need advice on shock and suspension setuo

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chevy art
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need advice on shock and suspension setuo

Post by chevy art »

my 67 nova with the 355 sbc(aprox 540 horse) used to 60 ft. around 1,48-1,50 and run about 11,00 to 10.95 on any given day and it had comp engineering slapper bars(tight to spring eye) and the old Koni Spa-1 front shocks. the car would launch and front end would come all the way up(no wheelie) and gradually settle down going down the track. car has 14 inch slicks, glide and 5,63 gears. front shocks were set all the way loose and i also had the comp engineering slinky front springs. rear springs were the stock parabolic mono leafs. and rear shocks were a mopar non_adjustable shock . syste worked fine. now i installed the cal_track bars and the cal_track 2 piece monoleaf springs and a good set of spherical end racing shocks with a single adjustment capability. they only have a 5 inch total travel capabilitr. i set the ride height at aprox 1 1/2 , so now i have aprox 3 1/2 inches of up travel and about 1 1/3 inches down travel from ride heigth. the rear shocks are set loose all the way(5 clicks). with new setup the car will not do better on 60ft times than the 1.50, but i ist extremely consistent. slicks are set around 10 1/2 lbs.(no less or the car wanders on top end) cat launches perfectly straight and now lifts the wheels off the ground maybe a foot. the problem is now the front end settlers straight down and then goes forward instead of the old way of settling on way down. i was told to correct this problem is to tighten the shocks about 3 clicks to tighten And see how that works. i know i need a better burnout, but i want to correct the launch problem. another thing i noticed is that when i push down on front of of car on the drivers side it really dont want to go down and the passenger side goes down with ease. i have not touched these shocks since 1995. caltrac bars are set like cavert said to do and the car goes straight so i wont mess with any preload on bars. any suggestion on getting my car to 60ft. better thanks Art in NY
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Re: need advice on shock and suspension setuo

Post by 6.50camaro »

I would agree with tighten the shocks. To soft of dampening uses up the shock travel to guickly. You have more anti squat with the cal tracs and getting more rise in the rear . Soft shock setting gives good initial bite but once the shock has no more travel the tires start to unload and you are losing maximum foward bite . Dan
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Re: need advice on shock and suspension setuo

Post by 6.50camaro »

Are you saying you haven't changed the shock setting since 1995 or are you saying you haven't touched the front suspension at all since 1995 . Either way maybe you shoud check for worn out or bent suspension components 24 years is pushing it a bit . You want the front end to move freely so the suspension falls under its own weight with no shocks and springs installed . If the shock is fighty friction in the bushings or bent parts it can not do its job properly . Dan
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Re: need advice on shock and suspension setuo

Post by chevy art »

hey 6-50 thanks for the reply. front shocks are the original 1995 build shocks: koni SPA-1. 9010 shocks. i checked them yesterday and they are still real loose along with the moroso slinky front coils.. the rear had the original Mopar non adjustable shocks up until last year when i switched over to the caltrac bars and leafs. the new rears are strange spherical end one way adjustable . has only 5 clicks worth of setting and 5 total inches of travcel' i set them up for 3 1/2 inches travel up and the 1 1/2 inches down.im gonna go out next week and adjust them from all the way l;oose to most of the way tight(3 clicks tightening them. car like 10 1/2 lbs air in the 14 inch slicks(d5 compound) but with 10 pounds the car ice skates a little at top end, and even a little at about 330 feet out. maybe after tightening the shocks i will be able to go to 10 lbs. of air successfully without the ice skating at top end. and if i feel it just out of hole i for sure wont go all the way down to the end with the 10 lbs in the tires. car does run straight as an arrow and is consistent as can be but the 60 ft. times are way off. i have a big motor and good converter so my 60 ft times should be in the low 140s instead of 150. all advice is greatly appreciated... thanks again art in NY
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Re: need advice on shock and suspension setuo

Post by prairiehotrodder »

I'd tighten the rear shocks. i have Calvert single adjustable rear shocks and the instructions say to set them at 1-3 for cars with a transbrake. If i do that its spins like crazy. I have them at 7 to get it to hook. Thats 7 towards stiff. The shocks need to push the tires into the pavement, not allow the body to fall down easy in my experience.
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Re: need advice on shock and suspension setuo

Post by 6.50camaro »

Art , just out of curiosity . Are you using normal shackles at the rear of the springs . If you are , the angle of the shackles as they go through the suspension travel is important . At no point in travel should the bottom bolt be closer to the front of the car than the top bolt .or angled forward from top to bottom . This unloads the rear tires . If you can , jack the car on the frame connectors with a jack on each side and watch the shackle movement and angle . I am using slider blocks similar to what calvert sells .to eliminate this problem . Dan
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Re: need advice on shock and suspension setuo

Post by chevy art »

dan thanks for that info. i know for sure that the shackles are straight up and down when the car is at dead rest. dont know where they go under load.. if the car is sitting on level ground and i push down on rear real hard,where should the shackle be moving to. is this a good way to test the shackle movement. if on the jackstands you didnt say what i should do to check movement of shackles. sure hope you can clarify this., as it sounds like an important step to check my suspension. thanks again art in NY
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Re: need advice on shock and suspension setuo

Post by 6.50camaro »

Pushing down on the rear of the car the bottom of the shackle should move to the rear. No this is not going to help since the cal trac bars create anti squat. which causes the rear of the car to lift which pushes the tires harder into the track. At rest the bottom of the shackle should be further to the rear of the car than the top . At full extension suspension travel the shackle should be straight up and down this is the point where it applies the most force of pushing the tires into the track. You can jack anywhere on the rear of the car but not on the diff. or suspension components. You want them to move in their normal ac of travel so you can see what is taking place .
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Re: need advice on shock and suspension setuo

Post by chevy art »

thanks dan. i guess from what you are saying is that i should put the car on the subfrme connectors and let the suspension just hang as much as it can and then look at the shackles and in this position the suspension will be hanging like it is at full extension and this is where the shackles should be straight up and down or maybe the bottoms could be pointing a little towards rear of car. i had mentioned that my strnge shocks only has 5 inches max travel and i have set them so i only get 3 1/2 inches up travel and the remainder is 1 1/2 inches down. what do you think of that setup. i know the calvert shocks have about 7 1/2 inches of travel. it has been in the back of my mind that i will need the calvert shocks to allow more up extension and allow a little more down travel. any comment on my shock situation art in NY PS any you tube flicks of your car at track?
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Re: need advice on shock and suspension setuo

Post by 6.50camaro »

I think your on the right track on checking the suspension movement while it is on the stands jack the diff. And remove the bottm shock bolt . Let the jack down so the rear is hanging free . Extend the shocks completely and see if they are short and what your shock extended lenght should be . Less than an inch short should be ok. If you could reposition the top mount of the shackle so the bolts are straight up and down . Just as a bit of info Competition Engineering used a piece of 1/2" I.d. by about 3/4" o.d. tubing as the top shackle mount in their frame rails . I'm not using this as I installed slider blocks like calvert sells . That would be anotyer option but a lotmore money the welding and bracing a piece of tubing forward of the stock frame mount.
Also pinion angle is important in leaf spring cars . 4to5 degrees of negative pinionangle works good up to about 600hp. Dan
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Re: need advice on shock and suspension setuo

Post by fordified »

chevy art wrote: Wed Jun 12, 2019 3:27 pm my 67 nova with the 355 sbc(aprox 540 horse) used to 60 ft. around 1,48-1,50 and run about 11,00 to 10.95 on any given day and it had comp engineering slapper bars(tight to spring eye) and the old Koni Spa-1 front shocks. the car would launch and front end would come all the way up(no wheelie) and gradually settle down going down the track. car has 14 inch slicks, glide and 5,63 gears. front shocks were set all the way loose and i also had the comp engineering slinky front springs. rear springs were the stock parabolic mono leafs. and rear shocks were a mopar non_adjustable shock . syste worked fine. now i installed the cal_track bars and the cal_track 2 piece monoleaf springs and a good set of spherical end racing shocks with a single adjustment capability. they only have a 5 inch total travel capabilitr. i set the ride height at aprox 1 1/2 , so now i have aprox 3 1/2 inches of up travel and about 1 1/3 inches down travel from ride heigth. the rear shocks are set loose all the way(5 clicks). with new setup the car will not do better on 60ft times than the 1.50, but i ist extremely consistent. slicks are set around 10 1/2 lbs.(no less or the car wanders on top end) cat launches perfectly straight and now lifts the wheels off the ground maybe a foot. the problem is now the front end settlers straight down and then goes forward instead of the old way of settling on way down. i was told to correct this problem is to tighten the shocks about 3 clicks to tighten And see how that works. i know i need a better burnout, but i want to correct the launch problem. another thing i noticed is that when i push down on front of of car on the drivers side it really dont want to go down and the passenger side goes down with ease. i have not touched these shocks since 1995. caltrac bars are set like cavert said to do and the car goes straight so i wont mess with any preload on bars. any suggestion on getting my car to 60ft. better thanks Art in NY
What does the car weight and what first gear is in the trans?

Try not to take this the wrong way but theres a lot wrong with your set up.

14" wide slicks is way to big. Your giving away horsepower and et. That car should hook like crazy on 9" radial slicks no matter how much it weighs. You don't need bias ply slicks for an automatic or tubes if thats what your using. 10.5 PSI on a modern slick with a 540 hp engine is also giving away et.

The shock settings are not right. The 90-10 theory worked okay 40 years ago but not any longer. Modern slicks and compounds are way better than they were 20 years ago. Suspension parts are also much better. You need to tighten the shocks at least mid way and then adjust up first and then down to see when you lose hook or drop et. Adjust the backs first and then the fronts. Then go back and forth a little to see where the car runs the best et.

Theres more to dialing in a suspension than that but thats a start.

Heres an example of where you could get your car

https://www.youtube.com/watch?v=rrA7skWUUzE
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Re: need advice on shock and suspension setuo

Post by chevy art »

hey fordified. thanks for reply. the car has (ithink) the 1.76 first gear in the glide(has trans brake). the car weighs 3270 lbs with me in it... what i think i neglected to say was that the current engine is a 383 cu. in engine. over 600 hp(maybe 625)( goes right up to 8000 rpm 's). so that is what i am trying to get my suspension to work with. i will tighten the rears up as some of the other guys and you, have suggested , and i will tighten the fronts up just a little , as they are all the way loose since i built he car 25 years ago.. PS how do i adjust the front shocks? they the old Koni spa-1 shocks and there are no external knobs for adjustment. do i have to disconnect them and turn something? thanks art in NY
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Re: need advice on shock and suspension setuo

Post by 6.50camaro »

Art you have to remove them from the car . Fully compress them and turn the shaft and you should feel them engage the adjuster if the are full loose they probably would turn in one direction . Count the number of turns it will go before stopping . Try the shock it should be stiffer . Now decide how stiff you want them and turn the shaft back the oppisite direction how ever many turns you decide. This is how my koni spa-1's adjusted they were newer just before the stopped making them .Dan
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Re: need advice on shock and suspension setuo

Post by chevy art »

thanks dan that is the next step(front shocks) after i tighten up the rears and see what happens. i will keep in touch. wont be going back out till after the july 4th weekend. art
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