So I have a 69 barracuda and was wondering if I should use longer springs ( front section) in order to get better traction and control.
In using a longer front section, does it act like an extension on a ratchet? More control with less effort?
Also in doing so I can centre the tire inside the wheel well so I don't have to cut my fenders for larger tires.
Matt

Drag use is a specialized application imo, but normal performance suspension design theory favors suspension links longer the better, within reason. However a leaf has multi tasks, each task assigned can negatively effect the others, depending on the parameters, its a compromise.

How much power? What tire?

The longer spring will move the leverage point, but the short spring will be stiffer. If you keep the front segment as stiff as the short spring there may be some gains.

With a Caltrac or similar traction device, the old stiff front segment idea basically becomes a moot point. If you choose to go this route, Calvert can build a split mono with either a 24" or 25" front segment.
I don't really see any negatives.

I do recall Monte talking about some theories of his that made a lot of sense. Hopefully he chimes in, I don't want to get it wrong and be misleading

IT will be split monos springs along with assassin or calvert bars. 275 drag radial.
Matt

The point of the two, listed bars is to make the front section stiffer, so I would go with the standard length A body length section. Unless you could use more front tire clearance on the tire vs wheel well clearance. Your best bet is to stick with the length you have now. A longer front section will have a effect on drive shaft length But, there is a spacer bracket you can use to negate effect as well.

How fast is your ride? What kind of performance et are you expecting or planning for?

I went from 20's to 25's and immediately noticed a difference on my 72 Dart at around 3050 lbs but I'm not that fast and heard Digby(sp) runs the 20's so ..............The rear sliders and mounting the shocks upright also made my car react quicker/better and so far a 1.33 60 ft. foot brakin at 2500 w/more to come here soon.........seemed like a smoother ride also........

How far did the longer segment move the wheel back Dom?

The spring is 5 inches longer, you move your front mounting point. You can then chose where ever you want your tire.

I'm setting the car up for low 8 secs. Whether I get there or not is another matter.
I want to build it once. If it's easier to set up a 25" over a 20" at the track then so be it I'll put in the 25.

Like what's been said, both can work especially in that range. On paper the 25 is better. My car has 20" segment and I haven't had any problems that I would blame them for.
I guess it's your call is kinda what it comes down to.

seems I remember people discussing the longer sections.... but then pointed out Jason Digby was still running the 20" segment.

Check out my build thread. I did 25 inch front with fabbed front and rear mounting.

Nice looking set up quick runner.

I didn't move the rear back just moved the ft. box 5"'s forward into my sub-frame connectors which stiffened it up even more........

I see, thanks for the info. I'm thinking of trying a longer front segment to move the tire away from the wheel arch a little. Looks like a call to Calvert is in order.

I'll assume a 4" longer spring won't move the wheel back 4". Thoughts?

Digby's car is fast, no doubt. But so far they haven't been able to get it to 60ft anywhere near where they would like it to. So, is that due to short segment, or they just haven't nailed the setup yet? Remains to be seen. So far when they have tried to 60 it much harder than 1.14 or so, it's knocked the tires off and we know of leaf cars that go 1.0s. So they still have work to do. Lyle and I were discussing this very issue in Bradenton.

Now while we don't have many fast leaf Mopars to base any conclusions on, we do know, as mentioned above that there are several fast leaf cars that 60ft in the 1.0s. Those are GM cars. That doesn't really mean anything either, EXCEPT those cars all have longer front segments........so, form your own conclusions. I think either will likely work, but maybe one is easier to make work

The hardest 60 footing leaf car that I know of, is Ron Rhodes. He has been 1.04, maybe quicker, but the car is light which helps. But I also know of some in the 3000lb range that have been in the 1.0s as well

Didn't know you were willing to go to 25" when I posted. In that case yes, I would go with it.

When you get the shorter segment to become stiff, it needs a lot more shock resistance to control its movement. The longer lever will be better in your case. It can be done though, as others are doing it, with the shorter stock option segments.

It comes down to HP and the CG of the car..
in theory you want the bars or IC to lift from
not too far behind the CG of the car to give the
max loading on the bars/springs... then if you
add boxes to it you would want to lower them for
a longer sustained hit