Make it handle

[nesox]

Thanks for the reply, good luck on your research. I'm in the middle of my own and will share anything positive.

As far as a backyard build, that's me, except in the front yard under a carport! Neighbors love my "fab shop".

[cajundragger]

Originally Posted by spike38

Rob

I lowered the truck 3" F / 4" R drop. (CPP springs and shocks)
So to regain most of the lost trailing arm pitch,
I flipped the brackets over. This reclaimed 3 1/4" of the 4" lost.

I removed the 12 hulk rivets, And replaced them with 16
bolts, Flat washers, Lock washer, And connicle nuts.(pics attached)

I also ordered a 24" adjustable track bar, And considering CPP's HD swaybay
kit ( 1 1/4" front, 1 1/8" back sway bars)

Now I'm not building a racer, It will be my DD. It's a 68 stepside sbc,
HD 350 turbo, PB and PS. Converted the front to a 72 disc brake system,
I will convert the back to SS Impala discs.(as soon as the axle arrive)
And moving the tank to the rear frame.

Are there any other mods you would recommend for basic handling.

Spike

if you weld all the factory crossmembers to the actual rails you will notice a substancial gain in torsional stability.

[spike38]

Originally Posted by cajundragger

if you weld all the factory crossmembers to the actual rails you will notice a substancial gain in torsional stability.

Thanks, I'll keep that in mind.

Spike

[robnolimit]

I had a chat with a friend of mine today, he runs vintage open wheel cars, and the topic of "roll stiffness" came up. I thought I would share some of this. Roll stiffness is the chassis/suspensions ability to resist the forces at play in a corner. Many things can affect this, such as roll center, CG, track...... and spring rates, and sway bar rates. If you isolate these two items, and look at them alone, you must see that the combination of the two would add up to a certain amount of roll resistance. You CAN have TOO MUCH roll resistance, and this causes a push (understeer). Stiffer spings will help in a corner, and so will a siffer sway bar. On a short track, such as an autocross, exceleration out of the corner is more drastic, and rear bit comes into play. Drag racers would tell you that soft front springs and a shock with soft rebound will help wieght transfer and rear bite. And there right. This knoledge can be applied to roadcoarse tuning if you add in the sway bar. Softening your springs will give you a better corner exit, but you will lose some roll resistance. You can get back to you original amount of roll stiffness by increasing the sway bar stiffness. The down side of this uproach is that under braking, the front may sink more. - Causing the rear to loose traction. (Back to the whole trade-off thing) The "soft spring - big bar" set up works well on the street because it still gives you a nice ride. In a truck, so much of your braking is on the front that you can get away with the loss of rear traction a bit. If you choose the right shocks, or run adjustable shocks, you can tune out the dive, and gain exit traction at the same time. Just some food for thought. Have a great weekend.

[52 choptop]

I am replacing the shocks on my daily driver 52 and was considering KYB Gas Adjustable. One friend swears by them and another says nothing but Bilstien. The $ of KYB makes them attractive, but buying twice doesn't make sense. I figure with the knowledge I've read so far in this thread this should be an easy question for you guys. Opinions?

[Mike Bradbury]

The single wall construction of the Bilstein shocks gives it the advantage of having a much larger piston, with much more efficient valving with much less fade. I have broken a set of Bilsteins bottoming out my truck when I hit a huge dip and they replaced them no questions asked. If you find a custom dealer then they can order you a set that is valved for your application. I also would not have any other shock on my truck.

[Tony@AirRideTech]

Originally Posted by robnolimit

The "soft spring - big bar" set up works well on the street because it still gives you a nice ride. In a truck, so much of your braking is on the front that you can get away with the loss of rear traction a bit. If you choose the right shocks, or run adjustable shocks, you can tune out the dive, and gain exit traction at the same time. Just some food for thought. Have a great weekend.

money.....

[robnolimit]

52 Choptop, Yours is always a tough question. $$ vs performance. Mike is right on about the monotube style construction. Here's something to consider. The rear of the truck has about 1200 lbs on it, vs. about 2500lbs on the front. You didn't spec the type of ft. suspension, but the front weight is normal, so it's easy to get the right shock valving. Out back, 1200lbs is split on two sides, 600lbs each. Unsprung weight of leafs and axle is about 340 lbs. or 170 per side. At best, the unsprung weight is above 28%, VERY HIGH. And, I'll bet that the rear springs are too stiff (150 to 175 lb per inch would be ideal) If you want to test the spring weight, set the truck on level ground, measure the top of the wheel opening, then add weight (sand bags...) directly over the rear axle until the truck drops 1". Divide the weight added by 2 (two springs). Anyway, To get the rear to ride good, you will really soft compression and a med/firm rebound. The Bilstein inertia valve is good for this, as are the Romic adjustable shocks. If I were you I would buy a pair of really good rear shocks first, and see what you think. Because the front is more 'normal' the KYB is OK up the if you don't see thegain in the back. A lot depends on you'r driving tastes. Hope this helps.

Tony - when can I get some new Ride-Tech shocks to test on the 'Bullit? RTTC is comin' up you know? Hotchkis is comin hard for me, it's going to be a good season. Have a great chistmas bro.

[Tony@AirRideTech]

Rob.... drop me a call or an email with lengths and spring rates and I will get them coming.

[Ian30]

A little off the current subject, but I have a couple questions about coilover mounting. Looking at the picture of one of your fatbar setups below. Have you ever had a problem mounting the bottom of the coilover single shear? It makes things easier to setup like that and have it be adjustable, but I worry a little about the strength. Everything I have built to now was for offroad so maybe I am overthinking it. Also, I see you have the coilovers angled in some. Is this necessary or done for handling purposes? I thought that a shock was most effective in the verticle up position, but now I'm thinking maybe you do this for cornering where the angle changes. Also should the shocks always be mounted with the bolt running parallel to the frame at both ends? (like in the picture) or does this matter. I hope that made sense because I wasn't to sure how to word it.

[robnolimit]

Ian30, Your project looks good, single sheer is fine for the street on this type of set up. I get the off road concerns, but we don't get those kind of forces. Besides, it would take about 8000 lbs of load to bend the 5/8" grade 8 bolts. As to the mounting, thats the way we layed it out, so that the bushings have as little amount of binding as possible through the suspension travel. Looks like your making great progress.

To all of you here, have a great christmas, and a prosperous new year!!

[robnolimit]

Tony, I'll get the lengths over the weekend. I hope you and yours have a great christmas. You coming out to Del-Mar, or spring Scottsdale?

[Ian30]

Just a disclaimer... The picture in my post above was borrowed from Blindman and is his project. Mine is not this far along.

[robnolimit]

Check out the thread - 58fleetside - in the 47-59 forum. He is using our parts / with a few mods to set it on the ground. To everyone here, Have a Merry Christmas. Hope Santa brings you lots of shiney truck stuff!!!

[robnolimit]

Merry Christmas folks, If your searching the after christmas sales for some new rolling stock, keep this in mind. Widening the track width will increase the trucks natural roll resistance (body roll in a corner). Even a 1/2" makes a difference. The front wheels on our Silver Bullit are 18 x 9 Intro's with a 5" backspace, and we run a 275/35-18 BFG KDW tire. Last week I bolted in some 1" wheel spacers (not very safe, I know) and did some light track testing. Speeds into and through some test corners on our local track showed a bit of an increase. I dropped the front 1 " to check clearance, and had a slight rubbing on a banked right hand corner, so this may be a bit too wide. With everything checked out, I will be pulling the wheels off next week, and have the centers cut out and re-welded at 4 1/4" backspace. It doesn't sound like much, but 3/4" per side gives 1 1/2" overall, a 2.3% increase. Every little bit, you know? So, if you searching for wheels, try to keep your stance as wide as you can, and still clear everything.

[pharmd]

Awesome comments Rob. I know the "details" are important, but its hard to know what all the details are. So I really appreciate you enlightening use on the considerations we need to make when we start putting our trucks together.
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[robnolimit]

HAPPY NEW YEARS to all !!! I hope your new years is prosperous and filled with happiness. - the best you can hope for. After some test driving, and a few close looks, we're getting ready to start moving forward on our '72 project. I started a thread, No limit 72, in the 67-72 forum. Not much is there yet. We're calling it "J.T.", from "Joe Touring", from some comments made by you guys. Our first step is an "as-is" trip to our local test track to see how she does. - don't hold your breath. We can't go out until the 11th of jan., and we have to put in some seat belts to pass tech, and if I can turn better that a 55sec lap, I'll be suprised. As we posted, it has heated springs, so the first step is a set of drop spindles, and stock springs, and a good inspection of the front end. It looks like we're going coil spring ft. and bag rr. - got to tow a 5k trailer. I may mix a set of coil-overs and bags, but we'll see. Until then, have a great new years, and keep wrenchin

[Conundrum]

Happy New Years Everyone!

Rob, I have a couple questions.......

First I am planning out my 74 project, and like most want a much better driving experience with my old truck. Not exactly race ready, but ready for what may be thrown it's way.

My plans for the front were to cut 1.5" out of the crossmember (have already done it to an extra one), do a slight Z on the frame (no more than 2" and reinforced ofcourse) and run drop spindles, maybe cut the coils slightly to get my ride height "just right". I had planned on raising my steering components up the 1.5" that I cut out of the crossmember to atleast keep the steering the same as factory. I realize that it will be around 6" of drop.

Are there going to be any problems with doing the front that way?

The rear I haven't quite figured out just what I wanted to do just yet.... I could just flip the rear nad modify the leafs as you said in an earlier post, and I thought about converting to the earlier swing arms. I have owned and driven a couple 67-72s and 73-87s, and the 67-72s are much smoother but I know as you start to increase the handling the ride quality will suffer a little.

Which would be best for the rear for performance and ride?

[robnolimit]

Well, Great start. As you know I'm starting a 67-72 build. At the moment, the front plan is like yours. I'm planning to use a 2 1/2" drop spindle, and raise the crossmember 1 1/2". (4" total) I settled on 1 1/2" because thats all I can get without raising the motor (bad). So if I need to get any more drop, I'll cut the springs. My plan is to use stock small block springs, a bit softer, and a HUGE swaybar. When it comes to the steering, if you raise the steering, you'll have to raise the motor. - so, for me, thats out. I plan on swapping the tie-rod end for a hiem end, and mounting on the bottom side of the steering arm. This may leed to a modified or custom centerlink to get the bumpsteer perfect. This could be the first C-10 steering kit from No Limit. A center link, tie-rod adjuster sleaves, and hiems. Z'ing has no effect on steering or motor placement, because in reality, your dropping the cab, not raising the suspension. (in relation to the ground) Out back, if your dropping 6" in front, I'll guess to a 7" or 8" drop in the rear. That means step notch and raised bed floor. So, trailing arms, or a four link. To me the ultimate would be a 3 link, with a bisquit style torque link up top, a watts link, and sprung on outboard on 7" coil-overs with dual adjustable shock. - But, that is NOT a user-or-builder friendly set up. So, keep it simple, so you can finish it, and have some fun!!

[Conundrum]

I was going to move the front suspension forward 1" while doing the Z to help recenter the wheels in the wheel wheels and also try to get the engine as far back as possible with out having to completely rebuild my firewall. I will just have to wait and see if I have the room to raise the steering when I get a chance to work on my truck again.

Thanks for the input.
This is one of my favorite threads!

[Slowmotion]

I just stumbled across this thread. I hae noticed that there has been no mention of the 60-62 trucks that have torsion front suspensions. Does this type of suspension offer any advantages from a handeling standpoint. Also any handling suggestions beyond Billstein shocks would be appreciated.

[mongoose]

Originally Posted by robnolimit

Well, Great start. As you know I'm starting a 67-72 build. At the moment, the front plan is like yours. I'm planning to use a 2 1/2" drop spindle, and raise the crossmember 1 1/2". (4" total) I settled on 1 1/2" because thats all I can get without raising the motor (bad). So if I need to get any more drop, I'll cut the springs. My plan is to use stock small block springs, a bit softer, and a HUGE swaybar. When it comes to the steering, if you raise the steering, you'll have to raise the motor. - so, for me, thats out. I plan on swapping the tie-rod end for a hiem end, and mounting on the bottom side of the steering arm. This may leed to a modified or custom centerlink to get the bumpsteer perfect. This could be the first C-10 steering kit from No Limit. A center link, tie-rod adjuster sleaves, and hiems. Z'ing has no effect on steering or motor placement, because in reality, your dropping the cab, not raising the suspension. (in relation to the ground) Out back, if your dropping 6" in front, I'll guess to a 7" or 8" drop in the rear. That means step notch and raised bed floor. So, trailing arms, or a four link. To me the ultimate would be a 3 link, with a bisquit style torque link up top, a watts link, and sprung on outboard on 7" coil-overs with dual adjustable shock. - But, that is NOT a user-or-builder friendly set up. So, keep it simple, so you can finish it, and have some fun!!

that being said... would you do truck arms or a 3 link? i mean.. is it worth all the extra effort to fab up a 3 link.. on a sub 3000lb truck? i'm tossing around a s10 build after seeing that hillclimb s10 blazer from back east..

[robnolimit]

Trailing arm or 3-link? When I said "not builder freindly", I meant that a well set-up 3-link, with long stroke coil-overs takes up a LOT of room.So, the bed area will be gone. Shifting away from fab work for a minute, Unsprung weight is a factor. The agerage C-10 will weigh in at 4200 lbs, give or take. So, even though trailing arms are kind of heavy, the percentage of unsprung weight it low. (becuase the truck is so heavy) The lighter the truck, the more 'unsprung' weight will be a handling factor. On my F-100, the rear axle is a 9" floater, with aluminum carrier and billit hubs. It weighs 122 lbs. add 1/2 the weight of the trailing arms, panhard rod, wheels-tires, brakes, and the rocker links, and the rear unsprung weight is 244 lbs. Yes, I weigh everything! Now, the truck weighs 3200 lbs, but only 1243 on the rear. So, the rear unsprung weight is at 20%. Thats pretty high, 15% is a good benchmark. I'd need to shed 60 lbs to get there. One advantage of the trailing arm set up is that it is very compact, not wasting much space. If my truck was heavier, and had 1600 lbs of rear weight, the rear unsprung would be 15%, and it would ride better, but the heavier truck would be slower. On an s-10 build, if you dont care about bed space, I'd go 3-link. A 8" ford floater, (mini-stock style) with light brakes and 17" wheel-tire combo could weigh in at just under 200 lbs. The 8" with a True-Track can take 400 hp easy, and uses less hp to run. We have talked about a project building a 72 chevy Luv. This would be legal for GoodGuys events, and could weigh in at 2500 lbs. A class Killer for sure.

[robnolimit]

New parts for the new year. Tony from Ride-Tech, with a blessing from the big man, sent me a set of their new Coil-Over shocks to test out. To start with, I am really happy with the Romic billit coil-overs that we use, and I am somewhat nervous about swapping coil-overs with the Run To The Coast event coming up in Feb. It has taken a bunch of tuning to get the Bullit to do what it does, and I really don't want to go any slower. So, here's what I think so far. RideTech has gone to bearing mounts on all coil-overs and Shockwaves. I think this is a great step forward, and no, it wount make the ride harsh. Most Coil-over bushings fade over time. The machine quality and finish is A+. Have twisted many a coil-over spanner, I have to say I like the 'Fine thread" aproach. It may take more turns per inch of adjustment, but it is easier to turn, and has less chance of thread damage. Last night we put one on my nieghbors shock dyno. (Canyon Racers, Pro Moto-x Tuners). Results look really good. The compression rates stay linear with stroke speed, and on the rebound side, each click of additional rebound adds an equal percentage of dampening, this is a plus, and will make tuning much easier. We ran them at a high frequency for about 15 min. A shock tortute test. Heat buildup raised the dampening rates by less than 2%. This means that the material used in the valving shim pack is top quality, and the piston seal is 100%. So far I'm impressed. It's nice to have friends with cool toys. I get one track test day before the RTTC, in about three weeks. I'll let you know. My big question for RideTech is, Are you going to make a NON coil-over version, for coil and bag guys?

[SCOTI]

Rob,

Once again, thanks for providing insight on suspension tuning that even the slowest of us can understand. I think you're on track w/a GM truck steering 'correction' kit too. Hopefully the cost factor doesn't kill the concept (there's a bunch of tight-wads around here.... me included ).