Originally Posted by forestb (Post 9115901)

If I were kens65fb I would have given up on reading this thread a long time ago.

Originally Posted by SCOTI (Post 9115899)

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'?

Originally Posted by SCOTI (Post 9115902)

Applicable information is still information.

My input was on highlighting the issue of clearances once one is curious about 'aggressive' lowering aka asking "how low can you go". Seemed related.

Originally Posted by SCOTI (Post 9114943)

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.

Originally Posted by theastronaut (Post 9116398)

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.

Originally Posted by theastronaut (Post 9116398)

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.

Originally Posted by SCOTI (Post 9116426)

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.

Originally Posted by short&wide65 (Post 9116578)

Geometry does matter and a correctly damped suspension with stiff springs and sticky tires is faster so therefore does make something "handle good" Period. I am solely basing this on the stopwatch.



Obviously, this is assumed. So the discussion is all things being equal.

Originally Posted by txinliner (Post 9277135)

im very late to this but my 65 has 3 inch belltech spindels 3 inch coils with a half coil cut in the front 5inch coils and inch and a half blocks

Originally Posted by EricS76 (Post 9116701)

My measurement is 27.0, but I’m running a taller tire that fills the gap more. (235/75R15)