Make it handle

[68swamprat]

rob i have a 68 c20 im looking to build two new track bars with adjustable ends. im also going to lower it but i still want be able to pull my camper or track car what brands have good streaght and whats a good ride highth for this thanks.

ps i broke the trac bars thats why im redoing the the stuff
and it was sitting in a swamp for 8 years

[jimmydean]

I can't wait for this show. It's always an interesting debate with friends of mine who like euro/asian tuner cars vs. muscle.

A friend of mine picked up a very nice BMW M3 that he felt was worthy, so I took him on a quick run out and back on HWY 219 (8 miles, 7 of it twisty) with my '94 Vette and my buddies '05 Vette. I lead out with the BMW behind me and the C6 in the rear. I had no issues leaving the M3, but could tell Joe was getting pissed in his C6. I let Joe lead home with me in the middle and his 30% more HP was very noticeable exiting corners.

Poor Dave in his $15k M3 was left hating the American "sports car"

My C4 was $4k, Joe got his C6 for $14k.

[INSIDIOUS '86]

Originally Posted by robnolimit

Last night i was invited to the premier of a new Speed CHannel show, "R U Faster than a Redneck" Its american muscle against import power, with a bunch of good guys in the mix. We know most of the "Rednecks" from autocross and American Streetcar series, and they did a great job showing off our hot rodding and pro-touring addiction. This show will air on monday nights on Speed. Special airing tonight, friday, on Speed, not sure of the time. CHeck it out for a fun 30 minutes.

So you think you may drive some of the cars? Be nice to see a truck lay waste to some top of the line cars
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[Goats86]

Insidious, where did you get HID projectors for your 86?

[robnolimit]

SPECIAL Motorstate (800-772-2678) has Howe Racing 63-72 tall upper ball joints on closeout. Item #HOW22300SA normal list is 36, closeout $12. they show 13 in stock. Good for a quicker camber gain with stock style arms/spindles.

FUN Check Speed Channel for the Optima Ultimate Streetcar Invitational, on this week. Got some god truck coverage.

[69gmcc10]

Rob,

I saw the Optima Ultimate Streetcar Invitational, you were in the top 10 in allot of events, congrats! I looked like everyone was havin a good time.

I called Motorstate to buy a set of upper ball joints and when I gave them the part number you posted they said they were standard 4 bolt upper ball joints and they were regular price. Do you have any insight?

[derrickmanx1]

Does anyone have a suggestion on a rear sway bar for the cpp rear trailing arms. I have a new stock style. I guess I could fab up some clamps on the arms but if there is anything else that works better someone let me know.

[derrickmanx1]

Hey Rob would your sb-190 work with my tubular trailing arms?

[CSGAS]

Derrick, for a rear bar you could go with a NASCAR (and other asphalt racers) splined bar but in order to get the effect down to what Rob recommends you would need a weak torsion bar in there (they make them hollow but the weakest still carry the same effect as a 1" bar) AND use longer arms to reduce the effect.

Another option is just to run the bar towards the back frame rails and attaching to the axle. There are a few pix around here of people using G-body rear sway bars and even F-body bars both with the links attached to tabs on the axle and the other way around with the links on the frame and the bar clamped to the axle. Those have a "hump" built in to clear the differential.

[CSGAS]

Rob, I started checking out the Caprice spindles you mentioned along with brake options (actually I was looking for an 11' 6-lug option to keep 15" wheels until I really spend money).

The investigation led to Astro van front subframes, 5/8" ball joints and Cadillac B-body front suspensions. The latter, along with 70's Caprices, use the same 11.86 x 1.25" 5x5" rotors the 73-87 trucks use, while the late 80's early 90's Caprices and the 5-lug Astros use the 11.86" x 1" version also used on light-duty 79-87 trucks.

How does the spindle height work out on those Caddy/early Caprice spindles, or have you checked any? Are they still two-piece on the early Caprice? I'm considering swapping the whole lower arm from an Astro or Caddy (to get the 5/8" lower ball joint) and use an early Caprice spindle if the news is good. It's still a ways off, but I haven't found a 6-lug option that works out the way I want (they all take money instead of junkyard--oops, I mean standard GM parts bin items.

ps (I really like the 2000-2006 Truck R&Ps, too bad the price difference is likely to lead me to an 80s+ box, p/s pump w/o-rings also, and trying to modify that centerlink we have. Not enough info to give an opinion on the 2007+ racks. Are the 2000-2006s the same rack as the Dakotas use with longer tie rods? Some parts interchange, but the Dakota's only about 58" track and the Chevys are 62-65")

[INSIDIOUS '86]

Rob. If a person was to get both a panhard bar and a watts link and was able to mount them in optimal positions with the roll centers at the approximate same level. Which would you choose? I would think they even a long panhard that's even with the ground would still take a corner better one direction better than the other?
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[laid67]

Rob, and anyone else who's listening. I just started on my 67 c10. Ive already taken a TON of info from this thread and its all great. I really appreciate those who put their ideas and knowlege up here. It's fed my desire to make my truck the best it can be. I just had a few questions to anyone with a little insight. Well, I'l put up my current plan for the frame and basic suspension and see if anyone has any objections.
Rear end-
-already notched in a manner simmilar to JT except with a little bit higher notch ~ 5 inches
-Keeping stock trailing arm for now, but am wondering if it might be a good idea to re-work the cross member they attach to so that on the axle end I can mount them farther out twards the tires. Then move my spring and shock mounts outboard of the frame so they line up with the trailing arms in their new location. I'm thinking this will allow me to run a bit taller spring for better ride and have wider legs on my bar stool as it were.
It appears I will not have any interference with the trailing arms hitting the frame, which was my main concern.
I have a ton more questions but I'll leave it at this for now.
Thanks!
-Brad

[laid67]

*edit for clarity.
-Keeping stock trailing arm for now, but am wondering if it might be a good idea to
re-work the cross member so the trailing arms can attach to the axle end farther out twards the tires. Then move my spring and shock mounts outboard of the frame so they line up with the trailing arms in their new location. I'm thinking this will allow me to run a bit taller spring for better ride and have wider legs on my bar stool as it were.

[laid67]

Insidious 86, I would think the additional un-sprung weight of a Watts link might offset whatever benefit it might have over a well designed panhard bar set up.

[Codez67Chevy]

How low can I go on my 3/4 ton coil suspension with out buying spindles? I've got to go cheap for now.

[robnolimit]

Locating Devices Good topic. For normal builds, there are a few types. - I know, but most street builds are not going to have a Satchel Link, Jacobs Ladder, Mumford Link..... Lets keep it simple.
1) Diagonal Links Such as in a triangulated four bar. This is simple and effective, but the same geometry that keeps the rear axle centered also creates a bind during the suspension travel. The fix is to use piviting joints, or rod ends, for the link ends, but this can be expensive and yeild a harsh ride. Also, this design is difficult to tune and adjust the roll center and anti-squat.
2)Panhard Rod Still pretty simple, this is the 'fifth' link in a four bar system. A panhard has only one job, side to side location. They can tend to 'push' or 'pull' the axle to one side during suspension travel. The fix is to use a long panhard rod. A 30" panhard rod has appx .190" of side motion in 6" of travel - if it is level at R.H. Packaging a longer rod into the chassis can be tough. Roll center tuning is easier.
3)Diagonal locator This is more of a drag car item. Typically on a four bar or ladder bar. This is a diagonal link that mounts to the front of one lower bar, and the rear of the other lower bar. Sometimes with a bend in the middle to clear the driveshaft. While easy to fit in most of the time, this is not a real 'street' friendly set up, as it does not want to let the car 'rotate' in a corner.
4)Wish Bone Used in Off Road and Drag racing, This can be used with, or in place of two bars in a four bar. We see this more and more in air bag installs. While this works, there is little to no gain in street performance. To work correctly, it needs piviting mounts on all three ends, rod ends or pivit links, such as Johnny joints.
5)Watts Link A watts link may be the most accurate locator, and one of the most complicated to get right. Packaging may be tough. Also, while the motion is very pure, it is more difficult to have a tunable set-up for the roll center.

[laid67]

with a panhard bar. is it possible to have it too low? would it be good practice to set it as absolutely low as I can while still having adequate ground clearance?

[Custom 68]

Ok all I have read and reread as most of you have and I wanted to address Bumpsteer again. I know this has been talked about a few times but here it is again.
First off the goals of my truck are like many I am sure I like to drive it! I have had this for over 20 years and it continues to evolve but one thing is I like to have it out even though I consider it somewhat of a show truck. I am also getting the urge to Autocross and I want to do it in this truck. I did this some many years ago and was in an A-mod class with a purpose built "car" for formula SAE while in college.
I have taken Rob's IC or bump steer drawing and have tried to create my own. From his drawing the upper and lower control arm extension lines both meet. Well as I have tried to measure and graph or draw mine out it appears that the upper line is running up hill and the lower almost parallel to the ground so these can never intersect.
As you know the lower arm mounts are parallel with each other so this is easy to figure however the upper has mounts where one is higher than the other What I did was average these to come up with my drawing.
Now as I measured with a tape measure there is some question on where at the ball joint you would measure too so there is some room for error but it should be close.
What I am working with is factory mounting points on my frame with a factory lower (modified for a coil over setup) and CPP upper arms. The spindle is the 2.5 inch drop CPP modular spindles. My mounting points should be "factory".

I am close to getting the rack and pinion setup mentioned in here but wanted to understand this better. Since the outer tie rod mounts on the bottom of the steering arm instead of teh top it seems backwards and will only hurt my bump steer unless the rack is much much lower.
That also brings up the question of why would you using the factory setup mount this to the lower side of the mount, I have read of this swap too.
Rob mentions the steering mount is too high from the factory I am having a hard time grasping that based on my sketch. Help me out, what am I missing.
Thanks
Dave

[Custom 68]

Alright my new tires came in and I got them mounted. I am probably going to lower the front another 1/2 inch or so to see if that will bring the upper a-arm back into a better position. Then off the the alignment shop I have them setup for tomorrow after work. Currently visually it looks like my camber is out of wack the top seems too far in. I will get them my specs and go from there.
After I get this all back home and where it needs to be I will get some more measurements. I would really like to understand this and get things to where it feels right.
I am still struggling with moving the outer tie rod piviot to the bottom of the arm that still seems backwards...

[modernbeat]

Originally Posted by laid67

with a panhard bar. is it possible to have it too low? would it be good practice to set it as absolutely low as I can while still having adequate ground clearance?

Yes, but everything else has to be planned around it at the same time.

Here's my old Lotus 7. The Watts link is parallel to the ground and under the axle. The rest of the suspension is a three-link with a LOT of adjustment in it.

[laid67]

Thats awesome, Never thought of a watts link working on its side like that. that has to be one of the most compact rear ends I've ever seen.

[modernbeat]

That axle is out of an '85 Mazda RX7. For reference the tires are 20" tall and 10" wide. The wheels are 13x10.

[Big Rick 53]

Thanks to all of you for showing how to make my truck handle. I hope I'm thinking right. Well I all ready have rebuilt the front end I used Moog parts bushing,ball joints,tie rod ends and Monroe magnum shocks both ends. I added power steering and disk brakes I'm using a fruit jar master cylinder(for now). The sway bar is a 3/4" bar with new bushing. Springs on both ends are Moog cargo coils,the rear end is a12 bolt 411 I have all ready cleaned up arms and welded up 1" skip top and bottom new Moog bushing. The first time I get a ride with a 12bolt 411 and I need 340 or 307. What I'm thinking is remount the the rear shocks out side of the frame and behind axle, the sway bar wider than the frame the arms mounting just in side of the brake backing plates. For the track bar the rod end on the end of the driver side trailing arm and bushed rod end mounted level and a mount to out side of frame at the level of the pass side trailing arm. I'm looking for a front sway bar about 11/4" and longer than the one I have to mount just in side of ball joint on both sides. Well am I thinking close to right? The power for now is a 283 punched 120 for close to 301ci down the road it will get a big inch sbc I'm putting a 700r in it has a 4speed Grannie trans (bad clutch) it will be pulling a small trailer and mostly road trips.

[Southern Shaker]

whats a good height for cornering ? how low can i bring her down and whats the best way to do it ? Thanks in advance -Aden

[jimmydean]

Rob, are you and Hellboy going to get a shot as a ringer on R U Faster than a Redneck?

The C10 they had was bad ass, but nothing your level. I would like to see what y'all would do against that GT-R.