Anyone running open headers?

I want to install a valve after the y pipe and relocate the cats after the valve so that when I open the valve ill have open headers to open up when racing or climbing up steep dunes.

Some concerns off the top of my head are

1. Will I lose power due to lack of back pressure?

2. I don't mind the check engine light, but will the fuel:air be affected?

Thanks.

 

I'm no expert, but your pic looks like its from a newer Jeep, probably with computerized mixture control. Opening the headers and removing the back-pressure, as well as eliminating readings from the sensor in the catalytic converter will almost definitely throw your mix off. You may be able to make some adjustments or change a chip or something ...

 

It will sound louder and give the impression of being more powerful but any gain will be negligible as you are still flowing the same amount of air in.
Your after cat Oxygen sensors are for emissions so though you will get a light it shouldn't effect the air:fuel, the O2 sensors before the cats do that.
I would say it's not worth the effort. Get a nice exhaust system instead.

 

Do you think adding a cold air intake will make the gains more than negligible?

I have a mustang gt with hollowed cats and cold air intake and it is a lot faster than stock.

Kinda hoping for the same with my jk.

 

Then give it a shot, it's your time and money.

 

Open headers you will lose lots of torque especially low end. You will likely gain higher RPM HP, but I believe you will feel like you have lost power due to the loss of low end torque... your O2 sensors will go haywire. I feel that Stock is the best unless you are going to do some computer programming changing the power curves and adding cam, larger injectors, supercharger etc. Any minor changes in my vehicles made after 2007 I have felt little if no gain and I did not feel it worth the cost. (not counting diesels).

 

CAI intakes are pretty spendy for what little they deliver. Perhaps with a complete CAI + performance exhaust system there may be some HP bump but reviews have stated lots of flash but little to no difference on JKs

 

This does it.

Thanks.

Back to the drawing board. Since getting power from intake/exhaust is probably not feasible I will likely do gears.

 

I'd just go with a RIPPS supercharger and gears if I had the money to blow. Your rig is probably new and young enough to handle to handle the added boost from the super charger. Then top it off with some serious gears and you'll be screaming some 40's down the road with no issues

 

35s and depending upon what your currently geared, 4.56 or 4.88 would be the best bang-for-the-buck.

 

And that answers my next question.

Thanks!