The disease has started

[Amused_NSX]

You figure that when you get a supercar like the NSX, that your appetite for performance has been satisfied, and that you have reached a level of automotive supremacy.

Little do you know that is only a matter of time untill the disease sets in and you find yourself wrenching away like I was this past weekend.....

The exhaust I decided to go with was the GT-One V3 titan. Sheds quite a bit of weight off the rear of the car, at a scant 12.5lbs! Plus it has some bling factor for those following behind me, as the canisters can been seen through the mesh on the rear valence.

My plan was to install the muffler with some Prospeed 200CFM cats. But the postal service here in Canada is on strike, so My cats are sitting neutral somewhere. Hopefully that gets resolved soon. But on the upside I can see the difference the V3 exhaust provides over the stock muffler, and what kind of difference hi flow cats will make with the V3 over it being installed with stock cats.

The install was quite easy as My car is a 2003 with 20,000 miles. So not much assistance was required in removing the stock muffler and all it's hardware:smile:

My impression of the exhaust so far has been very pleasing. It is not too loud in the cabin. At idle it is not much louder than stock. At cruising speeds it it deep,no drone and at certain RPM's it is dead silent, at first I thought My car shut off! As the RPM's climb the car has a deep growl with no raspiness, and at WOT it is still quite deep with a hint of high pitch to it. I don't have much to compare with, but it sounds pretty good.

My only complaint thus far is when I rev, and allow the rpms to drop the muffler emits a bit of a snarl, or fluttering sound. But it doesn't sound like a leak to me.

Any idea what this could be? I shot some footage this evening:



The other component I installed was a STMPO RSTB. Definitely a must have for all Targa owners. I haven't tested it on the circuit yet, but from some spirited cornering so far, I can tell that it will be a big + at my next
event at Mosport.

I don't see a remedy insight, as I am awaiting on a set of Volk TE37 SL's to arrive from Japan shortly, along with some Direzza star spec Z1 tires. Those will be dialed in with some KW V3's that have been waiting anxiously since the winter months.

 

[SuperSonic]

Next is the body kit then sc or turbo. I thought i had mine done till i swaped calipers again, got slotted rotors, the shorter zandari stick to install along with all the gauges

 

[socold57]

what are the specs of the sl you getting didnt know they made nsx spec sl

also where can you get that exhaust and how much was it btw

 

[Amused_NSX]

what are the specs of the sl you getting didnt know they made nsx spec sl

also where can you get that exhaust and how much was it btw

The TE37 SL's I picked up are 17x7.5 40+
18x10 40+

The rears have concave facings as well. It is not listed on the Volk site, but I inquired with Mackin Industries and they confirmed that this this configuration could be made. I have been waiting on these wheels since January.

As for the exhaust I picked it up from Prime member NSX-R GT. He is local here in Toronto, but frequents Hong Kong, and Japan. He is actually over there now and asked me recently if I need anything from Japan. So I would contact Him if you are interested in obtaining a GT-One exhaust.

 

[Mikexike]

Tastefully modded Love it!

 

[swimmingpie]

It looks beautiful. Nice sound, too!

 

[Oyagi]

Good choices, I like.

Aside from a blower to let you keep up with the looks, you're about done.

 

[Amused_NSX]

Good choices, I like.

Aside from a blower to let you keep up with the looks, you're about done.

I would also like a set of DF NSX-R seats in Black. Then I'm done!

what are your thoughts on the snarl of the exhaust when I let off throttle? is that the nature of the baffles in the exhaust canisters?

 

[shawn110975]

STMPO RSTB you mean the targa brace thing that looks bad ass
I am putting one in my coupe going to drill 2 holes to make it work though

nice

 

[Amused_NSX]

STMPO RSTB you mean the targa brace thing that looks bad ass
I am putting one in my coupe going to drill 2 holes to make it work though

nice

Yeah that STMPO piece is awesome. Wicked build quality and substantially more rigid than the stock piece. Ross is a great guy, and does some great work. Of all the mods this far, this is the only piece I wouldn't part with.

 

[Oyagi]

I would also like a set of DF NSX-R seats in Black. Then I'm done!

what are your thoughts on the snarl of the exhaust when I let off throttle? is that the nature of the baffles in the exhaust canisters?

I get that too in my car with a Taitec Centre-exit. It almost sound like a backfire and its normal.

 

[Amused_NSX]

I get that too in my car with a Taitec Centre-exit. It almost sound like a backfire and its normal.

So that little snarl when the revs drop is normal then? I thought that my muffler was shot!

Thanks Oyagi

 

[davidf]

Seriously, a sound clip is in order.:wink:

 

[RYU]

So that little snarl when the revs drop is normal then? I thought that my muffler was shot!

Thanks Oyagi

I believe that exhaust nuance is the same as what is quite common on most NSXs. It's especially loud with an aftermarket exhaust. I got rid of most of that with a dynamic exhaust bypass valve that closes upon deceleration.

 

[StmpoRaceProducts]

So that little snarl when the revs drop is normal then? I thought that my muffler was shot!

Thanks Oyagi

are you running a stock clutch?

It is not normal at all... but when you mess with exhaust or intake diameter... you must compensate the opposite.

A lighter flywheel will also help this... that is why i'm asking about your clutch

 

[Amused_NSX]

I believe that exhaust nuance is the same as what is quite common on most NSXs. It's especially loud with an aftermarket exhaust. I got rid of most of that with a dynamic exhaust bypass valve that closes upon deceleration.

I wonder if installing the high flow cats will subside it a little? Or would it make it worse?

 

[RYU]

I wonder if installing the high flow cats will subside it a little? Or would it make it worse?

If we're talking about the same deceleration noise, it will make it worse only because it gets louder. That doesn't mean something is wrong your NSX though.

I couldn't find a vid and will have to look more later.

 

[StmpoRaceProducts]

I wonder if installing the high flow cats will subside it a little? Or would it make it worse?

Think of it like a fireplace at a cabin.

If you increase the chimney diameter from 8" to 12".... more air would need to enter the fireplace.

This can be done by increasing velocity or the air... or a wider opening.

There are many tweaks to make on your car... it is possible to eliminate that noise.

BTW - another sign that this is the issue... is when you first hit the gas... there is a slight pause in the rev... hinting at an intake restriction

 

[Amused_NSX]

are you running a stock clutch?

It is not normal at all... but when you mess with exhaust or intake diameter... you must compensate the opposite.

A lighter flywheel will also help this... that is why i'm asking about your clutch

Clutch, FW, are stock. The only other mod is a DF stack intake. I should open it up to see if anything is restricting it, but this noise only came about after the install of the muffler.

I wonder what else it could be?

 

[StmpoRaceProducts]

Clutch, FW, are stock. The only other mod is a DF stack intake. I should open it up to see if anything is restricting it, but this noise only came about after the install of the muffler.

I wonder what else it could be?

I'll answer that via pm... you can post it if you want.

 

[StmpoRaceProducts]

Clutch, FW, are stock. The only other mod is a DF stack intake. I should open it up to see if anything is restricting it, but this noise only came about after the install of the muffler.

I wonder what else it could be?

the stack intake isn't bad at all.. it just has less volume of air and less surface space on the filter.

It is the reason you cough when you press the gas... the cough could have gotten worse now that your exhaust flows more freely.

your leaving tons of performance out with the heavy flywheel though...

someone else commented about there exhaust that has lead me to believe why the decel is doing what it is doing...

nice mods man... if that decel tone bothers you... I could attempt to help get rid of it

LMK

 

[StmpoRaceProducts]

I believe that exhaust nuance is the same as what is quite common on most NSXs. It's especially loud with an aftermarket exhaust. I got rid of most of that with a dynamic exhaust bypass valve that closes upon deceleration.

I would like to ask....

which exhaust were you using?

if that happened with your hks muffler... I know what is wrong with all 3... it also explains why the bypass valve fixed or made it better...

LMK so I can help amused out

 

[OPTIONS]

where did you order that exhaust from?

 

[StmpoRaceProducts]

well.... It has occurred to me now that we are 3/3 on exhausts that don't x-pipe or use a "plenum chamber" to x the gases. Causing back pressure on decel

1) the op exhaust

2) taitec center exit

3) HKS (the hks muffler looks like the oem style but it actually 180's the gases and they never touch

The oem muffler is the example of the plenum chamber style... notice the exhaust pipes that end with tips exit the same location of each side of the muffler

Without combining the 2 banks of the motor... back pressure is causing your problem











Regards

 

[RYU]

^^^ The pics don't show up Ross. Can you repost? It seems like really interesting info.

Btw, I wasn't using an HKS exhaust when I got that nasty "wet fart" decel noise as some would describe it. I usually hear it on the various pretzel exhausts like the Pride which has a double x-pipe (so are we talking the same thing?). My HKS is great. Still one of favorite exhaust and don't think i'll ever part with it.

I'm still in the process of building my own exhaust for fun. This is the one i'm using the valve on. It won't be of any use for the OP since it's a one-off.