I ordered some genuine r-pkg ball joints and put them on the car. I measured the bumpsteer both before and after, but only on one side. The measurement below is per side, not total.

Pertinent car info

• Complete NA front suspension (subframe, knuckles etc)
• 1/2" garagestar rack spacers
• Bauer ELBJs (changing inner to outer pivot distance on the arm will slightly affect bumpsteer)
• Generic parts store standard NA tie rods and genuine r-pkg ball joints
• Only measured the range of travel I get for my ride height with my dampers (Xida race) - at 74mm compression the 195/50R15 tyre was scrubbing the top of the arch.

https://cimg5.ibsrv.net/gimg/www.mia...3be86caaa9.png
Caveats... This was measured with a string alignment kit setup at ride height, ie at large displacements from ride height, the toe will be slightly under-reported since I'm not measuring across the total diameter of the wheel. Also, it's pretty tricky to do this accurately by yourself, but every point should be at least within 1mm of toe and 1mm of vertical travel...

I went back to standard after this measurement, and am now strongly contemplating an NB subframe swap before this car does a trackday at the 'Ring this coming May.... 20mm total bumpsteer would be pretty interesting during some parts of the track, especially the 140mph huge compression that is the Foxhole....

Thanks for the data points! Would be interesting to see what happens without the rack risers.

I measured bump steer on an NA with v8r’s subframe, customer wanted rack spacers installed. Measured a little toe out with compression, put a 1/8” spacer in which made it worse. If anything I wanted less space. You might try the same.

Im 90% certain this was stock ‘90 knuckles, don’t remember if he had different outer tie rods.

The unknown variable there is V8R's dimensional accuracy. I'd give that data an *

But overall, it would be more useful to the community to start a new thread with bumpsteer data.

Emilio, do those upper ball joints fit v8r upper arms? I believe I saw someone had used the v8r ball joints on stock arms but can't find that. Any idea if they are the same? Thanks

No idea, sorry. If OEM NA ball joints fit the V8R FUCA, then ours will. If they are built for some other non-OEM compatible UBJ, then no.