. I have created miracles on customers cars just measuring the rollout and showing the customer.

 

At least it seems like the drag radials are a little better at being the right size, M/T slicks are a crapshoot..

 

I put a 1x6 standing straight up on both bulges of the tire, sticking under the fender lip. I marked it on the top edge with a sharpie at the rear fender edge. Kept adjusting until they were equal. Got it close, not been on an alignment machine yet though.

Alignment machines are very accurate if you use them to get it dead nuts, yes you can make it pass in the "green" spec "window"...but you can also split the "window" numbers and get it dead nuts.


David

 

KP, by rollout, are you saying as the tire spins, the width changes a little?

 

roll out is the true distance covered with one rotation of the drag tire at race pressure

 

I am in the mood to buy in the next week or two if I can get an answer

Will the Madman TQ arm fit my 4inch exhaust?

 

No the crossmember wont clear 4" exhaust. I am still working on a reponse to your PM.

 

So if a tire is undersize by X amount do you overinflate to stretch it into spec? I my tires are old, and I haven't checked them, but I wonder if with age it gets harder to do.

What kind of tolerance is acceptable? Madman?

 

could you please explain how to measure rollout and how to use that information in setting the rear suspension? im very interested, as im sure others are as well