91 Engine Specifications

[dteirney]

Does anyone know where I can find the engine/gearbox specifications for a JDM 91 NSX?

Cheers,
David

 

[Edo]

Try the Hyper Rev NSX book.
Hey oddly enough, I found that the JDM NSX pushes 280ps..which doesnt quite work out to 270hp of the US spec NSX.
What does the JDM NSx have on it that makes it a *shade* more powerful? Anyone know?

 

[NSXPERT]

my guess is that it is the cat converters, the US has stricter emissions requirements. this is the same reason that if you look at HP readings in CAR (uk) and Car and Driver the euro spec cars are usually about 5hp stronger.

 

[Tel]

You will find that Japanese power outputs given for the JPD cars are based on 100 Octane Fuel.

 

[Jimbo]

I don't believe that the 100 octane would make a difference. Higher octane doesn't in and of itself translate into higher power output.

The octane rating is an indication of resistance to knocking at a given compression level. The higher the octane rating the higher the compression.

But for a given compression, higher octane provides no increased power.

At least that's how I understand it.

Jim

------------------
1992 NSX Red/Blk 5 spd #0330
1991 NSX Blk/Blk Auto #3070 (Sold)
1974 Vette 454 4 spd Wht/Blk
Looking for a 76-79 Honda Accord

 

[ak]

True, but you can use more agressive timing/fueling ECU map with higher octane gas.

 

[Jimbo]

Do the Japanese cars use a more aggressive timing/fueling ECU map?

-Jim

------------------
1992 NSX Red/Blk 5 spd #0330
1991 NSX Blk/Blk Auto #3070 (Sold)
1974 Vette 454 4 spd Wht/Blk
Looking for a 76-79 Honda Accord

 

[Lud]

Originally posted by dteirney:
Does anyone know where I can find the engine/gearbox specifications for a JDM 91 NSX?

Cheers,
David

Specifically what specs are you looking for? I can probably dig them up for you.

 

[SpeedDemon]

Originally posted by Jimbo:
I don't believe that the 100 octane would make a difference. Higher octane doesn't in and of itself translate into higher power output.

Correct.

In practice though, adding race gas (with no other changes) can in fact increase power/acceleration on many newer cars, because the ECU itself will change conditions.

For some cars, the ECU attempts to modify the timing curve over time to try to keep it as aggressive as possible without hitting knock. Usually they'll advance it, get a hair of knock, then back it off. This process usually occurs in closed loop mode during cruising.

Because race gas allows for more advanced timing without knock, cars with these types of ECU's will benefit from simply adding race gas, as the factory ECU will bump up the timing curve beyond typical specs.

I've had firsthand experience with this on Eclipse Turbo's. The ECU's on Eclipse's are quite aggressive. You can gain significant power just by adding racing gas, without making any other change. In the case of modified Eclipses, it would sometimes translate into gains of over 20hp with no other changes.

For those who have the ability to tweak their fuel settings, running race gas also allows you to run leaner and generate more power. Race gas runs cooler than normal gas, I've seen exhaust gas temp's drop 40-50 degrees Celcius with the addition of race gas. (We then had to lean the car out to dial the temperature back up to optimal).

I wouldn't be surprised if the NSX ECU pays attention to octane/knock (it has a knock sensor) and it could very well advance the timing if you run race gas.

Once I get my datalogging cable repaired, I can log the timing curve on pump gas and on race gas and see if there's any difference.

Best,
Marc

 

[BITeR]

Correct.

In practice though, adding race gas (with no other changes) can in fact increase power/acceleration on many newer cars, because the ECU itself will change conditions.

For some cars, the ECU attempts to modify the timing curve over time to try to keep it as aggressive as possible without hitting knock. Usually they'll advance it, get a hair of knock, then back it off. This process usually occurs in closed loop mode during cruising.

Because race gas allows for more advanced timing without knock, cars with these types of ECU's will benefit from simply adding race gas, as the factory ECU will bump up the timing curve beyond typical specs.

I've had firsthand experience with this on Eclipse Turbo's. The ECU's on Eclipse's are quite aggressive. You can gain significant power just by adding racing gas, without making any other change. In the case of modified Eclipses, it would sometimes translate into gains of over 20hp with no other changes.

For those who have the ability to tweak their fuel settings, running race gas also allows you to run leaner and generate more power. Race gas runs cooler than normal gas, I've seen exhaust gas temp's drop 40-50 degrees Celcius with the addition of race gas. (We then had to lean the car out to dial the temperature back up to optimal).

I wouldn't be surprised if the NSX ECU pays attention to octane/knock (it has a knock sensor) and it could very well advance the timing if you run race gas.

Once I get my datalogging cable repaired, I can log the timing curve on pump gas and on race gas and see if there's any difference.

Best,
Marc

I find this topic very interesting! Has anyone concluded anything since this discussion? Does the NSX ECU advance timing if better fuel is added?

I know my NSX can run on 92 Octane and I have 98 easily available. If the ECU does indeed advance timing I'd like to know.
Can't find more in the forum search.
here is the complete thread: http://www.nsxprime.com/forums/showthread.php?s=&threadid=1718

EDIT: Well the thread is this one, so never mind clicking the above link.

 

[docjohn]

On the subtopic ? if jdm ecus are diferent,I do know that the s2000 ecu has a more agressive profile due to higher octane in Japan and makes about 5-10 hp more,you can search on s2kinternational.