Greetings,

I Have a 2004 C5 Base that I really love. The C5 Corvette is an amazing car and mine has only 25K miles on it. My Vette is stock, but I did install a new Borla Cat-Back exhaust and mufflers, wheels and tires, upgraded the sway bars and shocks, and did all new fluids with a tune-up this past Spring. I'm really not interested in doing any engine mods, but was thinking of adding headers to my Vette. I would get the headers myself and then have my mechanic install them. I am pretty sure it will not be cheap to do.

What benefits would this do for my car? A nice bump in horse power? A better sounding/breathing exhaust system? Would a Tune be required if I install the headers? Should I eliminate the catalytic converters if installing new headers? Without catalytic converters would I need to use a non/oxy fuel or would E10 Premium still be good? Again, I am not interested in doing any engine mods. I have been down that rabbit whole before with my GT500 Shelby Mustang.

Any recommendations on what type/manufacturer of headers I should get for a 2004 C5 Base Corvette? Is installing headers just a waste of money for me? Sorry for all the questions, but I am only a novice any you guys are the experts.

Thank you for your answers in advance.
Edgemerski.........

 

Headers will give a nice bump in HP all around, especially if paired with an x pipe that goes back to the mufflers. I'm guessing you don't have emissions testing? In that case, removing the cats shouldn't cause any issues as long as your mechanic is OK with removing them. You'll need to kill the codes for the rear O2 sensors, so may as well have the fueling and spark optimized to add to that bump while you're in the PCM. As for which headers, what's your budget like would be my first question.

 

Thanks for your response. My budget would be $2,000 or less...............

 

That would be $2,000.00 installed

 

Headers will help power AND gas mileage. You WILL need a tune. But usually the tune won't be too difficult with a stock internals engine. Tunes at WOT are open loop. The closed loop, variable throttle tune is the more difficult part, but, again, should be a breeze with a stock internals engine. If you go Kooks, American Racing Headers, LG, or Stainless Works, you'll be looking at maybe 30+hp. Id go with 1-3/4" diameter pipes. Probably close to 40hp without cats, a 3" X-pipe, and good mufflers. Only drawback is considerably more underhood heat. If you do go to this expense, kick in another $300-$400 (pre-covid prices!) to have them coated, which will reduce the underhood heat considerably. Hope this helps.....

 

Definitely do headers and related tune. You didn't mention if your car is man or auto but maybe pry open the coin purse a little further and go with 3.42 or 3.73 gears.

 

Im taking the opposing side and recommend against headers. For a stock engine it’s going to sound a bit throatier, and there will be some additional power, but nothing transformative.

BUT…the by far and away best “sit you back in your seat” mod is lower gears in the differential. Depending whether you have an auto or a 6sp, the ratio would vary. Say 3.42/3.73 for the auto and 3.90/4.10 for the stick. Lower gears will absolutely improve overall driveability, and will wake that sucker up without molesting the engine. You wouldn’t even need a tune for a gear swap. (You buy headers, better add another $500 or more for a tune).

Gears = Transformative improvement in acceleration and fun factor.

 

It would be a waste of time, money, and effort on an otherwise stock engine. The post 2001 factory exhaust manifolds perform well. You will regret removing the cats, there is no appreciable gains in HP and the exhaust smell is overwhelming.

 

Overwhelming might be an exaggeration. My daily driver 04 Z06 has full exhaust (longtubes, x-pipe, no cats [prior owner, not me]) and I hardly ever notice any smell.

 

Gear swap would be a better mod,
wont effect emissions or hurt resale value either and leave the cats on the car

 

He will need a tune if he changes the gear ratio. Especially an A4, because shift points will be way off.......

 

I’m considering similar mods for my winter project on my 2004 A4. I’m leaning towards American Racing headers (with cats) to match-up with my existing Corsa Indy Pro axle back exhaust. I will lose my existing Corsa x-pipe but will maintain the cats. The American Racing headers are above your budget target, however they include the cats.

I already have a Callaway Honker CAI, a new DeWitts aluminum radiator/fan kit, a new water pump, and low-temp stat installed with tune. In addition to the headers, I’m planning to swap out my 3.15 rear gears for 3.73 rear gears and adding the GM LS-6 CAM or other CAM, a higher stall, new springs and new balancer. That should get me to a street drivable, and very quick off the line roadster. Car only has 30K miles so I have a lot of fun miles ahead with the car.

 

Thank you to all. Your feedback is appreciated!

 

My Z06 had headers when I bought it 2004 LS6, cold air intake headers with cats and other wise stock exhaust. Tuned by Jerry O at Vettesport. It made 364 RWHP and 361 RWTQ on a dynojet. That is only a few horse power more than a total stock LS6 would make.
Suggest you do a search for dyno results on a stock car vs on with only headers and a tune.

 

While headers sound nice and give a small increase in hp, they also increase underwood temperature, you also have to protect spark plug wires and the starter from the heat generated by headers.

 

I stand corrected, you’re right on the auto, shift points need an update.

The stick, does not need a tune, since the speed sensor is read from the axle and your mood decides when to grab another gear!

 

My opinion as well. I remember seeing a documentary on the development of the LS1 and how much engineering went into the stock exhaust manifolds. They're brilliant as originally designed.

 

Opinions are cool, but reality would disagree with you both. Strongly.

 

They are cast iron and too heavy. That's not a "brilliant" design to me.

There's good weight savings by going to stainless steel headers.

 

Now I wish I could remember the name of that documentary.......