Hi,
I've been driving my stock '09 Z51 now for about 5 months. Not that I got money burning a hole in my pocket , but I'm thinking about bolt-on mods. Seems like headers and CAI, might be a reasonably effective thing to do. I would like to keep my NPP mufflers and I'm wondering what my choices are for the best headers and cold air intake for the money.

I have a couple of questions:
a. how much power increase can I expect from my LS3 from these mods?
b. (I know this might be controversial, but..) what are the best units?

I know this questions can be controversial, but I hope that some of you have tried various combinations and various brands and you can give me some fairly balanced and objective advise.

Thanks in advance,

Manuel

 

LG's with X-Pipe and Snake Charmer CAI

 

You can expect 20-30 rwhp from the headers. We have installed many sets of Kooks headers. Their quality and fitment is great.

Seth

 

I would spend the money on headers and a tune... I had headers, exhaust, intake and a tune but my intake was a VaraRam and I was not overly impressed with the build quality, and then in the end I sold it anyways because I went with a blower... If I did it again I'd have skipped the intake.
Best headers = no such thing... The top 3 are Kooks, LG and American racing; I had Kooks and the fit and finish were perfect, plus they didn't cost a lot; that would be my recommendation, but word on the street is that the LGs make more low end torque..

 

Thanks for the good input gentlemen. I think I'm going to spring for headers and a tune. I'm pretty sure the Cold Air Intakes do not do much if anything for a dyno run. Of course, I've been hearing for years how much good they do in various cars. The thing is, I don't know how restrictive the stock intake is on a new LS3. Is the stock intake in a modern C6 with LS3 very restrictive?

In my old Miata, a little messing around with the intake produced a little bit of extra power on the dyno, but it was almost insignificant. I had no way to verify the improvements if any of cold air intakes in various cars that I've owned. Maybe they produced some power while under way but I never tried a scientific test or comparo of CAI vs. stock.

There is another question. Are long tube headers available for the '09 Z51?

Thanks

 

Horsepower sells cars, and when it comes to a sports car like the Corvette, you can rest assured if there were big gains with no compromise from changing the intake, it would have come that way from the factory... I didn't notice too much of a change from the intake when I did mine. Headers are a different story of course since they have to run crappy short ones with massive catalytic converters for emissions reasons... Plus the sound you get from long tube headers is priceless...
AFAIK all C6 headers work on all C6 cars, but I could be wrong....

 

 

Yes, with Kooks the headers are the same 05-09. The difference is in the X-Pipe/Crossover.

Seth

 

Good info! I'll start looking into it. I hope to use them with the stock NPP mufflers.
Sorry if I'm boring some of you, but, there are more questions of course. It occurs to me that I don't know just what the headers comprise. Do they use the stock cats? Are there more parts that need purchasing to complete the installation? Just what all do I need to get? I'm not knowledgeable about the C6 Z51. I hope you can cure my ignorance

Thanks

 

 

The debate on headers, CAI and tune could go on for days. I m sure that it will be great reading and very informative.

 

Here is a set of factory C6 headers (left) next to a set of Kooks Long Tube headers with a catted X-Pipe. You can see that the long tube headers terminate at a different location so you will have to use their X-pipe also. There the options are to go with or without cats. I recommend with; there is virtually no loss in power but it will be slightly quieter, you will be able to pass a tailpipe sniffer test, and your exhaust won't smell like a chemical factory.


It may not look that way but they both terminate at the same point, allowing you to run any exhaust you want in the car, even the factory one. You just have to make sure you specify your car is not a Z06, as the Z06 pipes are 3" diameter vs the C6's 2.5" dia.

Here is that same set of Kooks 1 3/4" headers and a Kooks catted X-pipe on my car:



The pipes are shiny because I had them JetHot ceramic coated; I highly recommend coating them; everything will run a lot cooler and they will look sharp for years to come.

 

Yes it could and doubtlessly it will be
I'm pretty sure that all these mods will deliver power improvements. I've had a lot of experience (both, good and bad) modifying cars. However I'm totally new to modifying Detroit iron, particularly this new Corvette LS3 engine. It's pretty interesting actually, since I began driving old V8s, straight sixes and even straight 8's. I did not even own a Japanese car until I was around 30 years old. Yet, all my hot rodding experience has been with Miatas, Hondas, and Mitsubishi EVO VIIIs..... While I'm sure all internal combustion engines share the same principles of operation, they are very different in design and execution. So, what works great in one, might not be worth anything on another. Not to mention that I've never tried to get more real power without force feeding motors. I hope to learn a lot before I start spending money and time.

 

Thanks! Great post and great pictures. This is the kind of input that will be useful to me. I really appreciate it.

 

The key phrase is "with no compromise"...the benefit from a true cold air intake is derived from it drawing-in cooler air directly from outside the engine compartment. The increased potential for ingesting water (risking hydo-lock) is why you don't see true, bottom-feeding intakes from the factory. The design of the C6 makes it less susceptible to ingesting water than the design of the C5 but the risk is still there....even with the stock intake the owner's manual cautions against driving through deep standing water.

I agree you won't notice much of a change from the stock intake to an after market intake. There is a benefit to be sure but the power increase is negligible. IMO an after market intake should be thought of as one component in your overall modification plan.

 

Very good info, for a new Corvette owner these photos are very handy, thanks.

 

This is very good. Good info without a lot silly arguments. I am so glad to see this, It's so refreshing after participating in similar discussions in other car forums. By now several "contributors" would have insulted the original poster and each other
BTW, I would tend to agree with the assessment of the CAI. I think it bwould be great to have one, but I gotta wonder of it's cost vs. benefit ratio...

Another thing that's very true is that the key phrase "with no compromise" is very important. In the import, turbo charged cars, the amount of compromise that some people put up with is incredible! I'm sure that there are many Vette owners who'll swear that the street driveability of their car was not compromised after installing a racing clutch, racing coil-overs and wild cams. But by the sober and measured responses here, I think that there are many who are far more realistic about the unintended results of modifying a great car like the C6.

 

The VaraRam was actually the first mod I ever did to my Corvette... I read all the rave reviews, bought into the hype, and picked one up together with the pre-cut shroud.
I installed it myself in about 2.5 hours with no issues. I actually thought it was a cool design with that "ram air" scoop up front:


Trouble is, even before I installed it I could see that the intake was very cheaply made; the edges bowed outwards and it did not seal perfectly. I ignored this and installed it anyways. For what its worth, I've driven it in some of the most severe thundestorms I have ever seen in this country (Ohio is good for that), hit a lot of standing water, and never had any problems with water injestion. Power wise, I can't say I saw too much of a difference, but then again what is an extra 10HP in a 400HP car? You gain more acceleration than that just by the weight reduction of going from a full tank of gas to reserve...
When I pulled it out for cleaning some 5000 miles later, there were leaves on my MAF screen! Oh man did that p. me off! I pulled the intake off and found that the foam had separated completely and there was nothing keeping dirt from entering the engine. I spent a lot of time re-doing all the seals with new foam and tape, and that help up fine, but by then I had already made up my mind to get rid of it... The VaraRam was actually one of the key things behind me deciding to supercharge: I wanted a new intake, and the 395whp/387rwtq I was making with a CAI/Headers/Exaust/Tune felt great at first, but was starting to get mundaine..
Here is my new intake:



I gained 200WHP with that intake

 

I can relate to that!, When I started trying to get more power from a Miata with Headers, exhaust, CAI, advance timing, etc. I quickly realized that the cheapest and most effective way was to add a roots blower, or better yet, a turbo charger w/intercooler. Forget !0%~15% gains. The real deal is 50% ~ 100% gains!
Of course, in a Miata a 50~100 rwhp gain is phenomenal Oh yeah, and a blower installation in the Miata costs just a few hundred $$ more than replacing the headers in a Vette.

 

I was an Import guy too... Had two Subarus; a 1999 2.5RS with an STI engine swap, and a 2005 STI... Clutches, street clutches, racing clutches, stiffer springs, coilovers, bigger swaybars, bigger turbos, bigger intercoolers, etc... You name it, I've done it... In the end I always ended up with a faster but also harsher, louder, less civilized version of the same car, and then stuff always broke