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2old4this
08-21-2018, 08:32 PM
Any thoughts on how many races you can run a chassis before it stars going down hill due to flex

talclipse
08-22-2018, 05:11 AM
Unfortunately the answer is it depends. Like most things it will depend on the specific chassis and how it has been used. A car ran as a crate some place that is typically smooth and slick is going to have a significantly longer life expectancy than a car ran as a full blown SLM, some place thats hooked up and rough all night every night.

I know of one chassis builder that not long ago the fast guys were replacing chassis' every 13 races (SLM) because the cars would be 'flexed out' (these same cars guys were having to cut the protrusions through their decking extra big in order to allow for the chassis to flex), conversely rocket says that their primary car has 150+ shows on it. I also have been told multiple times from guys in Shinnston that their cars would get better with some age and got really fast once they started to crack out. It would just eventually reach a point where it was not worth the time/ effort to be continually fixing cracks.

If the car is responding to adjustments as it always had and its not acting strange when you put it on the scales (assuming youre still doing that) it should be fine.

With all of that said, my OPINION is a car will be 'teched out' well before its 'flexed out'.

7uptruckracer
08-22-2018, 08:48 AM
Also depends what It is made of. DOM Vs. Chrome Moly Vs Docol. Ive heard 18-30 on Chrome Cars Once you go from pole to cant hit your butt with both hands sell it as a low races new car lol. the new Docol stuff is what seems to be claiming the longevity


Unfortunately the answer is it depends. Like most things it will depend on the specific chassis and how it has been used. A car ran as a crate some place that is typically smooth and slick is going to have a significantly longer life expectancy than a car ran as a full blown SLM, some place thats hooked up and rough all night every night.

I know of one chassis builder that not long ago the fast guys were replacing chassis' every 13 races (SLM) because the cars would be 'flexed out' (these same cars guys were having to cut the protrusions through their decking extra big in order to allow for the chassis to flex), conversely rocket says that their primary car has 150+ shows on it. I also have been told multiple times from guys in Shinnston that their cars would get better with some age and got really fast once they started to crack out. It would just eventually reach a point where it was not worth the time/ effort to be continually fixing cracks.

If the car is responding to adjustments as it always had and its not acting strange when you put it on the scales (assuming youre still doing that) it should be fine.

With all of that said, my OPINION is a car will be 'teched out' well before its 'flexed out'.

fastford
08-22-2018, 12:38 PM
ask ronnie johnson , you would be amazed at how old some of his chassis are......

Matt49
08-22-2018, 12:56 PM
DOM is a manufacturing process that can be compared and contrasted with ERW. It doesn't specify a material. DOM tubing can be mild steel, chrome-moly, or anything else for that matter.

7uptruckracer
08-22-2018, 01:16 PM
Sorry I refer to DOM as Mild Steel I know they are different but most people don't ever reference them that way anymore. I just never liked Chrome Moly always had problem with them cracking around the HAZ of the welds. An Old asphalt car I worked on every dang week was cracking something. Maybe it was the builders technique? When it cracked the Main LR frame Rail where it went into the clip thats when it got sold

Matt49
08-22-2018, 03:11 PM
Sorry I refer to DOM as Mild Steel I know they are different but most people don't ever reference them that way anymore. I just never liked Chrome Moly always had problem with them cracking around the HAZ of the welds. An Old asphalt car I worked on every dang week was cracking something. Maybe it was the builders technique? When it cracked the Main LR frame Rail where it went into the clip thats when it got sold

I've heard people say that if you're getting cracks like that in chrome-moly it is because it wasn't welded right. Too much heat, not enough heat, I can't remember...But I certainly don't know from any real experience. I would be curious to get some feedback from some really experienced welders.

billetbirdcage
08-22-2018, 03:22 PM
I've heard people say that if you're getting cracks like that in chrome-moly it is because it wasn't welded right. Too much heat, not enough heat, I can't remember...But I certainly don't know from any real experience. I would be curious to get some feedback from some really experienced welders.

How many rockets from 2000 to 2015 cracked?? IIRC 2000ish is when they went to moly, moly gets a bad rap on the cracking, when it's not really true if done right. This has been hashed out numerous times here.

fastford
08-22-2018, 05:55 PM
drag chassis builders figured it out first that if you mig or tig welded it using a mild steel wire or filler , it created a more flexible weld that would last , ive been welding moly with a millermatic 200 mig and mild steel wire for several years with out any problem with normal weld cracks , a hard crash can crack any weld though , you still have to know proper heat settings though..

7uptruckracer
08-22-2018, 07:05 PM
MID 2000s I think around 2004-2006 Rocket had a problem with cracking a local super guy who ran the tour as well was always fixing cracks BUT I think that was those fews years we were getting a lot of or metal from overseas as well.



How many rockets from 2000 to 2015 cracked?? IIRC 2000ish is when they went to moly, moly gets a bad rap on the cracking, when it's not really true if done right. This has been hashed out numerous times here.

King1
08-22-2018, 08:15 PM
Man I had a 2002 TNT that I finally retired at the end 0f 2012 and it was still winning. I won 29 races in it and Greg Lucas won almost 80 races with it. I started driving in 2009 and we were welding on it weekly long before then around the J bar mount and around the down tubes connecting to the rear frame rails. It would waller out the holes for the decking where the tubing would pass through. Had to weld on the upper control arm stands, front cross member, weld gussets in it. the front frame horns were twisted so bad I had to mount the nose off center and it looked like mid 2000's cup car. It was dangerous honestly but dang it was a rocket ship. Never had another car like it since then. I'd saiy if you aren't welding on it weekly it isn't broke it yet.

2old4this
08-24-2018, 05:12 AM
Thanks for all the replies guys. Looking at buying newer longhorn with 30 nights I’m it as a traveling super just looking at how much life it could have in it

fastford
08-24-2018, 07:51 AM
it should be fine , until the next greatest thing comes out...lol...

Kromulous
08-24-2018, 09:11 AM
I looked at a Longhorn Chassis pretty close, i love how there built, very adjustable.

Krooser
09-09-2018, 09:16 AM
After seeing another thread discussing chassis wall thickness and using .063 tubing for the roll cage i see why they flex out after 20-30 races.

zeroracing
09-10-2018, 08:15 AM
I have not been a fan of the chromoly chassis, other than rocket which seemed to have a good reputation. Local guy had a major name brand mod chassis at the time, which is still in business. It was a chromoly car with about 20 shows on it and no crashes. If memory serves me right it had around 40 cracked and broken welds in the car (this was early 2000's). That scared me, it told me that many guys out there don't know how to weld it, the welds looked fine (other than crack adjacent to weld) but when new the thing would have looked great. That always made me shy away from chromoly cars by most builders.

fastford
09-10-2018, 09:19 AM
if that car only had 20 races and 40 cracked welds , then i agree , who ever welded it didnt know what they were doing , not the moly,s fault.......

zeroracing
09-10-2018, 04:06 PM
Yes, it was the welders fault, but showed the flaw in chromoly in that people can easily screw it up.

fastford
09-10-2018, 07:34 PM
Yes, it was the welders fault, but showed the flaw in chromoly in that people can easily screw it up.

This is true , I can still weld fine , just give out faster now , finally found a young man that could satisfy me , he is as natural of a welder as i have seen in a while........