No Limit '72 C-10

[69gmcc10]

This build and the “make it handle” thread have been the most influential information on the board for me and I want to say thank you! Just so I have this clear, and I am sure others are curious as well, with the 4" of kick to the frame and the 2" blocks this truck sits 6" lower in the rear than stock, or do the 9000 bags lower the truck even more?

[robnolimit]

The 9000 bag on Ridetech bolt in mounts sits 2" lower than stock at ride height. That is the same as the spring we had. The JT sits appx 8" lower in the rear. 4" from frame mod, 2" block, 2" from bag/spring.


We did some basic plotting og camber gain/steering geometry on the lines of just sectioning the lower crossmember 2". This puts the upper arm at a pretty steep angle at RH. First problem was bumpsteer, this is fixable by bending the idler and pitman arms to adjust the inner pivit points. Next, the rear problem, this moves the Instant Center inboard a good ways, and raises the Roll Center causing more 'push'. But the real problem is that the IC moves all over the place during suspension travel, and the RC shifts left/right in a corner - thats bad. So, didn't pursue this to far, at this point the drive quality is heading down a rocky trail, and only going to get worse. if you section a crossmember, you should move all the mounting points.

[mooseknuckles]

.....I'm sure you will figure it out....can't wait to see whats next!

[Greywolf200]

Originally Posted by robnolimit

We did some basic plotting og camber gain/steering geometry on the lines of just sectioning the lower crossmember 2". This puts the upper arm at a pretty steep angle at RH. First problem was bumpsteer, this is fixable by bending the idler and pitman arms to adjust the inner pivit points. Next, the rear problem, this moves the Instant Center inboard a good ways, and raises the Roll Center causing more 'push'. But the real problem is that the IC moves all over the place during suspension travel, and the RC shifts left/right in a corner - thats bad. So, didn't pursue this to far, at this point the drive quality is heading down a rocky trail, and only going to get worse. if you section a crossmember, you should move all the mounting points.

Two inches seems awfully drastic. The ball joints raises the UCA maybe 1/2" and increase camber gain. Wouldn't a 3/4"-1" section cause fewer problems and still yield camber gain benefits?

Thanks,

[robnolimit]

The reason for going 2" on the section is that the first thought of doing this is usually to drop the truck. so, a 3/4" section isn't done too much - it's a lot of work for a 3/4" drop. I was trying to see what would happen if the common mod was done just a bit different. As I am writing this, I am thinking I need to re-visit this. If your doing the section, perhaps 2" on the lower side, and 1 1/4" on the upper side. This would close up the hieght between the upper and lower arm mounts by appx 3/4" - hmm...

[Greywolf200]

Originally Posted by robnolimit

The reason for going 2" on the section is that the first thought of doing this is usually to drop the truck. so, a 3/4" section isn't done too much - it's a lot of work for a 3/4" drop. I was trying to see what would happen if the common mod was done just a bit different. As I am writing this, I am thinking I need to re-visit this. If your doing the section, perhaps 2" on the lower side, and 1 1/4" on the upper side. This would close up the hieght between the upper and lower arm mounts by appx 3/4" - hmm...

I'm coming from a different place than most people. I only want a 4/6 drop at the most. I don't want to tuck the tires or lay frame. I want a lowered truck that is still a truck, but handles like a cup car....lol. Drop spindles, a sectioned cross member with 1" drop springs yields 3-4" drop with improved camber gain....maybe? Relocate the LCA 1" and add your front sway bar and I'm thinking I'd have much improved front end handling.

[68 TT]

Thanks for the great build and for all the new parts you developed for our trucks because of it. Keep it up.

[Conundrum]

Originally Posted by robnolimit

If your doing the section, perhaps 2" on the lower side, and 1 1/4" on the upper side. This would close up the hieght between the upper and lower arm mounts by appx 3/4" - hmm...

Could you give a little more detail here?

I don't see how the 2" + 1 1/4" will give you 3/4".
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[Greywolf200]

Originally Posted by robnolimit

The reason for going 2" on the section is that the first thought of doing this is usually to drop the truck. so, a 3/4" section isn't done too much - it's a lot of work for a 3/4" drop. I was trying to see what would happen if the common mod was done just a bit different. As I am writing this, I am thinking I need to re-visit this. If your doing the section, perhaps 2" on the lower side, and 1 1/4" on the upper side. This would close up the hieght between the upper and lower arm mounts by appx 3/4" - hmm...

So you're thinking that the 3/4" drop of the UCA is the correct amount to improve the camber gain?

Thanks,

[robnolimit]

Updates

[67cheby]

Sweet
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[robnolimit]

More updates

[tubbedII]

^ Fender rolling?...

[robnolimit]

Yep, the old way. We put the spacers on to check clearance for wider wheels. Also, we wanted to check the handling with the wider track. So, next week we're going back to the track for some testing. I'm not a big fan of spacers, these are billit, well made, so we'll see. I do like the look.

[Mechanic77]

Rob might correct me, but I think he meant sectioning the crossmember 2" and moving the upper arm pivot up 1.25" which makes it to where the upper and lower pivots only move 3/4" closer to one another and you gain the full 2" of ground clearance plus an increase in camber gain

[Conundrum]

Well that makes much more sense, thanks.

And if you were to section the whole crossmember 2" wouldn't that also lower the coils upper mount the same, eliminating any drop you were trying to achieve? So it would still be best to section inbetween the uca mounts, correct? And then you could just lower the uca mounting points the 3/4"?
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[Mechanic77]

Depending on how you section the cross member.....yeah. In my opinion, I would just notch the frame rails 2" to allow the crossmember to be moved up and just lower the uca mounts 3/4"......probably have to notch the crossmember for oil pan (and possibly balancer) clearance so that you can keep the engine as low as possible.......

[robnolimit]

Originally Posted by Mechanic77

Depending on how you section the cross member.....yeah. In my opinion, I would just notch the frame rails 2" to allow the crossmember to be moved up and just lower the uca mounts 3/4"......probably have to notch the crossmember for oil pan (and possibly balancer) clearance so that you can keep the engine as low as possible.......

I'm with you, this is a lot less work.

[Conundrum]

Got another one......

Once you drop the uca mount X" and if you decide to narrow the track width by removing X amount from the lca or a custom lca, will that have a negative effect?
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[robnolimit]

We may be going a bit far here. I'm not a big fan of narrowing arms. If this is just for wheel/tire clearance, get a wheel with more backspace. Narrowing the track to get this done tends to have negative effects on everything else, so, i'd stay away from that if I could.

[Conundrum]

Thought so, thanks Rob

[Conundrum]

I have another question on the caster mod.....
Is there a reason for moving the lca forward 3/4" and uca 1/2" rearward instead of moving them both 5/8"?
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[Low Elco]

Aggie-Page 8&9.

The headman part # is 45660. They are available plain, or HTP ceramic coated.

[hairlesshobo]

The more you move the lower forward the more it will center the tire in the fender well. Other than that, I don't see a reason. Someone correct me if I'm wrong...
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[Conundrum]

When I Zed my frame I moved the whole front suspension forward so my wheels are centered.
I was wondering if it had something to do with the steering?
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