How low can you go ??

[AcampoDave]

Have you considered getting a tire with a bit more sidewall Ken? A little more side rubber would fill the opening a bit and bring the fender closer to the tire. I'm just saying that you have a mighty nice truck to risk driving it at highway speed with your undercarriage barely above the pavement.

The roads where I live are not good, rolling along with cut bump stops and avoiding obstacles in the name of style may work most of the time, but it's also nice to have a smooth ride and feel at ease behind the wheel. Stuff happens out there.

[forestb]

You could always put Some weight in the front to lower it down an inch and then see if you start scraping on things. I think if you go any lower you are probably going to start scraping on stuff.

[SCOTI]

The front x-member needs to be minimum 3" off the ground w/4" being better to limit contact.

Aftermarket front 'raised' x-members shine here but add complexity/cost because they need matching arms & the swap to R&P steering.

'Z-ing' the frame is best for a old-school/budget build approach. Combine it w/drop spindles & springs & you can yield close to 7" front drop while keeping the x-member close to 4" off the road. There is still complexity but it comes @ different areas vs requiring different parts.

There's also sectioning (pancaking) a stock front x-member. It fits somewhere in between the above choices & can be an easier solution complexity wise.... but it has compromises.

Having done all three options.... I'd do a frame-Z. Properly done, it yields the same results as an aftermarket x-member while using the tried & true OE chassis set-up.

4/6 dropped trucks drive around w/o issue & work well. Going to that next level of drop is where it get's complicated. The 'Z' would utilize the same proven 4/6 parts combo but get you that much lower. It all comes down to each guys specific needs/wants.

[short&wide65]

Originally Posted by SCOTI

Aftermarket front 'raised' x-members shine here but add complexity/cost because they need matching arms & the swap to R&P steering.

Having done all three options.... I'd do a frame-Z. Properly done, it yields the same results as an aftermarket x-member while using the tried & true OE chassis set-up.

For me, the aftermarket front crossmembers correcting the poor factory geometry while converting to rack & pinion is what makes them so attractive. Their only downside is cost.

[SCOTI]

Originally Posted by short&wide65

For me, the aftermarket front crossmembers correcting the poor factory geometry while converting to rack & pinion is what makes them so attractive. Their only downside is cost.

You can tweak the factory stuff to correct the Geometry. Tall BJ's, Caster mod, perf alignment vs stock spec, a new/faster ratio steering box, & lower center of gravity change things completely.

R&P set-up's are nice but again significantly add to the cost/complexity vs whats already there.

[short&wide65]

Originally Posted by SCOTI

You can tweak the factory stuff to correct the Geometry. Tall BJ's, Caster mod, perf alignment vs stock spec, a new/faster ratio steering box, & lower center of gravity change things completely.

R&P set-up's are nice but again significantly add to the cost/complexity vs whats already there.

It would still be just tweaks that make it slightly better than stock so I disagree that it would change things completely.

I should add that I'm setting my truck up for autocross use so handling is paramount to me.

[SCOTI]

Originally Posted by short&wide65

It would still be just tweaks that make it slightly better than stock so I disagree that it would change things completely.

I should add that I'm setting my truck up for autocross use so handling is paramount to me.

You can disagree but tweaks made to the original 63-87 C10 geometry can change things completely; it just depends on one's definition of 'tweaks'.

There is nothing 'wrong' w/the stock set-up. It's not ideal vs. what's offered under current performance cars/trucks but neither are the aftermarket x-member kits being sold to achieve aggressive drop heights. R&P steering set-ups are an improvement over the original equipment steering box/set-up but only when everything is set-up & dialed in w/o compromise. Otherwise, it's just R&P steering that's easier to adapt to the raised x-member arrangement. A new perf spec steering box would also make a big difference in steering function.

If you're building something for autocross, using a Porterbuilt, GSI, Choppin Block, or Thorbeck Bro's raised x-member style set-up seems like a poor choice vs other more specific options. The aftermarket x-member kits do have updated geometry but again the OG stuff can be tweaked to rival the those offerings.

Autocross would benefit from a No Limit Engineering, Detroit Speed, SpeedTech, Scott's, or something from Roadster Shop (or maybe one of the very recently released to market QA-1 set-ups). These would be more aligned w/purpose built driving w/a nod toward autocross ambitions. They're also an even bigger investment vs. the aftermarket raised x-members.

So.... My question would be what do you consider to be 'just tweaks'?

[theastronaut]

Originally Posted by SCOTI

You can tweak the factory stuff to correct the Geometry. Tall BJ's, Caster mod, perf alignment vs stock spec, a new/faster ratio steering box, & lower center of gravity change things completely.

R&P set-up's are nice but again significantly add to the cost/complexity vs whats already there.

The setup I had on Goldilocks' build (stock crossmember raised 1.5", 1" narrowed PB tubular arms, .500" taller upper ball joints, and CPP Modular drop spindles) had more camber gain per inch of travel than No Limit's WideRide front end. Depending on how much body roll you have that could be a good thing or a bad thing. I like softer/more compliant suspension that absorbs mid corner bumps and curbing so having more camber gain to add more camber as the body rolls is a good thing- you can run less static camber. Stock camber gain is .86* per inch inch of travel, No Limit is 1.56*, my setup was 1.61*. The PB arms corrected the lack of caster and the No Limit rack & pinion corrected bump steer. The factory crossmember already has about 10* of antidive built in so that's good as-is. Now, if you like stiff suspension and no body roll because everyone thinks that's what makes something handle good... you don't really need geometry anyway, just throw some static camber at it.

The factory geometry with a few tweaks, plus an appropriate spring rate and good shock valving can be really good, and plenty good enough for autocross if you're not trying to be top level competitive.

[SCOTI]

Originally Posted by theastronaut

The setup I had on Goldilocks' build (stock crossmember raised 1.5", 1" narrowed PB tubular arms, .500" taller upper ball joints, and CPP Modular drop spindles) had more camber gain per inch of travel than No Limit's WideRide front end. Depending on how much body roll you have that could be a good thing or a bad thing. I like softer/more compliant suspension that absorbs mid corner bumps and curbing so having more camber gain to add more camber as the body rolls is a good thing- you can run less static camber. Stock camber gain is .86* per inch inch of travel, No Limit is 1.56*, my setup was 1.61*. The PB arms corrected the lack of caster and the No Limit rack & pinion corrected bump steer. The factory crossmember already has about 10* of antidive built in so that's good as-is. Now, if you like stiff suspension and no body roll because everyone thinks that's what makes something handle good... you don't really need geometry anyway, just throw some static camber at it.

The factory geometry with a few tweaks, plus an appropriate spring rate and good shock valving can be really good, and plenty good enough for autocross if you're not trying to be top level competitive.

I'm betting unless one has done the 'driver mod' (actually attended a driving school), the modded C10 set-up is more than enough for said driver.

[verdell]

Originally Posted by AcampoDave

Have you considered getting a tire with a bit more sidewall Ken? A little more side rubber would fill the opening a bit and bring the fender closer to the tire. I'm just saying that you have a mighty nice truck to risk driving it at highway speed with your undercarriage barely above the pavement.

The roads where I live are not good, rolling along with cut bump stops and avoiding obstacles in the name of style may work most of the time, but it's also nice to have a smooth ride and feel at ease behind the wheel. Stuff happens out there.

Very good point here. I switched from a 245-45-18 on the front to a 235-50-18
and it works great.