NemesisC5

http://www.breathlessperformance.com...&productId=879

One possible low cost alternative in link above. Early in the mod process I had this with other bolt-ons and a "Hypertech" canned tune. I had Kooks catless headers installed and dyno tuned and gained 7rwhp and 9rwtq. Not much Return On Investment (ROI) in my opinion. The C5's are known to have some of the best factory exhaust manifolds made. Headers deliver a % gain based on engine flow needs. At your current sate of mods the cam will yield largest gains if it is one or the other choice. The catless weld-in x-pipe (in link) will help your flow and help your sound greatly. Further down the road would be my choice for the headers again considering what gains you receive for $ invested.

Also read link below about C5 exhaust manifolds versus headers:

http://www.carcraft.com/techarticles...t/viewall.html

dbs1vette

I had heard C6 Z stock exhaust manifolds flowed very well, but the C5, not so much. Not unusual to see 25-30hp gains on the C5 with LT's/cai/tune.

I would also say headers before cam, but since you have the cam ordered, maybe you would be best to wait until you can secure headers with the hi flow cats and keep the wifey happy?

MrJonMan

Yea....I'm biting the bullet and ordering some headers this week.

NemesisC5

Any component can be a bottleneck in a system and in a stock C5z you can find a few but the tune is always a big contributor to anyone that does headers/tune. If dyno tuned already you won't notice much (8-16 rwhp) with the addition of headers. If not dyno tuned you'll likely gain somewhere from 16-32 rwhp with LT headers and dyno tune.

I would never deny the value and benefit of headers in modded applications. In this case the OP was asking about the gains he could achieve in his application so I shared my real world experience in my application which was similar to his.

Cheesecake 07

Disagree. My car made 363rwhp bone stock. LT's/X pipe made 383rwhp at peak(No tune, bone stock LS6)…under the curve gains were similar or better.

Car maxed out at 394rwhp with a Halltech intake/Tune. Intake/Tune made the remaining 11hp, where simply bolting on the headers made 20rwhp peak and 20ftlbs in some spots.

Same dyno. Same day. Same car. The factory manifolds on the LS1/LS6 are terrible.

dbs1vette

I agree. I have heard the C5Z exhaust manifolds are not very conducive to flow like those found on the C6Z.

NemesisC5

C5 Factory manifolds are very good without cats, it's the factory cats that suck....C6z factory manifolds and cats are even better. In post 41 I put a link to a weld in x-pipe that replaces factory cats and I was using that as a low cost comparison to LT headers. I stand behind my opinion as I witnessed the results with much remorse of my header install on my C5 with before/after dyno tune. Years later I read the Car Craft magazine article with the 3rd party comparison data in post 41.

I'm merely providing a lower cost alternative to the OP at this stage of his mods if he's looking to save coin and still have good performance and sound. Calculate the dollars you spend for each horsepower on tune, cam install, header install, heads install, etc....having an estimate of what each horsepower costs you may sway your opinion on which path to take to achieve your goal.

C5Dobie

Yeah well, bottomline is a cammed muscle car like a vette is chintzy w/o headers. OP can do what he wants w/ his $$$ & his car, but if you were to poll LSx car owners who mod their vehicles I can guarantee you beyond a shadow of a doubt 90%+ would say headers before cam, and the cars just SOUND and breathe better w/ headers.

NemesisC5

Bottom line is how much power you get for the money invested, period.

troyguitar

No way dude, louder and hotter is better.

C5Dobie

Used blower on an otherwise stock Z then! No supporting mods whatsoever, just grab the blower from ebay or a wreck, bolt it on the Z and tune it. Stock airbox, fuel system, everything.

NemesisC5

Go ahead on Dobie.....

ThumperNC24

You should DEFINITELY get headers with a cam of that size. You'll be choking that engine otherwise.

Mechanical

I haven't read all of the posts so I apologize if I'm repeating what has already been said. IMO it definately seems pointless to do a cam install without upgrading the headers simultaneously. Not only will it save you lots of money in the long run, but you will be utilizing the maximum potential of that cam by allowing the motor to breathe properly and exhaust faster with the headers. I would personally never to a cam install without making sure I have the headers the accommodate it. Adding just a cam or just headers will get you decent power gains with decent sound from either one. But combine the two and you will get incredible power, mean engine sound, crisp throttle response and smooth feel all together. It's a no brainer to me by that's just my opinion. If you plan on having both at some point then just wait until you have the money to do them both at the same time, that way you won't spend the extra money on additional labor and possibly a second tune. If you want just one or the other, do headers.. Less labor, still great sound and almost equivalent power gains with the right components. I'm running a slightly larger cam (233/239) with 1 3/4" Longtubes, stock intake and I'm making 434 whp. GL with the install! Hope this helps and sorry for rambling LOL

MrJonMan

Lifters ordered from Colorado Speed yesterday, headers ordered from TSP this morning.....now ready for everything to arrive and get to working on install!

Mechanical

Great choice on the headers! I'm running a full TSP setup and I couldn't be happier with the quailty and performance of these parts! GL and let us know how it goes!!

C5Dobie

You coating the headers or no? If I lived in TX I may leave them uncoated and watch 'em get all rainbowy, but then again the ceramic coating does keep the heat down some.

Z06ness03

This reminds me of my Mustang Cobra friend who wants to push 19psi through his motor with a supercharger swap but leave his cast iron logs still on the exhaust. You're supposed to work from the outsides in.