I also think your sitting too high for maximum traction.

I have a 73 Challenger street car with 440 4 speed.
Superstock rear springs clamped in the front.

I'm certainly no expert and haven't really tried to tweak my suspension yet.
I have small block torsion bars that are not cranked up.
Shocks are stock with extentions on the rear.
First picture is the car launching on ET Streets.

Second picture is the car sitting in the staging lanes. It really stretches out at launch and has pulled the front tire a few times.
Best time of 11.83 on a very close to stock 440.

might go faster if youre window was up all the way

...and they let you run without a helmet?

I have been puzzled some by the 5" rise recommendation. I fully appreciate the need to maximize the front end rise. However, solely lowering the front of the car to get that result seems over simplified.

If the front end of the car drops below a neutral, level stance (horizontal), then in a static sense you are pulling weight off of the rear. Obviously that weight can be transferred back onto the rear as the front end lifts back up to the horizontal stance. Does such a motion (back to attaining a level, horizontal stance) actually help traction?

It seems to me that the recommendation should be to maximize lift above a level, horizontal stance. This would be accomplished by increasing total front suspension rise distance thru techniques like reducing the snubber height, and making sure the shock is long enough to not be the limiting factor.

Obviously the faster the rise, the quicker the tires could try and bite. The weight needs to get on the rear tires before they spin, since traction (coefficient of friction) on a spinning tire is less than one that is not.

I realize that some may say, "then why not crank up the torsion bars and put as much weight on the rear in the static stance?". I think the answer to that lies in the dynamics of the motion. Without any ability to rise further in the front, any body stance changes in the rear could result in harsh shocks to the body, which could potentially upset the equation.

Those are the thoughts I have pondered about for some time regarding front end rise. Anyone care to comment on why these are valid/invalid ways of looking at it?

I love E body's!
http://www.youtube.com/watch?v=zYH4_q9SKHQ

I got to mess around with the Cuda tonight. It appears I did have the front drivers side cranked up a bit. I measured to the top center of the wheel well lips. I took measurements before and after putting the original small block torsion bars back in it.

L Front: 27 3/8" (before)
25" (after)
R Front: 26 13/16" (before)
25" (after)

L Rear: 29 9/16" (before)
29 1/16" (after)
R Rear: 27 15/16" (before)
28 1/4" (after)

Before I made the switch, when I jacked up the front end to see what my suspension travel was getting a measurement of 30 1/8" on the left side and 29 5/8" on the right side. So there was 2 3/4" travel on the drivers side and about 2 3/4" travel on the passenger side. I didn't recheck to see what the max height number was after the changes up front. I will have to do that tomorrow.

In case you missed my comment before, it took a combination of lowering the ride height AND cutting down the upper control arm bumper to free up enough travel.

Well I put the rear springs in the upper mounting hole today and readjusted the front end using the upper pivot of the lower control arm as the measuring point. I ended up with the following:

L Front: 25 3/4"
R Front: 25"
L Rear: 29"
R Rear: 27 1/8"

It measured 7" from the bottom of the K-frame to the floor and I get around 9 1/2 - 9 3/4" from the upper pivot in the LCA to the ground. Measuring the rake it is level to 1* nose down on both sides.

While this did lower the car front and back the car still sits really lopsided. Basically the whole right side of the car sits much lower than the left. Is this much "tilt" to be expected with the SS springs? If so...I may switch to the Caltracs set-up just for the fact that I would like to level the car out?

I have a set of ESPO (+1" I think) leaf springs for my car that I bought before I raced it. Would these springs work with Caltracs or would there be an advantage going with the mono-leaf?

The front tire diameter works out to be 27.1" for what its worth.

The problem I had with setting it down any lower is that the frame is sitting down on the LCA bumpers. The way I have it set now I have about 1/2" or better between the frame and the LCA bumpers which the Mopar Chassis Manual recommended. I am not sure if cutting down the bumper is an option or if that would cause other problems?

i missed posting on this thread earlier..i was reading..
i have read alot of recommendations...
at a risk of confusing the situation..
first..i am gonna say..
after looking at all of your posted videos..
your right rear tire is loosing traction first..
you can see it almost all of the launches..and its exaggerated..in one of the burnouts..
the car drives right out of the hole ..and your steer it back to the left.
I was gonna suggest/ask about your routine in air pressure settings for the rear tires..
if one tire has more air..it could be the cause of this..
(if we rule air pressure out)
next..is preload.youve mentioned you measured the car at 4 corners..ill have to go back and try to decipher what you changed and what you had.
but..
Pre load or more ride height in the right front can unload the right rear..causing this loss of traction..and drive out to the right.
trying to keep things simple so you dont get lost...
i need to re-read what youve done..and changed.


before i do this..i will mention..moving the front spring eyes up..i doubt will fix anything..
rear ride height doesnt concern me that much.right now..
however..you dont have alot of action on the rear of the car..it doesnt extend (rebound) when torque is applied..this needs to be addressed.
this comes from pinion angle..
i fear moving the spring eye up will raise the i/c and it definately moves the pinion in the wrong direction...based on where you say it is now.
i will pace my comments ...so as not to confuse.

so..
1 vote for the softer tortion bars...(and a tad lower front ride height..ie suspension rise.
2.fix pinion angle.
3.change out the rear shocks with more/adj. rebound.
(please explain your tire pressure routine.)
cheapst

As for the tire pressures....I check them before ever run when I am in the staging lanes and both rear tires are always the same (i.e. 20, 18, 15, etc.) so we can rule that out.

Now that you mention it....whenever I do a burnout the ass end of the car always slides to the left on me. I am not sure if this is something in my technique or in the suspension set up but it does prevent me from doing any pro-mod style burnouts

I think the biggest issue is that I had the front of the car jacked up too high. I remembered today while I was under the car that one of the reasons I did this was to get the steering linkage to clear the #2 primary tube. I put a call in to a local chassis guru that also does headers and he is going to fix this problem for me near the end of June (hopefully).

I will trim a 1/2" off the LCA bumpers per Mr P Body's recommendations. I think I also saw a low-profile bumper that I could use for the UCA. I would like to have something up there so it doesn't just slam down metal-to-metal. I already swapped the small block torsion bars back in it last night so I am all set there.

I will get a set of the Calvert 90/10's for the front and am still debating the Ranchos for the rear. I just like the idea that they are adjustable for fine tuning. $40.00 for std. Monroe truck shocks or $178 for 9-way adjustables?

Did moving the rear springs to the uppper mounting hole in the front do more harm than good? It dropped the car a little lower in the rear but are there adverse effects when doing this?

More misc. comments.
- I used +1" ESPO springs when I first switched to CalTracs, but eventually changed them out for Calvert's mono setup in the standard ride height
- My best results w/ that size MT ET Street Radial on an 8" rim was between 17.5 and 18.0 psi
- I didn't cut my lower control bumper, but it does ride pretty close to it

With the SS springs there are 5 leafs on the left(drivers) side and 6 leafs on the right (passengers) side. Why is it then that the right side sits lower? I would have thought that with the extra leaf the right side would sit higher and that would be the side you would want higher since the front left would want to rise and twist the car forcing down on the right rear?