Hello All,

My dad and I are doing a build together. We chose the C6 Z06 platform because of the all around comfort/performance for the price (and because there is just something special about a high revving NA 427).

we’ve done a number of appearance items; CCW SP500s, lots of interior leather from Apsis, etc (will post pics later).

Build Goals: Address the known LS7 issues with no compromise in driveability. Dad and I have done the loud/ big cam/ on-off clutch cars in the past; not for this build.

Heads: Advanced Induction full CNC port (280cc) 66cc combustion chambers
-Stock intake Valves
-Fierra 2042 one piece stainless exhaust valves
-PSI 1511 springs w/Ti retainers/locks
-Full bronze guides

Cam: Stock
If we upgrade in the future the list is narrowed to
-TSP Stage 1 (V1.1) - 220/238 .635/.635 on 118+4
-EPS - 222/242 .63x/.63x on 117
-EPS - 224/244 .63x/.63x on 118+5
These are all +25-35HP cams designed for manifolds and little driveability impact

Intake Manifold: Stock LS7 ported by AI
-I’ve seen these support 600RWHP with no fear of fitment issues. I also like the look of the stock engine bay.

Throttle Body: Stock, ported by Mamo

Air Intake: Callaway Honker / WCC Smooth Bellow
-Was a toss-up between this and Halltech. Wanted the true ‘cold air’ from the Honker. Had a Honker on my C5, pretty good quality unit.

Exhaust: Corsa Xpipe/ Gutted Cats (OEM Manifolds/ Downpipe/ Cat-Back)
-Stock manifolds. This one is also controversial, but I do not like the sound of LTs inside the car, hearing each exhaust pulse hit the primary. The LS7 manifolds flow surprisingly well (I’ve seen 550 RWHP with a modest cam)
-Down pipes: Gutted cats in stock downpipe
-Mid pipes: Corsa X pipe (mainly for sound, but it didn't change much, actually reduced drone a little with valves open at low RPM).

Tune: conservative with street and dyno tune
-A/F 12.5 throughout (.85 Lambda) - Tuned for 93 octane pure gas (non ethanol)
-Timing: 20-21 at peak

Clutch: Tick adjustable Master Cylinder:
Improved pedal feel a bunch also reduced weak/shudder engagement and the occasional 2nd gear scrape at high RPM shifting

Head-Swap Parts List: Thanks SDPC!
-head gaskets (12582179 – 40.99ea) x2
-intake manifold gasket kit (89017852 – 69.95)
-exhaust manifold gaskets (12594171 – 20.23ea) x2
-Manifold to cat down pipe exhaust gaskets (15272179 – 23.34ea) x2
-ARP head bolts (Backordered w/no ETA currently)
-GM LS7 head bolt kit (17800568 – 35.37ea) x2
-ARP LS7 Block Head Bolt Hole Thread Chase (912-0011 – 68.99)
-Valve cover gaskets (12637683 – 16.92) x2
-NGK TR6gp Platinum Spark Plugs (5141 – 4.23ea) x8
-AC Delco Spark Plug Wires (19417612 – 83.25)
-Pushrods: After checking it took 7.700 (1 turn method) Trend T775803-16 - 4130 Chromoly Pushrods, 3/8" Diameter, .080" Wall, 7.750 in. Length

Results:




Changes/Updates: Gutted Cats (gain) and Richening the A/F from 13.2:1 to 12.5:1 - or - .90 lambda to .85 lambda (loss).


SAE Numbers Were 520/485

Driving Impressions:

The car looks like stock, sounds like stock, drives like a very angry version of stock (made more power than expected). Between 3.5-6K RPM its a totally different car, the 345 Michelin's are not up to the task in first gear and second gear requires some 'care' from 3.5KRPM up. Putzing around town, the car is more punchy/ fun in 2-4 gear from 2-4K RPM. Gutting the cats made a tremendous difference in throttle response/ how freely the LS7 revs (+15RWTQ from 2500-5500rpm). First gear is not usable, needs some Nitto NT-01s.

The Tick master cylinder is a big improvement for pedal feel and clutch disk engagement, not an easy/cheap install but well worth it for me (the factory clutch pedal feel/ disk engagement was the one thing I did not like about this car).



very best,
Nick

 

Sounds like a really nice, fast car that you can drive comfortably anywhere. Nice job! The C6Z06 is my favorite all-around vette of all time & I like your take on warming up the factory performance without killing it's every day livability.

 

Thanks! That was our goal exactly, getting old I guess

 

C6-Z06 FTW!!!!! Nice!

 

Funny I did a stock cam build with AFR 205 heads on a c5 zo6 and made right at 405 whp SAE which was the rated flywheel number. You did a similar build with the LS7 and made 515whp SAE vs 505 flywheel. The LS7 exhaust and cats on my C5 sounded fantastic, but I also like the sound of headers.

I can confirm these stock cam builds are super fun, and really easy to drive and live with every day.

Hiosilver has a really fast stock cam LS6 car, and Lazer has done a couple stock cam LS3 builds. All of their cars went solid 10's.

 

i am getting old, I had to look up FTW LOL

 

yep, it’s hard with the LS7 because people over-cam the heck out of the 427. A cam with no shake at idle (what I wanted) would only net about 35 HP, and for me, it wasn’t worth it to crack open the front of the engine. The other consideration for me was additional valve train stress on the LS7 heads.

 

Nice build. Street driveability is underrated.

 

That's a cool build, sounds like a lot of fun to daily.

 

Sounds like a nicely done build. I guess the clock is ticking while I contemplate how to proceed on my 427. I am another one who doesn't want to lose any drivability while looking to improve my car. You are practically a neighbor. Thanks for sharing!

 

I like how you justify your decisions regarding specific components, namely stock camshaft and exhaust manifolds.
I would still be tempted to install aftermarket camshaft and definitely install quality headers.
But fully understand stock driveability and NVH as top priority in this build.
Well done!

 

Changes/Updates: Gutted Cats (gain) and Richening the A/F from 13.2:1 to 12.5:1 - or - .90 lambda to .85 lambda (loss).

Driving Impression:

This feels like even more than 15RWTQ and 10RWHP throughout the midrange. The LS7 revs much more freely, feels more like my old LS6 (a shorter stroke lighter rotating mass engine).