bud miller

before i begin with pic's, i want to thank a forum member for a used set of ls7 manifolds , cats and ls3 midpipe modified to fit the ls7 cat flanges...and also a BIG THANKS to benny's man cave with lift..and MIKE and DAN, i could'nt have done this without all their help...
now pics
before install ls7 parts used ,new gaskets..,leave radio off, disconnect battery..re-set presets after install

removed midpipes first

some will recommend using an ls7 midpipe and modify to fit ls3 mufflers..more 3" in in the system..i didn't have..

removed front 02 sensors from ls3

remove dipstick and sparkplugs.





did not have 02 extensions so had to peel back harnesscarefully, and increase length..real hassel,but it does work




very tight to connect cats to ls7 manifolds..must use skinny hands and wrench..should lift car and let ft suspension drop ..easier to reach..also use bolts on some rather than stock nuts.


finally finished


here is a pic of the o2 sensor extensions from Auto wiring Solutions.finally got two..fit nice....

AORoads

nice of them.

rcallen484

Thanks!!! What is your very first impression of difference (if any) in sound and feel?

bud miller

yes its definitely an improvement between ls7 airbox and filter, and the exhaust , its worth it maybe 10rwhp...great sound..much deeper and some exhaust poping on decel or shifting..i have M2W switch , so it loud when open..still quiet at cruzing..
i was not looking for any huge gains..it just adds to the car's uniqueness and looks fairly factory stock..... 1 0f 52 c6's

peter pan

Nice mod and I did the ZR1 Complete exhaust on our 09 Coupe, much better sounding than the base setup I had

AORoads

is that a direct, no changes bolt up like the Z06 retrofit?

mike100

Here's the secret tool you need to reach "the 4th nut" on the Z06 cat flange. What we really needed was a proper special order mid-length socket (between deep and regular lengths), but since we didn't have that, I managed to torque the one impossible to reach nut using a cut-off el-cheapo imported 5/8 spark plug socket. 5/8 is about 15-1/2 mm and being 6pt pretty much fit well enough to get the job finished. As Bud mentioned, you can easily reach it if the wheels are off the ground and the suspension droops. We couldn't really reach it with the car settled down on the 4 post lift we did the work on.




The other tip was to load the new LS7 manifolds from the bottom- they won't come in thru the top- (the pass side ls3 manifold came out the top- the collectors on those are so much more compact). Holding the manifolds at an angle, have a helper guide the LS7 cat pipes to mate the flange. It is a bit tight, but it all goes together with about 5 minutes worth of wrangling. The passenger side is a little more difficult and we ended up removing the post catalyst O2 sensor on that side to get more room to angle the pipe.

last hint is that the LS7 manifold with the heat shield is passenger side (for the starter), but that becomes obvious when you mock it up on the floor before you start.

mike100

And yes the car is quicker over 4500 rpm. Bud let me drive it, and even though it was around 90 degrees here when we finished, I could tell the car had more rev up high compared to mine.

Hoping to do this before years end along with some other supporting mods.

bud miller

ttt

bud miller

AUTO Wiring Solutions..This o2 sensor extension is 24'' in length. This extension fits 05-08 C6 Corvette front sensor applications and several other applications using this same connector. The Rear oxygen sensors on the C6 corvettes use the 4-pin square “Gray” connector, These extensions are available in our ebay store "Auto Wiring Solutions" as well other o2 extensions to meet your needs. see um on ebay

BadgeZ28

Am I correct thinking the swap won't work on a automatic car?

2009CSR #45

Auto's should be ok with the swap.

You're copying me Bud!!! Well sort of, I dropped in some 1 7/8's LGs on my CSC last year. That upper rpm acceleration is definitely nicer than stock.

RobVette

Great job and thanks for posting pictures.

bud miller

have you done a tune??
..one reason i went with factory z06 mods, is smog in CA, and i wasn't gonna do a tune to leave my extended warranty unmolested...

2009CSR #45

Yeah I've got a tune. The smog laws are changing next year, no more tail sniff for cars made in 2000 and up. Just an OBD scan to check for SES codes and electronically check the emissions equipment.

bud miller

have pic's of the o2 sensor extensions..see pics above...

bud miller

ttt

Boomer111

My LS3 picked up 40 rwhp with same system and tune.

30 rwhp on dyno and an added 10 for having 4:10 differential.

Good for 15 hp above a tune only.

rcallen484

No.

Pinky...

I have to ask, why not go with a quality aftermarket solution like headers and high performance exhaust such as Corsa? I would have to imagine you would get better gains out of it than just adding Z06 parts.