poisx7

iTrader: (1)

My gas mileage suffers terrible after installing my comptech headers and running 3 inch pipes from headers to cat to exhaust. flows better , feels a tad slower on lower rpms but once past 3k rpms it gooooooooos then comes the bad MPG.
its got a CAI aem also.

IS THIS NORMAL AFTA HEADER INSTALL

mclarenf3387

No. Headers will get you better gas mileage if you're not on the gas all the time.

3" piping is not needed on a CL if it doesn't have forced induction. You will lose low end torque. Probably could have affect on the mileage as well.

How long have you had them installed for?

poisx7

iTrader: (1)

1 month and a half

Lord Helmet

Lose the 3" pipe and don't get on it so hard as often.

MarbleGT

If anything your mileage should increase. I wonder what the deal is???

ghost_masterCL

there's your problem right there. Shoulda kept the stock exhaust. Since most of the time you are at less than 3k rpms, and by putting such huge piping on there you are basically making it so that you're car makes less power with the same amoutn of gasoline. less power = less mpg.

Bobbydoedoe

nonsense, don't u know? the bigger pipe the mroe flow therefore more power but yeah, lose the pipe

braveheart

I am not inviting an argument here, but let's be the devil's advocate about the headers. While I do not doubt that the headers produce more power at high RPM's--mostly. You need to consider the dynamics of a low pressure on the exhaust valve at lower RPM's when the intake charge has lower inertia. It's called scavenging, and some normally aspirated engines don't take to kindly to it. I don't know what kind of overlap, if any, a VTEC uses at low RPM. But type "exhaust scavenging" into google and learn about it. My bet is that the mystery lies within or perhaps if his collector is too big. For every gain in NA engines there is usually a trade off somewhere. I am no expert, so please don't be offended if you have headers. Just food for thought.

RaviNJCLs

iTrader: (4)

I saw an increase in mileage when I had headers. Define suffered. Is it just 1 mpg or more? Are you sure you're not just stepping too hard on the accelerator?

GreenMonster

Yeah, the stock exhaust flows fine (with or without headers). Aftermarket catback exhausts are only good for 2-3hp since the stock exhaust flows so well. I'm thinking the 2-3hp is probaby from the mufflers, and not the piping.

Like brave heart said, scavenging has probably been affected (negatively) by the 3 inch pipes.

Lots of members (like Ravi) have gotten better gas mileage after the header install...

BTW, someone should buy Ravi's car... I saw it in person this past weekend, and it's a great car at a great price.

RaviNJCLs

iTrader: (4)

Thanks.

Lord Helmet

uhh... you just completely contradicted yourself.

JBlueCLS6

iTrader: (2)

My gas mileage seems the same but my foot also gained about 10 pounds,

Sun Diego CL-S

why, did you go to the RJ meet at Ross Dock? it looked like an okay turnout.

GreenMonster

New avatar with the George Washington bridge in the background for proof

edit: see related mpg thread for mileage to/from...

RaviNJCLs

iTrader: (4)

Check out the pics. It's in the Meets section. I would say we had about 60 cars, maybe more.

typeR

he was being sarcastic

Titand19

3 inch exhuast and better gas milage expected