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Author Topic:   Thoughts On Chassis Flex
o5racer
Dirt Freak

Total posts: 402
posted January 31, 2005 08:57 PM  
What is everybodys thoughts on chassis flex? For as long as I can remember I have always heard to make the chassis as rigid as posible without making it too heavy and let the suspension do the work. Latley I have heard of car builders intentionally making the cars flex. Wouldnt there be some inconsistentcy(sp) with the handling? Just looking for other ideas.
Nick

zeroracing
Dirt Forum Champ
Total posts: 1875
posted January 31, 2005 09:16 PM  
Many new mods and latemodels are built to flex.
pro-easy to set up, car is easy to change for track conditions, set up is not as important, car is more driver friendly.

con-cars dont last as long as they should, fold up on crashes easier. if the car flexes too much then it will become a large leaf spring and bounce all over the place.

tips-i would not recomend too much flex in a street stock, mainly a mod or latemodel where set ups are about 100 times harder(on too rigid of car the set up has to be perfect all the way around). other tips are most the flex built into cars is infront of the halo down tubes(infront of cockpit area, on the rf.) common ways of making flex are just not traingulating that corner as much, seen some cars just plain cut a bar and leave a small gap in it.

i would not try to get too much flex in a street stock. but in a mod there is potential, just go thru cars very quickly.

hobby10k
Dirt Freak

Total posts: 226
posted February 01, 2005 02:59 AM  
See, what I grew up on I was told to make a chassis so that it flexes, and what I have read alot is to make a car Rigid, so like you said that the suspension does all the work.
also was taught to put pull on two corners of the car and a little push on the other two to allow weight transfer.

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LIVE RACING, WHAT ELSE IT THERE?

JDF Motorsports
Dirt Freak

Total posts: 216
posted February 01, 2005 03:40 PM  
I know of 2 cars that made the A in the 10k Batesville race in 04 did not even have the subframes connected......one of them finished 3rd.....

DAYTONA392005
Dirt Roller

Total posts: 9
posted February 02, 2005 11:35 AM  
quote:
Originally posted by hobby10k:
See, what I grew up on I was told to make a chassis so that it flexes, and what I have read alot is to make a car Rigid, so like you said that the suspension does all the work.
also was taught to put pull on two corners of the car and a little push on the other two to allow weight transfer.



Ihave run cars both ways.I like to build with car level on jackstands.Seems easier to get good setup that way and change to track conditions.

ryan
Dirt Forum Champ
Total posts: 776
posted February 02, 2005 08:41 PM  
Nick the car I built before this one didn't have the rails boxed or x'ed whereas this one did and you could really tell a differance. The old one it seemed like you didn't have to touch it all year and it was real close on handling and with the new stiffer one it seemed like it was very touchy with track conditions. I wouldn't mess with yours it already does pretty well in the main you just need to get those Heat races figured out. Maybe get rid of that ole' cam and run something decent. Ran that cam didn't care for it.

o5racer
Dirt Freak

Total posts: 402
posted February 02, 2005 08:54 PM  
Ryan, was your old car a metric? I can remember for sure. I wasnt looking to change, I was just trying to see why guys want to build a car that flexes. I think I might have found something that will help with the heats. I will find out in a couple months.
Nick

Ego Racing
Dirt Forum Champ
Total posts: 724
posted February 03, 2005 01:43 PM  
A flexing chassis is an undampened spring and will also cause welds to crack and tubing to fatigue causing the chassis to wear faster. Also when you bend a peice of steel enough it will break at sometime, When is just a question of time. Also if the chassis is flexing and twisting it is also going to allow damage to transfer farther into the cage and chassis in an accident.
A chassis is desighned to allow crush in an accident but be rigid enough to handle racing conditions. If you built a rock solid car when something went wrong the weakest link would give, if the car is build without crush areas the weak link becomes the driver.

ryan
Dirt Forum Champ
Total posts: 776
posted February 03, 2005 08:33 PM  
Yeah it was a metric. How about I help you with heat race and you help me with the main. You must be whipping out those cheater parts a little more this year.

[This message has been edited by ryan (edited February 03, 2005).]

racin78p
Dirt Freak

Total posts: 333
posted February 04, 2005 04:50 AM  
zeroracing and Ego Racing have it right. Points to ponder: keep the cage that is around you really strong (rigid) and in front and behind your drivers cage not as rigid. These will be your crush zones. I build mine that way on a 85' metric and after the "crash" last season (that ended my season) it proved to be oh so true and correct. I do believe in X bracing the middle and rear parts of the frame though. I want my suspension doing the work, not my frame. Race on (safely!)

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racin78p
if it ain't fun, then don't run

o5racer
Dirt Freak

Total posts: 402
posted February 04, 2005 08:15 PM  
Im not cheating. LOL Russ never said that the converter had to work. And this one dont. Ill see what we can do about swaping ideas.
Nick

ryan
Dirt Forum Champ
Total posts: 776
posted February 04, 2005 09:03 PM  
Looks like there might be a cement pad open right next to me where Hames used to park. I bet I'm the only one that ever got a free cement pad out there. I bet tech never notices your hi-tech converter.

[This message has been edited by ryan (edited February 04, 2005).]

    

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