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Chris Birdsong lower ball joint lowering bracket #3236997
06/06/24 02:43 PM
06/06/24 02:43 PM
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roadrunninMark Offline OP
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Just been watching the Chris Birdsong video about a bracket he is making. It lowers the lower ball joint mount 1 1/2 inches. He also talks about a raised upper ball joint, 1 inch. He shows all the work on why this is a nice upgrade for handling, suspension travel, and control. I was curious to see what the engineers/ experts on suspensions think of this upgrade. He is selling these on eBay, quite pricey at 350. I also don’t know if the the bracket needs to have the gussets, since a spindle doesn’t have it. I also wonder when he says it makes your track 3/8” wider, thickness of the plate, how are you getting 3/8” more on the upper ball joint to keep the spindle angled correctly. He also says itt eliminated about half of bump steer issues. Lastly, would it be possible to just weld a plate to the bottom of the spindle to get the same 1 1/2” drop without increasing track? Here is a link to his video.. https://www.youtube.com/watch?v=SDVM-zFs3fg

Last edited by roadrunninMark; 06/06/24 02:57 PM.
Re: Chris Birdsong lower ball joint lowering bracket [Re: roadrunninMark] #3237019
06/06/24 06:16 PM
06/06/24 06:16 PM
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Shopping @ HoBo Fright
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I follow his channel and saw that when he 1st put it up sure seems interesting


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Re: Chris Birdsong lower ball joint lowering bracket [Re: roadrunninMark] #3237026
06/06/24 06:55 PM
06/06/24 06:55 PM
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I am not a suspension expert. But i would take this modification with a large grain of salt.
I will rewatch, but my first impression:
1.Not sure how this added bracket exactly reduces bump steer
2. I'd like to know the added weight
3. The obsession with body roll is not supported here, if roll is such a problem, then add a 3" Dia sway bar?
4. I have been told by experts (Ron Sutton) when measuring suspension pickup points, accuracy better than 1/16" is the goal
5. I would think a possible upgrade here might be, f there is indeed suspension improvement to be had, would be simply 1" 7076 alum plates with no gussets or welding, and then find an additional 5/8" greater track width per side over the 3/8" steel brackets, and use a more offset wheel if needed, and go to an adjustable upper A arm.
6. I like the designer's [censored] (meaning backbone, courage, fortitude, grit, spirit) and can-do attitude, just not sure if he has crossed all the T's and is connecting all the dots.
7. I see little potential downside with this solution other than maybe finding little improvement to be had.
8. I'll stay tuned.




Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
Re: Chris Birdsong lower ball joint lowering bracket [Re: roadrunninMark] #3237067
06/06/24 10:55 PM
06/06/24 10:55 PM
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Originally Posted by roadrunninMark
Just been watching the Chris Birdsong video about a bracket he is making. It lowers the lower ball joint mount 1 1/2 inches. He also talks about a raised upper ball joint, 1 inch. He shows all the work on why this is a nice upgrade for handling, suspension travel, and control. I was curious to see what the engineers/ experts on suspensions think of this upgrade. He is selling these on eBay, quite pricey at 350. I also don’t know if the the bracket needs to have the gussets, since a spindle doesn’t have it. I also wonder when he says it makes your track 3/8” wider, thickness of the plate, how are you getting 3/8” more on the upper ball joint to keep the spindle angled correctly. He also says itt eliminated about half of bump steer issues. Lastly, would it be possible to just weld a plate to the bottom of the spindle to get the same 1 1/2” drop without increasing track? Here is a link to his video.. https://www.youtube.com/watch?v=SDVM-zFs3fg



Local guy, Dr Bob, had a set of welded spindles like you mentioned made up 15 years ago or so.

Re: Chris Birdsong lower ball joint lowering bracket [Re: autoxcuda] #3237077
06/07/24 12:29 AM
06/07/24 12:29 AM
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So what was the verdict?

The brackets here have gusset stiffeners welded, which if properly welded, concerns me little, but a welded non bolted extension would concern me.


Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
Re: Chris Birdsong lower ball joint lowering bracket [Re: jcc] #3237086
06/07/24 06:46 AM
06/07/24 06:46 AM
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He definitely gives those that want to change/correct their suspension for their specific handling needs another choice. Several questions have been asked (Sorry, I didn't do the quote thing correctly):

1.Not sure how this added bracket exactly reduces bump steer?
When you deviate from the factory alignment which was for bias ply tires (not autocross/aggressive handling/radial tires) the outer tie rod pivot location changes and bumpsteer is induced because the outer tie rod link pivots are not parallel with the lower control arm pivots any longer. This bracket moves the steering arm/outer tie rod pivot location to a better spot for low bump steer.
2. I'd like to know the added weight
It is unsprung, but negligible due to the fact that it is not rotating weight which is harder to accelerate. Given the fact it may improve your individual handling would outweigh the weight (lap time/tire wear).
3. The obsession with body roll is not supported here, if roll is such a problem, then add a 3" Dia sway bar?
It really is. Reducing Roll Couple = less body roll. It appears Chris likes high travel, low roll suspension and low budget (I'm a big fan of that as well). Reducing body roll while maintaining high travel can work both front tires and unload the inside rear tire just enough to let the car turn faster. I'd like to know how much body roll the test car would have before and after the brackets. I understand the test car was just a fun project, but I like facts/numbers.
4. I have been told by experts (Ron Sutton) when measuring suspension pickup points, accuracy better than 1/16" is the goal
Ron does put the cookies on the bottom shelf where I can get to them, but he's not the most ethical business person either.
5. I would think a possible upgrade here might be, if there is indeed suspension improvement to be had, would be simply 1" 7076 alum plates with no gussets or welding, and then find an additional 5/8" greater track width per side over the 3/8" steel brackets, and use a more offset wheel if needed, and go to an adjustable upper A arm.
I can't do FEA, but I'm pretty sure the stress in that area goes up exponentially and you'd want quality steel and gussets. I know one trick for a better camber curve in a B/E body is to use A body lower control arms which are close to 3/8" longer.
6. I like the designer's [censored] (meaning backbone, courage, fortitude, grit, spirit) and can-do attitude, just not sure if he has crossed all the T's and is connecting all the dots.
Birdsong does have a huge amount of charisma. I agree with the T's and I's not being crossed. I'd like to see a stock camber curve, bump curve, and ackerman (@25*?) for his alignment stock, with a 1" taller upper only, with the lower bracket only, and with the 1" taller upper and lower bracket.
7. I see little potential downside with this solution other than maybe finding little improvement to be had.
Somebody correct my understanding here but raising roll center more than about 1" above ground starts to take away from optimally working the front tires for autocross and street driving. I think this idea is great, but I don't know what camber curve, IC, RC, CG (about camshaft height), F/R weight bias my car has.
8. I'll stay tuned.
I hope Chris chimes in to set us keyboard jockeys straight.

Re: Chris Birdsong lower ball joint lowering bracket [Re: glhs0426] #3237097
06/07/24 09:39 AM
06/07/24 09:39 AM
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Originally Posted by glhs0426
He definitely gives those that want to change/correct their suspension for their specific handling needs another choice. Several questions have been asked (Sorry, I didn't do the quote thing correctly):

1.Not sure how this added bracket exactly reduces bump steer?
When you deviate from the factory alignment which was for bias ply tires (not autocross/aggressive handling/radial tires) the outer tie rod pivot location changes and bumpsteer is induced because the outer tie rod link pivots are not parallel with the lower control arm pivots any longer. This bracket moves the steering arm/outer tie rod pivot location to a better spot for low bump steer.
]t's not clear to me how/where this mod changes the physical relationship of the tie rod to the LCA that would change/reduce bump steer, He mentions something about "offset holes" and there is a left and right version being important on install, but if that is a bump steer correction, where is the OEM shortcoming he is correcting?
2. I'd like to know the added weight
It is unsprung, but negligible due to the fact that it is not rotating weight which is harder to accelerate. Given the fact it may improve your individual handling would outweigh the weight (lap time/tire wear).
Until I know what "negligible" is, I'll reserve judgement
3. The obsession with body roll is not supported here, if roll is such a problem, then add a 3" Dia sway bar?
It really is. Reducing Roll Couple = less body roll. It appears Chris likes high travel, low roll suspension and low budget (I'm a big fan of that as well). Reducing body roll while maintaining high travel can work both front tires and unload the inside rear tire just enough to let the car turn faster. I'd like to know how much body roll the test car would have before and after the brackets. I understand the test car was just a fun project, but I like facts/numbers.
Well, soft sprung/big swaybar somewhat achieves the same goal. I'm not clear how unloading the inside rear tire on a non spool car herlps a car faster.
4. I have been told by experts (Ron Sutton) when measuring suspension pickup points, accuracy better than 1/16" is the goal
Ron does put the cookies on the bottom shelf where I can get to them, but he's not the most ethical business person either.
No Comment grin
5. I would think a possible upgrade here might be, if there is indeed suspension improvement to be had, would be simply 1" 7076 alum plates with no gussets or welding, and then find an additional 5/8" greater track width per side over the 3/8" steel brackets, and use a more offset wheel if needed, and go to an adjustable upper A arm.
I can't do FEA, but I'm pretty sure the stress in that area goes up exponentially and you'd want quality steel and gussets. I know one trick for a better camber curve in a B/E body is to use A body lower control arms which are close to 3/8" longer.
IYes, 'm a believer in almost every case, longer is better in suspension components, in proper proportions
6. I like the designer's [censored] (meaning backbone, courage, fortitude, grit, spirit) and can-do attitude, just not sure if he has crossed all the T's and is connecting all the dots.
Birdsong does have a huge amount of charisma. I agree with the T's and I's not being crossed. I'd like to see a stock camber curve, bump curve, and ackerman (@25*?) for his alignment stock, with a 1" taller upper only, with the lower bracket only, and with the 1" taller upper and lower bracket.
I was thinking more "diamond in the rough" or maybe "authentic"? grin
7. I see little potential downside with this solution other than maybe finding little improvement to be had.
Somebody correct my understanding here but raising roll center more than about 1" above ground starts to take away from optimally working the front tires for autocross and street driving. I think this idea is great, but I don't know what camber curve, IC, RC, CG (about camshaft height), F/R weight bias my car has.
I agree, his guess on COG was a bit high, camshaft is bit better
8. I'll stay tuned.
I hope Chris chimes in to set us keyboard jockeys straight.
I'm all ears.




Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
Re: Chris Birdsong lower ball joint lowering bracket [Re: jcc] #3237120
06/07/24 11:07 AM
06/07/24 11:07 AM
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something different for sure.
however, if i wanted a max handling machine, i think i would investigate complete systems designed for such.
i will keep an open mind, as i enjoy learning, and i will ponder this latest idea some to see if there is merit in this.
beer

Re: Chris Birdsong lower ball joint lowering bracket [Re: moparx] #3237145
06/07/24 12:44 PM
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I believe I have gained some clarity here on the bump steer improvement in the video. The vertical spacing on the brackets original mounting holes vs the new BJ holes is slightly different front and rear. This rotates the BJ tie rod end down slightly I believe, which effects bump steer and leads to the designers claim for an improvement. Orientation of brackets as to side as designer mentioned is specific. Seems like adding copious amounts of caster would inadvertently have the same result


Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
Re: Chris Birdsong lower ball joint lowering bracket [Re: jcc] #3237155
06/07/24 02:19 PM
06/07/24 02:19 PM
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Quote
3. The obsession with body roll is not supported here, if roll is such a problem, then add a 3" Dia sway bar?

It really is. Reducing Roll Couple = less body roll. It appears Chris likes high travel, low roll suspension and low budget (I'm a big fan of that as well). Reducing body roll while maintaining high travel can work both front tires and unload the inside rear tire just enough to let the car turn faster. I'd like to know how much body roll the test car would have before and after the brackets. I understand the test car was just a fun project, but I like facts/numbers.

Well, soft sprung/big swaybar somewhat achieves the same goal. I'm not clear how unloading the inside rear tire on a non spool car herlps a car faster.


We run soft spring/big swaybar in circle track without a spool. We use a True-Trac (Torsen Gleason) all geared setup. I would guess that's what Chris uses at the Bullring (his local 1/4mi short track). Unless there is a class rule that limits them to a spool.

Also he's looking for a tall spindle to get camber gain. The extension effectively makes the spindle taller.

Last edited by autoxcuda; 06/08/24 10:53 AM.
Re: Chris Birdsong lower ball joint lowering bracket [Re: autoxcuda] #3237250
06/08/24 08:04 AM
06/08/24 08:04 AM
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Answering the call of the wild
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The verdict is not available as we do not have enough data...he should post some lap times before and after this modification and stop talking. He does some interesting drawing...on the floor...i guess he cannot afford a white board. Are you all entertained enough? 69,300 people giving him money.

Put the car on the alignment rack and prove it with real numbers. Show us the bump steer. I don't have this "problem" with my lowered cars so what's with the mysterious bump steer?

If his modification is so needed my lap times would be reduced significantly and they are already great for any car esp a big fat iron pig so what is the benefit? Great means the car gets a lot of attention at the track due to it's lap times...

Last edited by ThermoQuad; 06/08/24 08:08 AM.
Re: Chris Birdsong lower ball joint lowering bracket [Re: jcc] #3237448
06/09/24 07:41 AM
06/09/24 07:41 AM
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Originally Posted by jcc
I believe I have gained some clarity here on the bump steer improvement in the video. The vertical spacing on the brackets original mounting holes vs the new BJ holes is slightly different front and rear. This rotates the BJ tie rod end down slightly I believe, which effects bump steer and leads to the designers claim for an improvement. Orientation of brackets as to side as designer mentioned is specific. Seems like adding copious amounts of caster would inadvertently have the same result


Was going to point this out but you beat me to it. And yes, IF you can get enough caster it can do the same thing.

But I'm guessing something like 15 degrees isn't practical.

Still seems like shimming the box and egging the idler would be easier.


Angry white pureblood male
Re: Chris Birdsong lower ball joint lowering bracket [Re: ruderunner] #3237462
06/09/24 11:25 AM
06/09/24 11:25 AM
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Originally Posted by ruderunner
Originally Posted by jcc
I believe I have gained some clarity here on the bump steer improvement in the video. The vertical spacing on the brackets original mounting holes vs the new BJ holes is slightly different front and rear. This rotates the BJ tie rod end down slightly I believe, which effects bump steer and leads to the designers claim for an improvement. Orientation of brackets as to side as designer mentioned is specific. Seems like adding copious amounts of caster would inadvertently have the same result


Was going to point this out but you beat me to it. And yes, IF you can get enough caster it can do the same thing.

But I'm guessing something like 15 degrees isn't practical.

Still seems like shimming the box and egging the idler would be easier.



Most caster changes effect bump steer readings. Now whether those changes in bumpsteer are significate is another thing. A bump steer gauge has dial indicators that read to a 0.001. Now is +/- 0.003 significant? doubtful.

For our circle track car, getting it close was just as much eliminating a variable in the setup (consistent) vs actually reducing the bump steer to a very small amount.

Bump steer adjustment shims come in all sizes. I remember changing 1/16" and making a difference

2024-06-09_8-16-50.jpg2024-06-09_8-10-37.jpg
Re: Chris Birdsong lower ball joint lowering bracket [Re: autoxcuda] #3238112
06/12/24 11:58 AM
06/12/24 11:58 AM
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roadrunninMark Offline OP
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Ok, part 2 is up and Chris has nixed the idea of the taller upper ball joint. He’s brought out some equipment to measure bumpsteer. He’s also added the bumpsteer kit as shown above. My only concern is that if you have a real street car, you are losing ground clearance. https://www.youtube.com/watch?v=-c8djIaugO0

Last edited by roadrunninMark; 06/12/24 12:01 PM.
Re: Chris Birdsong lower ball joint lowering bracket [Re: roadrunninMark] #3238204
06/12/24 05:16 PM
06/12/24 05:16 PM
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Most mopars have a short spindle, so this weldment should be good, in the old days there wasn’t much to do except cobble another taller spindle in. Now days speedway sells ball joints that are taller to help you with your roll center, lowering the up a frame mounting point also works but usually the factory frame is in the way. On circle track cars we would weld in new ball joint sleeves to alter the top a frame length to get our camber better, longer left , shorter right. Bumpersteer takes a lot of tinkering to get right, we were on dirt so tried to get it better but not perfect.
I made a bumpsteer gauge by using a 4 x4 piece of plywood cut in half with 2 hinges in the middle, acouple of bolts protruding the the top sheet where the tire sidewall was at its widest point (half way up the tire) take the spring out and raise and lower the chassis and watch the gap of the bolts. Very simple but worked very well,guess if your finicky you could slide a feeler gauge between the bolt and tire. Grinding out the steering box and idler holes or even bending the steering arm on the spindle, they now make the adjustable stud mentioned above. Takes a lot of beer to make it all work. A stock factory Mopar front end is horrible for circle track racing.







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