I've read many previous threads on C5 header options and now I'm more confused than ever.

I'm going in later this summer to install a CAM, swap out my harmonic balancer, install a new oil pump (while I'm in there) and upgrade my 3.15 rear gears (A4) to 3.73 with a new stall. I also just installed a new water pump, new Dewitt's radiator/fan kit and installed new plugs and wires. The only bolt-on performance mods I currently have is my Callaway Honker CAI, a low-temp stat/tune, and Corsa Indy Pro axle back with x-pipe.

As a result, I'm considering adding some long tube headers and still have some questions after reading multiple threads on the pros/cons of adding headers and which headers to add.

1. Since I have a stock LS1, what size header tubes fit? Also, assuming I will lose the Corsa X-Pipe but want to maintain the Corsa Indy Pro Axle back that was originally installed way back in 2004 and still runs and sounds great, so does that limit my choice of headers?
2. I do not want to eliminate the cats and run pure straight pipes as this is s street car and want to maintain somewhat of a friendly neighborhood tone until I put some foot into it. Any recommendations of which brand is best?
3. I also want to have the headers ceramic coated both to reduce engine bay heat as well as for looks. Any recommendation on brands that sell the headers pre-coated so it's a simple bolt on vs. secondary coating or wrapping?
4. Any other mods or OEM part replacements I should consider while in there?

I'm willing to pay more for the better, American-made options vs. cheap alternatives, however don't want to spend more than I need to based on quality, fitment, ceramic coating, etc. I've read positive things about Kooks, American Racing, and LG.

Thanks!

 

1 3/4" long tube headers are perfect for a stock C5. Your Corsa Indy Pro Axle back will bolt right up to whichever header system you choose. You may consider installing a thicker torque tunnel plate with a thermal shield.

 

Hey MSG
A few years ago I put LG Pro longtube headers on my stock 2004 C5 and have been very pleased with them. They come with an x-pipe. I also got them with their high flow cats. For a mostly stock engine LG recommends the 1 3/4" tubes. Great sound and performance. LG explained these are the headers you want for mid-range torque as in an autocross car as opposed to high rpm torque if you are taking your car to the drag strip. My research suggested the American Racing headers excel in that application.
A guy named "Tusc" on the forum knows a lot about the AR headers.

My experience has been very positive with the LG Pros. Those are the expensive ones as opposed to the Street model the sell. LG recommends the Pro model over the Street model unless you just can't afford the Pro.
You will benefit greatly from getting a dyno tune. You might even decide you don't need to go to a bigger cam!

VERYSOON

 

Thanks. Great input. It’s definitely not a drag car, rather a strong street roadster. Will the 1 3/4 tubes match up with my Corsa Indy Pro axle back? Do you know of LG sells them ceramic coated?

 

I believe the headers will match up to any axle back. Mine are Z06 titanium which I really like. The collectors on the Pro model are, I believe 3" whether you get the 1 3/4 or 1 7/8" tubes.
I asked Sergio at LG about getting the headers coated. I live about an hour from LG. Sergio runs things and is quite a racer and tech. He performed my dyno tune. I ended up with 340 hp at the rear wheels. He said there was absolutely no need to coat them. They are super high quality stainless and they still look new. Have not had any heat problems. I got them to put on their plug wires, too.

Driving them:
I run Michelin runflats (about to get some new AS4 non-runflats). The increased horsepower is enough to really change the way I start out in first and hit second gear. Tires break loose a lot more easily now! I've tracked my car a bit, but not since I got the headers and tune. Probably can hang with the C6s better now!! You will love the sound once you hit 3000 rpm!!
I have found that I need to downshift to 5th gear when below 1500 rpm (say going below 65) to have decent acceleration. I attribute that to some loss of low end torque. Not a problem, just thought I should tell you. Mileage is excellent. Right at 30mpg at 80mph on highway. (Mine is a 6speed.)

I might can dig up some pics if you want.

VS

 

+1 for the LG 1 3/4 Super Pro Headers with catted X/Mid pipe will bolt up to any axleback made for C5. 1 3/4" primaries is all you need unless going FI. Just remember to tell them if you want the air pump connection or not. Gives you a 3" exhaust from the collectors back to you axleback connection. I have B&B Bullets which are also 3', so great flow all the way out.

Also agree with the tunnel plate (while you're there anyway). I have the Elite Engineering 1/4" with thermal abs.
LG also has a G5X2 cam that is highly recommended by Lou, if you want a good performance bump without getting too radical. They offer 112 or 114 LSA option.

As to the ceramic coating, I didn't have my LG 1 3/4" headers ceramic coated and they never changed in appearance or caused any heat issues that I noticed. However, for appearance and heat mitigation I had my 1 7/8" American Racing Headers done when I went FI. (I didn't think to specify LG Headers and that is what Vengeance Racing choose)
I also added plug wire socks for heat protection. Something I didn't think of at the time, but would if I had it to do over would be starter and wiring heat shields.

 

Good advice so far. I think Kooks are the best quality, and you can get them pre-coated if you want. With that said, you can get just about any quality brand of headers to work the way you want. Any header and x-pipe combo will work with the exhaust that you have. Although some brands are not sold with cats, you can have bullet cats welded into them. That opens up your options, and might save you some money depending on what choices you make. I agree that an EE tunnel plate and some wire heat shielding are both good ideas. Another thing that you may want to consider is ground clearance. If you're running at stock height, this may not be an issue. However, if you are lowered, the setup you choose can make a big difference. It sounds like you have a good plan though. Good luck!

 

If your willing to pay for ceramic coat, it might be worth a call to determine if they are properly coated inside and out. You may have read the experience Tusc had with TPS, and after everything else, they were only exterior coated.

With regular steel headers we coated them to prevent rusting, but obviously that’s not a concern with SS. I haven’t pointed a heat sensor gun on coated headers, though I can assure you they get very hot. I couldn’t tell the difference between bare and coated, both left burn marks. 😡

 

Another +1 for LG, I have there 1 3/4 inch, cats, xpipe, bullet exhaust. Mine are about 16 years old, never had a problem. Made 340 wheel horsepower through an A4 with 3.15 gears. Last year added 3.73 gears and yankSS3200. You will like this combo. Miles of smiles.
Top end kit will be a future mod.

Best 1/4 mile on street tires is 12.5@111mph. 1.97 60foot. I probably could use a drag radial when going to the dragstrip. Tires spin if you try and load the converter, or flash converter.

 

Thanks. With your 3.73 gears and Yank SS3200, did you also install a trans cooler? If so, where? I installed a thicker Dewitts aluminum radiator last year and I'm running a Calloway Honker CAI. Not sure where the best placement would be for an auxiliary trans cooler. Also, did you swap out the entire rear differential or just install new rear gears?

If I don't do the rear gears and just add a CAM and headers, will I feel any significant improvement off the line. Goal is to improve off-the-line performance but not necessarily chase a lot more HP.

 

You will definitely want the higher stall converter if you're doing the cam. This will help keep the car drivable. As far as off the line performance, that will depend on your cam profile. The gears will certainly provide more low-end torque. That will get you more off the line. However, you also need to keep traction in mind. None of this matters if you can't get your tires to hook up.

 

yes, I have a trans cooler, installed by a shop about 10 years ago. Transmission temps have not been a problem. My entire differential was swapped, it’s an RPM stage 2. Off the Line performance has definitely improved, do the gears and converter, don’t look back. You will be happy you did.

If you just add a cam, you have to add a cam that is stock converter happy. My car is completely set up now for a heads and cam swap with longtubes, cats, gears, and converter.

 

I would definitely do gears ahead of time so you’ll be in a much better position to decide on cam/head plan. Oh, and the new cam will actually be happier that way, especially if you have a narrow lobe separation angle.

 

I put one in the front license plate area. If I had this to do over again, I wouldnt do that. Instead, I'd get a good cooler with a thermostatically controlled fan. That would free up a lot of different mounting locations that wouldnt be useable without a fan.

 

Moved to C5 Tech.

 

I will have almost this exact setup this winter, did you find the move from 3.15 to 3.73 was the right choice? I keep going back and forth between 3.73 and 3.42 with the yank SS3200.