Megaman

Does anyone manufacture an exhaust system that has an actual 2.5" inner diameter? The Ark has a 2.5" OD (outer diameter), which really means its a ~2.36" inner piping.

Also, does anyone know the inner diameter for PPE headers? Does anyone make headers more aggressive then theirs?

TRACK3DiS

Bump, I really want to know this as well. Hell, I had a 2.5 inch on my 2000 Civic Si for a 1.8 liter JDM GSR motor let alone a 3.5 liter V6! There's so much more power to be made on our cars and I want it!

bucanero

You can probably send an email to SIKKY Manufacturing to see if they have anything for the IS350. I know they have something for the IS-F so it could be a possibility. As for the 2.5 inner diameter question, any reason why you are looking for that diameter width on the exhaust? Be it you can't tune the ECU to maximize the exhaust's potential, I really don't see much reason why it would be an option on this engine platform.

flowrider

iTrader: (9)

First off, Pipe size is measured by the ID. Tube size is measured by the OD. Exhaust pipes are tubing so the size is measured by the OD. Now as far as the tubing size for a 3.5 liter engine is concerned, IMHO, a 2..5" dual exhaust system would be loo large. 2.5" pipes (tubes) are used on the 5 liter ISF. Exhaust systems are all about optimizing exhaust flow, and I believe 2.5" dual exhaust tubing would be detrimental to the exhaust flow of a 3.5 liter engine. Again IMHO, 2.25" would be ideal.

Sikky makes headers for the ISF only. PPE makes headers for all the current IS series cars. And note, their headers are different for the IS250 and the IS350. They're interchangeable as far as fit, but the tubing sizes are different, again, to optimize the exhaust flow.

Lou

JE

iTrader: (1)

Sikky does have a header for the is350, we installed one of their initial production run as part of their testing and R&D process. Great fit and power but I don't think this will be available for a couple months.

bucanero

That is very great news to hear! Any issues with the o2 sensors? I know the PPE headers would have the "check engine" light on.

JE

iTrader: (1)

We have a customer that has been driving on the original prototypes we installed over a year ago without any check engine lights. So I would say confidently no problem with that.

PPEHeaders

iTrader: (4)

No, you will not get a check engine light with our headers or exhaust for any of the Lexus models. When installed correctly there are no codes or check engine light.

bucanero

That is great news and I apologize for the uninformed comment. Thank you for clearing that up for anyone that had any concerns.

flowrider

iTrader: (9)

^^^^And after close to four years of having PPE Headers installed on my ISF, I can attest to the accuracy of PPE's statement. Best Mod I ever did.

Lou

Megaman

Thanks for your input, I guess.

I understand exhaust companies sell systems based on the OD. What I am looking for is an exhaust system that has a larger OD than 2.5".

As far as your opinion, I disagree. The piping size of an exhaust changes the deliver of power throughout the RPM range. A larger exhaust will naturally provide more top end power; a smaller size pipe will deliver more low and mid range power.

If our cars were able to be tuned, than I suspect more companies would manufactured larger piped exhaust systems.

The horrible aftermarket for our brand is why I chose a IS350 F Sport daily, and leave money for a weekend race car.