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12/6/19, 11:35 AM   #1
Differences on a 4 Link & Z-Link on Mini Sprint?
hoscalecody is offline
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Hello, so I was wondering on a Lightning sprint/mini sprint, what would the differences be and the pros and cons of running 4 link (4 rear radius rods.) vs a standard z-link? (Excited to hear what the member DAD has so say to this if he sees this.)

We've been running 1000cc Lightning sprints for 6-7 years. Only time I ran z-link was first 2 years, other than that we've been running 4 link.
We converted a 1999 34" Combo Stealth midget chassis to a lightning sprint and made it a 4 link. I had the birdcages and I hate buying and selling stuff so I kept with what I had. We are building/converting another 1998 34" Stealth midget and considered making it a z-link car. We run mainly Non-wing (I don't like wing racing.) Just wanted to hear the differences and what may be better or worse and why.
Cody "SlideWayz" Downard
Faith Auto Racing #3D
1999 Stealth with a 2011 R1
1998 Stealth with a 2009 R1 (Building)
18-1 Designs.
Last edited by hoscalecody; 12/6/19 at 11:36 AM.
1 member likes this post: tirespinner
12/6/19, 1:15 PM   #2
Re: Differences on a 4 Link & Z-Link on Mini Sprint?
jjones752 is offline
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The z-link acts like a parallelogram and moves the birdcages more or less straight up and down which is great for preventing unwanted roll steer but terrible for keeping constant chain tension. Granted, the radius rods and torsion arms aren't equal length so there are some intended geometric changes but for simplicity's sake let's leave that there.
A 4-link keeps the birdcages relatively in the same "clocking" attitude but the arcs of the trailing-arms/radius rods are closer to the arc of the chain so (in theory) there should be less of a variation in tension. the birdcage clocking should remain static since the arms are equal length.
A third alternative is the wishbone, which, if your front heim joint is as close as possible to the centerline of your countershaft will produce nearly zero chain tension change, and the birdcages remain fixed in relation to the arc of the wishbone instead of staying relatively vertical. There are pros and cons for all 3 setups that involve drive off the corners, bind, and a lot of stuff I don't understand but those are the basics.
My old Zonker had a wishbone setup and I never had an issue with the chain. I did break a couple of front heims and in one of those incidents dug the left wishbone into the track with unpleasant results, but I put a pair of drag link tethers on the new set and never broke another heim joint. Funny how that works...
Jim Jones
Midwest Thunder Speed2 Midget #97
Last edited by jjones752; 12/6/19 at 1:16 PM.
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12/6/19, 1:58 PM   #3
badcoupe is offline
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Join Date: Aug 2008
Posts: 693

I know the wishbone setup is really popular with the 600cc cars. Do you run a Jacobs ladder or panhard with your current setup? There are pros and cons to both of those as well especially with a wishbone setup. The z link setup can allow for some rear steer depending on your particular geometry. Hyper racing has some good info on the different setups advantages etc. Iíve not messed with the chain drive stuff myself.
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12/6/19, 2:09 PM   #4
Tom23 is online now
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Join Date: Dec 2007
Posts: 372

We ran a chain car pretty successfully for a few years, I started with the z link and changed it to wishbones the last two years. I would never run anything but wishbones on a chain car based on that experience. Car rolled free, no chain bind, gears changes were a snap, and when we got the pickups right it was better off the corner especially as the track got slicker.
2 members like this post: fish, tirespinner
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