08 smackdown updating

[TheJet-09]

CDNRocket18R: The crossmember is simply raised up. I cut mine horizontally just above the tube that the R&P plate is welded to, then literally cut and fit it to sit inside/on top of the down tubes (where the lower control arms bolt to). With the R&P now higher, you need to go to slotted ends on the R&P, or you'll probably never get bump steer even close. The supports for the crossmember that run back towards the motorplate will also need to be cut/realigned/welded. For the right hand support tube, I just cut/welded it from underneath the right hand motormount.

Another difference between the Smackdown and Gen-X is the lower control arms on a Smackdown bolt behind the crossmember whereas they bolt in front of the crossmember on a Gen-X (which puts it further back, helping to keep it out of the ground even more).

I believe a few years back someone (I forget who) posted pics of an updated crossmember they put on a Smackdown (I'm fairly certain), and it resembled that of a Rocket. I remember thinking it looked like some high quality work. If I can find the thread, I'll post the link.

[MasterSbilt_Racer]

CDNRocket18R: The crossmember is simply raised up. I cut mine horizontally just above the tube that the R&P plate is welded to, then literally cut and fit it to sit inside/on top of the down tubes (where the lower control arms bolt to). With the R&P now higher, you need to go to slotted ends on the R&P, or you'll probably never get bump steer even close. The supports for the crossmember that run back towards the motorplate will also need to be cut/realigned/welded. For the right hand support tube, I just cut/welded it from underneath the right hand motormount.

Another difference between the Smackdown and Gen-X is the lower control arms on a Smackdown bolt behind the crossmember whereas they bolt in front of the crossmember on a Gen-X (which puts it further back, helping to keep it out of the ground even more).

I believe a few years back someone (I forget who) posted pics of an updated crossmember they put on a Smackdown (I'm fairly certain), and it resembled that of a Rocket. I remember thinking it looked like some high quality work. If I can find the thread, I'll post the link.

Jet,

I am pretty sure the rack mounting holes are up and back. The Gen X style cars have more angle in the tie rods when looking down on them from above. This gives the car more "Ackerman" and is part of the reason they turn so well.

[TheJet-09]

^^^ Agreed, I have noticed the amount of Ackerman on the Gen-X as compared to the Smackdown. Almost looks like something isn't right when looking down on it. I believe the Gen-X also calls for only 3/8" of toe out while the Smackdown was more like 3/4".

So when they raise the crossmember, they also move the rack plate back? Or maybe I misunderstood. I just raised mine up in the same location front to back.

[Krooser]

I noticed on my car that the steering arms do not run parrallel to the lower control arms... parrallel and equal length with the lowers was what we strived for when we searched for zero bumpster with a Ford stub 30 years ago... a shorter steering arm on my MB spindles would fix that plus give my old 3.4 rack a little quicker ratio, too.

Comments?

[MasterSbilt_Racer]

I noticed on my car that the steering arms do not run parrallel to the lower control arms... parrallel and equal length with the lowers was what we strived for when we searched for zero bumpster with a Ford stub 30 years ago... a shorter steering arm would fix that plus give my old 3.4 rack a little quicker ratio, too.

Comments?

That's old thinking.

[Krooser]

Well I AM old... so that would explain some of it.

[let-r-eat]

What's the new thinking? Geometry change over the years?

[Krooser]

The "old way" with a rear steer setup was to have the steering arms angle inward at the back of the spindle...when drawing a straight line from the ball joint thru the tie rod end the lines from each side would intersect at the differential... That was good. If you had straight steering arms the line would run parallel to infinity and that was bad.

You could never get zero bumpsteer with rear steering arms because the lca's and the tie rods we're operated on different planes and we're different lengths. I ran Impala steering arms on a '65 Ford stub and fabd my own centerline to correct bump steer...but that took all the Ackerman away.

[CDNRocket18R]

Ok another question. If I decide to keep this car and updates the cross member I’m thinking about running a stacked RF.any suggestions where to start for springs

[fastford]

most call it a 2 stage , which is what it is , on rt front , if you will search this section , you will find some great info already posted......

[TheJet-09]

I just started messing around with a two stage (I know, I'm behind). I first tried a 600/600 and felt that was maybe too stiff. I've since dropped to a 500/500. I've heard of guys running a 800/400, and from what I understand are crazy soft now. My numbers are also on a Gen-X using the inboard lower mount, so the motion ratio is softer than what those same springs would be on your Smackdown. I think a 250# on the outer mount is roughly a 225# on the inner mount (but don't quote me on that).

You have a lot of options overall, especially at this time of the year. Cars are starting to come up for sale more, so depending on where you're located you might find something. I saw a Smackdown on racingjunk just now. Has a new stub and interior.

[fastford]

thats what i found worked best for me, 500/500 , I floundered around to start with , and then hooked up with jerry link , whos now at afco , and he put me on the 500/500 , which worked best for me.....

[TheJet-09]

^^^ Drifting off topic now, but is anyone running the new AFCO shocks that Jerry came up with? I only saw an add for them that someone shared on here, but I don't see anyone selling them. I like the set I got from him while still at SHY, but I need something for next year.