Top Fuel "front half" SFI/NHRA??? (1 Viewer)
- Thread starter ScottRod
- Start date
Frustrating that you have to purchase the spec to see what it's all about. I face the same problem in the software engineering field. If I want to get my grubby hands on a programming language or operating system specific specification, I have to pay at least a Benjamin. It adds up quickly
EDIT: not too bad for an SFI spec - looks like they hover around $38. Add to my list of first world problems, lol
How about cluing the rest of us in as to what the heck the "U" spec is so we can all play along here?
5150 mechanic
Nitro Member
So new tune ups/chassis setups on the horizon during the winter?
This will most likely change how the car loads which will result in upright and diagonal placement changes or possibly built in pre loading. While this only increases the overall weight of the chassis about 4/5 lbs. over .058" it changes the flex rate which most likely will change how the car loads resulting in how the clutch reacts. Maybe not so critical on really tight tracks but probably a whole new learning curve on marginal ones.
The million dollar question - if this SFI spec is mandated by the NHRA, who will figure it out first? And what does this mean for the low budget teams? Even fewer races because now a new chassis? Or will it be sufficient to front halve the car, lessening the cost?
5150 mechanic
Nitro Member
I would think the 6 or so chassis makers will help to some degree.
T.Smith
Nitro Member
That's a big if. I believe there would be some push back from the racers.
jimbo
Nitro Member
For us non tech guys - I understand the .065 is thicker than .058 and furture understand thicker means less flex, but it seems like comparing a .05 point pen to a .07 pen. But that is wall thickness. Can anyone say how much stronger it is? Lbs. per inch or however you would compare strenght?
I don't think strength per say is as important as fatigue and flex cycles before it takes a set. This tubing is 4130 condition N which is stress relieved. Everywhere you weld on it puts stress back so it has to be "Drawn Back" to as close as can be to its original condition. The way it is welded is not just - Start at one end and keep going until you get to the other end. You basically chase the stress out by welding in directions that even the stress out and then heat the welds to a temperature and direction to renormalize it. Most of the time SS309 wire is used vs SS310 because it has less of a chance for Hydrogen Embrittlement that can cause cracks. The plus of the .065" tubing is it can withstand more stress cycles before you have "Tired Pipe". Another thing most people don't know is that these chassis should be able to to hold 15 PSI nitrogen pressure to prove that they are not cracked which means that all tubes would be inter- connected with small holes to pressurize the frame.
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jimbo
Nitro Member
Thank You! As I thought more of my previous post - if one of the results of the change is to help elimate flex, I would also think that said lower flex results in less weight transfer thus liminating lower ET'as and higher speed's than we see today. Maybe another way to extend the life of the Goodyear Tire?
NEVER underestimate the people who make these machines run way past their intended capabilities. They will always find a way to be smarter than a few pieces of pipe. Goodyear doesn’t have a chance in the long run
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jimbo
Nitro Member
Been proving that for years! They will forever find ways to run faster and quicker!NEVER underestimate the people who make these machines run way past their intended capabilities. They will always find a way to be smarter than a few pieces of pipe. Goodyear doesn’t have a chance in the long run
Dragracer
Nitro Member
There was discussion on this after Leah had her car break in half. Don't most of the regulars front half and back half the car at least every year? There are only a few 2022 chassis now. The rest like Torrance are 2-3 years old. Don't t/f & f/c have to be recertification yearly?
That would make sense since there is another 4/5 foot section in the car that added probably 300/400 lbs with the extra Rider in the car. Also this car would never be able to be tuned to actually race. It probably has a bunch more bracing in it too. This is apples and oranges and not related to needing a spec change for competition.
stitcherbob
Nitro Member
The most beloved AA/FA was made out of muffler moly and Willie did alright….
