Does anyone have measurements of the stage 4 bushings? Has Indy released any info on aftermarket bushings for the stage 4s? Would Ace bushings work?
Someone needs to nerd out properly on these and post all the measurements for us other nerds to go over. The madness sure seems to be creeping in strongly for me.
Here are my notes after comparing models. In front of me, I have a:
146 Stage 4
215 Stage XI
169 Stage XI Standard
169 Stage XI Forged
All fairly fresh, nothing is super squished or destroyed on these, for the record.
HEIGHT
Interestingly, the 215s are the only ones that measured a full 55mm to the center of the axle (taking measurement from each axle end and averaging the four). All the others were 53-54mm like the forged model, including the Stage 4.
BUSHINGS
The Stage 4 bushings are indeed taller like the 215 bushings. They have a 14mm barrel and 12mm cone, same as a fresh set of AF1 bushings.
HANGER
Apples to apples, the Stage 4 hanger looks to be the same geometry as the 215 hanger. Only difference I can see with the naked eye is a very slightly longer pivot on the 215 hanger (like 1-2mm at most).
BASEPLATE
The Stage 4 baseplate is slightly different. With the naked eye, it’s a little lower than the Stage XI 6-hole plate (not thinner like the forged plate, but the kingpin base and pivot base sit lower than the Stage XI plate, and I’m guessing the angles are slightly different, but can’t really confirm without a better set of measuring tools). The lettering running up the sides of the baseplate is smaller as well, so you can easily tell these baseplates apart that way if you get things mixed up on the workbench.
COMPATIBILITY
So, NHS says no, but I say yes. The 215 (to me) looks like it comes on a Stage XI plate with a longer kingpin, and the the 215 and Stage 4 hangers are so similar to the naked eye, if not identical, logic would dictate that the Stage 4 hanger would also fit on a Stage XI baseplate, and it does.
I popped the Stage 4 hanger on the regular 6-hole plate from the 169s (for the shorter kingpin) as well as the smaller bushings that come stock in Stage XIs, and it all comes together quite nicely, no red flags on the fit of anything. You get a couple extra millimeters of kingpin clearance, too. May need to play with Ace washers or flat washers or something if they start hitting the hanger yoke, but that’s the only issue I could forsee happening with shorter bushings.
Hope this helps you get the most out of these. Here are a couple pics of the shorter pin with the Stage 4 hanger.