Currently have a stock 04 Corvette (except for a Volant cold air intake installed by previous owner) and am considering these mods, in this order.

- maybe upgrade the cold air intake to Vararam or Callaway Honker
- Borla exhaust 140039
- LG Street Series Long Tube headers w/ X-pipe and hi flow cat
- tune

I decided on these after hours of reading these forums but wanted a second opinion before I started spending all this money lol products and order all check out? Something else I should look into? Also what kind of hp could I expect these things to get me to? I've seen that each of these adds about 10-20hp?

 

Those are great mods. Every car should have that combo. Those together with a tune will net you about 30hp but more importantly you will also get more usable Torque and a wider powerband. Of course it will sound 100% better too.

You should get all of those things installed before the tune. Its not the greatest to run the car without a tune after adding a new intake and/or headers. You could run lean if you do. You would have no problems installing the mufflers and running them without a tune though.

 

HP is not really additive like you are expecting......Personally, I like the mods you mentioned, but what are your goals? Is the car an auto or manual....If auto, i would consider a high stall converter and\or 3.42 gears IF you happen to have a 2.73 rear diff........If you have the 3.15 gear already then getting just the converter will give it a lot more noticeable punch...

 

ah ok I misunderstood the hp thing then. I was just quoting other people I’ve heard or things I’ve read. But I’m still learning, my knowledge base is fairly new on this.

goals is to go faster lol but not trying to go crazy with it and spend way too much or do anything to compromise the reliability of it.

it’s a manual. I also have to do some research to understand that last part lol how do I know which rear diff or gear I have?

 

If it's a manual you have the 3.42; the only thing offered on the manual.
From personal experience, the most rewarding mod I ever made was a 3.90 diff. It just transforms the street driving experience.
Yes, it makes zero horsie gain, but from the driver's seat on the street, feels like you added 50 HP.
And 6th gear becomes becomes the perfect balance of economy and torque on the highway.
Downside - - you'll buy more rear tires!!!!

DG

 

Be totally honest with yourself and tell us your actual HP/TQ desires.
Like most of us, (including ME) I wanted a good bump in power. LOL!
For my "FIRST MOD encounter" I purchased and installed:

1. Stainless Works SS 1 3/4 Primary Mid length Headers, High Flow CATs, 3" midpipe , 3" X Pipe 3" Mufflers and 4"tips,
2. Self Ported stock TB
3. VARARAM
4. Professional Dyno Tune.
6 New Ripper Shifter

That got me 390 RWHP & 375RWTQ. Car, Clutch and driver were happy as clams, Until I got beat by a friggen GM Truck at the track. DAMN! That CRAP won't happen again if I can help it!

Next set of mods (MORE BUCKS) (LOTS MORE)

Saved, researched, purchase and installed the following: MODs

1. Patriot Performance High Flow ported Heads, gold springs, TI Retainers
2. EngladndGreen Whiplash Cam,
3. Hardened correct length push rods
5. Caddy Racing Lifters and new GM lifter buckets
6. LS2 90 mm TB (home ported with adapter harness
7. FAST 90 Intake manifold
8. Home Ported the fast 90 to MAMO Specs,,, YEA BABY!
9. LS2 Timing Chain and Timing Chain Dampener Kit
10, VARARAM Cold air intake.

The first set of mods made the car was significantly more responsive and a LOT MORE fun to drive . I soon learned how to handle and drive the newfound HP and TQ,, I immediately wanted M O R E power!! Losing to a damn Chevy truck at the track immediately solidified the need for the NEXT LEVEL of HP/TQ! MODS! MORE $$$$$$$$$$$$$$$$$$

When you add 20-50 HP to, the suspension and drivetrain of an OEM healthy moderate to high milage C5, it can "usually can up the increased power/ TQ without too much issue. Going the NEXT LEVEL will rapidly show you where the NEW WEAK LINKS are in a hurry!!!

Mine was the CLUTCH. Immediately after the first tune session and first WOT PULL, , the clutch started sticking to the floor under hard WOT pulls. DAMN!

So, I saved a LOT MORE money, purchased: and installed the following::

1. A new spare C5 ZO6 hardened transmission. (JUST BECAUSE I WANTED TO ELIMINATE TRANS PROBLEMS!)
2. New GM TT Rubber Couplers
3. 1/4" Coated Tunnel Plate
4. Spec Dual Disk Clutch and new lighter Flywheel (Offset balanced by local machine shop) IMHO, SKIP THE LIGHTER FLYWHEEL!.
5. New GM OEM Throw out bearing, OEM Slave Cylinder, OEM Pilot bearing.
6. Remote bleeder kit
7. New TICK Master cyl
8.New GM pilot bearing
9. (New "MANDITORY" Harmonic Balancer (Power Bond Dampener) C5 LS engine weak link.! Pinned to the new dampener to the crank!
10. Melling High pressure pump.
11. MAP Sensor relocation kit
12. 42 gphr Green Top Injectors
13. ARP DAMPENER BOLT
14. ARP Head stud kit! (Trust Me, You will appreciate up-grading to head studs for MANY REASONS!)


NOTE, IMPORTANT FACTS: When you make ANY modifications to any modern engine, you "should" do preventive tune up mods so you can base line the New Tune that you will be getting. What is a BASE LINE?

IMHO, you should install the following mods/upgrades so its ALL NEW to the TUNE and if they any of the components fail in the future, replacing any of them will put you back to your new BASE LINE tune. They are as follows::

1. Plugs
2. Spark Plug Wires
3. New Air Filter
4. New PCV Valve with intact PCV pluming (check for cracks. splits and leaks)
5. All Vacuum lines
6. New Fuel Filter and check the Fuel Pump! Pump ! It needs to be fully tested for pressure and flow rate at 100% full Throttle at red line
7 NEW PROPERLY FUNCTIONING PRIMARY O2 Sensors If you are tuning to use them in your TUNE LEVEL.
8. Check the intake air ducting from the MAF to the TB for any unmetered air leaks on the piping behind the intake manifold! (especially on early C5s - 97-2000~~.)
9. Clean Throttle Body and throttle blade for fully open at WOT and properly cleaned.
10. Sensor check: Is/are the engine sensors working/reading and sending out the correct data to the PCM? Example. If the outside Ambiant air temp is 75 Deg, Is your Intake Air Temp (IAT) reading and sending the same temp to the PCM? (Engine COLD) Is your Coolant Temp Sensor reading the same temp as the cold iron block?
11. If you are using the OEM Stock CATs, are they functioning properly and NOT clogged????? (Switching between 100-900 millivolts during closed loop operation)

NOTE: If you Remove, Repair or REPLACE the intake manifold, I highly recommend replacing the Intake Manifold "O" rings/gaskets and TB gaskets.

Well,,,,,, Being a perfectionist and going well ABOVE and BEYOND the norm, just because of the ole racers creed ( FAST, RELIABLE AND CHEEP ,, Pick TWO cause you cant have all three) I also did the following::
2
1. Had that spare C5 ZO6 Hardened trans inspected and rebuilt. I was ripped off because all it had different than stock was a hardened output shaft.. SAD I had it transformed in*/to a C6T60/60 by TRANSZILLA!
Installed the new C6 T60/60 Moded my spare MN12. It was installed in place of the Stock OEM MN12 only because of reliability.
2. Inspected my 42xxx mile OEM ZO6 Differential and found a broken Limited Slip Clutch Belleview Spring on the passenger's side. Ordered All the parts to up-grade the OEM 3:42 Diff to the next C6 OEM level: Installed the OEM C6 ZO6 Output shafts, OEM C6 Limited Slip Belleview Springs and OEM Clutch Pack clutches, Hardened Spider Gear shaft. All mods done by ME on jack stand in my garage.
3.RECOMMEND that you Check the OEM High milage Engine Mounts and Differential Mount for being broken, deteriorated or defective. Many C5 have BROKEN drivers side engine mounts. and or damaged deteriorated Differential mounts.
4. SHIFTER: , For the MN6/MN12 Trans. If you have a Stock OEM shifter, I STRONGLY recommend up grading the lower BOX and shifter. There are TWO types of "aftermarket shifters" Ones like the OEM WITHOUT shifter handle return (to Neutral) springs and Shifters WITH the return to neutral springs! YOU WILL NEED TO EXPIRMENT AND pick your poison! I choose the Ripper Shifter with the shifter return springs and LOVED IT!
5 Wider Low Profile more sticky tires. and wider rims! YEP, An ABSOLUTE MUST for 90-100 HP increase!!!!!!!!!!! Got the CCW 505a rims and TOYO R1a tires.. Hoooraw! I Still melt the at will!!!

Another C5 FACT: IF,, You have over 40,000 miles on your C5, The shocks are most likely SHOT!!! I found my 02 Z was suffering from high-speed handling issues at 42.000 miles. I Purchased and installed the C6 ZO6 Shocks and I have NOT looked back since! YEP,, Best bang for the buck and a DIRECT OEM BOLT IN UPGRADE! If you have the FE-1 Base Suspension, I strongly recommend up grading to the C6 Z-51 Sway bars (front & Rear) along with the C6 ZO6 shock up-grade. Also ADD the C6 sway bar end link upgrade replacement/upgrade. And the C6 tunnel plate.

Well, I've rambled on far too long, spent WAY TOO MUCH of your budget and I am POSITIVE that I missed a few more cash expenditures.
I went from a STOCK C5 ZO6 with approx. 360 RWH, to a first mod with 390 RWHP to a SECOND LEVEL Mod at 450 RWHO 425 RWTQ. Totally Satisfied and the car loves it.., NO ISSUES! The clutch and drivetrain is SOLID and the valve train is very QUIET!

Send me a PM if you ever want more detail. on what I did to my car. YES, YOU CAN CALL ME if you desire. Put a phone number in the PM.
I'm very sure I left something out in this post. I Just had minor elected surgery. All is good!. LOL! RECOVEING! GOOD DRUGS!

Hey,,,,,,,,,,,,,,,,,, If I had it ALL to do it all over again, I would have saved the cash to go Forced Induction! (SUPERCHARGER RULE!)

Bill

 

Since it's a manual then you have 3.42 as mentioned above in another post.....But Bill is right in that the mods start and never seem to end. You will end up spending a few grand no matter what you choose. An A&A supercharger may be all you need. Drives like stock until you get on it....I ended up with one after all the other famous mods were already added...

 

I'm replacing my trans and clutch very soon. What transmission mount would you recommend? My '04z has 250k on it.

 

Start by making sure the car is a solid base to work from, since we don't know your miles / condition.

Good tires (huge mod on their own)
Fuel filter
plugs / wires
change oil, diff, trans, clutch fluids,flush coolant and brake lines
make sure the balancer is good
address any codes you pull from the DIC

Mods for power:
Headers / cai / x-pipe / cat-back / tune = ~345 rwhp, fun, noisy, good times (not 390 rwhp as the dyno where Bill went - Bill knows his stuff rock solid, but that dyno was Jen 'R Us)

Mods for better driving which greatly improve the car's feel and driver experience:
MGW shifter (presuming 6-speed?)
TMODcustoms shifter tub (unless you get the newer MGW which comes with its own tub)
coilover suspension (smooth transitions and lowered)
Corbeau A4 seats (keeps you from bouncing around the cockpit)
Pfadt or HPI trans mount (stops the drivetrain bounce which can crack a trans/diff case and plants your rear tires)
decent rotors / brake pads

Easy power along with easy drivability and ease of return to stock-ish:
New or used A&A or ECS blower kit and 10psi 500 to 550 ish rwhp

Power support mods for blower:
Straub bushing kit
fresh PAC springs
McCleod RST clutch / flywheel (I prefer lightweight flywheels, but to each their own)
when doing the clutch add a Katech remote bleeder (they don't leak like some of the Tick bleeders do)
Tick master cyl
walbro 430 in-tank pump replacement

It's all fun and it's all good.