LexusIS-TL

Now that's true cat-back I like to see. So you actually had the stock pipe cut from the front cat convertors and had custome pipes done? I'll bet it sounds nice. I'm assuming that you got rid of the resonator too, right?

It's surprising that the off-road version of Borla is quieter because usually off road exahust tend to be really loud from other manufacturers. I've never seen the X-pipe before. Any link to it?

I don't think installing a Borla off road will fail emissions right? As long as the cat is in place, I can do anything I want (just being careful about the loudness since CA is being tight on decibal levels).

Gernby

iTrader: (1)

The off road Borla exhaust won't pass emissions since it deletes both secondary cats. It is quieter than the street version because it has resonators before the mufflers, and the street version doesn't (strange).

All I did to my mid-pipe is cut out the secondary cats. I didn't want it to be very loud so I left the stock resonator in place. However, the stock resonator is just a straight pass-through.

LexusIS-TL

I've been reading quite a few back threads and there's quite a few people that actually suffer power loss with an intake and exhaust upgrade? You have an IS350 so you probably don't experience that much loss on the takeoff. Does adding on an axle-back exhaust system really hinder that kind of performance loss? If so, the back pressure must be really important on our cars and we shouldn't mess with factory specs.

nrsk4u

Sounds like the people you were talking to weren't very knowledgeable. The "off road" Borla exhaust seems to be the best design of anything else available since no other design implements an X-pipe, and the off road version is relatively quiet. I really wish I had waited for it instead of going the custom mid-pipe / HKS Hi Power route.[/QUOTE]

thanks for clearing that up for me....Ive also herd that the HKS Hi-Power is signifigantly louder than the OEM HKS or Tanbe, I atribute this to the removal of the resonator. One of the guys in a different thread got a ticket for his HKS Hi-Power because of it.

https://www.clublexus.com/forums/sho...ernby;2745611]

Gernby

iTrader: (1)

None of the axle-back exhausts remove the resonator. The HKS Hi-Power is louder because it uses straight through canister mufflers.

Regarding power loss, I don't believe that anyone would actually lose power by installing any of the exhausts currently available. The issue that you are hearing about has more to do with the hot air intakes that people are installing. Many people are also doing dyno tests without controlling the variables. Dyno numbers (like track numbers) vary from day to day too much to judge a 5 HP gain or loss.

LexusIS-TL

I also saw that Youtube video regarding that IS350 with the K&N intake and I think a Tanabe exhaust. Boy, peak HP is like 266 or something. Those guys in the shop running the dynos were pretty dissapointed. That scared me to death since I like to do more in the future.

nrsk4u

i was going to throw on an injen intake, but everyone here says it just sound that is the difference , some even said they noticed a power decrease ... not a single person has said they have noticed a power increase. then the JOEZ or injen pole came out and my mind was made up.

LexusIS-TL

Regardless if exhaust does hinder performance or not, I still want it . Too quiet....