Guys, just got an extremely clean and well maintained 2003 Z06 today. I am super excited.

I had driven a few of them and this one being so clean and bone stock is what I wanted. I drove one with headers, x pipe, borla exhaust, intake and a custom dyno tune and it was almost too much. It was also a little rough in other ways (janky aftermarket stereo that still sounded like crap, lots of paint defects, whole dash vibrated/buzzed at higher revs). It was dynoed 394 to the wheels and I would like to maybe get halfway from stock (I believe I have heard it’s around 330) and there but with more easily reversible (and less expensive tbh) mods than headers, and less deafening sound haha.

Stock performance is great, but I am definitely interested in some minor reversible / stealth mods. I was thinking intake and maybe an x pipe? I don’t want to get rid of the Ti exhaust, and headers with Ti exhaust and x pipe to me still sounds a little too attention grabbing.

What intakes should I be looking for?

Would a new x pipe with freer flowing cats get me a little more sound and HP while keeping stock manifolds and exhaust? What ones should I be looking into?

And then if I maybe get it tuned after do you think I could pick up total something like 370 to the wheels?

Also looking to keep cost reasonable. Like if one x pipe over another may net me another 3HP and it costs $1000 more, I’ll probably pass.

 

Can’t go wrong with a lower rear gear for stealth.

By intake, I presume your are referring to the air box/filter/air bridge? If so, put that money toward your tune. They don’t really result in more power.

 

Nitrous in a gym bag.

Otherwise I'd just leave it alone.

Without going to at least long tubes and a good tune there really isn't anything butt dyno to gain.

 

But if I didn’t have any mods to tune… wouldn’t there not be much benefit?

If I understand correctly, if I were to put on a Blackwing or Vararam, I could expect some gains like 15-20hp. Then maybe get more from a custom tune that fully takes advantage of that, no?

 

It would take the dyno tune to get the 15 to 20 and not so much the intake.

The intake alone is probably worth less than 10.

These cars are very efficient right out of the box.

 

When people start talking about intakes and cat backs and air filters... Just forget it. You're not really looking at
power or mods. That's just tinkering or customizing.

Ultimate bolt on / reversible: blower kit.

Change the pulley to make more or less. Easy on. Easy off. And they sell for almost as much as you buy them for. Also, cool factor.

Car sounds cool though. Send pics on here brother!

 

This is the meat and potatoes of it. Better typed than what I was saying.

 

Thanks everyone so far for feedback and opinions. Will have pics soon. Taking delivery on Monday. But, really not much to see for you folks. Looks like a super clean, stock, torch red C5Z!

 

If you don't want to do a super charger (I did it and love it), you can get a decent amount of power from headers, CAI and a tune.
the cat back you have is already pretty decent, I put on a zo6 ti exhaust on my '00 and love it.
I dynoed the car before and after, I went from around 310hp/310 lb*ft bone stock (I forget the exact stock numbers, but they were right around there) at the wheels to 331 hp/330 lb*ft with the upgrades. I went with Kooks headers, vararaam CAI, hi flow cats and a tune from a vendor (who shall remain nameless for various reasons). I probably could have squeezed out a little more if I went with a z06 intake manifold, but, eh.

Anyway, I don't know how much that translates to a z06. I attribute the vast majority of that increase to the headers, cats and tune, so I think you'll see a decent bump as well if you go that route. I agree with others that the CAI does little to nothing on its own, I don't buy manufacturer claims for a minute, and I don't think there's any *major* flow differences between z06 cat back and stock. The z06 I believe only has 1 cat per side vs the non-z06 c5, so that could make a difference in gains.

But that's really about it unless you want to start getting into more substantive upgrades, like a super, cam, and/or heads. You'll see an increase .. but what i got with my c5 is about the most you can expect. The good news is that if you DO add on headers/hi flow cats, they'll compliment a future upgrade to a super/cam/or heads. I recently added an AA super and a cam to my car, and saw a 200hp increase-- I think z06 owners that do this see even more.

By the way, I also did 4.11 gears in my car--that made a HUGE difference to me in acceleration. obviously doesn't impact power numbers, but gives the car a much more aggressive launch and makes sixth gear usable.
I still have the gears in, and so far living with them with the super charger, though may end up dropping them down :-)

 

I think I need to get with the local Corvette club guys to see and ride in theirs. Seems like maybe I was judging headers too harshly and they also seem to be the most meaningful source of bolt on power w/o FI.

Anyone either know the Dallas area clubs, and/or have a modded C5Z around Dallas I could see and ride along?

 

I had headers and z06 ti exhaust in my 00 for years. It gave the car a little more rumble at idle and noticable at WOT, but it was really not a huge difference over stock. if that's what's holding you back from getting headers I wouldn't worry about it. the cat back you chose will have FAR more impact on the sound than headers.

 

The header sound, well…it sounds awesome. The last time I had headers was in SoCal, and heat was never a concern.

Now, living in a hot climate (as does the OP), my concern is the engine bay heat. It gets hot enough already. Would appreciate your experience in that regard.

 

cooling system is more than up to the task in a vette. Even in hot, humid, 90+ degree weather in NY, temps never got a degree above normal.

This should come as no surprise though... headers generally do shed more heat than manifolds due to increased surface area, but the stock "manifolds" really are basically short headers, I doubt there's much difference in how much heat they're shedding.

 

From experience, I have run 10psi on a blower in 102* heat stop and go on the highway with headers and full exhaust on factory cooling system and coolant in that situation didn't top 200. Normal temp in summer is 194-196, and reduces into the low 190s and high 180s in cold months. This is with the fan relays programmed to kick on at 175. So the parts already in the car are very capable.

 

Yeah, sounds like the car I drove with headers and Borla may have either just had a really bad rattle in the dash from aftermarket stereo and also the Borla was more responsible for the super loud sound than the headers. Looking forward to seeing and riding in some other C5Zs before making any decisions.

 

fake news, cai doesn t do much if anything. maybe at 100mp plus it might.
as previously mentioned, your money is well spent elsewhere. gears, headers, tune.

 

Congrats on the new to you Z06! Given what you say you want, I would just go with headers and a tune. Stick with the stock Ti exhaust, and I think you'll be happy with the results. Anything less wouldn't get you the gains you're looking for.

 

I have an 04 Z06 with full exhaust system, CAI, and a mail order tune from ECS. Not been on a dyno but once at the track I was consistently trapping 4-5mph faster than a bone stock 2003 C5 Z06

 

Just got home before the hail storm comes in! About 20 miles home on Central Expressway. Man that’s different than the past 10 years in a truck / Jeep / Land Rover. It was raining so couldn’t have too much fun. But I am excited.