Straight pipes, drop-in K&N, bad A/F ratio?

[laffstang]

I've had my '04 Mach for almost 5 years, and finally did a "performance" mod, straight pipes- no mufflers with stock cats. I need to change the air fliter, and am thinking about a drop-in K&N. Will this combo be enough air-flow to lean out my a/f ratio to a dangerous level, or am I just being paranoid? I don't have a dyno near my location, so any ideas would be appreciated.

[311-420]

You'll be fine.

I've got longtubes, offroad x, magnaflow catback, jlt intake, intake spacer etc. My car runs like a bat out of hell on the stock tune.

[4a7191a]

straight pipes wont net much if any HP though. the motor wont run lean til you do catless mid's or longtubes.
311-420..... your car is running lean. lol we have knock sensors though, so no biggie.

[Keith.red.mach1]

Agree with above, you will be fine.

When I added a tune to my set up it came alive, ran much better with a tune.

[laffstang]

Thanks for the info.

[Mach828]

Yes, you'll be fine! Just run the stock tune.

The stock midpipe with straight pipes actually sounds pretty decent. I ran that when I first bought mine, with a K&N drop in as well.

[laffstang]

Yeah, I'm happy with the sound. No drone, a mellow burble at idle and cruising, but it screams like a banshee at WOT, especially in the higher rpms. It's not as bad-*** sounding as my 5.0 with full exhaust and flowmaster 40s, but still pretty good for the money.
Since everyone seems to think there's no problem with A/F with a drop in, what about a JLT ram-air intake? I've seen some comments on older threads that do warn about lean conditions with a JLT and cat-back.

[Mach828]

Unless your buying it for looks, the power difference between a drop in and the JLT is minimal and not really worth the cost. Your better off investing that money into another mod. Like a midpipe or 4.10s.