Landracing Forum
Tech Information => Steering - Suspension - Rear End => Topic started by: javajoe79 on October 06, 2014, 10:19:28 PM
-
So we are starting to try and figure out the front suspension on the firebird. We have some parts laying around but after some measurements, it will be hard to make them work. We are sitting at about 4" of positive scrub.
What we have is some 15" skinny wheel with close to zero offset and some nascar spindles and hubs. From my measurements, we would need a wheel with as much positive offset as possible, a hub with the flange basically in line with the inner bearing and a spindle that is short enough to fit all the way inside the wheel with ball joints or heim joints.
Does anyone know of an off the shelf spindle and hub combo that works? Also thinking of cutting up the nascar spindles to make them shorter and machining some hubs like I described. Anyone go this route?
-
I did, but for a different reason. I needed more clearance under the fenderwells in order to lower the front end. I wound up with a little bit better scrub angle after I was done. I've since had other issues with bump steer, which will be handled with reworked steering arms. If you can whip up some steering arms that relocate the rod ends and still maintain a reasonable arc with respect to the suspension arc, you can move the hub in closer. But it's always a compromise when you're using stock locating points.
Skipping the front brakes helps - gives you more room to work with - but if you're really fast and intend to run Wilmington, that could be a problem.
Terry (aka Podunk) did my work and has worked with Sparky on getting his angles right. I'd drop him a PM.
-
Cool thanks. I can make whatever we need but it would be nice to find some off the shelf parts.
Even though the skinny tires won't do much braking, the car will run at Wilmington with very high speed goals in mind so we will need all the braking power possible.
-
Late to the party, again...dont get here much, these days.
If you use zero scrub under hard braking your driver may find it spooky. Typically, we keep just a little positive scrub on rear drivers for good balance of steering feel on or off the throttle.
I've never tried skinny fronts with less than 3/4".
-
So we are starting to try and figure out the front suspension on the firebird. We have some parts laying around but after some measurements, it will be hard to make them work. We are sitting at about 4" of positive scrub.
What we have is some 15" skinny wheel with close to zero offset and some nascar spindles and hubs. From my measurements, we would need a wheel with as much positive offset as possible, a hub with the flange basically in line with the inner bearing and a spindle that is short enough to fit all the way inside the wheel with ball joints or heim joints.
Does anyone know of an off the shelf spindle and hub combo that works? Also thinking of cutting up the nascar spindles to make them shorter and machining some hubs like I described. Anyone go this route?
Chris, thanks for talking to me about the scrub radius on the phone the other day!
I found this link that gives a visually representation of what you told me. For anybody else who does not understand what scrub radius is, here is a link:
http://www.racecartuner.com/03/307.html
I measured my scrub radius to be about 2.5" positive. My hub is about 3" wide.
I can't get the nut off the spindle because I do not have a socket that large. If I go narrower on the hub, I will nost likely need to change the spindle?
Is there a slightly wider front runner tire that with the correct back space and width wheel would would move the center of the contact patch inwards to get the zero scrub?