More Sportsman Tech... Straight Rail vs Perimeter vs G body

Since the Built vs Crate discussion yielded some good info from both sides, why not start another discussion for some fun and to get some people talking on this board? A discussion like this could help potential new drivers understand more and better chose their chassis to start with.

So, let me ask. Which do you prefer and why and what (in your eyes) are pros and cons of each chassis assuming they all have the same total weight and left percentage

GO!

[Phil Jacques]

Really... NO ONE? lol

[OldSchool+]

Phil,

Will try to get your ball rollin' (!).

"...assuming [perimeter, straight rail, & G body chassis] all have the same total weight and left percentage."--PJ

On the surface, the above statement would tend to indicate they all will perform about the same, but...

Back in the day, the cars were largely stock frames with a rudimentary cage to hopefully protect the driver.

When the '64 Chevelles were mostly used up, and unibody "pony" cars became popular, specialized chassis from Ed Howe and etc. became popular.

They were superior because additional thought was put into how the loads were distributed through additional bars to the rear (and elsewhere) of the chassis, and eventually torque arms and etc. came into play, coil overs, and on and on.

So, I would suggest that passenger car chassis were engineered to get groceries, and the more a chassis is specifically engineered and/or modified (low and left weight, roll center, geometry and so forth) for racing, the more sucessful it is likely to be.

Of course there are a bazillion other factors. Motor, driver skill, setup skill, new tire$, etc.

Probably at the end of the day the amount of cubic bucks that are invested is the biggest factor, and the rest shakes out from there.

[PatMennenga16]

straight rail in my opinion. Better build options. of course the 3 L's. low light and left.

[sbracer58]

To quote Mike Eddy, "Iron is iron...you can make 'em all work."

[Patrick Thomas 25]

Anything except a G body will work, including the one you left off the list the camaro leaf spring car.

The front Geometry on a G body is terrible.

Patrick Thomas 25

[Phil Jacques]

To quote Mike Eddy, "Iron is iron...you can make 'em all work."

Mike Eddy was THE MAN!

[Phil Jacques]

Anything except a G body will work, including the one you left off the list the camaro leaf spring car.

The front Geometry on a G body is terrible.

Patrick Thomas 25

I definitely know how terrible G Body front geometry is lol That's what they make us run in most divisions here...

[OldSchool+]

Re: Anything can work...

Below is info regarding Dickie Anderson's "new" chassis (article is from '07).

Note the use of full sized springs.

http://www.circletrack.com/techartic...hassis_design/

[Phil Jacques]

Re: Anything can work...

Below is info regarding Dickie Anderson's "new" chassis (article is from '07).

Note the use of full sized springs.

http://www.circletrack.com/techartic...hassis_design/

That's all great for Super and Pro Late guys, but we are talking Sportsmans here... By the rule book, it seems to specify that control arms in the front must be located in factory location. On this car that Dick has built, things are likely adjusted to optimize the front Geometry. I'm all for allowing creativity and moving around the geometry personally, but "if the rules don't say you can then you can't" to quote the NSS book lol

[OldSchool+]

Dickie was good for about a second a lap all by himself, and Wayne pretty much has the same touch...and more Andersons are on the way!

How about the ball joint PJ? I have seen a stock (that is, Chrysler) ball joint mounted, well, somewhere, in a stock "A" frame.

[Phil Jacques]

F. Tubular upper control arms optional. Stock lower control arms in stock location. Lower control arms must be per original manufacturer’s specifications for year/make/model.

Per the rules, there is not really a whole lot you can LEGALLY do.

[Mike Bresnahan]

If you have the option to choose, then you would certainly want to choose the Straight Rail car.

A good rule of thumb for a pavement car is as little weight as possible in front of the ball joints, behind the rear axle, or right of center. One of the most common mistakes beginners make is moving weight to the rear to increase traction. Picture a weight on the end of a rope and how that would react if you were to swing to around your head?

Also don't fall into the trap of buying fancy lightweight chassis components because you're just going to replace them with lead... A very well known racer was showing off a car he had just built to me, he was very proud of his Billet Aluminum Super Light Weight lead brackets... Think about that.

Then he showed off his new state of the art seat. This was one of the Kirkey ones with huge holes in it to save weight... This guy was easily 65-70lbs overweight...

In this sport perception often times seems like reality... I left his shop thinking "man, I'm way behind the curve". Then I realized I can use a much cheaper steel lead bracket with a slightly lighter piece of lead and if I need to save a few ounces in the seat I'll push back from the dinner table a bit sooner than normal. So don't fall into the trap of buying every fancy new part just because the guy that's winning has it. Often times what you have will work just fine.

[Phil Jacques]

If you have the option to choose, then you would certainly want to choose the Straight Rail car.

A good rule of thumb for a pavement car is as little weight as possible in front of the ball joints, behind the rear axle, or right of center. One of the most common mistakes beginners make is moving weight to the rear to increase traction. Picture a weight on the end of a rope and how that would react if you were to swing to around your head?

Also don't fall into the trap of buying fancy lightweight chassis components because you're just going to replace them with lead... A very well known racer was showing off a car he had just built to me, he was very proud of his Billet Aluminum Super Light Weight lead brackets... Think about that.

Then he showed off his new state of the art seat. This was one of the Kirkey ones with huge holes in it to save weight... This guy was easily 65-70lbs overweight...

In this sport perception often times seems like reality... I left his shop thinking "man, I'm way behind the curve". Then I realized I can use a much cheaper steel lead bracket with a slightly lighter piece of lead and if I need to save a few ounces in the seat I'll push back from the dinner table a bit sooner than normal. So don't fall into the trap of buying every fancy new part just because the guy that's winning has it. Often times what you have will work just fine.

I agree completely with everything said here... Funny thing about lead placement... A lot of people are scared to put weight on the nose of the car. I have noticed, at least with the street stocks and the late models I work on, that if you can put lead right behind your left front wheel, the more you add, the better the car gets. One night, on the Late Model we moved 150lbs(est) of lead forward from the left rear frame rail just in front of the rear axle, to directly behind the left front tire in a new lead box AT THE TRACK, and gained 2 tenths without scaling. Prior to that, the nose was sliding and then when it would finally grip, the rear would snap out. After the change, the nose gripped and was using both front tires almost equally when it came to temps and the rear end didn't snap around.

Once we got around to scaling the car and getting everything squared away with numbers again, the car picked up another 1/2 tenth. If not for having a rookie crew cheif (me) and a 5 season old 603 crate, I think we might have been able to get a win before the season ended this past weekend.

I personally have a perimeter chassis for my FL car. If I find a straight rail any time soon, I would love to have it, but that's unlikely here. I plan to just throw the Perimeter together to bring down and learn the tracks and eventually build something new. I still have a hard time understanding how exactly a Straight Rail can perform better than a Perimeter chassis, because in my head, 57% left, is 57% left, the only difference in handling between the two I can think of would be top weight, which can create more roll on the perimeter than the straight rail. I would need to sit with someone and actually have them give me a hands on explanation. I am definitely still learning when it comes to these cars, I am not afraid to admit that. But if you aren't learning something new on a daily basis, in my eyes, you are wasting days.