Make it handle

[Custom 68]

Make sure you don't have any binding in your steering column. As I'm sure you know the u joints have a limit on angles. If you are over that you will get some notchy binding.
Dave

[SCOTI]

That's a good point.

[Rob Fisher]

I took the tires off and have the suspension at Ride height and it cycles left to right as smooth as can be. With the tires back on and driving around it returns to being knotchy.

[93Polo]

Originally Posted by SCOTI

True. There's a big difference between Vette vs truck weights; especially on the front hub. I know my research on comparable aftermarket high end spindles suggested there is a tug-o-war going on about the reliance of sealed bearings.

The spindles using the C5/6/7 sealed bearing set-ups recommend only using the top tier Zr1 parts because of short life span on alternative replacement parts. Those suckers are ~$400 a pop; pricy if you're replacing things more frequently. Thus the old stand-by wheel bearings w/their easy serviceability & 'common-folk' friendly purchase price are a value to those that have limited resources.

I see value in both. But, w/o having first-hand exposure on the lifespan of unit-bearings I'm @ a disadvantage of how 'worthy' they are in the scheme of things (return on investment).


I have tall upper BJ's on my C10's. I just know from my previously mentioned research that the disc brake style C10 spindles were taller than most for their era. From my notes:

67-72 A/F/X/& G body 'short' spindles ~7-7.5"
70-81 F/B-body & 73-87 C10 'tall' spindles ~9"
C4 Vette ~11"
ATS & Wilwood aftermarket spindle ~9"

*I can confirm the 73-87 C10, G-body, & C4 Vette spindle heights as I own them & actually measured for the research when trying to source something better for a g-body. The other numbers were from online look-up & could be suspect/incorrect.


This is true & apparently time consuming (I'm still waiting for ATS spindles paid for in June). The ATS spindle is forged & I believe the Wilwood is as well. But, even the forged versions have an expected lifespan (x-miles/x-years) before they SHOULD be replaced. It's a limitation most don't even think about for their steel spindles


I confess I haven't really studied the Wilwood spindle because I'm a fan of being able to source the parts used from OE applications (Have a brake part issue in Podunk, TX. Pop into Oreillys/Auotzone/Advance Auto & ask for a Wilwood pad/caliper/master cyl/hose etc....). However, you can usually do the same for PBR & Brembo parts & they'll have something.

I'm 100% w/you on a spindle designed for optimum set-points of the geometry & tuning for the steering. I'm on the fence about the sealed hubs being 'better'. I assumed they were until reading about the alarming failure rate for typical store-bought replacement parts.

If you are going to C5/C6 bearing, I would only run ZR1s or SKF X trackers. They do take much more abuse than the OEM bearing. LG replies in post 10 listing how long they used bearings. They are about $400 and you'll likely have to go to a shop that supports the Corvette HPDE/ race community. The x tracker is basically the same design as C6 Zr1 bearings. Splines and abs signal change.

https://www.corvetteforum.com/forums...e-upgrade.html

The post was for World Challenge Racing which was aero, big brakes, basically heads and cam LS6s, wheel to wheel, hard racing. Failure rates for various parts were higher than what most club racers experience now. I also assume this was for SKF x trackers as SKF also offers a more OEM replacement bearing which is what you'll get at NAPA, Autozone etc. Corvettes were also running world challenge before the x tracker came out and the regular SKF is an improvement over stock.


His reply:
For us on one of the World Challenge cars.....closest to what you guys run on track this is what we would see time wise out of the bearings on track.

OEM GM bearings
1 weekend event (80 mins practice, 20 min qual, 50 min race) Approx 2.5 hrs track time

GM blueprinted "race" bearings
3-4 weekend events, approx 10 hrs total run time on track

SKF bearings,
28-34 hrs total run time on track
...
I help a friend maintain a C5 HPDE car which has a Nine Lives wing and splitter on 100 tread wear tires and he has been a few seasons on X trackers. I believe they would last a long time on C10 especially on the street. I'd have more faith in them than Silverado bearings. As posted above they are 5x4.75. If I went that route I'd set the rear up to use the same. DSE is likely using the X tracker in their front suspensions for F-bodies, Novas etc. AFX spindles have also used X trackers on 64-72 A-bodies.

I agree with you on parts which you can find in OEM applications. I have toyed with idea of a No Limit wide ride and CPP tall spindles (2 gen fbody) for the C5 bearings. But, then you're mixing parts to run a few OEM parts but using aftermarket control arms etc for their suspension.

Aluminum spindles/knuckles do have a life span. Another part that changed thanks to the C6 ZR1 was the spindle. The early spindles have had the ears which mount the caliper break off. GM discovered flex in the spindle and changed the manufacturing process when the ZR1 came out. I have not heard of the later knuckles failing. The failure on the original design were after many seasons of racing. I do know of one that failed on a 72 Charger with an aftermarket suspension using C5/C6 spindles and big Baer brakes with many autox days.

[cab4word67]

Question with caster. I have a 67 stepside with tube up control arms and the truck sits very low. 245x35 20s. it has about .5 degree of of camber and close to 4 degrees of caster. What I notice is when backing out of my driveway the front tires seam to drag? is that the caster? it drives nice a straight, and handles the corners like on rails.

[Rob Fisher]

Can you offer some advice on brake pads.
I don’t take the truck to the track so mainly looking for something that will give me good bite when cold and still perform well when driving a little more spirited.
I have Wilwood brakes front and rear and a 1” bore master brake with no booster. I have contacted EBS and they recommend their Yellow Stuff and Hawk Performance recommends their HPS 5.0.

[aggie91]

Originally Posted by cab4word67

Question with caster. I have a 67 stepside with tube up control arms and the truck sits very low. 245x35 20s. it has about .5 degree of of camber and close to 4 degrees of caster. What I notice is when backing out of my driveway the front tires seam to drag? is that the caster? it drives nice a straight, and handles the corners like on rails.

It is not caster causing the drag.

How much toe it or toe out does your set up have?

[cab4word67]

Guys I have leafs in my 67 and lowered 5-1/2" ft and into the C notch tell I almost hit on the rear. My truck will go around 50mph corners at 75mph and the back wont even break loose, street corners the same. What kinda 'G's do you think Im pulling?
Next week we are adding the caster mod and the bump steer mod.
Just a 1-1/4 ft sway bar and viking shocks, oh and cheap tires.

[SCOTI]

Originally Posted by cab4word67

Guys I have leafs in my 67 and lowered 5-1/2" ft and into the C notch tell I almost hit on the rear. My truck will go around 50mph corners at 75mph and the back wont even break loose, street corners the same. What kinda 'G's do you think Im pulling?
Next week we are adding the caster mod and the bump steer mod.
Just a 1-1/4 ft sway bar and viking shocks, oh and cheap tires.

What are the wheels/tires?

[cab4word67]

275/40x20 rr, 255/35x20 ft all Amazon Fullway HP108s. They may be cheap but they sure do grab

[cab4word67]

Originally Posted by aggie91

It is not caster causing the drag.

How much toe it or toe out does your set up have?

It has 1/8" of toe in, thats a 1/16 on each
Drive strait as an arrow with no pull on the highway

[SCOTI]

Originally Posted by cab4word67

275/40x20 rr, 255/35x20 ft all Amazon Fullway HP108s. They may be cheap but they sure do grab

I'd say if you're not running high-end sticky rubber with </= 200 tread wear rating, they're not sticky enough to grab & hold beyond a .8x G. I bet it feels like it is >.8 simply because of where it was/what a typical truck can do.

High end G's are recorded & possible in controlled/maintained track surface environments. Not so much on the state/city maintained road surfaces.

[theastronaut]

Originally Posted by SCOTI

I'd say if you're not running high-end sticky rubber with </= 200 tread wear rating, they're not sticky enough to grad & hold beyond a .8x G. I bet it feels like it is >.8 simply because of where it was/what a typical truck can do.

High end G's are recorded & possible in controlled/maintained track surface environments. Not so much on the state/city maintained road surfaces.

Those are 380 treadwear, I would think that .80, maybe .85 is all they're good for with normal truck suspension.

As far as old cars/trucks go, I've only seen lateral grip test results posted by Mark Stielow's "Jackass 2.0" Camaro that does 1.15g on 200tw BF Goodrich Rival tires. A thing to note about modern 200tw tires- they're labeled 200tw just to pass class rules, they're much stickier than traditional 100tw track tires. So going by treadwear isn't a good indication of how much grip a tire will have.

Here is a list of cars and the amount of grip they have for comparison.

https://fastestlaps.com/lists/top-grip-kings

[Custom 68]

Just to add to this as well, when folks like Stielow are recording the "Gs" they would be done on a skidpad that is setup specifically to measure this as a sustained reading. At least that was years ago.
With the sophisticated equipment they will monitor the course and can pull off the Gs as well.
It does sound like your truck is working well and makes you happy when you drive it. I say that is a win regardless of Gs. keep enjoying it.
Dave

[SCOTI]

Originally Posted by theastronaut

Those are 380 treadwear, I would think that .80, maybe .85 is all they're good for with normal truck suspension.

As far as old cars/trucks go, I've only seen lateral grip test results posted by Mark Stielow's "Jackass 2.0" Camaro that does 1.15g on 200tw BF Goodrich Rival tires. A thing to note about modern 200tw tires- they're labeled 200tw just to pass class rules, they're much stickier than traditional 100tw track tires. So going by treadwear isn't a good indication of how much grip a tire will have.

Here is a list of cars and the amount of grip they have for comparison.

https://fastestlaps.com/lists/top-grip-kings

Yeppers. I follow many of those top tier 'Pro-Touring' guys. Mr. Stielow is one of the elite of that group & a super nice guy as well.

I 100% agree w/your assessment on using/going by the TW numbers as an absolute value but it's a decent indicator of where in the range it's supposed to be. Something around 200TW should stick much better than something w/a 500TW rating w/the suspension set-up being the same (kind of a Cliffnote version). I had 300TW rated Comp G's on our 4th GEN T/A. They were decent as far as 'stick' but wouldn't surpass 10k miles on the street.

--Scot

[cjohnson6772]

For a street driven c10 what is the recommended compression travel for the front end before contacting the bump stops? Front of the truck is approximately 2000 lbs. Front spring is moog 6542 with 842 lb/in spring rate.

Thanks in advance.

[SCOTI]

Originally Posted by cjohnson6772

For a street driven c10 what is the recommended compression travel for the front end before contacting the bump stops? Front of the truck is approximately 2000 lbs. Front spring is moog 6542 with 842 lb/in spring rate.

Thanks in advance.

I like as much as I can get.

3" of travel is always my target. Of course there's limitations depending on individuals set-ups so you gotta work within those.

[SCOTI]

Deleted.

[theastronaut]

On the subject of bump stops… I like progressive rate bump stops, I use them on my autocross car to increase the spring rate as the body rolls but they’re still soft enough to absorb bumps. Then have a traditional harder stop to keep the suspension from bottoming out. This lets you have a softer spring for ride quality and compliance but still have firmer cornering once the body rolls a bit. I leave about 1” of free travel before the soft bump stop engages. It also lets you use softer sway bars so the suspension is more independent side to side. You don’t want a super hard bump stop to limit travel either, hitting a hard bump stop in the middle of cornering hard can cause the tire/truck to skip sideways.