NA2 headers on my NA1 - what additional parts do I need?

[bruckner]

I am running the stock 1991-1994 cat converters. To run these you need adapter pipes that go between the header and the cats and o2 wire extensions. There are only 2 02 sensors on 1991-1994 nsx’s. Now if you have a 1995-1996 nsx you don’t need the adapter pipes mentioned in my 2nd sentence, you will use your factory adapter pipes between the cats and your exhaust but you will need o2 extension wires for the front two o2 sensors , your rear sensors on a 1995-1996 nsx are in the cats and will stay in the same place.

I'm actually looking at swaping in the whole NA2 setup (headers, cats and muffler), hence my question regarding the clearance of the 91 sway bar. I remain unclear about this.

Thanks for pointing out the 2 secondary o2 sensors are not found on my 91. I suppose these plug into the NA2 cats and should be blocked off for an NA1 application?

Also, using NA2 primary o2 sensors would eliminate the need for extensions?

 

[socalx]

Yes if you are swapping everything, your primary o2s would go in the header, and your cats would either have the o2 sensors plugged or you can run actual o2 sensors just not connected.
1) I still think you need o2 extensors for primary o2, however you may be correct that if using the new o2 sensor maybe you don’t need thes? 2) I honestly don’t know on the rear sway bar, but I think the rear sway to run (and what I run anyway) is the nsx type s / 99 nsx zanardi

 

[JLCoolman]

I'm actually looking at swaping in the whole NA2 setup (headers, cats and muffler), hence my question regarding the clearance of the 91 sway bar. I remain unclear about this.

Thanks for pointing out the 2 secondary o2 sensors are not found on my 91. I suppose these plug into the NA2 cats and should be blocked off for an NA1 application?

Also, using NA2 primary o2 sensors would eliminate the need for extensions?

I started out with a full NA2 setup on my 92 (well, I was running a set of NA2 test pipes, but same concept).
I've never heard of certain years having clearance issues with the 91 sway bar. I didn't have any problems, but I have a 92.
Yes, like [MENTION=9515]socalx[/MENTION] said, I would use a set of o2 bung plugs on the NA2 catalytic converters, and probably steer away from just plugging them with the NA2 secondary o2 sensors to prevent from damaging them.
Or, if you had a set of bad o2 sensors, you could cut their wires and use them to act like bung plugs. I have o2 bung plugs on my test pipe.
Finally, once again like [MENTION=9515]socalx[/MENTION] said, I still think you will need extensions, as the issue is not with the length of the primary o2 sensor wires (NA1 or NA2), but lies with the length and location of the o2 sensor connectors on the engine's wire harness.

Good luck and let us know how it goes, unless you've already completed this project, which if you have you'll know all the ins and outs of it yourself now, lol.

 

[BAVARIA]

Regarding the rear sway I want to weigh in. I have a /94 acquired 10 years ago. After owing the car for 1 year or so I was able to buy a full NA2 header to muffler (including cats) system at a very reasonable price (thank you again Paul Brylek and hope all is well at your end) and it was relatively new. I needed a later year rear sway bar to clear the NA2 cats. I'm 100% sure of this since the NA1 bar is still adorning my garage -- LOL. Here's a link that might be worth a read. http://nsxprime.com/forum/showthread.php/107140-NA2-Exhaust-install-in-NA1

I never did a dyno test but by the seat of my pants car was somewhat more lively.

Best,
Jeff

 

[JLCoolman]

Regarding the rear sway I want to weigh in. I have a /94 acquired 10 years ago. After owing the car for 1 year or so I was able to buy a full NA2 header to muffler (including cats) system at a very reasonable price (thank you again Paul Brylek and hope all is well at your end) and it was relatively new. I needed a later year rear sway bar to clear the NA2 cats. I'm 100% sure of this since the NA1 bar is still adorning my garage -- LOL. Here's a link that might be worth a read. http://nsxprime.com/forum/showthread.php/107140-NA2-Exhaust-install-in-NA1

I never did a dyno test but by the seat of my pants car was somewhat more lively.

Best,
Jeff

Thanks for the clarification, Jeff.

I guess I didn't run into that issue since I was using test pipes and not NA2 catalytic converters.
Good to know if I ever have to/decide to run some cats.

 

[mwagner10702]

Assuming you haven't purchased parts yet, I would recommend going with a set of Pride headers. I put a set on my 1994 and it made a big difference and I didn't have to mess with adapters and the like. No issues with the rear sway bar either (I am running the Zanardi rear sway bar).

See my thread here for more information: http://www.nsxprime.com/forum/showthread.php/210193-Headers-going-in-this-week