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Must Have Items for the NSX (Future-Proof)

Joined
21 February 2019
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I have a 1991, 1995, and an 03 that I would like to "future proof", meaning get parts that would eventually become hard to source or keep parts that should be kept on hand. I know most of you keep an extra relay and all, I dont have it.

Would you please assist to start a list of let me know what to start buying, I plan on keeping these cars for at least another 10 years. Would appreciate any feedback and also where is the best place to source them.
 
Similar discussion already going on in NSX General Discussion forum. Might want to close this discussion and just add to that one.
 
Buy Main Relays. Lots of them.

Or buy the new main relay conversion kit, so that you can walk into Autozone and purchase a modern $10 relay whenever you need to.
 
 
Would like OEM preferably for anything that is visual, but the guts (relay, etc) dont matter.
Then nothing visual is going to keep the car from running, but anything that dissipates watts (ie electronics) or made of rubber is going to be an issue eventually. I'd be on the lookout for a spare ECU for the 95, very rare. For the purist keeping the interior of an NSX in OEM trim is getting harder and harder as so many of the original parts are out of production.
 
Side window glass. The lack of it is a problem and insurance will (and has) total out the car. It can be shipped in from Japan at great expense., but unsure if it would meet USDOT regs. And if it doesn't meet DOT then insurance can't specify it as replacement and, hence, a full write off.

So I don't recommend reporting a window smash to your insurance.


I strongly suspect the odd ball 1995 ECU can be retrofitted with a 1996 or 1997. I am speaking from ignorance as I don't own either of these cars, but I don't know of any control or feedback systems or sensors that are different or cannot be changed to suit the later ECU. One day this question will be answered.
 
I'm replacing all the wear and tear items on my car. All the brittle trim pieces that degrade over time and crumble to pieces. Door window trims and switch covers, all the rubber seals, door handles (interior & exterior), sash covers, front lip, headlight, tail lights, floor mats, console trim pieces, window regulators, coil packs, relays, plastic covers in the engine bays etc...
 
Then nothing visual is going to keep the car from running, but anything that dissipates watts (ie electronics) or made of rubber is going to be an issue eventually. I'd be on the lookout for a spare ECU for the 95, very rare. For the purist keeping the interior of an NSX in OEM trim is getting harder and harder as so many of the original parts are out of production.
Are NSX ECU's prone to failure? I have not heard anything of ECU's failing, this is the first time I've heard of keeping a spare ECU. Now I'm running an aftermarket Mine's ECU but holding on to my OEM, but it wasn't really for keeping a spare as much as returning to stock. I know that the ECU in my 1997 Lotus went bad but that's because Lotus workmanship was always poor and they used low-quality solder inside the ECU that is prone to cracking. I would expect Honda quality and workmanship to be much better.
 
Are NSX ECU's prone to failure? I have not heard anything of ECU's failing, this is the first time I've heard of keeping a spare ECU. Now I'm running an aftermarket Mine's ECU but holding on to my OEM, but it wasn't really for keeping a spare as much as returning to stock. I know that the ECU in my 1997 Lotus went bad but that's because Lotus workmanship was always poor and they used low-quality solder inside the ECU that is prone to cracking. I would expect Honda quality and workmanship to be much better.
Not really. The ECU is built to near military-grade for the 1980's. It's a robust chassis with an isolated PCB and uses high quality components. The only real danger are the liquid capacitors that, like the other ones on the car, can swell and burst causing damage to the PCB. There are only a few of those on the 91-94 boards. Not sure about the 95-96.
 
There's only 2 electrolytic capacitors on 91-94 ECUs. On some of the ECUs I've chipped for people I've replaced them, but so far have never seen any that have been leaking.

As far as ECU retrofits for 95/96 go, I think the only thing I would bother with is either full standalone or converting to cable throttle and installing a 91-94 ECU. The 97+ is either going to be an auto ECU which won't run quite right and is tuned for the milder automatic cams or a C32 ECU, which would probably run ok but still won't be optimally tuned for the C30.

Parts to stash: Door front sashes, exterior door handle assemblies, exterior window trim, door and trunk gaskets, window regulators, engine gaskets, transmission synchros and bearings.
 
The 95/96 model was a bridge between the early NA1 and later NA2 cars. Its the first year of TBW and early OBD-2 with some of the 97+ upgrades but still with a 3.0L/ 5 spd. Though the 5 speed itself is unique with a different 2nd gear and mainshaft. The ECUs for those years have unique part numbers from all other NSXs. Probably for a reason. I seriously doubt a 91-94 will work on a OBD-II/TBW car. I suspect a 97+ won't either, their ECU internal components look significantly different than the NA1s and are also completely different PNs. I guess it might kinda work, but doubt it'll work right. Love to see someone try it and see what happens. Do ECUs fail? All things electronic that radiate heat will eventually fail, entropy is a bitch, but its true NSXs are very well designed although Ive seen more than one thread of folks looking for replacement ECUs so yes, it happens. And getting them repaired is iffy at best, when I see some repair house say they have a refurbished NSX ECU I always wonder, "how did you check it?". Of course if you're willing to do some re-engineering of the car to fit in an aftermarket solution go for it, but its definitely not a original car anymore and even that road has its limitations. The ECU does a lot more than just control the engine. So yeah, it should probably be on your list if youre planning keeping the car a long, long time because without an ECU a car is basically a doorstop. Again Just one mans opinion.
 
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It should work, it just won't be easy, you'll have to convert to a cable throttle and you'll lose OBD2 functionality. The engines are pretty much identical with the exception of the DBW throttle. At that point you should just go standalone though.

The 5 speed transmission being "unique" has absolutely nothing to do with the ECU.
 
It should work, it just won't be easy, you'll have to convert to a cable throttle and you'll lose OBD2 functionality. The engines are pretty much identical with the exception of the DBW throttle. At that point you should just go standalone though.

The 5 speed transmission being "unique" has absolutely nothing to do with the ECU.
I believe @docjohn is running a 3.2 long block with the 96 intake manifold, TB and ECU. So, the maps are probably close enough, since it has never been tuned. I believe LarryB did the conversion long ago.
 
I have a 1991, 1995, and an 03 that I would like to "future proof", meaning get parts that would eventually become hard to source or keep parts that should be kept on hand. I know most of you keep an extra relay and all, I dont have it.

Would you please assist to start a list of let me know what to start buying, I plan on keeping these cars for at least another 10 years. Would appreciate any feedback and also where is the best place to source them.

The 1991 and 1995 have a huge amount of parts interchangeability (forget the 1995 ECU issue; just swap the engine & ECU). Purchase another '03 - '05 and you are now future proofed in terms of a 'parts car' to keep at least one of each running.

People are obsessing about the wrong stuff. What is going to stop you dead is body damage and it doesn't have to be major body damage. Are bumper covers and fenders and the glass that Drew mentioned going to be around in 15 years? We had a period where critical transmission components were unavailable for a while. Damage to an A arm or hubs are a stopper if they are out of production. Main EFI relays will be the least of your issues and work arounds are cheap easy if you do not want to repair your existing relay.

Perhaps stock up on the parts for that J swap kit in case your 1991 blows a head gasket on the track in ten years.
 
I may try oil of Ole^ on the wrinkling interior trim..
 
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