Why is the NSX-R 4.235 final drive not compatibel with power-steering

Recently, I was looking at the NSX-R 4.235 final drive.
SOS sells these for both teh 5-speed NA1 and 6-speed NA2 cars

However, they state that the NSX-R final drive for teh 6-speed is not compatible with the power steering.
Does anyone know WHY this is??

Probably shouldn't have started another thread for this if you did a search... There's a lot of info out there on this, iirc it's about the pulse generated by the final drive not matching what's expected by the power steering brain and thus it disables itself. You can drive the car but you will have no power steering in a ratio that was designed to be power assisted.

This is only an issue for 1997+ cars (US) These have a revised PS system and it does not seem to like the 4.23. The thing that is strange that when I was in Japan at Suzuka, a member of the NSX Club of Japan gave me the keys to his Type S for a lap around Suzuka, it had a 6 speed, PS, WITH 4.23!!! Uehara san thought it was strange we had an issue with this in the US. So still a mystery for sure.

Regards,
LarryB

hi Larry -- Are you sure the Type-S had a 4.23:1 final drive? The parts catalog shows it only applying to NSX-R.

ScienceofSpeed said:

hi Larry -- Are you sure the Type-S had a 4.23:1 final drive? The parts catalog shows it only applying to NSX-R.

Click to expand...

Hi Chris,

I thought it was based on revs/gearing. Maybe I am mistaken.

With that said what Chris and I both commented on is true, 1997+ w/4.23= no PS

So the window is actually 1991-96 for 4.23 and PS to be working fine.

Regards,
LarryB

...so the 95-96 cars with power steering will work with the 4.23?? If you happen to be wrong about that, I do have a rebuilt manual rack ready to install to save weight (a la Zanardi) but I'd rather not be a guinea pig! I was going to install it but I just drove a non-PS early car and I don't think I like it.

Larry, you are making life harder for me by tempting me to purchase the 4.23 again if so! I had all but given up on the idea of the 4.23 FD because the 6spd swap is expensive already, but still think if one is spending so much to swap anyways then why not go for broke and do the 4.23 and get something really special. I had taken comfort in the fact that I couldn't do the 4.23 anyways due to my power steering so I should just save the money but if the opportunity is there then I must reconsider.

Edit: I think I remember that the 4.23 ratio only works with the 91-94 diff, so still that hurdle to jump.

.my ps works works in my 96 with the 4.23