Just purchased a 66 valiant, slant6. It has sbp disc conversion up front and super stock springs. The car is sitting to high ,looking to lower by a 1.5 to 2" to get the car to handle better. What leafs are recommend at around a 120 to 130 spring rate or something else. Thanks
Lowering leaf springs
- Thread starter BooBoo
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If you are replacing springs, contact Espo Springs and Things. They can fix you up.
Ok thanks
Treblig
Well-Known Member
Lowering blocks are a lot cheaper!!
That’s true if the swap is only supposed to be cosmetic. But the SS springs are also super stiff, usually 160 lb/in. If the OP wants to lower the car for better handling the SS springs are too stiff for that, not to mention that they’re not the same rate side to side.
Hotchkis makes 130 lb/in springs for handling, if you leave off their front hangers they will probably drop that car 2” or so from the SS spring height. You can also call Bergman Autocraft. ESPO is a good source as well, although I don’t know if they have anything off the shelf in the 130 lb/in rate. Their 6 leaf springs are basically like factory XHD springs, which were around 110 lb/in.
I would say 120-130 lb/in is the ballpark you should be looking in. The exact rate will depend on how your car is set up, what the weight balance looks like, what front torsion bars you’re running, and what tires you have. Lots of variables.
But the folks that do road tracks and autox, like Peter Bergman @BergmanAutoCraft, Hotchkis, and even Mopar Performance with their oval track springs, all have springs in the 120-130 lb in range.
if i remember correctly, if you spec a 69' 383 dart, they list 130lb springs
This is the setup on the car now:
Slant6, small cam, dual 1 barrel carbs,dual exhaust
Disc brake conversion sbp 11" rotors
Stock torsion bars
Tires 205 65 r 15 front/ 215 70 r 15 rear all new rims and tires
Kyb shocks all around
S/S springs
7 1/4 rear 9" drums
Trying to setup as a good handling daily driver
Future setup :
Rebuild front end
Full poly kit all around
Adjustable strut rods
Off set caster bushing
Sway bar kit( front and rear or just front?)
Borgeson power steering kit
New leaf springs
10" rear drums if possible
Will the 11" rotors and 9" drums sbp setup will this be enough stopping power . Trying not to convert bbp setup.
Any help with name brands on parts will help. Also changes on future setup that would work better. Thanks
Slant6, small cam, dual 1 barrel carbs,dual exhaust
Disc brake conversion sbp 11" rotors
Stock torsion bars
Tires 205 65 r 15 front/ 215 70 r 15 rear all new rims and tires
Kyb shocks all around
S/S springs
7 1/4 rear 9" drums
Trying to setup as a good handling daily driver
Future setup :
Rebuild front end
Full poly kit all around
Adjustable strut rods
Off set caster bushing
Sway bar kit( front and rear or just front?)
Borgeson power steering kit
New leaf springs
10" rear drums if possible
Will the 11" rotors and 9" drums sbp setup will this be enough stopping power . Trying not to convert bbp setup.
Any help with name brands on parts will help. Also changes on future setup that would work better. Thanks
The SS springs are for drag racing. Specifically to develop the suspension sit and angles for a good launch with slicks under high torque. The car will rise and nose lift shifting more weight onto the axle.
For what you want to do, I would not start with a matched rt/left pair.
A '66 is fairly light wieght compared to the next generation.
Yes a pair of 'hd' springs in the 110 to 130 #/in range would be good, 130 especially if you will be carrying tools etc in the trunk and have larger torsion bars up front.
The other characteristic to check is the free arch. With a higher rate sping, this needs to be matched with a slightly lower free arch to get the proper rear ride height.
Chrysler set the springs up flat at normal ride height so the rear tracks in on a turn. For more about that see. Extra-Duty Options (Session 253) from the Master Technician's Service Conference
In most cases the limitation on stopping power will be the road surface, the tire and the driver's skill.
The rear brakes are most important in the initial application of braking and in more gentle braking situations.
If you have doubts, then my suggestion is to copy what the factory did. I'm not aware of that F/R combo on anything they produced.
That would mean getting 10x1.75 drums on it and a proportioning valve if the previous owner didn't do this already.
Proportioning valve is explained here starting on page 7 Disc Brakes (Session 219) from the Master Technician's Service Conference
Replace those immediately with just about anything else. You can try them again if you must when the car gets larger torsion bars.
Regardless the high frequency damping is too stiff. The lighter the car the worse it will be.
A Front anti-sway bar is the best bang for the buck in terms of improving the street handling.
Adding a rear bar is requires knowing enough to be sure that it won't put the car into oversteer under the worst conditions. Generally not recommended for a general use unless its part of a complete package specifically design for the car and use.
Future setup :
Rebuild front end - Yes, or since good parts these days are harder to get, replace joints and bushings as needed. The shop manual chapter on front end is really good.
Full poly kit all around - Unneccessary for your goal and not worth the drawbacks in this case. (and yes I use some poly and nylon bushings on my car, that doesn't mean you should)
Adjustable strut rods - Not needed at all.
Off set caster bushing - Can be helpful in getting a little more positive caster. Worth doing when changing the UCA bushings.
Sway bar kit( front and rear or just front?) - Front. For the end links, if they are strong enough use polyurethane. For the bushings, use poly if you are willing to deal with the maintanence. Zerk fittings to add grease are a big help. The polygraphite (TM) are an option too. My impression was the claimed self lubrication does work - at least somewhat.
Choose a sway bar with the car's weight and springs in mind. Also the tires and road surfaces it will be operating on.
You might start with a stock sway bar. Later if going to larger torsion bars, you may then want to try a larger diameter sway bar. If the road surfaces are generally poor, loose, or wet, then softer springing will develope the most traction. Softer and stiffer being very relative here. I'd suggest stock v-8 t-bars and front sway bar as the softest setup regardless of surface and tires.
Borgeson power steering kit - Very much a personal preference. I'd suggest going with Bergman if you do this since he's worked out the bugs.
New leaf springs - Yes for your goals. Already discussed.
10" rear drums if possible - Yes its possible. Requires a change in backing plates and you'll have to transfer the parking brake cables.
Rebuild front end - Yes, or since good parts these days are harder to get, replace joints and bushings as needed. The shop manual chapter on front end is really good.
Full poly kit all around - Unneccessary for your goal and not worth the drawbacks in this case. (and yes I use some poly and nylon bushings on my car, that doesn't mean you should)
Adjustable strut rods - Not needed at all.
Off set caster bushing - Can be helpful in getting a little more positive caster. Worth doing when changing the UCA bushings.
Sway bar kit( front and rear or just front?) - Front. For the end links, if they are strong enough use polyurethane. For the bushings, use poly if you are willing to deal with the maintanence. Zerk fittings to add grease are a big help. The polygraphite (TM) are an option too. My impression was the claimed self lubrication does work - at least somewhat.
Choose a sway bar with the car's weight and springs in mind. Also the tires and road surfaces it will be operating on.
You might start with a stock sway bar. Later if going to larger torsion bars, you may then want to try a larger diameter sway bar. If the road surfaces are generally poor, loose, or wet, then softer springing will develope the most traction. Softer and stiffer being very relative here. I'd suggest stock v-8 t-bars and front sway bar as the softest setup regardless of surface and tires.
Borgeson power steering kit - Very much a personal preference. I'd suggest going with Bergman if you do this since he's worked out the bugs.
New leaf springs - Yes for your goals. Already discussed.
10" rear drums if possible - Yes its possible. Requires a change in backing plates and you'll have to transfer the parking brake cables.
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Mattax thanks for the info got some reading to do.
I live in New England so the roads here are pretty beat up, so I'll be looking into a little softer setup.
If I go with poly setup I need to keep them lubricated?
But stock rubber should work fine for me?
Any brands recommended for ball joints ,tie rods and shocks?
Why no adjustable strut rods?
Torque bars 1" or under?
Sorry for all the questions new to this forum stuff. Just trying not to waste money on buying the wrong parts. Thanks
Yes. And even then they may squeak. Under high loading they provide less compliance amd therefore hold the control arm geometry slightly better. If you were planning to autocross, or maybe even if you were planning to do a non-timed road course experience using sticky tires (near race tire level of sticky) then it can be worth it. On the street, not really.
The sway bar end links are not rotating. Its one place where polyurethane bushings should give a more immediate and noticable response. However I learned the hard way that the additional load can cause weaker washers and even the end links to break.
The bushings where the sway bar mounts to the K-frame is another place that polyurathane might be worth the reduction in compliance, even in street use. But because the bar needs to rotate, lubrication is needed.
I think so. Heck there is a guy on moparts whose brother brought his stock road runner to a road course event and had a great time.
My knowledge on good manufactureres or lines of joints and rod ends is probably out of date. I know well made seems to be more difficult to buy with certainty. Its the main reason I suggested doing a check of each joint and rod end. You can also check for movement in the idler and pitman arm connections.
Then replace what is needed.
Shocks.
I don't know the best bang for the buck for decent parts store shocks. I think this was discussed recently but I didn't pay close attention.
For the more reasonably priced hi performance shocks, probably can't go wrong with Bilstiens. But there are a number of choices these days without having to go to adjustable/custom Koni reds or something semi-exotic like that. (I'm using SPAX shocks for Australian Valiants but thats a special import effort to get them)
Because they're not supposed to be adjustable. It creates the final leg of the triangle fixing the lower control arm position. All the caster and camber adustment is done in the upper control arm.
The main reason Firm Feel came up with them was to let builders compensate as needed. A big reason for compensation was 'one size fits most' polyurethane strut bushings. These were particulaly a problem when the car also had polyurethane lower control arm bushings. Here's anotehr way to fix the issue Making A-Body Strut rod Bushings Work
That's probably a good match for everyday use on crumby roads. I'd say the largest factory torsion bar is probably good with a factory sway bar. There use to be some aftermarket bars in the .9xx" diameter range.
There certainly some aftermarket bars new and used in the 1.03 and 1.04" diameter sizes. With those I'd think a larger aftermarket sway bar would be a better match.
Proforged is currently making good quality bushings, ball joints, and tie rod ends. Moog is not, their stuff has been trash for a few years now.
I think rubber bushings for your application should be fine, especially with the amount of stock parts you're retaining. Like Mattax I run poly and delrin on my car, but, poly and delrin have additional requirements for upgrading components.
With rubber bushings you can still use the standard strut rods, they'll work the same as factory. If you use Poly or Delrin bushings at the LCA, adjustable strut rods are needed because the length of the stock strut rods depends on the big rubber bushings.
I wouldn't bother with anything under 1" for a torsion bar, but that's just me. PST's 1.03" bars are a good all around bar if used with good shocks like the Bilstein RCD's.
KYB's are garbage.
The reason for adjustable strut rods really doesn't have anything to do with using them to adjust caster or camber. Having adjustable strut rods allows you to tune the length of the strut rod so that there is no binding or resistance from the strut rod as the LCA moves through it's full range of travel. Even on factory cars they likely wouldn't all be identically the same length if you actually checked the LCA's range of travel for resistance/binding, but they only had to be close enough to meet the alignment specs off the production line.
But the length of the strut rod becomes more critical as you stiffen up the suspension and bushings. Poly doesn't have as much give or flex, so the geometry of the suspension has to be more accurate.
The factory got away with non-adjustable strut rods because they used giant rubber bushings on them. That lessened the penalty for having them not be exactly the right length, but it also allows the LCA to move around more. If you keep all the rubber bushings the non-adjustable strut rods work, but, if you start getting rid of the rubber bushings for poly, or especially Delrin, the length of the strut rod will need to be different than factory, I promise you. Not to adjust the caster/camber, but to provide an LCA that moves free of binding.
SixPaksRule
Well-Known Member
front and rear bars in a matched set - use rubber bushings on the rear bar - this allows for tuning of the suspension via how tight the bushings are held. It works very very well. I have lot's of experience making old cars handle [rotate in the turns] and stop.
Rubber suspension bushings including the lower control arm.
Adjustable strut rods with the rod end are best. Use of these allow you to square all 4 wheels to each other as well as making sure the suspension moves freely thru the travel and holds the wheel steady under duress.This requires a plumb bob, masking tape, a very accurate tape measure and a good assistant.
They will help to a degree with the caster.
Bilstiens are one size fits all, adjustable shocks are way better.
Too bad you can't weld/box the k frame because a welded up k frame vastly improves everything. Weld plates to the lower control arm.
Rear springs- do not do not use lowering blocks-those are for amateurs. You can have the right side extra leaves removed and the springs de-arched or buy some thing in the 130-140 range
Brakes - rear need 10 inch drums with semi metallic shoes
Rubber suspension bushings including the lower control arm.
Adjustable strut rods with the rod end are best. Use of these allow you to square all 4 wheels to each other as well as making sure the suspension moves freely thru the travel and holds the wheel steady under duress.This requires a plumb bob, masking tape, a very accurate tape measure and a good assistant.
They will help to a degree with the caster.
Bilstiens are one size fits all, adjustable shocks are way better.
Too bad you can't weld/box the k frame because a welded up k frame vastly improves everything. Weld plates to the lower control arm.
Rear springs- do not do not use lowering blocks-those are for amateurs. You can have the right side extra leaves removed and the springs de-arched or buy some thing in the 130-140 range
Brakes - rear need 10 inch drums with semi metallic shoes
I am a welder, fabricator by trade so welding up k- frame, lower control arms and frame connectors will not be a issue.
When squaring off the wheels you hang plums in all four corners and cross measure ?
With suspension under load?
I'll look into proforged parts. As far as leaf springs should I stick with shackles or look into rear sliders?
I think you’ll be fine with shackles. Sliders are a pretty minor improvement. Again, if you were racing or competing they might be something to look into. I do have them on my Duster, just another step in optimizing the suspension, removing binding and flex. But they’re a really minor change compared to the work needed to install them, I can’t say I noticed any big difference in handling after I installed them.
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