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Long wheelbase vs short wheelbase

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one finger john

Active Member
Here I go into a little theory. I have seen and have heard that on sprint cars, esp dirt cars, that with the torsion bars infront of and behind their respective axles the car thinks it has a longer wheelbase and has the qualities of a long w.b. car. To compensate for the the long w.b. feel and stability on a short dirt track (less than a 1/3 mi, almost continuous left turn) the actual turning agility is tuned by shortening the actual wheel base. That gives you long w.b. stability with short w.b. turning quickness.
I would like to know if that applies to 'suicide" front ends and rear suspensions with coil springs mounted either fore or aft of the rear axle or mounted directly over the axle.

Just thinking, John
 
I dont think the term Turning agility and a T bucket belong in the same sentence. I will bet the guys here have tried every configuration times two. As far as the length of the frame you know what they say better 3 inches to long than 1 inch to short. I added 6 to my CCR plans and used every bit of it.
 
The longer the wheelbase the better she tracks. Most buckets I have driven go round corners like on rails, although they tend to push because the front/rear weight distribution is usually rear heavy. Short wheelbase can look really cute but they a bit squirelly, swap ends too quick.

Whaddaya say, Ted???????
 
The T's I've rode in, the ones that got squirrly, either the rear suspension was to stiff or to soft, to stiff and they spun and the light rear wanted to come around on me,

too soft and the rear suspension would try to hook up some and that would get the front end to teeter on the spring perch, basicly trying to turn the car to the right..

Ive never been in a T that didn't spin either, you can baby them off the line sure, but I haven't seen a T on the street that will hook up and not point for a ditch if it has a posi or limited slip, i just don't think it'll happen. Especially with street tires, maybe with cheater slicks, but that's a big maybe.... I've driven big block T's and blown t's, T's with 406's, 383's and plain smallblocks they all did it, might have been the way they were built but the older guy that was building them knew what he was doing..
 
From My experience I think a short wheel base would be really squirrely in rain. You have to think wet surface because unless you live in desert you will get caught in rain eventually.
 
it's true that in theory your wheelbase is the points where your springs attach to the frame. and the shorter your wheelbase, the more attention you will have to pay at getting a straight launch. most every bucket owner experiences a side ways launch the first time they step on it off the line. puts a smile on your face, a lump in your throat and a bowel movement all at once .... it's great!!!!

Ron
 
Well guys, this is what I have been trying to get across to all the new guys building a rocket on wheels.. I for many years did nothing but make AG/S cars get a hold of the ground and leave straight, without wheel spin (or wheelies, if possible:)welcome:... A true T Bucket is nothing but an AG/S car in disguise, put a 33 Willys body on a T chassis and off you go.. I now can tell how to keep your car from spinning and thous being out of control, as I do not build those type of cars for a living anymore... (well??)
My T has a 95 1/2" wheelbase (wheelbase=where the center of the axles are, not anything to do with where the spring mounts are located) where the rubber meets the road... hehe
I only ran slicks once in my life, at first, for looks ONLY.. they are not good on the street, at all.... a good large diameter rear street tire works really a lot better than one would ever think, mine have only a 10" wide foot print X 33" tall, and my car has NEVER been sideways, or spun out of the gate..
You have to set your suspension up so that things do the right thing, and kill a bit of bottom end horsepower, I happen to use large diameter header tubes, and not too much squeeze... more as needed later. :)
 
Here is something that I did when building my car. It is an adjustable four link. With it, you are able to adjust how you want the car to hook up and launch.

IMG_0650.jpg


As for wheelbase, mine is 108 1/2" because I am using a turtle deck which is longer than the usual short, pickup type, box.

Jim
 
What I'm using is NOT a 4 bar but rather a 4 "LINK" like many drag cars use. A 4 bar is not adjustable. The bars must remain parallel to one another. Whereas, with adjustable 4 link you are effectively making a longer or shorter traction bar moving the mounting points further or closer together. It works very effectively on my car.

Jim
 
Junk i like the looks of that center y support to the rear end it that your design??? And where did you get the rod ends i like those better than my split clevises.
 
ok ...here's my take on this subject. we could sit here for hours takling about this and that type of suspension, or wheelbase perfection. for the vast majority of the guys that come here looking for answers, a hairpin or split 'bones are gonna accomplish what they want from there T. if you're running a basicly stock motor these will satisfy your needs. if you're running some serious horse power then you want to look at a rear suspension like ex-junk and ted are talking about. for the new guys here, the KISS rule is one you should follow. concider this, simple is trick too.

Ron
 
Rooster, to answer your question, that is a "wishbone" locator for the rear end. It serves the same purpose as a panard bar except it allows the rear to travel in a completely vertical path rather than in a parallelogram path the way a panard bar does. A watts linkage also allows only vertical movement.

The bars I made using 7/8" heavy wall tube that I tapped with left and right hand threads on either end. The rod ends are the stainless ones from Speedway. By simply loosening the locking nuts on either end of the bar I can turn the bar to either lengthen or shorten it thereby changing the pinion angle.


And Youngster, what you said in your post I agree with 100%. I, too, am a firm believer in the KISS principle.

Jim
 
Very nice i am a novice at this t bucket stuff. I wish i would have studied all the options longer before i built mine. Their are so many options to choose from. But i guess its easy to out smart yourself tring to build something that is way more complicated than" in my case anyway" than it needs to be, this is where the KISS method is handy i suppose. My original plan was safe, simple, and inexpensive. Well 2 outa 3 aint bad.
 
Dont you hate it when some one has to explain the obvious to you.:hide:
I have been call so many things i know all of these little dittys.
 
Just like Junk said, he refered to his "links" as bars, not links when just talking about building them .. well I just happen to call them bars, OR links, both the exact same thing, they only do it in less of an ark when they are longer... Like you say, I very much like to KIS, that is how a CCR chassis is built, as simple as you can get, and still work... :hide: Variety is the spice of life...
 
Ted, without getting into the semantics, the point that I was trying to make was that a 4 bar works differently than a 4 link. In a 4 bar setup, as I stated, the bars must remain parallel to one another whereas in an adjustable 4 link they do not. That is not to say that a 4 bar can not be used on the rear but it will not allow for the adjusting of the angles for proper hookup on launching. By changing the angles you are effectively making a shorter or longer traction arm or bar.

Conversely, a 4 link on the front would not work. On the front you must use a 4 bar setup where the bars remain parallel to each other at all times.

Jim
 
There is nothing that says the bars need to be parallel with each other, just where did you get that notion?? Did you read it somewhere, or have you tried it to see just what exzatly happens when you change how they are mounted, I have tested them in every position there is, and you can use what ever you want to call it, a 4 link or 4 bar, they are stronger when shorter, and cause more axle movement.. But I am NOT bad mouthing your setup, as it is better for the street, lets the rear end move in any position without binding, and that is what they are for...handeling... Just not the T look I am wanting for my ride, maybe the next one, as I am only going for ride on the new one...... Done :hide:
 
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