Hello guys. I'm in the middle of swapping an ap2 subframe/upper control arms to my ap1 and have a question about the rear knuckles. Per their respective part numbers, ap1 and ap2 have different rear knuckles. But my question is are they interchangeable? Has anyone looked at them side by side? Are there any(if any) differences between the two? Thanks in advance.

 

it's different geometry

go get the ap2 components for your swap

 

I know there is a difference between the suspension geometry of both and my question is would using the ap1 knuckle have any negative effect on the handling of the car?

Have you seen both knuckles off the car, next to each other?

 

no I haven't but Honda isn't the kind of company to make 2 different part numbers without a significant difference

Here's what I a search revealed:
http://honda-tech.com/honda-s2000-5/...rison-2173176/

"One owner’s research found the front suspension received a new front upper arm (left side only); some owner’s speculate that was to correct difficulties in setting the camber on that side. There’s a new part number for the self lock cam nut and bolt at the lower arm’s adjustment point. There’s a new part number for the front lower arm but no apparent geometry change; it’s thought to be a test spec. There are no apparent changes to the front sub frame. The rear suspension received a new knuckle and they moved the mounting point for the control arm. The bushing for the upper arm now has a separate part number; previously it bundled with the part. The tabs for the rear upper arm in rear sub frame have a new part number; it could be durability or geometry change. Front and rear hubs remain the same. "

my advice; if you want the benefit of the ap2 suspension; then do the full swap with the ap2 knuckles

 

Ok, thank you.