History Traction in a Pre-Slick, Drag-Strip, World

After watching your video of your '40 at '15 Billetproof, it is very apparent, as you said earlier, that you are losing all your traction to that right rear spinning so much. Nobody has come up with a suggestion on my twice asked question about any sort of available limited slip for a banjo rear, so I'm assuming not available.
You can "jack" some weight into that right rear using the method that was done in the day of transverse springs on oval tracks, and then return to stock for street use with some work with "wedging" the right rear.
The term "wedging" is still used in oval racing, even though it's not done with wedges anymore. But back "inna day", you loosened the U bolts holding the transverse rear spring to the crossmember with the car supported by jacks or stands under the frame and the rear axle of the ground. Then you drove a "wedge", a piece of flat metal tapered on the inserted end all the way in till it contacted the spring center bolt, retighten the U bolts, and now you had moved weight to the side on which wedge was inserted. The wedge was often fabbed from the tapered end of a leaf from a spring.
For oval racing this wedge would go under the left rear and right front to try to keep the weight equalized while turning left off the corner.
In the case of drag racing, you'd want to wedge the right rear for additional weight and traction on the right rear. Be sure to remove any and all wedges and retighten evenly and securely before driving on the street, because handling will be radically different, and could cause loss of control.
But you still are going to have that old bugaboo of broken parts that will have you digging in that spare parts bin, and that spinning right rear is helping to avoid that as you now have the car built.
A T5 and someting like an 8.8 rear would do wonders for that car's abilities on street and strip combined.
ON EDIT: But don't build up your hopes for beating a lightweight like that rail job with a full bodied '40, LOL

 

"That's just what I was looking for" It's also frustrating, the information is so scant! Weight probably stock...rear was most likely 3.54 in a Merc, not real good...though probably killed off the wheelspin! Engine condition...a compression test would have been good, but of course part of the whole point is that they were just souping an ordinary as-is car.
Only pure bolt ons...and no tuning. The car as I mentioned was probably jetted a bit rich, and it is also shown with a speed shop chrome air cleaner, something that was often about equivalent to a stuck choke.
Tires were often partially chosen for large diameter, back when, simply as an additional way to get a larger contact patch...and naturally this often conflicted with good drive ratio.
It would be fun to flog a car like that for a couple of days on tune and driving technique to see what you could accomplish!

 

There was a thread on here about racing and related cheating stories. Someone posted that one method to make the bias plys "stickier" was to fill a mounted tire with paint thinner and let it rotate a couple of days on a balancing machine so that the solvent soaked into the rubber from the inside. I have no idea if this worked, but I read it.

 

I used to race in a true radial class, there were no flatheads or anything like them in the class when I ran on 07-08 we were still trying to put nearly 1khp down on tire store radials. I found that the front suspension is often more important than the rear, and it's all about weight transfer. You could probably do a lot for your car with a set of scales and some shock tuning. Yeah, modern stuff, I know, but it was still a chore getting down the track on crap tires with a ton of power, kinda made me think I knew what some of those old timers dealt with back in the day during the smoke shows.

 

Limited slip is not necessary if you can get both tires to plant evenly. Often with a cross leaf all that is necessary is a good set of shocks to control wheel hop.

In the later '60s when I first started racing and before I ever got a pair of slicks is used to start soaking my tires with bleach on Thursday to race on Saturday. The bleach would soften the rubber some. Back then you could still buy sawdust tires. They were sold for winter tires but were softer then normal tires. I tried them a time or two and they worked real well.

If you look at old pics of racers you sometimes saw duals being used on some of the higher out put cars.

 

https://www.airliftperformance.com/blog/throwback-thursday-air-lift-drag-racing/

http://forums.corral.net/forums/drag-racing/572565-air-lift-bag-how-much-psi.html

 

We're talking 11 second 1/8 mile- and 17 second 1/4 mile

With some work you can get a limited slip differential carrier into your banjo rear end.
All your torque is being delivered to the wheel with the least traction. That's why 1 leg burnouts are quasi spectacular.

In the video of pass 3, it appears the drivers side tire smokes at first, the front end comes up a bit and then the passenger side smokes. Thats caused by a multi factorial weight transfer and teetering on buggy springs and unloading the passenger side.

 

So, here's my two-week-or-so plan of attack:

1) 700-16 tires for the rear to gain contact patch but possibly at the expense of gearing

2) Rear Shocks, replace the levers with tubes. Keep that rear end in place.

3) Rear Sway Bar. Henry installed one on his cars a few years after he built mine...

4) Exhaust cut-outs. Not so much for performance, but so I can actually hear my engine, since they seem to like pairing me with uncorked rails.

I think that these few things should help with the questions of traction, transfer, and technique, with a fairly minimal outlay in time or money. The "wedging" is quite intriguing, and if I can, I may experiment there too.

I may play around at a test-n-tune day with the two sizes of tires, tune, and technique. I've got till the end of August before the drags...

 

Great thread Evan.... doubt anything I have will hit the strip anytime soon... Don't want to end up with a bunch of wood splinters & tooth picks with the 51 ( could really race a 51 Ford Woodie) now that's a barge my friend.... maybe tow duty..

 

But what about your '60 land-barge Rob?

Might even give me a run for the money on slowest ET.

 

Back in 1960 I ran Bucron's, on my '40 with Olds & '39 topshift until I could afford a set of early Bruce slicks.
Wheel hop is never an issue with a torque tube rear end like you have with the '39 box. One very important
issue, with the older Ford boxes, is to make sure it is good and tight with no slop in it. It will last longer.
If you don't mind the extra work, before and after a weekend of racing, you could install a set of welded up
spider gears to kill the differential action and deliver equal power to both rear wheels. That would result in
tire "scuffing" in turns if you tried to use them on the street.

 

my luck I will spit the spider gears out of the rear end.... Now the 60 Sedan Delivery is one big boat..
maybe give ya a run for the money .. lol

 

Hmmm... Nobody's mentioned weight reduction, but that's what the fast guys were doing when building early rails.

 

How did the stock cars go that fast?

They didn't. Most flathead stock cars turned quarter mile times in the 17-18 second range. Pretty good when the average flathead six was over 20 seconds in the quarter.

The cars were heavy and the old engines didn't have that much power. Their saving grace was that tires had very poor traction so those old gearboxes and axles could survive for awhile.

Even so those woodruff keys in the axle ends shelled out. To much traction and those gearboxes would shuck the teeth right off like an ear of corn. Spider gears were welded, dangerous.

The old Top Dragsters used to burn the tires the entire quarter mile.

If you get any traction, with a powerful engine that old banjo or gearbox will blow in a heartbeart.

The key will be to get power to the ground without grenading. Wheelspin is the key, not too much. Burning rubber is preferable to blowing up.