Terry from looking at your profile and the mods that you've already completed, it appears to me that you're on your way to some serious modifications. I bought the Supermaxx headers with out the cats, they're long tube and a copy of the LG's. I paid about $900 and installed them myself. I welded up the adapters from 3" to the 2 1/2" Corsa cross overs to the Corsa Pace Car mufflers. They are really loud but the sound is great. A friend has the LG's and dynoed with and without the high flow cats and had a one HP increase without the cats. The Supermaxx headers are quality, beautifully made and fit perfectly. PM me if you have any questions. Face it, the headers are the necessary first step to where you're going to end up, as with cam and heads.

Cheers, Curt

 

How rich is "slightly" rich? What were the numbers? Were the A/F ratios measured in front of or behind the cats? Can you scan and post your dyno sheets? If it was slightly rich before the headers it could very well be a whole lot rich after them. You could also have KR which could be limiting your performance, could be any number of things, and untill you have it looked at by someone, and someone logs some real time data on it, you won't know whats going on with it.

If the car was rich before the headers it could very well be running pig rich now. And no one knows.

304 RWHP before with stock manifolds, and you have virtually the same mods I do, and you get 304 RWHP after the headers? Something is clearly wrong with that.

No offense intended, but in lieu of doing the legwork and putting forth the effort to find where the problem may lie, you seem eager to want to blame the headers. The same thing could very well have happened to you with LGs, Dynamaxx, etc.

I don't know why so many think that you can just bolt on headers, do no tuning afterwards, and consistently get good results.

It is a fact that KOOKS are on some of the quickest cars on this board. But I would bet you dollars to donuts that virtually all of those cars, mine included, has had some tuning after the header install.

Do yourself a favor, get the car looked at and tuned by someone else who knows C5s. You could have a false knock, the car could be pig rich, and on down the line. You just don't know at this point.

 

Ya, after reading all of the replies I think it's not a question of if I am going to put headers on but what kind. It really does sounds like the next step in my long list of mods! What about cat vs no cats? Has anyone every pushed a Conv with big HP? Just curious..... Still open to suggestions on makes of headers.......

Appreciate the relpies so far!!!!

Terry

 

The CAT's VS NO CAT"s is sort os a mute point for the normal every day driver. The HP gain normaly 5-6 HP on a good day is not worth the hastle, smell of untreated exhaust and legal problems. Just get a set of high flow cats and dont worry about it. Most complete systems will provide a CAT eliminator if you ever want to remove them for track applications.

My 2 cents.

BC

 

outside of cali will the high flow cats pass emisions? (not the visual of course...) thats what my biggest worry is......for an extra 400 500 i could buy my "ticket" twice to three times........but what do you guys say? will they pass?

 

My biggest worry with the header install is the emissions testing, both visual and sniffer. I have heard some nightmare stories. Any input on this aspect of the header install?

 

So far it looks like Kooks and LG are very popular here! Not sure the extra money is worth the LG's at this point though. As for heads and cam, at first I though I wouldn't go that far, now I'm starting to think about it. So who know's...... Damn mod thing, When do you say O.K. it's all done??????

 

You're never done.

To answer a question you had above - there is a member here that putting down 720rwhp in a convertible.

Headers : 3 main players - LGM, Kooks and Dynatech. Here's my Dynatech Supermaxx headers, high flow cats, x-pipe and Borla Stingers.

My Dynatech's cost just under $1400 complete with cats from Corvette Garage.

Here's what they sounds like - Flyby

EG

 

I installed my LGs last friday. I think I have the same air flow problem. I get alot of popping at WOT, hope to get a tune this week. The new sound is great.

 

Not really alot to ad here, I think it will come down to personal preference from here. I will say this though, $3000+ seems high for a mod that you can do at home on a weekend. There are several threads on the forum that will help you with installation. Some set-ups are alittle more involved than others but none so involved that you can't do it yourself. Food for thought.

Good luck with your decision,

Darion

 

 

Price sounds aput right for the products, and yep, get that dyno tune to max the performance of the mods.

Resale, well I've modded almost every car I've ever owned and never had trouble with resale. Subtle mods are the key, wild paint or extremely chopy cams put off many prospective buyers.
you should not have resale problems with exhasut mods you mentioned.

 

I have Supermaxx LT's on mine, and I would definately do it again. Great horsepower and sound!