headers

[LCPLPunk]

Here are some shorty vs longtubes dynos - https://www.hotrod.com/articles/headers-dyno-test/

[1JEWLDSSRS]

Like said above, the first guy has lost his marbles and is very wrong, and 80 gain? There would have to be more to it than just the LT's for that. Mine stock exhaust with an axle back dyno'd at 331 and with the LT's and off road mids and an axle back dyno'd 365..

[morepowerjoe]

Originally Posted by 1JEWLDSSRS

Like said above, the first guy has lost his marbles and is very wrong, and 80 gain? There would have to be more to it than just the LT's for that. Mine stock exhaust with an axle back dyno'd at 331 and with the LT's and off road mids and an axle back dyno'd 365..

That definitely sounds like it's worth it to me.

[morepowerjoe]

Originally Posted by LCPLPunk

Well, the first guy is wrong, the second guy, I guess its' possible, but probably on a forced induction build. I don't think adding longtubes to a ZL1 gets you 80...so it would have to be a pretty extreme build.

But what about cats? Do I need high flow cats with o2 extensions or run no cats and have it tuned to run with only the upstream o2's

[1JEWLDSSRS]

Originally Posted by morepowerjoe

But what about cats? Do I need high flow cats with o2 extensions or run no cats and have it tuned to run with only the upstream o2's

I'm running "off road" mids, no cats. Had them tuned out, but that depends on if you need them for emissions where you are located. No measurable HP gain for the off road mids over the HF cats from what I have read on here.

[LCPLPunk]

I'm running catless, and I did need o2 extensions. If you don't need cats I'd go with Speed Engineering longtubes, I've been running them for 4 years and they use the same 304 steel as Kooks and make the same power.

[morepowerjoe]

Originally Posted by LCPLPunk

I'm running catless, and I did need o2 extensions. If you don't need cats I'd go with Speed Engineering longtubes, I've been running them for 4 years and they use the same 304 steel as Kooks and make the same power.

But are you running two o2 sensors or four? And if I run two o2 sensors do you know how much it will cost to get the tune done? Oh and where? And one more question, what type of exhaust will bolt directly to the headers to the tips.. Thanks

[Warship2k15]

Originally Posted by morepowerjoe

But are you running two o2 sensors or four? And if I run two o2 sensors do you know how much it will cost to get the tune done? Oh and where? And one more question, what type of exhaust will bolt directly to the headers to the tips.. Thanks

Ok once again the big question is do you need to pass emissions?
If no then speed engineering headers with no cars will work and you will be not using the two sensors.You might also have a unburnt fuel smell at times.

If having to pass emissions then Texas speed headers with high flow cats would probably give you what you want.Depending upon how strict the emission standards are.

[LCPLPunk]

Ok, so, honestly, I would get the longtubes and get an x-pipe and keep the stock mufflers. I have this setup and I think it's perfect, it sounds great at idle, awesome at WOT, and no drone on the highway. Axle back exhaust does nothing for you for power, so for me, the cost isn't worth it.


As far as tune, I got a tune from RDP Motorsports using their SCT X4 tuner with lifetime tunes. I paid $400 (4 years ago) and have gotten multiple new tunes for my new mods, it's a no brainer. https://www.rdpstore.com/p-6042-tune...tom-tunes.aspx

[morepowerjoe]

They don't do sniff test here in Texas only check for cel. So I don't think I actually need cats. But don't I need at least two o2 sensors for the pcm to run the air and fuel ratio? And when I bought the car it has no mufflers with an x crossover and 4" tips. It actually sounds pretty darn good I just think the headers will push it to far.

[dino2012ls3]

No cats long tube headers and no mufflers the tune eliminates the light. Been passing inspection for 4 or 5 years. This year they hit me for no mufflers.

[morepowerjoe]

Originally Posted by dino2012ls3

No cats long tube headers and no mufflers the tune eliminates the light. Been passing inspection for 4 or 5 years. This year they hit me for no mufflers.

But how does the pcm run in closed loop without o2 sensors?

[LCPLPunk]

The tuner takes care of all that crap. I just did emissions recently and had no issues.


If you are already no mufflers, x-pipe, your car is gonna be LOUD with longtubes...