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S2k Steering Rack retrofit review

Joined
2 February 2016
Messages
67
I recently purchased the s2k steering rack from nsxmugen and wanted to give my feedback to help anybody who has been contemplating this modification.

Background:
Since I purchased the car in 2016, I had always found the steering to be incredibly slow. it was sometimes annoying on the canyon runs where i would have to steer hand over hand. Moving to lighter weight wheels, a momo monte carlo wheel and installing the steering rack knock bushing as well as the steering rack bushing kit from SOS helped me enjoy the steering more, but it was still really slow.

I had been following this thread http://www.nsxprime.com/forum/showthread.php/205188-S2k-rack-on-NA1/page7?highlight=steering+rack since it started and messaged RYU about it in 2019 after he installed it on his car. After a year of contemplating, I traded emails with nsxmugen about the kit and since my primary goal was a quicker ratio over power assist, the s2k rack was a better choice for me than the accord rack. I was very worried about losing the feedback of the manual rack but decided to try it out.


Results:
It took a little getting used to, but after logging 30-40 miles, I got used to it. I often read reviews for modifications that state "the car should have come this way". While I agree with that, I find that the revised steering feel for my type of driving is great - and that "the car could have come this way". At higher speeds I still have all the feel I was looking to keep - what a relief! At low speed, the assist isn't overpowering - its easy to point the car and you stop thinking about it - similar to how I don't often think about the steering in a modern car. The turning radius is also noticeably quicker which was a nice bonus. Similar to the S200's I have owned, I do feel a degree or two of muted response when the wheel is on center. However, some of that may be my alignment which I need to dial back in following the install. I may adjust to zero or near zero toe out and play with that.

Recommendation:
who is this rack for? I would say anybody that "notices" the slow steering speed and those looking for a significant improvement in low speed drivability - this rack is probably for you. I drove my friends nsx and mine back to back last night just to make sure i wasn't imagining things and the difference was night and day. At speed in the canyons, I could still feel what was happening under the front end - but it just required a lot less effort on my part (in both steering angle and force). If you are worried this will take some of the character out of the car, I would argue strongly that simply isn't true - it "modernizes" it.

Shout out to nsxmugen - he made himself available for a couple of calls during the install and provided great support for the questions I had. The rack and cross member are very well put together - and the wiring feels solid - like the OEM harness. it bolted right up and did not need any modifications to mount the rack to the chassis. I am not an expert when it comes to wiring and had a friend install at his shop - the controller was placed on the passenger frame rail - just as the instructions recommended. This has greatly improved my enjoyment of the car - i'm absolutely thrilled with this modification.

some pictures:
IMG_6401.jpg

IMG_6403.jpg

IMG_6411.jpg

IMG_6412.jpg
 
Beautiful NSX! I just had my first track day with the car. I'm very happy to report I was quite satisfied with the performance of the AP1 rack. I'm still saving oem manual rack but not looking back any time soon.

If anyone wants a more detailed on-track review just say so
 
Beautiful NSX! I just had my first track day with the car. I'm very happy to report I was quite satisfied with the performance of the AP1 rack. I'm still saving oem manual rack but not looking back any time soon.

If anyone wants a more detailed on-track review just say so

that would be great - I havent been taking the nsx to the track the last couple of years but I might just park the other car for the next event.

I also bought the S2K rack, but haven't installed it yet. How long did it take you?

I would guess 5.5 hours. 1 hours to bolt it up, and then we were incredibly careful with the wiring & installing the controller and we deviated a little from the instructions. If we were to do it again, it would probably be half that time now that we have done it once.

I did also do the front brakes while the car was on the lift - so that added to the time.
 
Someone sells a complete power steering retro fit? You can install a S2k power steering rack into a first gen NSX?
 
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A quick update - I had the front alignment adjusted today and went with approx 1/32” toe out. The car had toe in following the install and this adjustment has definitely dialed in the quick response/turn in I was looking for. The couple of degrees I was experiencing as a dead zone are essentially gone in the short drive from my friends shop back to my house. With the revised alignment, the car has transformed into exactly what I had envisioned. More miles to be logged this weekend. I can’t wait to take it to the track now.
 
I'm very interested in this mod as the slow steering of the NSX is probably my least favorite thing about it. My concern is reliability especially when on a canyon road where going off means more than just hitting a barrier. Is there any reason to think that going to a s2k rack would be any less reliable than the oem rack?
 
A quick update - I had the front alignment adjusted today and went with approx 1/32” toe out. The car had toe in following the install and this adjustment has definitely dialed in the quick response/turn in I was looking for. The couple of degrees I was experiencing as a dead zone are essentially gone in the short drive from my friends shop back to my house. With the revised alignment, the car has transformed into exactly what I had envisioned. More miles to be logged this weekend. I can’t wait to take it to the track now.
Toe-IN makes the turn-in sharper, but also makes the car more 'darty' in a straight line.
 
Toe-IN makes the turn-in sharper, but also makes the car more 'darty' in a straight line.
I didn’t summarize that correctly. It should have read “had less toe in following the install”. A more clear way for me to state it would have been “the car had more toe out” after the install. Anyways, that’s what the reasoning was behind my original post where I was contemplating to go towards zero toe - and adjusted today until I got the car where I wanted it.

‘I’m nowhere near articulate when I’m excited with a car mod.
 
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I'm very interested in this mod as the slow steering of the NSX is probably my least favorite thing about it. My concern is reliability especially when on a canyon road where going off means more than just hitting a barrier. Is there any reason to think that going to a s2k rack would be any less reliable than the oem rack?


Thats a good question Rainman. I would say the others that have done this mod and have had it installed for over a year or so are the only ones with any type of long term experience and testing. From my previous s2000's, the steering rack itself didn't seem to be an unreliable fault of the car - which leaves the integration to the NSX as the failure to be looking out for.

Are you thinking of a situation where the unit fails and locks the steering movement mid corner or something like that? if so, i'm going to try and not think about that this weekend when i'm driving the car.
 
[MENTION=32318]Ap2GT3[/MENTION] - I've been careful about expressing my thoughts on this mod. Throughout the years I've grown to despise reviews that pander to owner's confirmation bias and what not. Reviews where owners/customers come off so elated because their subconscious needs justification of their expensive purchase or simply are excited for a new mod. I think we all fall into this and it's human nature *shrug*. I probably go too much the other way now and I'm too conservative expressing my thoughts about things I really like.

I like this mod a lot for the manual steering gen 1's. There are trade-offs, but the gains outweigh them for me. I try to have the mod speak for itself. [MENTION=25108]illwillem[/MENTION] has driven it on track. He initially drove my car pre-alignment on the street and he didn't like it. After he drove it on the track I think he dislikes it less now haha. I'm not an amazing driver like he is so I've found the EPS and quicker ratio to be welcome. Perhaps someday [MENTION=16531]stuntman[/MENTION] can drive the rack on my car or someone else' car and he can provide a more objective review. Much thanks to [MENTION=6927]nsxmugen[/MENTION] for the work here! I can go another couple of years w/o wanting to sell my NSX.

btw... I did do 2 alignments on my car since the install. Each time I went closer to zero toe in front and each time it's felt better. I'm pretty close to zero toe now just like you are and will try a bit of toe in just to try it. I don't know exactly where i'm at yet because i've been making changes in the garage with a 1/4 to 1/2 turn on the toe links every few drives. I reckon i'm still at a slight bit of toe-out.

Glad you're still enjoying this old car! Seems like a nice compliment to your GT3.
 
Beautiful NSX! I just had my first track day with the car. I'm very happy to report I was quite satisfied with the performance of the AP1 rack. I'm still saving oem manual rack but not looking back any time soon.

If anyone wants a more detailed on-track review just say so

I also bought the S2K rack, but haven't installed it yet. How long did it take you?

[MENTION=32318]Ap2GT3[/MENTION] - I've been careful about expressing my thoughts on this mod. Throughout the years I've grown to despise reviews that pander to owner's confirmation bias and what not. Reviews where owners/customers come off so elated because their subconscious needs justification of their expensive purchase or simply are excited for a new mod. I think we all fall into this and it's human nature *shrug*. I probably go too much the other way now and I'm too conservative expressing my thoughts about things I really like.

I like this mod a lot for the manual steering gen 1's. There are trade-offs, but the gains outweigh them for me. I try to have the mod speak for itself. [MENTION=25108]illwillem[/MENTION] has driven it on track. He initially drove my car pre-alignment on the street and he didn't like it. After he drove it on the track I think he dislikes it less now haha. I'm not an amazing driver like he is so I've found the EPS and quicker ratio to be welcome. Perhaps someday [MENTION=16531]stuntman[/MENTION] can drive the rack on my car or someone else' car and he can provide a more objective review. Much thanks to [MENTION=6927]nsxmugen[/MENTION] for the work here! I can go another couple of years w/o wanting to sell my NSX.

btw... I did do 2 alignments on my car since the install. Each time I went closer to zero toe in front and each time it's felt better. I'm pretty close to zero toe now just like you are and will try a bit of toe in just to try it. I don't know exactly where i'm at yet because i've been making changes in the garage with a 1/4 to 1/2 turn on the toe links every few drives. I reckon i'm still at a slight bit of toe-out.

Glad you're still enjoying this old car! Seems like a nice compliment to your GT3.

^that's a good point [MENTION=20915]RYU[/MENTION]. However, I think that's what the forums are all about right? Providing feedback on mods like this. There have been mods where I haven't bothered reviewing and posting (and there have been a few of those on my nsx), but this one, really fit the need I had. I think its the mod I waited the longest for as well - over a year kicking the idea around. Had I had some kind of sponsorship etc, I think getting somebody else to drive the car like you said would be more appropriate. On top of that, every time I have reached out to you for your thoughts on a mod, you have cost me $$$.

Yes - the GT3 has been going to the track the last couple of years - the steering was one of the things I enjoyed most about the gt3 over the nsx. Might be time to get the nsx back out there now.
 
Reading through the opinions about this modification it reminded me of a comparaison done on Youtube between the different Cayman generations.
Two of the later models have an electric assisted steering while the earlier Cayman R has the hydraulic system.
The dead on center feeling was noticeable on the "electric" models while the "hydraulic" won the contest hands down.
https://www.youtube.com/watch?v=fxikL9CxBiM
 
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