The truth about NA1 vs. NA2 OEM Header/Exhaust - Dyno inside!

Adrien, glad the header worked out for you. I have always believe what Honda has been telling the world (C&D article from 1997). The HP gain of 3.2 mainly came from the "newly" designed header system, not from the 3.2. The increase in the engine capacity was mainly for the additional torque.

Congrat!!! It is too bad that we don't get to fiddle with DC, CC, and CT header with your car to see what they can do. You can always add the 1700$$ Mugen intake to get maybe 5 to 10 more hp!!!

yeha, but I want 500 rwhp. So what headers do I run??? :biggrin:

FUJITSUBO!!!!:biggrin::biggrin::biggrin::biggrin:

245 is pretty good. stock should be about 230-250 depending on the dyno.
Regardless what dyno to use, it was done at the same time with the same dyno, therefore, the 15hp is good solid legit number. If the Dyno was done on two different system, of course we can question it.
 
lol Jason and Ron, easy there. Causing fire on Prime is my job:biggrin:

But anyway, my car was dyno'd at autowave at 302 rwp. That was with Fujitsubo header, GT-One v.2 Titan exhaust (the most free flow, thank you), and test pipes. Before I got the Mugen AIS.

I was very skeptical about the number my self, even though I was pertty proud of the result, but after driven an stock 04 couple of weeks ago at SCA meet, I was convince my car has that kind of power. It was day and night difference, and I was shocked by just how much stronger my car after VTEC point.
 
Adrien, glad the header worked out for you. I have always believe what Honda has been telling the world (C&D article from 1997). The HP gain of 3.2 mainly came from the "newly" designed header system, not from the 3.2. The increase in the engine capacity was mainly for the additional torque.

yep, just like the differences between the AP1 and AP2 S2k. More displacement to gain torque, not horsepower.
 
thinking the same thing. 2.0-2.2L on the s2k :wink:

it was late, i was a week behind on work, was watching a bad movie and eating old pop corn :D

needed excitment and truth.
 
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I am really interested in the real life performance gain of that 15 HP.

Can you really feel that gain during normal daily driving or you have to get above 6k rpm to feel the different?

Looking at the information here, seems like the after market header is a better alternative on a NA1 since the cost is about the same, but would probably put out more gains even with the OEM muffler.
 
This is a great post to reiterate to those perhaps less mechanically savy than the next member. The results are directly related to the differences in design between a cast exhaust 'manifold' and a welded tubular 'header' The 97+ header manifold is just that - a 'header'. They have equal length tubes that scavenge the volume of exhaust from the cylinder prior to joining together into one common pipe. The 91-96 exhaust manifold is just that - a manifold. Great comparisson photos quickly show those reading the noticeable differences between the two and why a manifold that has one common plenum directly off the cylinder head doesn't enable the individual exhaust pulses from the cylinders to exit the engine one after another. 15HP is a direct result of not having all the engine exhaust rumble around in a common plenum prior to exiting the exhaust pipe and as a result less back pressure.
 
yep, just like the differences between the AP1 and AP2 S2k. More displacement to gain torque, not horsepower.
The 3.2 is an increase in crank stroke and not cylinder bore isn't it? That would be logical if desiring an increase in torque.
 
Thanks bigg :)

When we went for the test drive, Adrian didnt feel much difference because he had my fat butt in the car. :tongue: The car did feel very good from the passenger seat and was much stronger than a stock N/A.
 
The 3.2 is an increase in crank stroke and not cylinder bore isn't it? That would be logical if desiring an increase in torque.

No clue. Sorry can't help on the specifics of that. Ron???

For me, my NA2 header came with my my NA1 car when I bought it from the last owner. So the price is the same :) Included. I would love to goto a big name header/exhaust though.

Damn it Ron, wish I lived closer. With a generous donation of dyno time and low rates, I would be there all the time trying out various exhausts and mods. All the local shops where I live, I wouldn't trust them to tighten my lug nuts.
 
Hey Ron,
If I put on NA2 or aftermarket headers on my mostly stock 91 (with DF scoop, UNI filter and ARK exhaust), I could potentially be putting down 280 rwhp? I need to save up for headers!:smile:
Perry
 
Its Rob :)

ron98 is high octane gas in europe

wish i could change my user name but i cant. :tongue:

Perry, that would be a good upgrade. i want to get a set of 3.2L for my nsx. ;)

we where acturally throwing around the idea of building a turbo kit by using the stock exhaust manifold. cheap alternative to the 8000$ kits out there. wonder what kind of HP gains would be realized by using the 3.2L stock exhaust manifold over the 3.0L ones.
 
Hey Ron,
If I put on NA2 or aftermarket headers on my mostly stock 91 (with DF scoop, UNI filter and ARK exhaust), I could potentially be putting down 280 rwhp? I need to save up for headers!:smile:
Perry

I would expect ~260-265 rwhp range with those mods.
 
you can not tune out dynojet numbers. the correction factor is built into their software and as far as i know, dynojet does not allow an user input X factor like the dynodynamics systems. The most you can change on the dynojet is elevation but that does not make much of a difference between the elevation chages we are talking about. me and the shop owner next door was having a good laugh at the X adjustment in the Dyno Dynamics system. I use to dyno/tune on the dynojet system and he owns 1 of 3 AWD setup here in California and there is no user adjustable correction in DJ. Its built in.
hmm, that is new info for me. So dynojet is the way to go for the most true honest #s?

lol Jason and Ron, easy there. Causing fire on Prime is my job:biggrin:

I was very skeptical about the number my self, even though I was pertty proud of the result, but after driven an stock 04 couple of weeks ago at SCA meet, I was convince my car has that kind of power. It was day and night difference, and I was shocked by just how much stronger my car after VTEC point.
Just ask Autowave for the uncorrected#s, it should technically be similar to what you would get at Rob's dyno.

While I think your NSX is quite a bit faster than bone stock 02+ however, sound can be very deceiving, especially when you compare it to a bone stock NSX running to 0~30mph in a parking lot. Proper way to test out a car is not in first gear, not in parking lot.

I test drove Simo's NSX last Friday, that thing is mad loud, if I were to use ear plugs, I wouldn't be surprised it will feel like it just lost 30rwhp. You need to test drive Simo's NSX. That is probably the quickest 3.0NA with bolt ons.
 
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sound = HP :tongue:

simo's car is so stinken light. it has nothing inside.... does it even have a passenger seat... NO it does not :smile: its completely gutted. He just took of the A/C system and shed an addition 40lbs of weight.

Simo's car is decieving between the actural Hp and the "butt" dyno.

we should make a LACR track day. take our cars out there and run them. based on weight, time, trap speed we can get a hp rating off that.

Im going this Friday to lacr to run my supra. if anyone want to make it a day and go out to lacr, kick back and do a few pull it would be good expereince.

also a few fellow evo are going too.

gates open from 5pm, racing starts at 5:30 and ends at 10pm?
 
sound = HP :tongue:

simo's car is so stinken light. it has nothing inside.... does it even have a passenger seat... NO it does not :smile: its completely gutted. He just took of the A/C system and shed an addition 40lbs of weight.


Correction, believe it or not I actually put a passenger seat back in. I have a pair of Recaro Pole Positions, so net net I guess the weight is less than the oem drivers seat.

Rob, my car has changed a lot in the past month. Stage 2 of my weight reduction is coming...... :smile:
 
I might be interested for this Friday. How crowed does it get on Fridays? Wednesday sound more ideal.

we should make a LACR track day. take our cars out there and run them. based on weight, time, trap speed we can get a hp rating off that.

Im going this Friday to lacr to run my supra. if anyone want to make it a day and go out to lacr, kick back and do a few pull it would be good expereince.

gates open from 5pm, racing starts at 5:30 and ends at 10pm?
Lets do it. Pick a date, then we can roll by to do the test. Anytime after May 1st.

Even better if we can get enough cars to rent the track for entire day.
 
LACR 1/4mile drag strip meet. It is real 1/4mile track.

May 9th Wednesday, 5pm~10pm, anyone interested?

I will leave at around 12~1 pm, to avoid traffic. Freaking far though, way past Burbank, wow!

Or Fontana, that is only 1 hour away.

lamap.gif
 
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Hello everyone,

I think we can resolve this by an understanding how the dyno industry works. First off, I don't disagree with anything objective that has been stated so far, by RON98 or anyone else.

Fact#1:The Dynojet IS the industry standard.

Fact#2: DynoDynamics does have a correction factor "X" This feature helps bring the DD dyno in line with the industry leader Dynojet. Why would DD even have this feature if their intention was anything other than to bring them in line with Dynojet).

Fact#3: Each DD facility chooses which correction factor to use.

Fact #4: The night before USCC, at Autowave (71 degrees), we dynoed 650 rwhp without cats, and 625 with cats (4% loss due to the cats). The very next morning at the USCC event hosted at the K&N facility in Riverside (82 degrees), we dynoed 677 without cats and 650 with cats (4% loss). IF Autowave is using an incorrect conversion factor, it is still too low relative to the K&N Dynojet (which SCC has been relying on for a few years now),at least in this example.

Differences between two DD dynos can exist based on what each particular facility chooses to use as a correction factor. However, the inference that a particular facility, in this case Autowave, "inflates" their numbers to support their tuning prowess can be true (although not so in this case), or just as likely, a facilty such as RON98's, can purposely "deflate" their numbers (relative to others) to appear "more honest" than anyone else, while at the same time cast undeserving doubt upon Autowave. The most valuable piece of information any dyno can give you is an indication of how much improvement a modification will get you (hopefully more).

Regards,

Danny
 
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Pardon me if I might have missed this point, but...

what does it take to swap from NA1 header to NA2 header? I have a 1992 and someone local is selling a NA2 exhaust (the whole thing I think).

Will I have O2 sensor problems? Will I have to extend the O2 wires?

Are the NA2 cats and muffler the same as the NA1? I feel like something is not the same betwen headers, cats and muffler between the two.

Thanks.
 
Great Thread! Thanks Hapa and RON98 for the writeup as well as others who have contributed.

I guess alot of people want to know how much HP their NSX is putting out to the rear wheels but like RON98 said, the best way is to take your car to the track and make a few 1/4 mile runs. Once you know the weight of your car with driver, and see the times and MPH, you can probably figure out your HP. This is a great way to gauge how much improvement a modification gives you as long as it is tested on the same dyno.

I don't know the weight of my car with my heavy 200lb rear end but I have a 1992 NSX and the only thing I removed was the spare tire and toolkit when I made my first 1/4 mile runs. The first time I took it out, I had a Comptech exhaust, K&N FIPK running on stock 15" and 16" wheels and turned a best of 13.609 at 103.486 mph with a 0-60' of 2.125. Hopefully someone can figure out what my HP is with these numbers. I do have an upgraded clutch, short gears and lightweight flywheel.

I did dyno my car with that same setup but had my 17x8 and 18x10 heavy Volk AV3 wheelset and dynoed my car on a Dynojet model 248C Dynometer and got a best of 257.2 max Power and 195.5 max Torque. 74.4 degrees F, 29.92-0.44 in.Hg. 110 ft. CF=0.99 RPM/MPH=78 Don't know what all those numbers mean but I guess is important to know. Didn't know what my tire pressure was set at either.

A few years later, I went back to the stock airbox with Unifilter and Cantrell AIS and changed to Comptech headers and went back to the track and turned a best of 13.258 at 106.335 mph with a 0-60' of 2.067. This time I kept my heavy 17/18 wheelset instead of changing over to the lighter stock wheels. Never had my car re-dynoed but I was extremely happy with the results at the track.

This basically proved to me that the headers made a pretty big difference in performance. I am sure the AIS also helped some too but you get the point.
Bottom line is you will get better performance out of your NSX if you remove the stock manifold from your 1991-1996 NSX and switch it out with the NA2 OEM header or any aftermarket header.

Just out of curiousity, are more NSX owners interested in how much horsepower on paper their car has or are they like me who want to actually test it out at the track and see what kind of numbers I can personally run?

All the horsepower in the world on paper means nothing if you don't know how to use it, right? I guess what I am trying to say is there are alot of variations in dyno testing and RON98 just clarified this for me with this thread. THANK YOU!
 
18spex32, You can swap out your NA1 exhaust for the NA2 with out any trouble, other than the slight pain-in-the-ass factor of working in the tight confines of our NSX's. Yes, you will have to extend the length of the wiring to reach the new positions for the O2 sensors, but this is straight forward, and if unsure, just send the cash to SOS, and plug in thier new harness's. Both the Cats, and exhaust are different in tubing shape, which you can easily see by going to a site like SOS and looking at the diagrams, but to my knowledge, are pretty much the same thing, just changes in flang locations. Cody helped me install '97 headers on my '91 earlier this Winter, and I'm happy with the change! Tom
 


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