that some good numbers i am going to try it out with the 70rr and see how much power it makes when i have time

 

I really think that you have had a freak experience -- look at all the other people on this site making power with the J's Header, look at all the races J's has won with the J's header, and then decide if it is really as crappy as you say it is. I think they either installed the header incorrectly or dyno'd the car incorrectly (i.e. wrong gear, turned off the fan, some silly mistake like that). It just baffles me how you could really lose hp when everyone else in the world is making power with the header, and then go to every thread in this entire forum and tell people that the J's header doesn't make power....

 

Generally speaking, a 4-2-1 header would gain low to mid range power, while a 4-1 would gain high end power...I just figured that since I already had the Competech SC, their header would be a nice compliment to it (not to mention that it comes with a CARB number stamped onto it, which will come in handy when I smog my car...California sucks when it comes to smog laws!) But if it were proven that the J's could make more power, I wouldn't mind having to swap headers everytime I had to smog the car.

BTW, Functional03, forgive the skepticism, but I would really like to see proof of the power loss...the info you could provide would be educational for all of us...in the meantime, I agree with zbrewha863 in that you may have had a 'freak' experience with these headers...

 

Hello Guys,

I know everyone swears by the JDM products, and I myself and running the J's racing intake on my 2.5l stroker motor. I dyno'd it on the stock airbox, and i put the intake, and did not notice a difference. I will re dyno it when i have free time.

As far as Functional03 is concerned, he dyno'd his car on the stock header with his exhaust, then put the j's on and it lost power.

The original member above recieved tuning. If he ran the AEM EMS, you can gain about 10-15rwhp on a STOCK S2000. If he put the parts on along with the EMS, then the gains is mostly from the EMS, and some from the exhaust system. He also called up the srouce he bought the header from and they haven't even dyno'd it.

If someone is local with an EMS that has a stock header, want to dyno the car and tune it, then put the header on, and retune it. I'll give them a GOOD discount just to see. In previous cases on our k motors and b motors, you put a nice race header on, on the same map it'll gain power. This was not the case in Functional03's and i'll still stand by the J's header lost power, if anything made the same power.

here is the dyno'

 

Why thank you Mr. Ya

 

ya@inlinepro.... i never received any tuning, in the form of an AEM EMS or anything.... so if you are talking about me as the "original member above", then no. i did not have any tuning whatsoever.

 

My 06' dynoed 217rwhp with no mods.The car is pretty well tuned by the Honda engineers.

 

on what dyno? a dynapack? that's a chassis dyno... you have to take about 10-15 hp off that number. there is zero way it made 217whp stock on a wheel dyno. sorry. average for an AP2, incl. MY2006 is between 195-205 WHP, i.e. mine made 197.6 stock. it's a honda, not a ford where the hp can fluctuate a noticable amount from vehicle to vehicle.

 

Interesting...

 

i am sorry but your the ONLY guy on the site with those numbers from i/h. the intake and the header are the two areas that tend to make the LEAST power with modifcation on NA cars.

17rwhp with j's 70mm single i can easily beleive but with a header on stock cat/exhaust i have to say no.

i am not calling but i am still very skeptical about 17hp gains WITHOUT tuning.