Recently bought a 03 anniversary, stock, 6 sp, convertible. Looking to make some modest enhancements at modest costs. Anyone's thoughts on each of these: changing air intake to dual cone? Diablo? X pipe? I have been told these will improve HP/torque and exhaust sound to a small degree. Appreciate opinions and which products you recommend.

 

A cold air intake is a good first step, the general consensus is that Vararam is the best one. If you're going to mess with exhaust and add a CAI you'll probably need a tune, but it would be better to take it to the shop. Manual transmission Vettes do not appear to gain much from a Diablo tuner from what I've read here. You might want to invest in some headers in place of the Diablo, and then go to a quality shop for a custom tune after installing the CAI and exhaust upgrades.

 

Thanks!

 

Mods to the front or the back will make only small gains, probably not noticalbe. GM did a superb job of doing all that for us.

Best "seat of the pants" gain you will make will be some gears. After that, you are either in the cam/headers area, or an NOX shot.

Your limit here will be your pocketbook. Lots of killer mods and great HP, but nothing is for free.

Have fun.

 

I'd put a Blackwing on it and a performance catback exhaust on it. Corsa Pace Cars or something with 0 drone.

 

Unless you get a true forced air intake system that gets cool fresh air from the front of the car or in the intake area for the radiator shroud, you’re not going to see much HP improvement. I also prefer VARARAM but there are other systems to choose from.

Do all the mods that you can afford at one time and then get a professional tune. You will save money and get the best performance improvement. IMHO,, Those twin-ram air filters are a joke! You could get the same performance with a free "FLIP TIE" Air filter mod.

Here are the easy bolt on things that will get you the best HP/TQ increases.

Long Tube Headers with high flow CATs
VARARAM
Ported LS6 manifold

If you’re going to get a professional tune, I would get a ported Throttle Body. It won’t add a significant amount of power but, will help with throttle response.
Don’t fall into the trap of removing the MAF screen from your MAF. It doesn’t decrease power that much and helps the MAF do its job properly.

The professional tune will make a significant difference. IMHO,,,, You will NOT see a major increase / improvement with Diablo Hand Held Tuner. It does a good job at improving transmission performance if you have an A4 Automatic Trans.

Things NOT to get for a power increase.

-Plugs (fancy high dollar miracle spark plugs)
-Fancy high dollar plug wires
-Mufflers
-Aftermarket MAF
-Aftermarket Coils!
-ANYTHING that claims amazing performance improvements from TV or Magazines!!

Replace the plugs and wires for a tune up item if the ones you have now are high mileage or causing an issue in performance/efficiency.

NEW WIRES (no matter what kind you purchase) WILL NOT "INCREASE" HP! PERIOD!!!

IMHO,, The best wires that are high QUALITY and fit perfectly are the GM Performance RED WIRES. They are around $60 for a set. www.gmpartshouse.com
Again, only purchase new wires if your old ones are no longer doing the job. NO "above what you already have" HP increase will be gained from new wires.


Make sure that you experience the muffler/s on a C5 before you purchase mufflers on someone’s opinion. If your new mufflers are too loud or have serious DRONE, you will HATE them and end up getting another muffler system $$$$$ later! Seen this too many times to count!

If you want more off the line haul ****, higher numerical gear set will do the job nicely 3:90 or 4:10 are the going gear upgrades.


My first round of improvements for my 02 ZO6 came from:
- Vararam
- 1 3/4" primary Long Tube Stainless Works Headers (Complete System, headers to mufflers)
- Ported TB
- Professional EFI Live tune
Results= 390 RWHP & 375 TQ

Second round of improvements:

Patriot Stage II heads
Whiplash Cam
Self Ported FAST 90 Intake Manifold & Self Ported 90 mm TB
42 lb/hr injectors
New professional EFI Live TUNE
Results= 450 RWHP


Mufflers should be purchased to make the car sound the way you want it to sound more than a HP improvement item. A better high flowing muffler will usually net you 6-10 HP.
For the $800-$1000+ they cost,, aftermarket mufflers should not be purchased for performance only improvement.

A set of used OEM ZO6 Ti mufflers ($350-$400) is about as good as it comes for increasing power and improving sound a bit. ZERO Drone and they are a direct bolt on improvement weighing 24 pounds less than LS1mufflers.

Make sure that you experience the muffler/s on a C5 before you purchase mufflers on someone’s opinion. Take a ride in C5s with different aftermarket mufflers before you plop down the cash for a new set. If your new mufflers are too loud or have serious DRONE, you will HATE them and end up getting another muffler system $$$$$ later! Seen this too many times to count!


That my 2 cents. Been there, done that!

 

Appreciated!

 

Unless you are willing to do the work yourself, have an adequate assortment of tools and a service manual along with a good working knowledge of the car I recommend leaving it alone.
These cars are not extremely complicated but probably more so than the average automotive enthusiast should take on to modify.
This forum is filled with hundreds of stories of builds and modifications gone bad.

 

I'm in the same situation as you.

I did the "zip tie mod" to the intake, where you basically re-use the stock intake and flip it upside down with a K&N filter. It basically costs ~60-70 bucks and an hour or two of your time.

I then bought the magnaflow "Magnapack" exhaust. Its one of the cheapest exhausts you can buy, and it has a built-in X-pipe. It has a pretty good sound, similar to GHL bullets or Billy Boats but probably a little quieter. Downside is its only weld-on. My shop charged me $150 for install, but the exhaust can be bought for less than $600 so you're still doing good on costs.

From what I've read that should give you about 25-30 hp. Probably need a tune to realize the gains. I felt like I got some more horsepower on the topend after doing them, but might just be psychological. Not bad for ~$700 bucks though.