I have a 1970 Swinger with mild 340, 4 speed and 3.90 posi. It has super stock springs, drag shocks, pinion snubber set at 1/4 inch, Hoosier Quick Time Pro tires and 310 rear wheel hp. I raced at Rock Falls WI yesterday and could not get traction no matter how heated the tires or what RPM I launched at. The track was supposed to be prepped but I still managed to spin through most of first gear and part of second. Ran a best of 12.93 @ 109.3 mph with a 2.0 60 foot. Any help would be appreciated.
Traction Issues
- Thread starter bensonr
- Start date
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Have you clamped the front segment and unclamped the rear? Also, what are your leaf spring U bolts torqued to? If they are over tightened, it will not allow the rear suspension to work. The springs will be in a bind. You should loosen the nuts and retorque them to 45 LB FT. Those two things are pretty much free, so try them first.
BB73Challenger
Well-Known Member
What was your tire psi?
Have you run this combo with good response or was this a 1st time with this combo?
Have you run this combo with good response or was this a 1st time with this combo?
72BBSwinger
Well-Known Member
That MPH is solid 12 teens or better. Tire psi and a good burnout or critical.
OldmanRick
Well-Known Member
I loved the sticky belted tires back in my day. They worked very well for me with 12sec cars, although not like slicks. If the track was indeed prepped right, i'm thinking you need to adjust your launch rpm or maybe you're just dropping more power on it then you think with the cooler conditions these days. 
P.S. RustyRatRod talking about the rear suspension also got me thinking about the front. You said you have drag shocks, does that included the front? I'm wondering how stiff things are up there also. Thick T-bars? I put 90/10 shock valving on many cars I raced and that definitely helped with the street/treaded tires.
P.S. RustyRatRod talking about the rear suspension also got me thinking about the front. You said you have drag shocks, does that included the front? I'm wondering how stiff things are up there also. Thick T-bars? I put 90/10 shock valving on many cars I raced and that definitely helped with the street/treaded tires.
famous bob
mopar misfit
I loved the sticky belted tires back in my day. They worked very well for me with 12sec cars, although not like slicks. If the track was indeed prepped right, i'm thinking you need to adjust your launch rpm or maybe you're just dropping more power on it then you think with the cooler conditions these days.
P.S. RustyRatRod talking about the rear suspension also got me thinking about the front. You said you have drag shocks, does that included the front? I'm wondering how stiff things are up there also. Thick T-bars? I put 90/10 shock valving on many cars I raced and that definitely helped with the street/treaded tires.
ditch the pinion snubber!--try it!----bob
tekslk
Well-Known Member
6 cyl torsion bars will transfer some weight for you.
The springs came clamped, so that's the way I left them. The U-bolts are torqued to 45 lbs./ft. The rear shocks are longer nonadjustable Mopar drag shocks. Stock T-bars with stock worn out shocks up front. This is the first time I've run this combo. It was about 42 degrees at the track. I tried 20, 18, 16 and 14 psi in the rear tires with about a 5 to 7 second burnout in first gear. Launching at 2500 bogged down the motor and 2750 spun the tires.
dusterdragracer
Drag Racer
Wow, 42 degree's is pretty cold, no matter how well the track was prepped.Anything under 60 degree's at our track, and it's like driving on ice.
But keep the snubber they have always worked for me.(see pic) S.S. springs, factory shocks, Comp. engineering 3 way adjustables rear.I realize my tires are slicks and bigger.
But keep the snubber they have always worked for me.(see pic) S.S. springs, factory shocks, Comp. engineering 3 way adjustables rear.I realize my tires are slicks and bigger.
bOb shingler
Well-Known Member
I know how to get traction with your hotrod, wait until spring when the temp is in the 70's and the track is warmed up, LOL. it's just too cold for any traction and also some slicks will go along way in hooking the hotrod up.
pettybludart
Well-Known Member
I,m just wondering what your expecting from a mild 340,4 speed at the track?If you spun through 2 gears and still managed a 12.90@109mph your doing pretty good IMO.Maybe a list of your engine build?
Good deal. What about the rear segments? They should be un clamped.
Get some heat in those tires,lol. The MPH in the traps pretty good.
tasvalowna
Well-Known Member
get it into secnd in the burnout and get them tyres properly hot
I will unclamp the rear segments and try it out next spring when the track is warmer.
The engine has 9.65:1 compression, heads have bowls and runners cleaned up, intake and heads are gasket matched, 4425992 purple cam, 750 Edelbrock and TTI headers.
I was hoping to run 12.5 to 12.6 with this combo. I do not have subframe connectors, so I guess I don't want to hook too hard.
The engine has 9.65:1 compression, heads have bowls and runners cleaned up, intake and heads are gasket matched, 4425992 purple cam, 750 Edelbrock and TTI headers.
I was hoping to run 12.5 to 12.6 with this combo. I do not have subframe connectors, so I guess I don't want to hook too hard.
Mopar to ya
Well-Known Member
They don't call it Slippery Rock for nothing. They are horrible at track prep.
dusterdragracer
Drag Racer
My wife ran her 360 Dart for years with snubber, stock worn out rear springs air shocks, stock front shocks and Tbars and NO frame connetors. It ran 11:99-12:36 depending on conditions.No damage to the car, and she is driving it on the street. With total de-tune, same springs etc.slicks only it ran 13:50 @ 5000'
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