stock rear leaf springs from slant 6 better for drag racing

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ultimatejay

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I just bought a 1970 Duster with slant 6 that I'm going to convert to 360 stroker. I came from drag racing 1971 Mazda RX2 with factory 4 link suspension and stock suspension. For stock chassis drag racing we always used really light springs in the rear to transfer weight to the rear tires. I am assume this is the case for leaf spring stock chassis cars as well? So wouldnt one be better off using stock slant 6 leaf springs that are lighter to transfer weight to rear wheels as well? I see a lot of people go out and buy fancy stiff rear leaf springs and dont know why?
 
No. Mopar engineers did a lot of R&D and came up with Super Stock springs. Or you could check out Cal Tracs.
 
There's ways to do it, but in general it's a quick way to get gobs of wheel hop. Stiffer springs help keep both tires planted, and short stiff front segments help minimize axle twist.
Light slant 6 torsion bars in front, however, allow the front end to rise quicker, shifting more weight onto the rear tires.
 
toolmanmike said:
No. Mopar engineers did a lot of R&D and came up with Super Stock springs. Or you could check out Cal Tracs.
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I am guessing that the Mopar Engineers R&D was built around max power and traction back when they were testing.
Fast forward to today, between tires, track traction compounds and available power, today it is a different game.
There is information to be gleaned from what was done then, but unless one is building a 70's replicar racer, things have changed.
 
Mopars respond to a very stiff front segment that acts like traction bars. Put spongy springs on the rear and it's be a slug.
 
I can only tell what I found.
I ran a b-body with what I believe were slant six rear springs (it was an original slant six car), with the front segment of the springs clamped as solid as I could. 60 ft was fair, not great, but rear end lift (of the body) was so extreme than the shocks would top out. I swapped in the correct weight super stock springs, the car left much nicer, cut the ridiculous body lift in half. (If you have too much rear lift, you won't have much front end lift... physics)
 
What is better super stock springs or mono leaf if its going to be driven on the street and raced occasionally?
 
my68barracuda said:
I am guessing that the Mopar Engineers R&D was built around max power and traction back when they were testing.
Fast forward to today, between tires, track traction compounds and available power, today it is a different game.
There is information to be gleaned from what was done then, but unless one is building a 70's replicar racer, things have changed.
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Hang out at the drag strip and talk to the Mopar guys. There's guys running in the low 10's or better with some impressive 60' times using Superstock Springs and drag shocks.
 
ultimatejay said:
What is better super stock springs or mono leaf if its going to be driven on the street and raced occasionally?
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I'm betting a pair of ss springs is still under $300, and would be more than adequate for a warm 360. Or a stroker.
I'm pretty sure monoleafs, or split mono's, are to be used with caltracs or similar. Mono's and caltracs will work better, maybe, but run around $1000 with shocks.
The caltracs will make noise on the street. Ss springs wont.
Oh, and by the way, the way four links with coils work is ENTIRELY different than the way leaf springs work. One doesn't translate to the other.
 
Check out "leaf springs and the anti-squat line explained" by Kevin Wilson, on you tube. He will recommend Caltracs cause he's a suspension guy, and wants adjustability. I think the o.p.can get by with ss springs and good shocks.
 
33IMP said:
Check out "leaf springs and the anti-squat line explained" by Kevin Wilson, on you tube. He will recommend Caltracs cause he's a suspension guy, and wants adjustability. I think the o.p.can get by with ss springs and good shocks.
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I will be doing mostly street driving and on occasion some drag racing so probably the SS springs will be in order. Also, I just put QA1 double adjustable shocks on the front and rear so i suppose those will suffice?
 
ultimatejay said:
I will be doing mostly street driving and on occasion some drag racing so probably the SS springs will be in order. Also, I just put QA1 double adjustable shocks on the front and rear so i suppose those will suffice?
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Just make sure you have enough extension so you don’t top the shock out and knock the tires loose.
 
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