How to drag race your classic

dennis112 said:

Running the 6 cylinder springs in the front and removing the sway bar should just about take care of the front end.

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This may be a noob question, but how does 6-cylinder springs and removing the front swaybar help?

Cannoball888 said:

This may be a noob question, but how does 6-cylinder springs and removing the front swaybar help?

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During acceleration, the front of the car will come up (more movement) and there will be more weight transferred to the rear wheels. The additional weight trys to plant the rear tires into the pavement which helps maintain traction.

So, it's just weight reduction of the front end? I know thick sway bars are heavy but I would think there wouldn't be that much difference in weight between 6 and 8 cyclinder springs.

Cannoball888 said:

So, it's just weight reduction of the front end? I know thick sway bars are heavy but I would think there wouldn't be that much difference in weight between 6 and 8 cyclinder springs.

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No, it's not an actual weight reduction you are messing with (although totally removing the sway bar would certainly reduce weight.)

Think of more of a teeter-toter effect with the weight being created by acceleration. Pretend that your teeter-toter is equal length on each side of the fulcrum and you have equal weight on each. What happens when you move the fulcrum off center--toward one of the ends? The opposite ends becomes heavier and the teeter-toter will go down on that end. That is sort of the principle.

For every action there is an opposite reaction.

Acceleration always tries to move the weight to the rear of the car (like moving the fulcrum forward.) Changing the springs to something lighter and removing the sway bar will allow for more and faster movement. The fulcrum will move a little more forward at a faster rate.

How do the parts assist this? The 6 cylinder springs will droop more with a heavier V8 plus they are not as strong and they won't resist movement as much as a heavier spring. So you get more up and down travel with less resistance at a faster rate.

Disconnect the sway bar (you only have to take the attaching ends off) and the car will have more upward travel in the front end because there is less resistance and this will also happen at a faster rate.

So, the fast upward movement during acceleration makes the front of the car "appear" lighter and the rear "appears" to get heavier due to a weight transfer (an opposite reaction.) Again, like moving the fulcrum of the teeter-toter off center.

Clear as mud?

Compare 6 cylinder springs to my 620lb/in (stiff) 1" drop front springs:
The 6 cylinder springs are much taller (several inches)
The 6 cylinder springs compress a lot when the weight of the car is on them so they have stored energy in them. Thus they want to push the front of the car up on launch.
My springs move very little if any with the weight of the car on them. So they store no energy and do not help push the front end up on launch.

Removing the sway bar does help with front end weight reduction. But the big issue is that it frees up the front control arms to extend upward which allow the springs to push up the front end more freely and transfer weight to the back of the car for traction. The sway bar ties the front end together and keeps the arms level for cornering. It only hurts straight line acceleration.

With the 6 cylinder springs being softer, is the ride height similar to the 620s or are they closer to stock V8 springs. I have 620s and want the 6 cyl springs but dont want to lose my stance. Are there any compromises? Also, where can I get some cal-tracks and how much are they? Do they show up on ebay often? Thanks, Brett

Also, I am about to change out my leafs because they are sagging and my tires are rubbing. If I were to get cal-tracs, would 4.5 or 5 leafs be benificial or not? Should I just go back with standard 4 leafs? I do not have any hp or torque numbers or track times, so I guess just going by my sig, what do yall think I can expect from a good set up (e.t. wise). Oh yeah i have bfg 235 60 15 street radials. Thanks again... Brett

All these mods sound great for a strictly dragstrip car, but there must be a happy compromise for a street car which occasionally sees the track. Personally, I don't want to give up a swaybar or my v8 springs for a sagging unstable front end. I may just go with only drag radials, a fast TruTrac rearend, subframe connectors, single leaf springs, and caltracs.

Cannoball888 said:

All these mods sound great for a strictly dragstrip car, but there must be a happy compromise for a street car which occasionally sees the track. Personally, I don't want to give up a swaybar or my v8 springs for a sagging unstable front end. I may just go with only drag radials, a fast TruTrac rearend, subframe connectors, single leaf springs, and caltracs.

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THis is pretty much what I want my car to be, a good street car and a good track car. I hope to hit 12s NA then 11s with the juice and I'll be fine. I'm not going to disconnect anything or fiddle with the timing or anything once I get it dialed in for the street. Basically I want to drive to the track run 11s drive home. For a classic street car I think that would be some good numbers.

Tons of good suggestions and alot of good advice on here but.....

Maybe my old 66 that I used to own, and will own again by the end of May is some freak of nature but I never had problems hooking with this set up, and a bunch of these items I list below go against some statements above. I am not contradicting what has been said so far, as a matter of fact most of the statements so far are right in line with drag sets ups that have worked forever. Anyway here was my set up which provided an excellent mix of street & track.....

5 leaf reverse eye - Contradiction # 1
off the shelf rear shocks
rear sway bar
Slicks (9.5X26X15)
9" Currie w/ detroit true trac 3:73's
NO TRACTION AIDS, caltracks, snubbers etc... # 2

620lb 1" drop springs... #3
Shelby drop... #4
tcp uppers
remove sway bar
tcp subframes
6 pt cage
C-4 2500 stall
tcp solid motor mounts

If you want to run good short times, don't overlook the cage and the subframes and the overall condition of your frame rails, floorpans, etc. Unibody + 40 years equals major flex which results in major delays to 60'

Here is what I attribute may car to running 1.59 short times and 11.28 1/4's.

1. My 347 had a ton of torque
2. I was not shocking my drive train (I had no transbrake, I had a low stall (2500, would stall to 3000) Did my car have more potential with more stall, yes, what would be the result? More stall, transbrake = not enough tire, stock suspension would not react like a 4 link - my street car would not be a street car anymore etc... This was not a race car, you could drive it anywhere, sit in traffic, the whole 9

Believe it or not, I saw 65-66 cars that had far less power than mine, running slicks, that didn't hook as well because in order to even run 12's they had to launch them at 6K RPM, cool looking yes, effective, not hardly.

Anyway my wife has interrupted me 5 times while I have been typing this so I hope it makes sense.

View attachment 472196

PS - I will have pics of the car in its present state soon, I'm not going to post them until I have the title back in my hands. It was mechanically sound before but had some body rust issues. It now has a $8700 house of colors silver paint job on it, all new interior, dash, seats, rack & pinion steering, disc brakes, more cam XE286HR (I had an XE274HR), more stall 3800RPM, motor has been freshened, tranny has been freshened and a transbrake added, cage is cut out (will have a new one soon) and it has not made one pass since I sold it to my buddy. I took a big loss when I sold it and he is taking a big loss selling it back to me (we are car idiots) I still have the Saleen for sale on autotrader.com - search 02 mustang in 63090

Good luck to all on your hookage....

PS - 1320stang can vouch for me for all that call BS....... Allot of people don't buy in to my car being leaf sprung....

Cannoball888 said:

All these mods sound great for a strictly dragstrip car, but there must be a happy compromise for a street car which occasionally sees the track. Personally, I don't want to give up a swaybar or my v8 springs for a sagging unstable front end. I may just go with only drag radials, a fast TruTrac rearend, subframe connectors, single leaf springs, and caltracs.

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There is - Sway bars come on and off quick, your on the right track other than drag radials are harder on your drive train, get some cheap wheels and soft slicks. Single leafs????????????

washMO66 said:

There is - Sway bars come on and off quick, your on the right track other than drag radials are harder on your drive train, get some cheap wheels and soft slicks. Single leafs????????????

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Mono leafs are recommended by the Calverts (Caltrac people.) Yeah, it sounds weird but they know what works.

Cannoball888 said:

All these mods sound great for a strictly dragstrip car, but there must be a happy compromise for a street car which occasionally sees the track. Personally, I don't want to give up a swaybar or my v8 springs for a sagging unstable front end. I may just go with only drag radials, a fast TruTrac rearend, subframe connectors, single leaf springs, and caltracs.

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You are correct in that the spring/swaybar mods are more for the drag racer.

Your formula will be a nice compromise for a street/drag car.

Can someone post up the NHRA rules regarding roll cages/roll bars?
For example:
11 second.......need 6 point cage
10 second.......need an 8 point cage..ect.
NOTE THE CAGE SPECS ABOVE ARE NOT ACCURATE, JUST AN EXAMPLE. That way people can just search for "roll cage" in the search and find the specs, because I've been looking for months online and cant find it. (and yes, I know I should just buy a rule book).

Does anyone have experience with the Competition Engineering Slide-a-links? They look and cost the same as cal-tracs but I found a good deal on a set and was wondering if they will work as well as the cal-tracs. Thanks

bleedfordblue65 said:

Does anyone have experience with the Competition Engineering Slide-a-links? They look and cost the same as cal-tracs but I found a good deal on a set and was wondering if they will work as well as the cal-tracs. Thanks

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Supposedly they work better on the street than the Cal-tracs. The Cal-tracs rule on the strip and have more adjustability. They can be a little noisy on the street.

Probably worth getting the Slide-a-links if the price is right as they work better than slapper bars in most applications.

How are cal tracs noisy? Do they just transmit road noise to the inside of the car? I mean I run flow 40s so they can't be much noisier than those lol.

they guy wants $225 plus shipping for a set of brand new leaf springs and used slide-a-links. I think im gonna go ahead and jump on it.

right now I cant even let off the clutch without my back tires jumping off the ground (literally-my friend behind me said he saw daylight under the tires). And that is not from hard launches, just easing off the clutch- no gas. But no telling how old these leafs are so I really think this will solve my problem.

Don't know if this is better to post in another thread but it is related.

I wheel hop in 2nd gear bad. If I leave from idle on the street, 1st is somewhat of a waste (but doesn't hop) but 2nd gear is all hop. I have gone back to look at the marks and its dark and then lightens up then the marks darken up again.

The car has a c4 with a 3500 edge converter, 5 leafs with poly bushings, homemade traction bars. The two possibilties are the 235/60/15 radial t/as or that when I got the traction bars welded to the frame rail that it screwed up the pinion angle or screwed up someother term that I don't know.