NYC ES3

iTrader: (7)

Hello all,


just put a Borla Axle back on my F and just wanted to write my opinion for those wondering if they want one or not...

My opinion...it sounds very nice cruising around and normal driving and at 1.5-2.7K RPM range.

nice stock but deeper sound

The hard accelleration sound of the stocks constant low-mid "roar-ish" sound is not there any longer tho..its actually quieter than stock in that "sweet spot" - the 3.5-5kRPM where the stock F exhaust starts soundin like it means business (u all know that spot where the exhaust note changes)...EDIT UPDATE: The sound is still there just Not as loud as the stocks were...lower in tone and volume...the Borla is not a agressive in that spot...but lower in note.

I actually wasnt too happy about that ..but everything else is fine about it.
much more agressive on start up and sounds nice in normal accelleration. so I'll hold onto it for a while

I got it for $680 shipped to the door New. (had a 15% OFF WITH free shipping coupon.

second.. I was just wondering if like the IS350 forum if the F forum can get an organized spot for suspension mods, intake and exhaust, wheel and tire fitments, etc
would be nice to have it .

caymandive

iTrader: (2)

Does anyone know if the stock mufflers are the variable capacity types? With this post it almost confirms my suspicion that they are. For those not familiar with these type of mufflers, they are mufflers which have the ability to be an almost straight through design under WOT and when the internal "flap" closes the muffler becomes more civilized. Hence the 3700rpm roar we get out of the OEM exhaust.

mugenh22a4

iTrader: (9)

post some vids if you can

mugenh22a4

iTrader: (9)

My suspicion is our cars are louder above 3600 rpm because of the variable inlet INTAKE

caymandive

iTrader: (2)

Nope. Even with after-market intake systems that replace the factory air box the crossover sound is still there. It is only when the exhaust is replaced that you loose this dual personality sound as the OP just pointed out.

melbitoast

iTrader: (1)

^^^ really?? That's really disappointing because I wanted to put the ISSForged track set up exhaust on mine.
Are you basically saying that I would gain the HP from the exhaust, but lose the dual sound when crossing over 3500rpm?

ming15237

iTrader: (3)

I believe what you are hearing and feeling is the VVTi kicking in.

flowrider

iTrader: (9)

I don't know. I can find no Lexus reference. However, I have read a lot of Lexus literature on the ISF, and the most comprehensive description of the exhaust I could find is:

I have always liked the stock mufflers, and my exhaust system pairs the stock mufflers to a fabricated dual system with 2.5" pipes starting just below the 02 sensors, running thru an X pipe and two glass pack resonators.

Lou

SCCAForums

I have the Borla 'Race' system... and the variable sound is still there? The Exhaust is slightly deeper than stock, and sounds great... and when you go over 3,500 you still hear the 'Intake Flap' in the engine, open up.. and get that additional 'roar' from the engine.

All Borla mufflers are a straight thru design, no internal flap.

Peace,
Dave

Joe Z

iTrader: (10)

With all the hacked oem exhausts out there, it shouldn't be too hard to get someone to cut an oem muffler in 1/2 ....

To the OP: are you running the OEM intake box??


Joe Z

ISFC6

James, I do not think so. What you are referring to is what I believe the Corvettes offer from the factory, which is the NPP exhaust system. Before 3500 RPM, the valves in the actual mufflers remain closed for a more civilized sound, but after 3500 RPM, they open up, thus increasing sound and power. They also offer a remote control that is aftermarket, which basicalllty allows you to select when you want to run with the valves open or closed. The OEM ISF exhaust does not have that to my knowledge.

ISFC6

Please see the picture below, and you will see the butterfly valve closed.

caymandive

iTrader: (2)

The kind of valves I'm talking about are like the ones found in the jdm dc5 Integra Type-R mufflers. They have a bypass valve built into them and I believe a couple other cars have a similar design. I believe the G35 is one of them and if I recall correctly my old EVO VIII had something similar too.

Picture below is a JDM DC5 ITR muffler.

lobuxracer

iTrader: (2)

The IS350 does have a flap in the muffler to allow more flow at high load. The IS F does not.

Joe Z

iTrader: (10)

Almost every OEM Exhaust Muffler design with secondary exit flaps I have seen, have been vacuum controlled...

From the Vette’s, Ferrari 599, Porsche Panorama and even the newest BMW 760i.

Now, those IS-F muffler chambers (thanks Lobux) probably make the noise difference in the higher rpms.
More than likely working in harmony with the Intake Flap that opens at 3600 rpms.

I didn't know the IS350 mufflers had a moving valve inside the mufflers...

Joe Z

P.S. - no need to cut an F muffler in 1/2 anymore.. LoL