1991 NA1 Honda Nsx parts suggestion

[podon81]

Hello,
I'm from Italy.
I own a 1991 Honda Nsx NA1 M/T with only 20k kilometers.
The car has been parked in my garage for 11 years and I'm in a restoration now.
I would like to change the COMPLETE exhaust system from the engine to the rear end. So I need headers, catalytic converters, exhaust.
For the headers, I aim for your suggestion about them and all the other parts, in order to achieve the more power possible from the engine. The only thing I ask is a valveled exhaust, quiet at low rpm and raging at full throttle.
I also need intake system. I need your suggestion. I don't want too much noise.
I need a clutch too, because my one's gone.
I want to put out of the engine more power and I thought to install:
1. New profiled camshafts
2. New injectors and throttle body
3. New standalone programmable ECU
4. New rims (same color and design as in the attached pictures)
5. Rear NA2 rear valance style (as shown in the attached picture)
Suggest me any other modification you think can increase the power of the car, but without distorting the nature of the engine.
Thanks!

 

[centerpunch]

Just in case this is a real request, these guys can fix you up.

Supercharger & Turbocharger Systems & Accessories - NSX, 1991-05

www.scienceofspeed.com

 

[asylum]

Once you have done header and exhaust, if you really want more power, you will have to look for a 3.5 liters kit or a supercharger/turbo. Yes you can gain some hp here and there with a lot of other (expensive) parts, but it will not be very cost effective.

If you want to give life to your 91, put the JDM gears. Perhaps (or not) with a shorter final. This will be more cost effective than any other NA mods once you have done header and exhaust.

Reputables headers and exhausts will give you more or less the same hp gains. So go for the sound and the look you like. Staying 3.0 l NA, high flow cats (or even test pipes) will give you a (very) little bit more. But nothing to write home about.

 

[Honcho]

Your list of mods will yield about 300-330 PS at the crank, depending on components and how well the car is tuned. That's about the max for the 3.0L. If you want more, you'll need to consider forced induction (turbo or SC) or ITB and a stroker. A 3.3-3.5L stroker kit with ITBs and big cams will approach the power of a small supercharger (~360PS), but will be vastly more expensive.

 

[edvc520]

20k km and the clutch is gone already?

 

[podon81]

Thank you guys! I do not want to make drastic changes to the car, such as turbo kits or strokers. I just want some improvements because it needs to be as original as possible. So could you give me some advice along these lines? Thanks!

 

[centerpunch]

Hey, what happened to the other “podon81” who wrote the first post and wanted to change everything?

 

[podon81]

It's always me! But I don't want to use kits, strokers or turbos. Everything else I confirm! Here is my car after 11 years stuck in my garage...

 

[centerpunch]

OK, here's a suggestion. For eleven years you've had a dusty old car with zero horsepower.

1) Wash the car. (Duh.)

2) Get the car running in totally stock form. That's 270 horsepower and 8000 RPM. (That's 270 more horsepower than you are used to having.)

3) It probably needs new tires. (I don't know about Italy, but here you can get sticky Falken 615's for $600 a set.)

4) Drive it for a few years.

5) You'll love it.

https://www.motortrend.com/features/1991-acura-nsx/

 

[podon81]

Please give me your suggestion. The car is already away from my garage and I need to order the parts.

I've driven the car as it is since 1991. At the time, it was an unsurpassed supercar. I've had many other supercars, Maserati, Porsche, Aston Martin and Jaguar. But the Nsx has something more...
Please help me to find the right compromise with the parties I mentioned in the first message and with your suggestions.
I really appreciate it!

 

[centerpunch]

Unless you go to supercharged/turbocharged, you can spend as much as you want and it will still be slower than your other modern cars. And you'll never get any of that money back when you eventually sell the car. In fact, stock is usually worth more.

Appreciate the NSX for what it is, don't try to make it something it is not.

(Just my opinion, and I am a crotchety old dude!)

 

[podon81]

I do appreciate the NSX more than one by one of the other cars I had!!!
May be I can't explain my purposes.
I just want give 30/40 hp or more to car not to achieve the power of a modern supercar, but to "free" the power Honda in the '80's couldn't express for the Japanese laws in terms of supercar. To say one, the headers are made of cast iron to limite thr power of the car.
I only want to update, as indicated in message number 1, these details that are from a car designed in the 1980s

 

[docjohn]

A comptech supercharger system can give you want you want, but get your barn find sorted first.

 

[Honcho]

I do appreciate the NSX more than one by one of the other cars I had!!!
May be I can't explain my purposes.
I just want give 30/40 hp or more to car not to achieve the power of a modern supercar, but to "free" the power Honda in the '80's couldn't express for the Japanese laws in terms of supercar. To say one, the headers are made of cast iron to limite thr power of the car.
I only want to update, as indicated in message number 1, these details that are from a car designed in the 1980s

If that is your goal, just add a set of quality headers and the exhaust you prefer. That's all you really need to do with the NSX. Enjoy the car!

 

[centerpunch]

I'm not sure how much time you spend driving on the street at over 5000 rpm, because if you spend a bunch of money on cams and intake and custom ecu and injectors, that's the only place where the slightly increased power will be.

But hey, knock yourself out, it's your car and your money, and whatever makes you happy, it's all good.

 

[podon81]

I'm not sure how much time you spend driving on the street at over 5000 rpm, because if you spend a bunch of money on cams and intake and custom ecu and injectors, that's the only place where the slightly increased power will be.

But hey, knock yourself out, it's your car and your money, and whatever makes you happy, it's all good.

I kindly ask everyone to address me. I saw the magnificent work @Honcho made on his car. So please tell me which are the best parts to buy as I asked in my first message and where. Thanks!!!!

 

[Honcho]

I kindly ask everyone to address me. I saw the magnificent work @Honcho made on his car. So please tell me which are the best parts to buy as I asked in my first message and where. Thanks!!!!

Contact MITA Motorsports and buy the RFY GT 4.1 exhaust and RFY headers.

 

[docjohn]

Is Adnan still in Business?

 

[Heineken]

Yes, he is.

 

[MotorMouth93]

Yeah he's still around. @A.S. Motorsport is his account here. Still sells the ITB kits and a few other NSX items and works on them.

For this sort of build, chipping the stock ECU might actually be a really good way to do it since the mods are pretty minor.

Headers/exhaust will get you 20-30hp, RFY makes really nice stuff as Honcho said, and Pride is a cheaper alternative that's still pretty decent. Stock intake and throttle body are fine, the big bore TBs are very expensive and offer little to nothing as far as gains go. Injectors can help a bit, RDX are a popular choice but there are other options.

Cams are probably not worthwhile, you're looking at $5000+ there for dubious gains by the time you've upgraded the valve springs and gotten adjustable cam gears, and if you aren't doing the work yourself it will be thousands for the labor to install them unless you do it during a timing belt service.

 

[TANTO]

I just want some improvements because it needs to be as original as possible.

I don't believe Honda left anything on the table for you to exploit except for the lack of a header you mentioned. Exhaust may or may not give you any more power - but likely make it feel faster. Generally folks do some type of Intake such as the Comptech/uni-filter which does enhance the sound and maybe a couple of HP at 8k. The R ring and pinion and/or non US tranny gears would be next but these parts are now hard to find and you WILL notice the higher rpms at freeway speeds which is not great for "cruising" -so you may not like. IMO many of the parts you are thinking of such as cams, ecu's, Tb's will not make any noticeable difference (sad but true - it's not a SB chevy) and take the risk of problems "way" up and not at all with your thoughts on "keeping close to stock". OE clutch is really good. This is just not the car to burn rubber or powershift. Regarding the sound, for most of the exhausts out there Honda's firing order ensures exactly what you say your want - ie quiet at low rpm and loudish at 6-8, so any header exhaust combo will likely please you as well as give you a solid 20 ft lbs or so of torque which you will really like. Comments from my antidotes over the years listening to "other" folks like the above - so FWIW.

 

[asylum]

Do the maintenance needed (TB, cooling hoses, various gaskets, LMA if sticking). Stock clutch is fine.
For performance : header, exhaust, JDM short gears will be cost effective.
For chassis : good pads, coilovers, good tires on nice wheels.