In Defence of the NSX Exhaust

[latzke]

Really? I have the RM/B&B and I don't find it loud at all. You can easily have a conversation in the car while hwy cruising and at idle. It only roars when you put your foot in it- kind of like the Comptech. Maybe your muffler was blown out?

It was starting to perforate and would be correctly understood as very broken in. I think it had the drone its whole life, but am not certain.

I may be more sensitive to sustained low-frequency noises than the average gear head. Driving a long distance (many hours on interstate) behind someone with a Comptech exhaust annoyed my senses pretty sufficiently. I do figure that the NSX is not a quiet car (not in the sense that a luxury sedan/SUV is, I do know is is quiet by other standards) because of how high I have to turn the radio up to overcome road/engine/etc noise when cruising on the interstate. So adding any noise to that is a negative if I intend to drive more than an hour at a time, converse, etc.

 

[latzke]

Rasp? I also wonder what would help solve this 'issue' though? Would a set of Angus Resonated Test Pipes solve this?

The Angus RTPs eliminated all of rasp I was getting with the Taitec GT Lightweight, it sounds amazing and smooth now.

Is it safe to correlate rasp with deleted catalytic converters?

 

[e.pie]

Is it safe to correlate rasp with deleted catalytic converters?

My GTLW was still pretty raspy with the cats in compared to the RTPs, especially on decel.

 

[ENT]

Is it safe to correlate rasp with deleted catalytic converters?

Not around here it isn't. LOL

People get stopped all the time by the enviro police for quick exhaust checks. No CATs and you're screwed.

Cheers,
Ian

 

[RYU]

Is it safe to correlate rasp with deleted catalytic converters?

Unfortunately no. Cats attenuate the "rasp/fart_cannon" unpleasant decel noise resonances and a straight pipe just makes it sing more in all it's Roseanne Barr glory!

My previous exhaust setup used a vacuum valving system where the valve would open at 0 vacuum (i.e. Wide Open Throttle) and closed when you released the gas pedal instantly. It was pretty much closed cruising around town until I got on it. The valved opened up to straight atmosphere so there was a very pleasant wail @ WOT yet no fart cannon decel sound since once the valve closed all exhaust gasses was bypassed to a traditional muffler. All the pretzel exhausts incorporates some type of straight-thru piping that bypasses the muffler canister which help give it that "F1" high pitched noise WOT.

That project is now getting reworked to swap the valve for a boost dependent one

I also agree that the stock sounds pretty good. Not great but it's definitely underappreciated. It's just so DAMN HEAVY.

 

[KSXNSX]

i can't hear my exhaust at all. I think you are hearing the intake.

 

[NSX2play]

Quote: Originally Posted by heySkippy ".......IMO most of what you're hearing with the stock exhaust when you step on the skinny pedal is coming from the intake."

Quote: Originally Posted by tof.......You aren't stepping on it hard enough...or else not long enough. Trust me, I know all the notes in the chorus. there's intake air for sure, but there is also a little gear whine, some faint valve train activity and mostly MOTOR.

Oh, we're stepping on it hard enough TOF. We didn't buy an NSX for putting around. :biggrin: heySkippy is exactly right. You're hearing the air intake not the engine.

At the track the NSXs with OEM exhaust go by with a 'pfffft' sound like a quiet jet. No roar and hardly any noise. Inside the cockpit however it sounds glorious, like no other noise that can stir a man's soul. Honda was brilliant. They designed the exhaust to offend no one, but designed the intake to please the person that matters most - the driver.

 

[oscar_driver]

At the track the NSXs with OEM exhaust go by with a 'pfffft' sound like a quiet jet. No roar and hardly any noise. Inside the cockpit though it sounds glorious,

+ 20000 that's exactly what I wanted to say but my poor english didn't allow me! :wink:

 

[tof]

Oh, we're stepping on it hard enough TOF. We didn't buy an NSX for putting around. :biggrin: heySkippy is exactly right. You're hearing the air intake not the engine.

At the track the NSXs with OEM exhaust go by with a 'pfffft' sound like a quiet jet. No roar and hardly any noise. Inside the cockpit however it sounds glorious, like no other noise that can stir a man's soul. Honda was brilliant. They designed the exhaust to offend no one, but designed the intake to please the person that matters most - the driver.

What I hear is pulses that correspond to firing events in the engine. It's analogous to the beats one hears from a motor cycle, not in frequency or tone but in texture. I would expect "intake howel" to be a smoother, more continuous sound. I know that the engine draws in air in a series of pulses as the intake valves on each cylinder open, but between the intake plenum and the air box I would think very little of this air pressure fluxuation would reach the intake snorkle where the sound would be most noticable.

I'll have to have someone do a fly-by in my car and see if it just goes "pffft" or if it makes some serious noise. Watch this space.

If in fact what you say is true then I agree that Honda was brilliant in the design. I don't mind if my car is nice and quiet and doesn't annoy most drivers or excite nearby gearheads. I am primarily concerned with what the car sounds like to me when I am driving.

In the interest of full disclosure let me add that I have a Dali aftermarket intake snorkle which I assume does make a difference in the intake sound.

 

[e.pie]

What I hear is pulses that correspond to firing events in the engine. It's analogous to the beats one hears from a motor cycle, not in frequency or tone but in texture. I would expect "intake howel" to be a smoother, more continuous sound. I know that the engine draws in air in a series of pulses as the intake valves on each cylinder open, but between the intake plenum and the air box I would think very little of this air pressure fluxuation would reach the intake snorkle where the sound would be most noticable.

I'll have to have someone do a fly-by in my car and see if it just goes "pffft" or if it makes some serious noise. Watch this space.

If in fact what you say is true then I agree that Honda was brilliant in the design. I don't mind if my car is nice and quiet and doesn't annoy most drivers or excite nearby gearheads. I am primarily concerned with what the car sounds like to me when I am driving.

In the interest of full disclosure let me add that I have a Dali aftermarket intake snorkle which I assume does make a difference in the intake sound.

Indeed the snorkel does make a substantial difference in sound. The NSX intake isn't very restrictive so you are in fact hearing the intake noise of the valves opening.