Mild steel vs 4130 Moly (LONG)

[myracecarshop]

Recently I have come under a ton of fire because I am building chassis from Mild Steel....

after a long drawn out discussion and a slight argument I felt compelled to write this if nothing else to defend myself from these critics....though I see their point, they misunderstand the market I am looking to....

I believe that everything has Its place in this world, Im trying to make mine......

Please read this without predjudice and with an open mind...and maybe you can understand what I am trying to do.


Mild Steel vs 4130 Moly
by: “My Race Car Shop”

I started building chassis for the bracket racers when I discovered an area in drag racing that was seriously lacking purpose built cars. This area has never really had anything except used pro stocks or regular cars pushed past the point of being safe. They are designed to go to 7.50 seconds and slower or up to 3600 lbs. Most of my cars are sold to the racers that run in the 8-12 second range. Until now I know of no other company that has offered cars specifically for this ET range…or what I will refer to as “Bracket Racers”.
The cars I build are NHRA/SFI Certified 25.4 spec Mild steel tube chassis.
In other words, single frame rail Pro Stock Cars made from mild steel.

Don’t let the words Pro Stock scare you off, as most know a 4130 Moly Pro Stock car can be quite the bankroll. But what if I could get you a “Pro Stock Type” for 1/4th the cost of a Pro Stock car…Interested now?

Hopefully by reading on you will see how you can have a purpose built car and not need to spend a ton of $$$.


Technical:

A 1' piece of 1.5 .120 thick mild steel weighs 1.769 lbs. and cost around $3.15 per foot,
A 1' piece of 1.5 .120 wall 4130 weighs 1.769 lbs. and cost around $6.10 per foot.
Because the 4130 are stronger you can use a thinner material such as .095.
A 1" piece of 1.5 .095 wall 4130 weighs 1.426 lbs. and cost around $4.90 per foot.
With this being said...your average chassis car will use about 400’ of tubing
400' of mild steel will weigh 707.6 lbs. and cost $1,260 in materials alone
400' of 4130 .095 wall will weigh 570.4 lbs. and cost $1,960 in materials alone
This is a difference of 137 lbs. and a cost of $700.
In other words, your spending $700 for 4130 just to save 137 lbs. in weight.

A 2400 lbs. moly car will run ¼ mile in 7.83 @ 176mph if it is putting out 1000hp.
A 2550 lbs. mild steel car running the same 7.83 @176mph will need 1075HP....
In other words... it ONLY takes 75hp to make up the 150 lbs. difference.... Think you can make 75hp with the $700 you saved by using mild steel... I do.

This tells me that with the money saved, you could actually go faster by using that money to make even more power…… Agreed… READ ON!

Construction:

Now lets talk about materials, welds and certifications…
The cars I build are NHRA/SFI Certified 25.4 spec,
Or in other words, single frame rail Pro Stock Cars made from mild steel.

To keep the cost affordable for the BRACKET RACERS, I use mild steel and MIG weld all of my cars…

Mild Steel? . Yes, it keeps the materials cost down and I pass this savings onto you.
Mig weld? . yes, it keeps the labor rate down and I pass this savings onto you.

As for being safe,
Yes they are safe… safe enough to pass NHRA/SFI certification to 7.50 seconds.

Safe enough for NHRA standards, is safe enough for me…how about you?


Cost:

As you have seen above, the materials cost is around $700 difference for a base chassis, Labor rates are something else…
Before I started the construction of my car I called several Chassis builders to get a quote on what a Custom Built 4130 moly chassis would cost.
4 out of 5 refused to even attempt building a custom chassis that wasn’t cookie cutter to their company, and the one that said he would require $16,000 to start the job.

Lets do some math…………$16,000 - $1,960 (materials) = $14,040 IN LABOR COST

I am sorry, but I cannot see paying someone $14,000 in labor to build me a Bracket Racer.

However, I can see spending 1/4th of that cost and having something that looks good, goes fast and is deemed safe all the way to 7.50 seconds @ 180mph.

My Race Car Shop custom-built tube chassis are built to fit your car.
Our base chassis start at $4,700.
Now for some math again…. $16,000 for their car - $4,700 for MRCS = $11,300 difference
What could you buy for $11,300?…………enough power to go 7s.

See where this is going?



Q&A

If a person buys a new chassis and over time they make upgrades to the car making it faster and quicker, eventually the car will not be certifiable to run because of the mild steel?
This is a true statement, it will only certify to 7.50 seconds...
It is has been shown that if someone has enough money in a car that lets them go into the mid 7.50s then they probably are ready to take the next step into the Professional Cars.
Remember I build cars that are for the guys who are somewhere between a streetcar and a Professional racecar.


When a person wants to sell the car, they will get nothing for it if it's not 4130 moly and certified?
Not exactly true…. Remember the price you pay for theirs vs. the price you pay for mine.
Naturally a 4130 moly car will bring you more $$$ at the time of sale,
You spent 4 times the $$$ for it.
A car will have resale value as long as the certification is updated regularly,
And if the car certifies to 7.50 it will have resale value even if it is Mild Steel.


If Moly is so inferior, why does SFI require it in a fast car?
I’m not saying it is inferior...it is stronger and lighter...and I can see why NHRA/SFI require it. What I am saying is, in a slower car...7.50 and slower, 4130 is NOT needed, that’s why I cater to the guys who BRACKET RACE, I cannot justify the cost of making them buy 4130 when it is not needed.

My car was built to the SFI rules and I have a turbo charged small block capable of over 2,000 hp. So 7:50's are easily attainable
I would say that My Race Car Shop chassis are not for you,
You are at that next level that we spoke of earlier...

If I built the 2x3 back half, I would have spent less money.
This is a true statement; my cars are for the guy who wants the tuning ability of a professional car at the price of a Bracket Racer. …. The cost of a tube chassis vs. a back half job is not a lot, less than $1000…it is harder to tune the suspension on a car with narrowed rear end than it is a tube chassis car.



Hope that I have helped you understand the type cars that I build at My Race Car Shop... understand that my cars are not for everyone.
I am building for a market that has never really had anything except used pro stocks or regular cars pushed past the point of being safe.
So if I can help get you going on the fast lane, call me!



Customer Service

After talking to racers around the country I have found out that many shops just don’t have the customer service that they should….
racers would bring their cars in for repair and they would end up sitting for months and sometimes years while other racers were rushed in and out. With deposits often being spent and not returned to the owner of the car. Or the quality of work was just not right when they came to pick up the car and sometimes there were “hidden cost”…

………..Its just wrong!



I have worked on cars from all over the country,
from Minnesota to Texas.
Each racer is treated as a friend,
because they are friends.



Mission Statement:

"To design, build and service the finest race car chassis, components and products, at the greatest attainable value to the customer."



The Way We Do Business At “My Race Car Shop”

1. We talk about the work you want done. We give you a rough ESTIMATE of the cost.

2. You pay a $50 non-refundable deposit* to get your name and secure your place on my work board. You don’t show up, I keep your $50.... this tells us that your serious about having the work done and not just window shopping.

3. We start at the top of the board and work our way down, when we get to your name you will be called to see if you are ready to bring your car in. If you are not ready, then we go to the next name on the work board. After each completed job we go back to the top of the list and start the calling all over again.

4. When you bring your car in, we sit down and discuss EXACTLY what we’re doing and the amount it will cost...the car needs to be here so that there are no hidden cost anywhere.... we will both sign off on an $$$ agreement and a projection date.

5. We require 1/2 the money up front.... this covers materials and hardware needed.

6. You will be sent e-mails showing you the work that is being done and a description of what has been done, this keeps us from stopping production to answer questions and phone calls. This will allow more time to work on your car for a faster turn around time....

7. When the car is completed, you will be called, and will be given up to 30 days to pay the balance of your bill. At this time you may pick up your car from “My Race Car Shop”.

8. The original $50 deposit* will be refunded back to you from the balance if paid with in the 30 days.

9. You will receive paper work that we have to go with your car such as weights, 4-link plots, etc.... You will be given a brief lesson on chassis tuning and set up...

10... Sometimes we offer a service of going to the track and tuning the cars that “My Race Car Shop” builds.


Please don’t keep “My Race Car Shop” a secret
let everybody know about us...
573 694-4088 ~ Mark


And as I said before, maybe mild steel isnt for you.....Im just trying to make a living and doing the best I can to support the guys who have worn my shoes...and maybe cant afford the alternitive....

Please dont turn this into a slam fest....I have been beat up enough over the fact that I use mild....im just trying to give us little guys a break here!

[BillyShope]

As Natalie Wood was told in the movie, "Gypsy": You gotta have a gimmick!

There'll always be a few like myself who'll go to a shop like yours, but, if you're really interested in that bottom line, "You gotta have a gimmick." Chrome plate anything that can be seen. Use Heims when rubber bushings make more sense. Hire people that can lay pretty TIG welds when MIG is more than adequate. And, of course, use the more expensive alloys. People want to be able to say, "Thet thar's a 4130 frame under my car. Paid a ton of money for it, but I'd be a fool to drive anything less."

[Adger Smith]

I usually don't respond to posts that don't have a name, but in this case I'm going to make an exception. I think discussions go better when people are known by a name. Just like constructive face to face conversation. This response is intended to discuss the difference in Moly & mild steel, not your business tactics/mission. (Which I think is good)
OK you have made a real good case for mild steel in the cost issue.
I also think it is great for the cost based racer if used correctly. I don't buy the case of spending your saved money to make more power. to me that is just the same old Catch 22 of racing. If a person saves money building a car to run brackets or a .90 class wouldn't you be using the savings to attend races, not go faster. That's what I tell my bracket race & circle track customers. If you build an engine for x amount why build one for 1.5x or 2x when x will run the et/speed you need or want. Use the savings somewhere else in the race program.
Besides cost the mild Vs moly has a strength vs metal difference. I have always been told that Mild steel bends upon impact & moly bends & springs back to the point of memory. In other words one has more memory than the other. This should be taken into account when building/designing the frame. What design do you need or does the customers program demand? A design with flex or a design that is stiff. In my opinion it is easier to have both with moly. Which is safer? Is it better to have a crash in a car that flexes & absorbs energy or a stiff design that doesn't? Here we go again, don't think mild steel can't be safe. Why are drag cars limited to a 7.50 ET with Mild steel?
Could it be the same reason Nascar trys to limit the top speed of their cars. I think all their cars are built from mild steel by rules. (or were a few years ago) I don't think Nascar is interested in cost savings. They don't care about weight savings either. They are built heavy. Could it be they want a car design that if crashed bad enough to bend it stays bent? Yet they are designed to bend & absorbe energy to protect the driver.
I have had several cars that I have drag raced through the years. Some were moly & some were mild steel. It just dependeds upon the application. I have won races & set National records with both.
My current car nees to be heavy &, because of the power levels, flex. It is a combination of mild steel & moly, by design.
I'm just an old engine guy that trys to use all the power I make. I think it would be nice to have a good discussion on this topic. Like you, Yourracecarshop, I feel there is a place for mild steel in the sport of drag racing.

[BillyShope]

I have always been told that Mild steel bends upon impact & moly bends & springs back to the point of memory.

Pardon my frivolous answer above. I guess I'm reverting back to my childhood.

To restate Adger's comments: What constitutes failure in a racecar chassis? Actually, that's not a good question, for there are two "events" and either would be considered a failure. If an oval car is involved in one of those "racing incidents" and, subsequently, looks like a dog that's chased one too many cars, that's a failure of the chassis. If a dragster ends up in two major pieces, that is also a chassis failure. In the first case, the yield stress of the steel was exceeded. In the second, the ultimate stress was exceeded.

The 4130 yield and ultimate stresses are better than those of 1010, but...and Adger might want to Google this for himself...the 1010 comes closer to the 4130 in the area of rigidity than in ultimate strength.

The ratio of yield stresses is about 1.2, but 1.5 is the ratio of ultimate stresses.

[Adger Smith]

Thanks Billy.
No need to Google. You said exactly what I was trying to say, but got tongue tied...
Thicker 1010 can be as strong 4130 in yield, but is still not as strong in overall stress. Bingo, weight advantage!
Has any one ever wondered why SFI specs require thicker tubing for mild steel? Read Billy's post.
There's nothing wrong with Childhood, we all went or are going through it.

[andyf]

4130 is only stronger if it has been properly heat treated. In an fully annealed state it isn't really going to have better material properties than mild steel All bets are off on the strength of 4130 after it has been welded since that is an uncontrolled environment and the weld zone could be in most any type of condition.

For many years the factory (Mopar Performance in this case) recommended that race cars not be built from alloy steels such as 4130 since chassis builders did not have the proper equipment to heat treat the tubing after welding. Obviously if the joints are weak due to the material properties changing during the welding process then the strength of the tube itself might not matter much.

[Robert Kane]

4130 is only stronger if it has been properly heat treated. In an fully annealed state it isn't really going to have better material properties than mild steel All bets are off on the strength of 4130 after it has been welded since that is an uncontrolled environment and the weld zone could be in most any type of condition.

For many years the factory (Mopar Performance in this case) recommended that race cars not be built from alloy steels such as 4130 since chassis builders did not have the proper equipment to heat treat the tubing after welding. Obviously if the joints are weak due to the material properties changing during the welding process then the strength of the tube itself might not matter much.

I'm not a weldor of any serious credibility, but is it true the reasons NHRA requires 4130 to be TIG welded is because of the above mentioned affects of excessive heat from welding?

Robert.

[myracecarshop]

SO,
I guess what Im asking is......

For Super Street and Super Gas classes......can we really justify the cost of a moly cage......

or is it as Billy said.... People want to be able to say, "Thet thar's a 4130 frame under my car. Paid a ton of money for it, but I'd be a fool to drive anything less."

Im thinking its what Billy said..........

[Ed-vancedEngines]

There should be an available market for your style of car.

Most wanta-be-racrs are working guys or girls and just can not afford to buy new or even used Chromolly cars.

You also may wish to offer different front suspension options too. Any good strut type is not cheap to buy.

There is now a gaining popularity in several forms of Heads-Up Racing that also will not allow strut style front suspensions. or in a lot of instances will not allow any tube front frames either. Might want to think about offering a Back Half style that is still using a newer chassis and cage design from Fire Wall back round tube.

I am also thinking that just offering a complete newer design full cage and chassis from FireWall back that for example that a person could either drop a glass body on or even cut out the floor and drop a car over and then be able to repalce the floor back could possibly also be attractive to some of the Little Guy racers.

In short, I wish you well and think it could work good.
Ed

[BillyShope]

I'm not a weldor of any serious credibility, but is it true the reasons NHRA requires 4130 to be TIG welded is because of the above mentioned affects of excessive heat from welding?
Robert.

Whether it's TIG or oxy-acetylene (essentially the same thing), the metal is melted and previous heat treating is no longer effective. (Okay, if some idiot is trying to weld with a torch while he's coating the shop ceiling with black soot or...at the other extreme...with the oxygen pressure set for the cutting torch, it's not the same thing. But, the same idiot might turn off the gas on the TIG.)

At my age, I've become a bit of a cynic, but I tend to look on the rules of sanctioning bodies as I do the laws passed by the crooks in Congress: I can't help but wonder how much they've been affected by lobbyists.

[ZEROMAN91]

There was a chassis builder in Penn who would build you a bracket dragster out of mild steel I think it was $1500.00 less than chrome moly.
His comment was the mild steel chassis would last longer before it would begin to work harden. I know 2 people who bought them and were very satisfied.

[CRE2004]

4130 is only stronger if it has been properly heat treated. In an fully annealed state it isn't really going to have better material properties than mild steel All bets are off on the strength of 4130 after it has been welded since that is an uncontrolled environment and the weld zone could be in most any type of condition.

That property actually keeps the welds from cracking. 4130 is better welded with E70S-2 which keeps the deposit flexible. A 4130 joint welded with 4130 filler is a crack waiting to form.

[Cobra]

Tig welding 4130 tubing with appropriate fillers and temperature will yield some loss of strength, which is regained by proper design and execution of joints. 4130 filler is used for joints to be heat treated and is not indicated for motorsports use. Properly handled 4130 tubing with less than 0.120" wall thickness normally requires no stress relief. Make certain all tubing is brought to room temperature, (70 degrees), before welding. Needless to say, all material should be clean and oil free. 0.120"+ wall 4130 tubing will require preheating and stress relieving. Please do not confuse stress relieving with heat treating. When building to specific rules make certain tubing wall thickness has some cushion, as tubing varies and tech inspectors do not! Just a note for: "myracecarshop", you are paying too much for your tubing!

[mike walker]

all the tech stuff is very interesting concerning moly/mild but my response as to why use 4130 can be summed up in one word.
"RESALE" if someone goes into a project like a racecar without an end plan in mind. then thats just poor planning. when i want to sell something i want it gone, i am not interested in educating them on metalurgical properties.

[myracecarshop]

Mike,
if a car will certify to 7.50 most bracket racers could care less what its made of.
naturally you wont get as much for the mild car as you would a moly car.....but then again you paid less than half the cost of the moly car when you bought the mild.....

i think its more about what people can afford than the resale.........

then again, ive been wrong before.....