Adjustable strut rods

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o1heavy

o1heavy

1974 dart sport
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Any advice on setting(adjusting) the strut rods
I feel mine are slowing down frontend travel
From being to tight
This is a 7.0 bracket index car
On leafs springs
Leaving at 5000 rpm
So
I Need all the help I can get
To stay consistent and cut a good light
Thanks guys
 
To adjust the strut rods you need to put the car up on jacks, pull the wheels, remove the torsion bar adjusters and their threaded blocks, and then remove the shocks. With that done, you should be able to lift the suspension assembly and move it through its range of travel, feeling for any binding. If there's any binding, you can then adjust the length of the strut rod and cycle the suspension through its range of travel again. Repeat until there is no binding as you cycle the suspension through its range of travel. As a general starting point, look at the LCA and see if it's perpendicular to the frame rails. If the LCA is pulled forward from perpendicular then the strut rods are too short, if it's pushed back they're too long.

You may also need to re-clock the pillow block for the heim, if the slot in the pillow block for the heim to travel isn't oriented correctly you can get binding there as well.

If you change the length of the strut rods significantly you will need to check your alignment settings, as they can change the caster setting. The strut rods should not be adjusted to gain caster, they should be adjusted for the free movement of the LCA. In some cases that will increase positive caster, but that's a side effect not the purpose of the adjustable strut rod.
 
Might want to look at Upper Control Arms with adjustable heim rods...
 
70aarcuda said:
Might want to look at Upper Control Arms with adjustable heim rods...
Click to expand...

Not based on my experience. If it's a track only car then fine. But the heims I've run at the UCA have all had VERY short life spans. My first set on the Hotchkis UCA's on my Challenger were shot after only 7,000 miles. The second set, sent free of charge by Hotchkis along with the boots that now come with their UCA's, are not going to see 10k.

Granted those were year round, all weather daily driver miles, so, maybe on a track car they would be fine. And that's not a heims in general thing, just at the UCA. I have QA1 strut rods on my Challenger and they've gone 70,000 miles, those heims are fine and they don't have boots either.

In general I have found most of the binding in the suspension comes from the strut rod and LCA bushings, the rubber UCA bushings add a little but not compared to the other two, so swapping out the UCA bushings is a much lower return of investment. Although the SPC UCA's I run now have delrin bushings.
 
72bluNblu said:
Not based on my experience. If it's a track only car then fine. But the heims I've run at the UCA have all had VERY short life spans. My first set on the Hotchkis UCA's on my Challenger were shot after only 7,000 miles. The second set, sent free of charge by Hotchkis along with the boots that now come with their UCA's, are not going to see 10k.

Granted those were year round, all weather daily driver miles, so, maybe on a track car they would be fine. And that's not a heims in general thing, just at the UCA. I have QA1 strut rods on my Challenger and they've gone 70,000 miles, those heims are fine and they don't have boots either.

In general I have found most of the binding in the suspension comes from the strut rod and LCA bushings, the rubber UCA bushings add a little but not compared to the other two, so swapping out the UCA bushings is a much lower return of investment. Although the SPC UCA's I run now have delrin bushings.
Click to expand...

I’ve had the same reliability issues with my heim UCA’s. Tie rods too.

But in this case, the OP has a:

“This is a 7.0 bracket index car
On leafs springs
Leaving at 5000 rpm”

That sure sounds like a fairly dedicated race car.
 
autoxcuda said:
I’ve had the same reliability issues with my heim UCA’s. Tie rods too.

But in this case, the OP has a:

“This is a 7.0 bracket index car
On leafs springs
Leaving at 5000 rpm”

That sure sounds like a fairly dedicated race car.
Click to expand...

Yeah it sounds like it's a track only deal to me too but what the heck.

You've had issues with the heim jointed tie rods? I was kinda looking at those as an upgrade given the tie rod end quality of late and the ability to make small changes to the bump steer. How long are the heims lasting there?
 
72bluNblu said:
Yeah it sounds like it's a track only deal to me too but what the heck.

You've had issues with the heim jointed tie rods? I was kinda looking at those as an upgrade given the tie rod end quality of late and the ability to make small changes to the bump steer. How long are the heims lasting there?
Click to expand...

Lasted no longer then on the UCA’s

I’d look at Howe grease-able, adjustable, rebuildable tie rods.

Or maybe top line Heims. Just cause they’re “Aurora” doesn’t mean everything. Aurora has different levels of quality. At all kinds of different prices to match.
 
Thanks for the help guys
I did just what 72blu said removed the coil overs and moved the front suspension they it’s range of Motion
I should have mentioned it was a coil over frontend
Everything seems fine up front
The car is just being difficult to get into a consistent state
These Caltrac’s monoleaf system work but
Can be very picky especially when trying to leave at such high rpm
I did find a good picture of the rear tire be wadded up I’ll post it
May try some more air in the slicks and see if that helps
Thing spins at the hit sometimes
Menser shocks by the way full tight
Rebound and compression
 
o1heavy said:
Thanks for the help guys
I did just what 72blu said removed the coil overs and moved the front suspension they it’s range of Motion
I should have mentioned it was a coil over frontend
Everything seems fine up front
The car is just being difficult to get into a consistent state
These Caltrac’s monoleaf system work but
Can be very picky especially when trying to leave at such high rpm
I did find a good picture of the rear tire be wadded up I’ll post it
May try some more air in the slicks and see if that helps
Thing spins at the hit sometimes
Menser shocks by the way full tight
Rebound and compression
Click to expand...

Remove the shocks from the rear and do the same thing.... bounce the car up and down. Lay under it, pull it down and feel the resistance and watch each joint pivot.

Even if you don’t see or feel anything odd to you, you have a baseline.

In our circle track leaf spring cars doing this was very helpful. When we checked the car on electronic scales every race, when a setup gave us an erroneous scale number or wasn’t reacting like it should.... many times it was a binding issue.

Just the way and stiffness the leaf shackle were tightened could screw things up. We learned a procedure and lubed them regularly.
 
125E55AA-3731-44C4-8E49-847ABF4B2684.png
autoxcuda said:
Remove the shocks from the rear and do the same thing.... bounce the car up and down. Lay under it, pull it down and feel the resistance and watch each joint pivot.

Even if you don’t see or feel anything odd to you, you have a baseline.

In our circle track leaf spring cars doing this was very helpful. When we checked the car on electronic scales every race, when a setup gave us an erroneous scale number or wasn’t reacting like it should.... many times it was a binding issue.

Just the way and stiffness the leaf shackle were tightened could screw things up. We learned a procedure and lubed them regularly.
Click to expand...
Wish I could load a video up
I have some good slo-mo and regular footage
Here’s a picture of it wadding the tire
And this is at 16psi
Stiff wall slicks and tube
 
o1heavy said:
View attachment 1715564709
Wish I could load a video up
I have some good slo-mo and regular footage
Here’s a picture of it wadding the tire
And this is at 16psi
Stiff wall slicks and tube
Click to expand...

Does that car have a sway bar on it?

I thought most drag cars don’t run them.

Do you have rubber or poly bushing end links on the sway bar?

End links like that will resist/bind when the suspension has a lot of travel (like you). The end links go at an angle and compress the rubber/poly which give resistance.

You can run spherical rod ends for end links.
 
autoxcuda said:
Does that car have a sway bar on it?

I thought most drag cars don’t run them.

Do you have rubber or poly bushing end links on the sway bar?

End links like that will resist/bind when the suspension has a lot of travel (like you). The end links go at an angle and compress the rubber/poly which give resistance.

You can run spherical rod ends for end links.
Click to expand...

I thing that gold part is the strut rod not the sway bar, but if it has one, remove it for drag racing.

I just when and re read your first post........leaf springs and leaving at 5000 rpm........stick shift or trans brake???
Either way, You need a double adj rear shock to control that violent hit and slow the reaction to it. think you will need stronger upper shock mounts to keep them from pulling threw the floor pan.

just a thought.
 
If you have video of the back of the car at launch and you can slow it down(even if you can't post it up here) watch at the hit. if the tire is being crushed buy the suspension pushing down on the tire, i think it in a shock adj. if the gap between the wheel well, and the tire is staying the same(weight transfer) then more air may help.

I'm just starting to deal with all of this stuff, maybe some one, season, at it can correct my way of thinking.
 

This is with a Nickle’s thickness of preload in the Caltrac’s 2 clicks from full tight on the rebound and full tight on compression
 
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Like i said before i'm not a suspension guy. just someone that is trying to learn suspension.
I think you need more front end travel. either lower the nose, or cut the upper rubber snubbers (extention rubber bump stop) down to get more up travel.
the rear end bounces(unloads) three time in the launch. i think its does that when the front suspension tops out and bounces off of the bump stops.
Let me ask you a question, did tightening up the rebound and compression of the rear shocks help the traction/60'?
 
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How many psi was in the back tires. seem to have a lot more then the picture you posted up with the tires all wadded up.
in slo mo its hard to see but i don't think the side wall was wrinkling at all.

I have no experience with cal tracks rear suspension, but i know my super stock spring have a bunch of lift/separation at launch.
 
Cudafever said:
Like i said before i'm not a suspension guy. just someone that is trying to learn suspension.
I think you need more front end travel. either lower the nose, or cut the upper rubber snubbers (extention rubber bump stop) down to get more up travel.
the rear end bounces(unloads) three time in the launch. i think its does that when the front suspension tops out and bounces off of the bump stops.
Let me ask you a question, did tightening up the rebound and compression of the rear shocks help the traction/60'?
Click to expand...
Yes when I tightened up the rebound and compression it did help
The restrictor plate system will be here today and if the rain stops I will be testing again Sunday
All the weight will be removed and we will see about getting this thing closer to being right
I think I will try to loosen the front shocks
And maybe even rebound rear
 
Cudafever said:
How many psi was in the back tires. seem to have a lot more then the picture you posted up with the tires all wadded up.
in slo mo its hard to see but i don't think the side wall was wrinkling at all.

I have no experience with cal tracks rear suspension, but i know my super stock spring have a bunch of lift/separation at launch.
Click to expand...
16psi stiff wall slick with tubes
I agree it doesn’t have much separation
But it also seems to hit the tire very hard
As seen in the picture I posted
That’s why I posted here , fresh set of eyes so to speak
It is giving me fits And if I can’t dead hook this think I will never be competitive
I will get lucky at times but I need it to dead hook to get the right info
 
The restrictor plate system will be here today and if the rain stops I will be testing again Sunday
All the weight will be removed and we will see about getting this thing closer to being right

I know noting about 7.0 index racing
how about a short explanation
 
Cudafever said:
The restrictor plate system will be here today and if the rain stops I will be testing again Sunday
All the weight will be removed and we will see about getting this thing closer to being right

I know noting about 7.0 index racing
how about a short explanation
Click to expand...
Just have to get to the finish first without running under 7.0
Both cars leave together on a 4ths pro tree
Which means you will need some killer reaction times and run very close to the number It’s a very competitive class
 
It's porpoising the rear which is usually a shock control issue. Watch the night video at .25 speed, can see it there. Also looks like it gets about 1/2 turn out and then unloads tire slightly in the day video.

Coil overs on the front lots of time limit the amount of travel which isn't optimum for cal trac setups.
 
crackedback said:
It's porpoising the rear which is usually a shock control issue. Watch the night video at .25 speed, can see it there. Also looks like it gets about 1/2 turn out and then unloads tire slightly in the day video.

Coil overs on the front lots of time limit the amount of travel which isn't optimum for cal trac setups.
Click to expand...
Not sure what else I can do as shock control
I bought the best shock I could afford because I knew this was gonna be a issue
Menser pro shock which are very close being full tight
I’m gonna work on front end travel
I do believe I was running the front to tight
 
o1heavy said:
Not sure what else I can do as shock control
I bought the best shock I could afford because I knew this was gonna be a issue
Menser pro shock which are very close being full tight
I’m gonna work on front end travel
I do believe I was running the front to tight
Click to expand...


Send the shock back with the settings intact and tell them to revalve the shock so those settings are in the middle.

As crackedback back said, you need more control over the suspension and that means the shock has to do it because you can’t move the IC.
 
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