A supercharged NSX.. revert back to stock or keep it?

[Rvdavid]

Hey Everyone.

I hope everything is going well. Earlier this year, I acquired a 96 NSX NA1 equipped with a supercharger. Unfortunately, the car has a vague history, and the seller didn't know much about its past. Over the year, I’ve encountered a few major issues:

Comptech Supercharger with Piggyback ECU

The supercharger seems to cause performance inconsistencies, especially around the 3000–4000 RPM range, where it stutters and fails to deliver a predictable, linear power output. Occasionally, it triggers an engine error, making the car run erratically. Thankfully, this can be reset by simply turning the engine off and on again.

Engine Crack

There was a crack found under the No. 2 cylinder, which led me to replace the engine. The lingering question is whether the supercharger contributed to this damage or if it resulted from mishandling by the previous owner.

Now, I’m at a crossroads: should I revert the car back to its stock configuration, or should I keep the supercharger and invest in tuning it? I’m working with a local shop that has quoted me $6,500 for tuning with an AEM chipset or $8,000 for a tune with the SOS LINK. However, I’ve heard that the AEM system is prone to issues and breakdowns. Alternatively, I could pay $2,000 to restore the car to stock and sell the supercharger.

Most people I’ve consulted recommend removing the supercharger. My goal is to achieve a smooth, reliable ride, but I’m also drawn to the thrill of a supercharged setup and the added speed it brings. I’d like to understand more about the supercharger’s impact: Could it potentially harm the engine again, or was the previous issue more likely due to mishandling? Is there a way for the shop to tune it safely to prevent further engine damage? And if I choose to run it with lower PSI for safety, would that defeat the purpose of having a supercharger?

 

[MotorMouth93]

Cracking a cylinder is a rather odd failure, usually the ring lands on the pistons will go out before anything else, poor engine management is very likely to be a contributor here. Old piggyback setups are highly questionable at best, so if you want to continue running the supercharger I think the proper standalone and tune option is the way to go for sure. With a proper tune there's no reason a CTSC car can't be reliable as they don't really make all that much power compared to what the block can handle, but when it comes to modifications like that there's no way to truly tell how long it will last. The big issue with the CTSC is that without an intercooler the intake air temps get absolutely insane, as @RYU and a few other members will tell you so that might be worth rectifying in the pursuit of reliability.

The car will be far more reliable in stock form and far less of a money pit.

 

[tdiggity]

$6500/$8000 for ecu + tuning seems high. I would give SoS a call to see what they would charge to install and tune. They are ~6 hours away and have a lot of baseline maps to start from to speed things up. Rates will probably be less too (they were for me when I did mine pre covid). If they can knock it out in a day, you could drive through the night, let them knock it out in a day and drive back. Or stay overnight.

 

[Rvdavid]

$6500/$8000 for ecu + tuning seems high. I would give SoS a call to see what they would charge to install and tune. They are ~6 hours away and have a lot of baseline maps to start from to speed things up. Rates will probably be less too (they were for me when I did mine pre covid). If they can knock it out in a day, you could drive through the night, let them knock it out in a day and drive back. Or stay overnight.

SoS is much more expensive than this - it could easily be a five figure job.

 

[tdiggity]

SoS is much more expensive than this - it could easily be a five figure job.

For the ecu install and tuning? That doesn’t seem right to me. Link ecu is $1400. I wouldn’t think uning is going to be $5000.

 

[Rvdavid]

For the ecu install and tuning? That doesn’t seem right to me. Link ecu is $1400. I wouldn’t think uning is going to be $5000.

Everything. It’s a package deal: pump swap, tuning and parts + labor.

 

[tdiggity]

Everything. It’s a package deal: pump swap, tuning and parts + labor.

fair enough -

Do you know the replacement engine's history? If staying FI, get the ecu and tune. No guarantees, but at least it's better than the piggy back (depending on what it was).

If you go NA, you could do something like JDM gears for same cost of ecu and tuning and it will give you a bit more thrill while driving.

 

[Rvdavid]

fair enough -

Do you know the replacement engine's history? If staying FI, get the ecu and tune. No guarantees, but at least it's better than the piggy back (depending on what it was).

If you go NA, you could do something like JDM gears for same cost of ecu and tuning and it will give you a bit more thrill while driving.

It has about 58k miles (the vehicle had about 59k when I bought it). 1992. I believe it was an original NA setup for that donor car.
The current setup already has a short gear. I'm thinking of upgrading headers + exhaust if I don't do the tunning.

 

[Spoolinfool]

Run the NA setup and get the kinks worked out. Enjoy the car like that for bit then you can throw the supercharger on later after more research or sell it now and find a better supercharger setup later. Life's short and there's no point in not driving it until you decide what path you want to take.That being said a supercharger will add more stress to an engine that was only designed for NA application. The pistons are fragile and prone to ringland failure and factory headbolts have less than ideal clamping force when subjected to high cylinder pressure spikes during detonation. Finding good tuning is another hurdle that you'll eventually come to. More setups fail due to poor tuning and lack of maintenance than anything else!The Nsx is perfect with 400-500hp but it takes abit of work to get there so after research you can decide if you want to reopen that chapter.

 

[Rvdavid]

Here are the decisions:
1. The supercharge currently runs around 70%, about +7psi. It adds ~60hp but eats around 20-30hp to drive it—the parasite loss. There is simply no point in keeping it.
2. The crack should be a mishandled issue.
3. I will upgrade a 4.4 LSD to finish that type-r full transmission set.
4. With a header and better intake.

Thank you all for helping me here!