flanders

3" single will make the most gains for sure.
Does your tuner have any thoughts on what's causing the low power? Do you trust him completely otherwise it might be a thing having someone else at least look at the tune.
What kind of fuel are you using by the way?

eMotion

He doesn't have any idea what might be causing the problem. I am using 100 octane shell Vpower fuel. On the tune I trust my tuner and think he has done it correctly. He has set the vtec at 3500 rpm and has set the ignition advance timing at 27 degrees at full throttle in vtec since the engine is making the most power there although he has tried other figures such as 25, 26, 28, etc.

Mike RT4

Definitely the 2½" exhaust causing a restriction:

flanders

Yeah I wouldn't be surprised if there is at least 10whp to be gained with a complete 3" berk system for example.
But you never know, might be a lot more power to be gained.

eMotion

If that 10 whp is.throughout the powerband then it may be worth it for track driving. If it is only above 7000 rpm then it wont do much good since on the track I stay most of the time below 7000 rpm.

flanders

You could try and disconnect the exhaust on the dyno just as a simple test.

s2000Junky

That custom TP looks like crap, it necks down on each end smaller then the connecting points. Just a clean through and through match size TP would be a good start. The cat back isn't exactly a quality piece either. Looks like a cut/modded stock system and wasn't executed the cleanest at the Y. You don't want obstructions and inconsistent pipe diameter through out the system for best results, creates turbulence and inconsistent pulse widths for best scavenging., which is important in a exhaust system. A 70-75mm Single merged to your stock header would probably be the best option.

Id still like to see what the stock cams deliver. I'm not sold on the Skunk 2.

Sylvain2000

You should try an open header test if your in doubt.

This exhaust gives me the creep ...

eMotion

I don't have skunk 2 cams but Brian Crower Stg. 2 cams. I will try soon disconnecting the exhaust and see what happens on the dyno.

s2000Junky

Not sold on them either. Point being, your complicating the system, so unless you have everything matched to the flow of the new cams (is that manifold proven? And matched to the cams, along with your custom CAI?). You could be shooting yourself in yourself in the foot. The stock cams make great power with a 2.4, and we know stock they have yielded significantly more then what you are making now 260-270whp) not trying to beat you up, just saying throwing a whole bunch of "go fast" parts at it and then things done work out, makes for a pretty messy thing to start sorting though. Certainly has taken peoples time in this thread grasping at straws.

Running with just the header is a good suggestion, it cost nothing and its easy to check if its an exhaust flow thing for starts. The way your hp flat lines ive seen in another thread where the CIA was sized too big and velocity was lost. Im suspect of the intake side of your set up, which would include the CIA, after market larger manifold and cams. Lets see what happens with your Exhaust and then might want to shift to the other end depending on what happens there.