So far I've only mod I've done to my SC400 is my cat-back exhaust. Its a completely split/dual 2.25" from the primary cats through to rod millen magnaflow mufflers. Now I'm looking to step up to the next stage for more power/performance. First off, I've been reading up on x-pipes. How much do they really help benefit performance wise? Do they help the low end torque, high end power, or overall?

Second, what would everyone suggest for changine the headers? Of course, S&S are the most famous that I've seen listed for the SC400, but what others are there out there? Which are best for performance? High end? low end? etc. I'm trying to get some ideas out here before I commit to anything so the more info the better

 

search..

but to give short answer, X-pipe/connector pipes and headers will improve overall gains

I've got the rush headers, 2.5 piping, x pipe, true dual

 

My current project is also like yours Brendon. My setup will be as followed Headers- Replacement Primary cats (IDK if I will use highflows or go back with OEM yet, but I am guessing they hold back a lot of flow due to their age/mileage) then to 2.25 inch pipe all the way back to my mufflers with an H pipe for the cross flow instead of an X

 

so.... anyone have any more info on what they think the best headers are for the SC400?

 

I can't speak for the SS or the Rush headers, but I can tell you I like mine.

https://www.clublexus.com/forums/sho...d.php?t=367942

There are three different styles available. The EKT headers which are 4 into 1, the tri-y SS and the Rush long tubes. I think the "best" set for your car depends on what you want out of it since they are three very different designs which all have their own list of goods and bads.

IMO, dual 2.5 inch piping is WAY overkill for an NA SC400. I plan on going to 2.5 inch but I'm making more than enough power to justify it.

KC