Lexus ISF / IS-F / LFA / LF-A  Forum banner
1 - 9 of 17 Posts

· Registered
Joined
·
119 Posts
Discussion Starter · #1 · (Edited)
I will be fully bolted shortly to include an Intake, Ported & Polished Intake Manifold and Throttle Body and Catless headers... I'm either going to put on a catless exhaust or I'm going to keep the stock exhaust and put on electronic cut outs. This thread will most likely determine which path I choose. I'm am looking for the highest, reliable horsepower possible. Here are my questions:

1- Will the IS-F's N/A 5.0L motor have enough back pressure to run properly if I run the cut outs directly after the O2 sensor in the headers?

2- Will cut outs yield a higher horsepower than a 2.5 inch catback with no cats?

3- Will the constant opening and closing of the cut outs have any affect on the ecu and not allow the car to run at it's greatest potential, as the cut outs would be installed after the O2 sensor?

4- Being that the headers will come with an electronic trick to prevent a CEL, wouldnt the O2 sensors be getting the same voltage all the time, thus eliminating any differences and the potential problem of #3?

Thanks
 

· Registered
Joined
·
119 Posts
Discussion Starter · #2 ·
Does anyone know the answers?
 

· Registered
Joined
·
119 Posts
Discussion Starter · #4 ·
I appreciate the response. I just went ahead and purchased an ISS Forged exhaust. Thanks
 

· Registered
Joined
·
119 Posts
Discussion Starter · #6 ·
I'm going to DYNO at Cobb in Plano most likely at the end of next month. Their DYNO would be a VERY fair DYNO as it's compared to a lot. I'm hoping for 425+ whp! Fingers Crossed!!!

Also, does anyone know where I can pick up some Random Technology 2.5" high flow 100 cell cats, or equivalent, for cheap?
 

· Registered
Joined
·
119 Posts
Discussion Starter · #8 ·
It's brand new. I bought from someone who purchased it new but never installed it.
 

· Registered
Joined
·
119 Posts
Discussion Starter · #10 ·
Awesome... That's why I won't back off from the K&N being the best intake... Period. Was this a Mustang DYNO?
 

· Registered
Joined
·
119 Posts
Discussion Starter · #12 ·
Good numbers... You hear anything about the headers yet?
 

· Registered
Joined
·
119 Posts
Discussion Starter · #14 ·
Thanks... Never been there but I've heard good things.
 

· Registered
Joined
·
119 Posts
Discussion Starter · #16 ·
Sounds good. Unfortunately I'm in Lubbock TX, out in the middle of nowhere and at 3,500 above sea level. Soo getting the headers installed, doing dynos, and hitting a drag strip basically requires me to go to either Dallas or San Antonio. Sucks. I'll prob be moving to Houston within the next year and a half. I can't wait.
 
1 - 9 of 17 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top