Stiffing an older chassis

[Mopar DLM]

What can be done to help stiffen an older chrome moly chassis to get a few more good nights out of it. I know the car is worn out and flexes way
to much so can you add bars in specific places to help bring back any rigidity. Car is a 07 black front end rocket

[grt74]

yes and go over the car to check all the welds, just remember when you stiffen a car it will react different and the sweet spot is going to have a smaller window, you may have to go up on spring rate because the car is not flexing, just some thoughts, triangles are very strong, we have done this with great success
hell alot of the so called built by so and so cars, they for the most part just have bars welded in places, some change the front end to there liking but most just add some bars

[hucktyson]

What good is a “ sweet spot “ if the car doesn’t respond to adjustments that are needed to get in that “ window “ ?

[RaceEngineer]

I have worked on very few cars that didn't respond to adjustment. My friend has an old 2006 smack converted to a Gen X. It takes very little to effect the car.

[fastford]

like GRT stated , if your chassis is CM and is flexing that much , you better check your welds very close........

[Kromulous]

We had a 05 Black Rocket and i was convinced it was possessed. No matter what you did, it always looked the same and was slow LOL. I suggest a torch / saw and a Blue / grey front end.

[grt74]

What can be done to help stiffen an older chrome moly chassis to get a few more good nights out of it. I know the car is worn out and flexes way
to much so can you add bars in specific places to help bring back any rigidity. Car is a 07 black front end rocket

it can be done, on a bullring the black car will still get it done, so if your just trying to save some money and still race, do the work you'll be fine, those cars did flex alot in the front end, ill bet you could weld 20 feet more of tubing in it, just remember what i said in the 1st post, your used to it flexing now, when you weld her up, there goes the flexing,youll have to compensate somewhere for the flexing
don't get me wrong your not going to set the world on fire with that car but you can still be very competitive with it, and win some with it, i helped some friends with an 06 car and they beat several new cars a few times this years was alot of fun seeing less than half of the money smoking them

[bullittwrench]

On the front, weld in an x brace in front of the radiator. Put ur right side header on, weld a shock mount approx. half way up the bar that has the right side engine plate mounts, weld a shock mount on the right front frame kick up. Put a link rod in first to make sure it clears header. That should stiffen the front so you can at least tune it with the springs. And the link rod is removeable if you want. Sounds like Huck is on to stiffening the rear of a Gen-X. He might give you some pointers on that end of the car.

[fastford]

the stiffest chassis we ever had , had a down tube running from the top off roll cage hoop to the upper front shock mount , have thought a lot about going back to this with the amount of load the right front gets now with soft spring and bump stop set ups .....

[bullittwrench]

Had a Ray Allen car way back when that had down tubes. Best leaf car I ever owned.

[Krooser]

I plan on stiffening my '04 smackdown, too. X brace in front on the radiator, a bar from the dash bar to the RF....maybe with an acme thread in the middle so I can put tension on the RF...old Indian Trick.

If the chassis gets stiffer it should react with softer springs...at least every car I built from scratch did. Never drove a car that wasn't scratch built. This MB will be a new experience for me.

[Mopar DLM]

Have to weld upper control arm mounts every year, always find several cracks through out the car. For sure going to add the bar under the right side header. Rocket also suggested that same bar. I have not heard of the X in front of the radiator. Did think about putting a front motor plate in it to help stiffen the upper shock mounts. Only thought on that was if the chassis does still flex I sure don't want it to crack or break the block. Thanks for all the suggestions so far.

[billetbirdcage]

You might be surprised on how much or little flex can effect at car.

While it's been a while since I did this, but was not so long ago that we wasn't already on bumpstops and what not, just not as stiff as shocks as now.

List of what I cut out (not cut the bar, I mean cut both ends and remove the bar completely). Cut one bar at a time and made 3 or 4 laps and came in and removed another. These are probably not in the 100% correct order they were cut out.

1. left side: bar from vertical mid-plate bar to left main frame kick up
2. Right side: bar from vertical bar behind mid-plate bar to right main frame kick up (2 bars actually as it goes thur the mid-plate bar
3. Dash bar to vertical mid-plate bar
4. Bar in front of radiator connecting both upper rails together
5. diagonal bar in top of halo
6. Right diagonal bar from RR lower 4-link area to main front down bar on front of halo.

[fastford]

that no. 4 should have made more than enough effect to feel......

[Austin34471]

You might be surprised on how much or little flex can effect at car.

While it's been a while since I did this, but was not so long ago that we wasn't already on bumpstops and what not, just not as stiff as shocks as now.

List of what I cut out (not cut the bar, I mean cut both ends and remove the bar completely). Cut one bar at a time and made 3 or 4 laps and came in and removed another. These are probably not in the 100% correct order they were cut out.

1. left side: bar from vertical mid-plate bar to left main frame kick up
2. Right side: bar from vertical bar behind mid-plate bar to right main frame kick up (2 bars actually as it goes thur the mid-plate bar
3. Dash bar to vertical mid-plate bar
4. Bar in front of radiator connecting both upper rails together
5. diagonal bar in top of halo
6. Right diagonal bar from RR lower 4-link area to main front down bar on front of halo.
Need to sell my spring smasher so I can buy a sawzaw and portable welder for at the track adjustments!

[Krooser]

Cars are fickle... everyone who's raced has had a car that worked better after it had been wrecked...

[spiderma4]

You might be surprised on how much or little flex can effect at car.

While it's been a while since I did this, but was not so long ago that we wasn't already on bumpstops and what not, just not as stiff as shocks as now.

List of what I cut out (not cut the bar, I mean cut both ends and remove the bar completely). Cut one bar at a time and made 3 or 4 laps and came in and removed another. These are probably not in the 100% correct order they were cut out.

1. left side: bar from vertical mid-plate bar to left main frame kick up
2. Right side: bar from vertical bar behind mid-plate bar to right main frame kick up (2 bars actually as it goes thur the mid-plate bar
3. Dash bar to vertical mid-plate bar
4. Bar in front of radiator connecting both upper rails together
5. diagonal bar in top of halo
6. Right diagonal bar from RR lower 4-link area to main front down bar on front of halo.

don't leave us hanging how did it change each cut ?

[MasterSbilt_Racer]

Cars are fickle... everyone who's raced has had a car that worked better after it had been wrecked...

I had one that was pretty consistent the first 2 clips. Then it went away.

[hucktyson]

One time at band camp I removed the entire right side lower frame rail ..... and dominated the heat race and ended up over heating in the feature since I had a return line on a pump that didn’t need one so I was going lean holding it wide open on a huge track ... I replaced that rail with a piece of cable that night .... I welded the rail back in and never felt the same since !! Then one time I removed the entire rack cross member and wire tied everything together .... you might be surprised how that worked !!!

[fastford]

well , i built a deck out of pine straw one time , worked pretty good till one of blackie,s girl friends showed up .........

[fastford]

Cars are fickle... everyone who's raced has had a car that worked better after it had been wrecked...

cant say i ever had that happen krooser , my sh1t was normally to tore up to fix....lol....

[Krooser]

cant say i ever had that happen krooser , my sh1t was normally to tore up to fix....lol....


My buddy Tom had a neat Chevelle he ran in the sportsman class... got nailed in the RF one night and he measured the car and the right side was a bit swayed to the left... kind of like a "turned stub". No time to fix so he raced the rest of the season that way claiming the car was never better.

Never did fix it...

My cars, new or smashed, were never fast enough to tell a difference.

Might have been the talent behind the wheel, too.