I just got a true duel 2.5" system for my 07 IS250 that bolt up to my stock headers. It consist of 2.5" tubing , two flexes and two magnaflow exit mufflers. Its going through a "break in" period then i will post video and try to gather stats and look into a dyno.































still working on the finish tips!

here is the sound and decibel reading of the first install

http://www.youtube.com/watch?v=a2I_TM-iGVY

http://www.youtube.com/watch?v=-9SkDKLaKFs

 

now you need couple nice tips

 

Nice work! Should have tried a twin loop muffler setup...heard vids and they're killer!

BTW, someone has got some decent welding skills there...very good.

 

I bet it sounds amazing.

 

1st - nice work
2nd - You should add an H-pipe or X-pipe.

Some of us "OG"s have dyno'ed various custom exhausts back in 2006.
We found that 2.5" piping with an X-Pipe made the most HP.
Also adding Hi Flow inline mufflers after the X-pipe will get rid of that Raspy noise your getting now.

 

just posted some videos of the first fire up. thanks for the feed back

 

+1 for x pipe

 

x pipe...
it sounds pretty raspy to me..
I have the Borla true dual one on my car and it sounds pretty sweet

 

oh ok i will look into the x-pipe. i was wondering if there is a chip or speed limiter delete for the is250. i know it will be hard to dyno with an automatic. any tips?

 

I believe everyone dyno's in snow/ECT mode in 4th gear. Never dyno'ed myself, so hopefully someone can confirm

 

Nope.

There's some piggyback systems that a few folks are trying out now, but they cost the folks trying em $1400 and $1350 respectively and mostly I think they're just being used for fueling adjustments... (the HKS one might be playing with some timing by now, HKS350 could comment further there)... probably not worth the cost for an NA car... certainly not worth it for a 250.

First tip is to dyno with the stock exhaust first, otherwise your "after" result is worthless as you have no idea of the actual gain.

Then dyno it again on the same dyno with the custom exhaust.

As to technique, there's a few threads on this but basically-

traction control/VSC off, S-mode on the shifter, set to 4, ECT-Snow mode on

 

nice setup!

 

Clean welds.....how much that run you? Not gonna get much HP increase on an IS.

 

Looks and sounds great.... I bet its a lot less weight that the OEM stuff too.

 

thank you... still have not received a final bill i am still testing it and might get some modification to it. well see the HP increase one i get a chance to dyno it. Defiantly a lot more torquey though