Traction problems

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73Scamp318

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Been awhile since I posted on here..I guess work and life got the best of me recently...

I've been having problems getting my Duster to hook up on drag radials and slicks pretty much since I put it together five years ago. Traction is really inconsistent...sometimes it hooks, sometimes it doesn't.

The best MPH I've wrung out of it is right at 111 and a 12.08 ET a couple years ago. I managed a 1.60 out of it at a different time on old, rock-hard, short, narrow slicks...about a 25x7 and 3.91 gears, which was about 5 years ago. I think that may have been on air shocks in the rear and 90/10 Lakewood drag shocks in the front. I have been running Mopar 002/003 super stock springs (clamped and unclamped), with and without a pinion snubber, and using small block front torsion bars (.850/.870?). The rear shackles are at the correct angle, according to the chassis manual. I'm also pretty certain that the pinion angle is right around 4 to 5 degrees down, though I was planning on rechecking it this weekend.

Since that time, I tried swapping out the air shocks for CE 3-ways in the rear, set to the firmest extension, front 90/10 Lakewood drag shocks for cheap Monroes with no real change. I swapped the rears to cheapie Monroes and had it out at the track last night, just to see if it wanted a softer shock...it annihilated the tires, spinning through 1st for a 2.02 60ft. Those shocks are going in the garbage tonight.

I also tried 28x9.0 slicks, which usually hooked, but not always, and 275/60/15 MT drag radials with the same result. I'm on Nitto 275/60/15 drag radials, which are about a 50/50 chance of hooking, but I figure I might as well get some life out of them on the street since traction is hit or miss anyway.

I have a video of the car that is a nice, slow-mo close up of the rear suspension, but I can't seem to find it. Below is the best I could find. At about the 0:39 mark, the car is leaving the line. I don't remember exactly, but I'm pretty sure it spun since the front is coming back down right away. The suspension is pretty much unchanged since this time and will typically run from the mid-1.6s to 1.8-something on the CE 3-ways.



My theory at this point is that the extension of the rear is happening too fast and it's trying to hop the rear off the ground or just running out of travel.

I'm not planning on going to go much faster with it than mid-11s, since I don't want to put a cage in it...I just want it to be consistent and predictable. The current configuration of the car is small block 360 at about 420 flywheel horse, around 3400 race weight, 8 3/4 with posi/4.30 gears, A727 auto trans, 9.5" PTC converter (flashed to 4400 on a data log). I plan on using the Nitto 275/60/15 drag radials and Lakewood 90/10 front shocks with the new rear shocks.

I'm currently looking at either putting the Rancho 9-ways on it or the Viking DA Warrior shocks, though Viking suggested that I use their Crusader DAs, which at $250+ a shock, I think is a bit much for a 12-second street car.

Any suggestions? Will the Ranchos do what I need them to do or will I need to pony up the cash for the Warrior or Crusader shocks?
 
73Scamp318 said:
Been awhile since I posted on here..I guess work and life got the best of me recently...

I've been having problems getting my Duster to hook up on drag radials and slicks pretty much since I put it together five years ago. Traction is really inconsistent...sometimes it hooks, sometimes it doesn't.

The best MPH I've wrung out of it is right at 111 and a 12.08 ET a couple years ago. I managed a 1.60 out of it at a different time on old, rock-hard, short, narrow slicks...about a 25x7 and 3.91 gears, which was about 5 years ago. I think that may have been on air shocks in the rear and 90/10 Lakewood drag shocks in the front. I have been running Mopar 002/003 super stock springs (clamped and unclamped), with and without a pinion snubber, and using small block front torsion bars (.850/.870?). The rear shackles are at the correct angle, according to the chassis manual. I'm also pretty certain that the pinion angle is right around 4 to 5 degrees down, though I was planning on rechecking it this weekend.

Since that time, I tried swapping out the air shocks for CE 3-ways in the rear, set to the firmest extension, front 90/10 Lakewood drag shocks for cheap Monroes with no real change. I swapped the rears to cheapie Monroes and had it out at the track last night, just to see if it wanted a softer shock...it annihilated the tires, spinning through 1st for a 2.02 60ft. Those shocks are going in the garbage tonight.

I also tried 28x9.0 slicks, which usually hooked, but not always, and 275/60/15 MT drag radials with the same result. I'm on Nitto 275/60/15 drag radials, which are about a 50/50 chance of hooking, but I figure I might as well get some life out of them on the street since traction is hit or miss anyway.

I have a video of the car that is a nice, slow-mo close up of the rear suspension, but I can't seem to find it. Below is the best I could find. At about the 0:39 mark, the car is leaving the line. I don't remember exactly, but I'm pretty sure it spun since the front is coming back down right away. The suspension is pretty much unchanged since this time and will typically run from the mid-1.6s to 1.8-something on the CE 3-ways.



My theory at this point is that the extension of the rear is happening too fast and it's trying to hop the rear off the ground or just running out of travel.

I'm not planning on going to go much faster with it than mid-11s, since I don't want to put a cage in it...I just want it to be consistent and predictable. The current configuration of the car is small block 360 at about 420 flywheel horse, around 3400 race weight, 8 3/4 with posi/4.30 gears, A727 auto trans, 9.5" PTC converter (flashed to 4400 on a data log). I plan on using the Nitto 275/60/15 drag radials and Lakewood 90/10 front shocks with the new rear shocks.

I'm currently looking at either putting the Rancho 9-ways on it or the Viking DA Warrior shocks, though Viking suggested that I use their Crusader DAs, which at $250+ a shock, I think is a bit much for a 12-second street car.

Any suggestions? Will the Ranchos do what I need them to do or will I need to pony up the cash for the Warrior or Crusader shocks?
Click to expand...

Not sure if this will be any help, but I've run consistent 1.66 60 ft times with ss springs and long cheap Oreilly shocks. That is on 275 MT drag radials. My dart sits way lower in the rear than your because I used lowering blocks. I think lower in the rear would help though if you like that look. Maybe some others will chime in.
 
Your car sits pretty high(not a fan of super stock springs)..$250.00 thats a lot of money for shocks for a 12 second car..in comparison i run the Mopar h.d. springs clamped in the front only w/ Summit $25.00 drag shocks 90/10 front 50/50 rear a pinion snubber,4.30's w/a spool..consistent mid 1.60's with a best of 1.62 running a 360 also...
 
My 60fts are very consistent. Same 420ish hp, but a stick car. Lowered all round. I think 4.30s as well
Yeah consistently 2.2 to 2.4.............lol
Over 4 runs, it averaged 2.3, and went best of 93 in the 1/8th.
Sucks to be my car, I know, pos....lol
 
AJ/FormS said:
My 60fts are very consistent. Same 420ish hp, but a stick car. Lowered all round. I think 4.30s as well
Yeah consistently 2.2 to 2.4.............lol
Over 4 runs, it averaged 2.3, and went best of 93 in the 1/8th.
Sucks to be my car, I know, pos....lol
Click to expand...
73Scamp318 said:
Been awhile since I posted on here..I guess work and life got the best of me recently...

I've been having problems getting my Duster to hook up on drag radials and slicks pretty much since I put it together five years ago. Traction is really inconsistent...sometimes it hooks, sometimes it doesn't.

The best MPH I've wrung out of it is right at 111 and a 12.08 ET a couple years ago. I managed a 1.60 out of it at a different time on old, rock-hard, short, narrow slicks...about a 25x7 and 3.91 gears, which was about 5 years ago. I think that may have been on air shocks in the rear and 90/10 Lakewood drag shocks in the front. I have been running Mopar 002/003 super stock springs (clamped and unclamped), with and without a pinion snubber, and using small block front torsion bars (.850/.870?). The rear shackles are at the correct angle, according to the chassis manual. I'm also pretty certain that the pinion angle is right around 4 to 5 degrees down, though I was planning on rechecking it this weekend.

Since that time, I tried swapping out the air shocks for CE 3-ways in the rear, set to the firmest extension, front 90/10 Lakewood drag shocks for cheap Monroes with no real change. I swapped the rears to cheapie Monroes and had it out at the track last night, just to see if it wanted a softer shock...it annihilated the tires, spinning through 1st for a 2.02 60ft. Those shocks are going in the garbage tonight.

I also tried 28x9.0 slicks, which usually hooked, but not always, and 275/60/15 MT drag radials with the same result. I'm on Nitto 275/60/15 drag radials, which are about a 50/50 chance of hooking, but I figure I might as well get some life out of them on the street since traction is hit or miss anyway.

I have a video of the car that is a nice, slow-mo close up of the rear suspension, but I can't seem to find it. Below is the best I could find. At about the 0:39 mark, the car is leaving the line. I don't remember exactly, but I'm pretty sure it spun since the front is coming back down right away. The suspension is pretty much unchanged since this time and will typically run from the mid-1.6s to 1.8-something on the CE 3-ways.



My theory at this point is that the extension of the rear is happening too fast and it's trying to hop the rear off the ground or just running out of travel.

I'm not planning on going to go much faster with it than mid-11s, since I don't want to put a cage in it...I just want it to be consistent and predictable. The current configuration of the car is small block 360 at about 420 flywheel horse, around 3400 race weight, 8 3/4 with posi/4.30 gears, A727 auto trans, 9.5" PTC converter (flashed to 4400 on a data log). I plan on using the Nitto 275/60/15 drag radials and Lakewood 90/10 front shocks with the new rear shocks.

I'm currently looking at either putting the Rancho 9-ways on it or the Viking DA Warrior shocks, though Viking suggested that I use their Crusader DAs, which at $250+ a shock, I think is a bit much for a 12-second street car.

Any suggestions? Will the Ranchos do what I need them to do or will I need to pony up the cash for the Warrior or Crusader shocks?
Click to expand...


Get a set of Assassin bars and a set of Calvert 9 way adjustable shocks. You'll see a difference.

image.jpeg
 
I run Caltracs and Calvert Racing adjustable rear shocks and 90/10 front shocks. At the track I have been running MT ET Streets in a P255/60R15 and never spin until the 5th or 6th run when the track is getting sloppy. On the street I went no Nitto NT555R Extreme Drag radials in P275/60R15 and they hook up so well on the street I am going to run them at the track this year. Not sure why you aren't hooking up. I push 500hp and 528 torque and can spin them at will, just not at the track with the stick em down.
 
Our '66 Cuda runs 10.68/123, with a pinion snubber/ radials/drag shocks. Start with the most economical change first. (pinion snubber) Then shocks. Do at least 3 runs for any one change to gather correct data. Then change tire pressure for 3 runs. Use a log book. Do not make the mistake of airing down radials if you encounter tire spin. Go the other way. Good luck
 
I am a fan of the SS springs, and they work! I think your shocks are two short. SS spring perk up the *** end a lot! stock length shock will bottom out and eventually tear out the shock mounts in the floor!!!

Jack up the car by the bumper or jack stands on the subframe so the suspension droops, undo you shock and find out how much more travel you have in you shock(I bet it's 0) you should have several more inch(at least 2") more travel, as the eng torque will stretch them SS spring even more, under load!

look at your launch, keep hitting the stop button so that you can look at it in little pieces. spring just start to push the body up and then it stops.....tire starts to spin. I could be way off, but if it was me, that would be my first step.

I run SS spring on my E body and the *** end is perk up just like yours. My lift at launch, when i had a 340 with a 2800 stall, was probably 3 time as much as you are getting.
Ok i have flapped my jaw enough.:D
 
The shocks need to be about 2.5" longer extended length than the stock shocks. The MP Chassis manual is a good place for you to start. If you can find one.
 
It looks to me your car is almost the same height at launch (don't see much movement), we should be seeing an obvious 2-3 inch rise of the body off the rear axle. Don't know what the remedy is though. I ran super stock springs with the recommended Mopar longer shocks and pinion snubber with 10 inch slicks (10 PSI) and it worked for me like a charm.
 
dibbons said:
It looks to me your car is almost the same height at launch (don't see much movement), we should be seeing an obvious 2-3 inch rise of the body off the rear axle. Don't know what the remedy is though. I ran super stock springs with the recommended Mopar longer shocks and pinion snubber with 10 inch slicks (10 PSI) and it worked for me like a charm.
Click to expand...

yup! and mine are 20 + years old and still running strong! OK the shocks are 12 years old. Some year, i will have to break down and by some of them double adjustable ones.
 
Also, another point. Any shock that puts pressure on the springs, whether gas charged, or especially air shocks, changes the way the Mopar suspension was designed to work. The shocks are supposed to be inert all except to dampen the spring oscillations. Tons of people try as they might to reinvent the wheel here, but a good old heavy duty hydraulic shock is all you need in the rear. They let the SS springs do their job. In fact, the MP Chassis manual even says in one chapter to use old style hydraulic shocks on the front, but to drill holes in them and DRAIN them of their fluid. I kid you not. It's in the book.......and guess what? It WORKS! I've done it myself. Of course that renders the front shocks all but useless as anything other than to help limit front end rise, but it makes them transfer weight like a big dog. And lemmie tell you, it makes the front end rise RIGHT NOW.

Course for a street car, that's a little extreme.
 
Last edited:
I pulled off the air shocks a long time ago...pretty sure they went with a load of scrap. The monroes are still on the car at the moment...even though they're gas charged, I can easily move the suspension through a lot of its travel by pushing and pulling on the back bumper. The motion stops pretty quickly, but it doesn't resist movement anywhere near as well as the CE shocks do.

I'm throwing the CE shocks back on until I get something else, since those seem to control the rear the best. One thing I noticed while playing with the CEs on the firmest setting is that they both extend at about the same rate, but one compresses a bit faster than the other (probably junk). Would I want that one on the driver or passenger side? My gut says driver side...

I'm running shock extensions on the CE drag shocks...they're about 27 fully extended with the extensions from center to center, ride height is right at 19.75 (measured it last night), and I have at least a couple inches of travel left when they're unhooked. The video posted above was with the CE drag shocks on the stiffest setting. watching the video, I see what dibbons means about the limited rise. I'm coming off of the line at 3k...you can see the suspension rise a bit when I load it up in after getting into the pre-stage light. Maybe coming off the line at around 1500 to 2000 would use up less suspension travel, giving it time to work.

I could try flipping the front hanger to bring it down, but wouldn't that mess with my instant center? Doesn't raising the front spring eye make it hit the tires harder?

Anyway...the reason behind me looking at the Rancho shocks is that I can get a really good deal on them, about $90 apiece instead of $120 each for the Calvert shocks. As long as they're long enough, would they be a good choice? Or do I need to bite the bullet and pony up the dough for the Vikings?
 
I will get flamed for this, but it is what "I" would do, have done with great success and would do again so here goes.

I would hawk Ebay for a pair of NOS hydraulic Chrysler Imperial shocks. Their extended length would need to be around what you have now. There is no need for fancy shamcy in the shock department. Just because they make them, doesn't mean you need them.

Let the flaming begin.
 
Last edited:
No flaming here! That was the hot set up when no other shocks were available. If your CE shocks are long enough I would work with what you have for now. Front segments should be clamped, to control axle wind up. Rear of the spring just holds up the car. How much front travel do you have? Need a good 5 inches to get weight transfer. Getting the front spring eye lowered may help as well, its easy enough to swap them from side to side.
 
i have pretty good weight transfer.
100% of my weight comes off my feet and into my azz, when I sit down in my favorite chair.heehee
Oh dear, I'm in the racers forum again, drive thru
 
73Scamp318 said:
Been awhile since I posted on here..I guess work and life got the best of me recently...

I've been having problems getting my Duster to hook up on drag radials and slicks pretty much since I put it together five years ago. Traction is really inconsistent...sometimes it hooks, sometimes it doesn't.

The best MPH I've wrung out of it is right at 111 and a 12.08 ET a couple years ago. I managed a 1.60 out of it at a different time on old, rock-hard, short, narrow slicks...about a 25x7 and 3.91 gears, which was about 5 years ago. I think that may have been on air shocks in the rear and 90/10 Lakewood drag shocks in the front. I have been running Mopar 002/003 super stock springs (clamped and unclamped), with and without a pinion snubber, and using small block front torsion bars (.850/.870?). The rear shackles are at the correct angle, according to the chassis manual. I'm also pretty certain that the pinion angle is right around 4 to 5 degrees down, though I was planning on rechecking it this weekend.

Since that time, I tried swapping out the air shocks for CE 3-ways in the rear, set to the firmest extension, front 90/10 Lakewood drag shocks for cheap Monroes with no real change. I swapped the rears to cheapie Monroes and had it out at the track last night, just to see if it wanted a softer shock...it annihilated the tires, spinning through 1st for a 2.02 60ft. Those shocks are going in the garbage tonight.

I also tried 28x9.0 slicks, which usually hooked, but not always, and 275/60/15 MT drag radials with the same result. I'm on Nitto 275/60/15 drag radials, which are about a 50/50 chance of hooking, but I figure I might as well get some life out of them on the street since traction is hit or miss anyway.

I have a video of the car that is a nice, slow-mo close up of the rear suspension, but I can't seem to find it. Below is the best I could find. At about the 0:39 mark, the car is leaving the line. I don't remember exactly, but I'm pretty sure it spun since the front is coming back down right away. The suspension is pretty much unchanged since this time and will typically run from the mid-1.6s to 1.8-something on the CE 3-ways.



My theory at this point is that the extension of the rear is happening too fast and it's trying to hop the rear off the ground or just running out of travel.

I'm not planning on going to go much faster with it than mid-11s, since I don't want to put a cage in it...I just want it to be consistent and predictable. The current configuration of the car is small block 360 at about 420 flywheel horse, around 3400 race weight, 8 3/4 with posi/4.30 gears, A727 auto trans, 9.5" PTC converter (flashed to 4400 on a data log). I plan on using the Nitto 275/60/15 drag radials and Lakewood 90/10 front shocks with the new rear shocks.

I'm currently looking at either putting the Rancho 9-ways on it or the Viking DA Warrior shocks, though Viking suggested that I use their Crusader DAs, which at $250+ a shock, I think is a bit much for a 12-second street car.

Any suggestions? Will the Ranchos do what I need them to do or will I need to pony up the cash for the Warrior or Crusader shocks?
Click to expand...



With your MPH your car NEEDS to get into the 11's.
 
Do you want the car to sit lower in the rear? That's what transfers weight. My little junkyard magnum 360 acts like its trying to pull the front wheels when I launch. As stated you need at least 5 inches of travel in the front end. Here is a crappy picture of the launch. Your car doesn't look like it's transferring much weight.
Dart 8.PNG
 
73Scamp318 said:
I pulled off the air shocks a long time ago...pretty sure they went with a load of scrap. The monroes are still on the car at the moment...even though they're gas charged, I can easily move the suspension through a lot of its travel by pushing and pulling on the back bumper. The motion stops pretty quickly, but it doesn't resist movement anywhere near as well as the CE shocks do.

I'm throwing the CE shocks back on until I get something else, since those seem to control the rear the best. One thing I noticed while playing with the CEs on the firmest setting is that they both extend at about the same rate, but one compresses a bit faster than the other (probably junk). Would I want that one on the driver or passenger side? My gut says driver side...

I'm running shock extensions on the CE drag shocks...they're about 27 fully extended with the extensions from center to center, ride height is right at 19.75 (measured it last night), and I have at least a couple inches of travel left when they're unhooked. The video posted above was with the CE drag shocks on the stiffest setting. watching the video, I see what dibbons means about the limited rise. I'm coming off of the line at 3k...you can see the suspension rise a bit when I load it up in after getting into the pre-stage light. Maybe coming off the line at around 1500 to 2000 would use up less suspension travel, giving it time to work.

I could try flipping the front hanger to bring it down, but wouldn't that mess with my instant center? Doesn't raising the front spring eye make it hit the tires harder?

Anyway...the reason behind me looking at the Rancho shocks is that I can get a really good deal on them, about $90 apiece instead of $120 each for the Calvert shocks. As long as they're long enough, would they be a good choice? Or do I need to bite the bullet and pony up the dough for the Vikings?
Click to expand...

I had the 3200 lb SS springs on my Demon. I did not like how high it set in the rear. I put 2 in. lowering blocks under it and it had the MP long shocks. On motor it had a best 60 ft. of 1.50 and on 100hp NOS it had a best of 1.36. It may help if you lower it in the back.
 
Walker434 said:
Do you want the car to sit lower in the rear? That's what transfers weight. My little junkyard magnum 360 acts like its trying to pull the front wheels when I launch. As stated you need at least 5 inches of travel in the front end. Here is a crappy picture of the launch. Your car doesn't look like it's transferring much weight.
Click to expand...

How do you do that? Front Shocks soft as possible for extend? Rear Shocks stiff as possible to avoid easy extend? please explain to a rookie like me :)
 
Your rear is unloading after initial launch and spins the tire, then grabs again.
This is what I would do with the parts you have.
Front shocks set to 90/10 Trim the upper control arm bump stops to allow more downward travel.
Rear shocks set to 70/30. You want the shock to extend easy to plant the tires. Firm rebound keeps them planted.
If your snubber is adjustable set it to within a 1/4" to 1/8" with driver in seat race trim.
Lowering blocks would also help weight transfer.

I run 255/60/15 MT drag radial 18 psi, small burnout just to clean.

Here's a video of my car. At :25 the car is stage and on the snubber. At ;28 the tires are planted and stay that way.
 
will try this setting. have the same tires but will also try semis this weekend. I use caltracs and currently my 60' is 2.02 ( on the semi Slicks ). I have a Manual trans
 
I have CE 90/10 shocks up front. Stock 318 torsion bars, this combo gave me over 5 inches of front end travel. My back shocks are cheap Oreilly brand shocks for a C body I believe... The main thing is making sure they are long enough. I un clamped the rear segments of the springs and added a clamp to the front section
 
RE: mderoy340 video

That is the way to set up a chassis and let me add: I don't remember hearing a sweeter sounding 340 ever!
 
Not enough front end travel and may want to slow it down just a little bit. It appears to top out at same time the rear unloads. Maybe lower the front a little and cut the upper control arm bumpers.

Slow the video down to .25 speed and watch it.

Good rear shocks, or better ones are not a bad thing. Calverts work well, ranchos may be OK as long as the valving hasn't changed. Vikings, etc are overkill here IMO.
 
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