Want to mod your exhaust? Look here first!
11-02-14, 11:46 AM
#1
Driver
Thread Starter
Want to mod your exhaust? Look here first!
Hi all,
Finally have some free time to post some thoughts and experiences with modding the 3IS stock exhaust. Got the car in January and I was always looking for that perfect sound while retaining a bit of the Lexus persona of being a comfortable and relaxing daily driver. A couple thousand dollars later
, with dozens of trips into shops for my own R&D, I can safely say that I have reached my goals.
This thread will be updated, but first, a foray into the exhaust reiterations.
Version 1:
Done: Secondary cat and resonator delete. Replaced with aluminized tubing.
Result: Not much different sounding, not a lot of drone. Sound generator seemed throatier. Was hitting subframe as pipes were not done meticulously. Shifted entire exhaust system.
V2:
Done: Added Joe Z axleback
Result: Super loud, raspy. Intolerable cabin drone but the car sounded beast. Lots of crackles and burbles and pops.
V3:
Done: Added in dual 18” GT Speed T304 resonators (basically Vibrant).
Result: Balanced sound, eliminated 95% of rasp, reduced drone by 80% but still noticeable around the 1,800 to 2,200 RPM range.
V3.5:
Done: TRD Diffuser warranted quad tips, so stock Joe Z tips cut.
Result: No difference in sound with added T304 3.5” quad pipes.
V4:
Done: Replaced all tubing O2 sensor and behind with T304 stainless steel. X pipe to even out flow and promote increased backpressure for increased torque. V-band clamp quick connects to eliminate gasket exhaust leaks. Custom T3404 Helmholtz resonators to greatly reduce 1,800 to 2,200 RPM drone.
Result: Much more even idle, no more machine gun putting. A more mellow and smooth sound reminiscent of the IS F or Infiniti VQ exhaust. I’d say droning is reduced about 100x from V2 setup.
Low-mid load sound reduced significantly (I’d say around 50%). High load and WOT about 20% reduction in sound. Drone at 2,200 rpm is now barely audible and reduced from V3 setup by about 90%. No more droning in the cabin causing vibration. In city acceleration and driving is more manageable.
X Pipe:
Resonators:
V band clamps:
Joe Z Quad tip axleback with a drone tube/1/4 frequency resontor/Helmholtz resonator:
Videos:
Finally have some free time to post some thoughts and experiences with modding the 3IS stock exhaust. Got the car in January and I was always looking for that perfect sound while retaining a bit of the Lexus persona of being a comfortable and relaxing daily driver. A couple thousand dollars later
, with dozens of trips into shops for my own R&D, I can safely say that I have reached my goals. This thread will be updated, but first, a foray into the exhaust reiterations.
Version 1:
Done: Secondary cat and resonator delete. Replaced with aluminized tubing.
Result: Not much different sounding, not a lot of drone. Sound generator seemed throatier. Was hitting subframe as pipes were not done meticulously. Shifted entire exhaust system.
V2:
Done: Added Joe Z axleback
Result: Super loud, raspy. Intolerable cabin drone but the car sounded beast. Lots of crackles and burbles and pops.
V3:
Done: Added in dual 18” GT Speed T304 resonators (basically Vibrant).
Result: Balanced sound, eliminated 95% of rasp, reduced drone by 80% but still noticeable around the 1,800 to 2,200 RPM range.
V3.5:
Done: TRD Diffuser warranted quad tips, so stock Joe Z tips cut.
Result: No difference in sound with added T304 3.5” quad pipes.
V4:
Done: Replaced all tubing O2 sensor and behind with T304 stainless steel. X pipe to even out flow and promote increased backpressure for increased torque. V-band clamp quick connects to eliminate gasket exhaust leaks. Custom T3404 Helmholtz resonators to greatly reduce 1,800 to 2,200 RPM drone.
Result: Much more even idle, no more machine gun putting. A more mellow and smooth sound reminiscent of the IS F or Infiniti VQ exhaust. I’d say droning is reduced about 100x from V2 setup.
Low-mid load sound reduced significantly (I’d say around 50%). High load and WOT about 20% reduction in sound. Drone at 2,200 rpm is now barely audible and reduced from V3 setup by about 90%. No more droning in the cabin causing vibration. In city acceleration and driving is more manageable.
X Pipe:
Resonators:
V band clamps:
Joe Z Quad tip axleback with a drone tube/1/4 frequency resontor/Helmholtz resonator:
Videos:
Thread
Thread Starter
Forum
Replies
Last Post
kumar9993
IS - 2nd Gen (2006-2013)
15
11-23-17 08:55 PM
