I have a 2005 Coupe, manual 6, Z51, 12K original miles.

Car is a weekend driver, never any racing!

This winter I'm doing a LS3 top-end build.

Planned items include:

• LS3 heads, milled .015, exact headwork still TBD (e.g. porting, valve job, etc.)
• .040 cometic gasket, with milled heads should get SCR in 11:1 range
• LS3 intake with 42# injectors, intake modifications TBD
• ARH 1 7/8 headers, 3x2.5 X-pipe with cats
• LS3 NPP mufflers with retrofit controller unit
• 10% under-drive pulley
• Reliability items (e.g. chain, trunions, new lifters, etc.)

I've already purchased most of the above (except headers). Working hard to get good deals.

As for the cam, what should be added. My thinking is to keep the cam small as the car is almost never over 6K RPM.

Cam thoughts?

Here's the car:

 

Don’t know what your horsepower goals are and how much good street manners play into the equation but a small cam can make a real improvement

 

Cam Motion 222/230 at the largest for your goals & rpm limit.

 

BTR stage 2 will work very nice for you
but get the LS3 version

 

Navy Blue - Very interesting suggestion. I've talked to Cam Motion several times about this cam.

However, I'm thinking about using Comp Cam's 1.8 steel roller rockers with this cam.

According to their cam designer thier would be no PTV issues even using 1.8 rockers.

Thoughts anybody?

 

Just remember that the more the cam lift (to include increased can lift from 1.8 rocker ratio) ... the shorter lifespan your valve springs will have.

Personally, I would use the stock 1.7 rocker arms along with a BTR trunnion upgrade kit, and a cam with no more lift than .600"

 

And as far a cam overlap ... The duration and LSA will determine cam overlap ... Too much overlap (plus numbers), and you will have driveability problems along with a rough idle and a big loss in engine vacuum.

I would look for a cam with no more than about -8 degrees overlap.

Be advised that your OEM LS3 cam has -26 degrees of overlap.

Here is a good overlap calculator: http://www.wallaceracing.com/overlap-calc.php
___________________________________

Cam Motion will grind any cam profile you specify .... This is what I would put in the engine if it was mine:

Duration:
220° / 230°

Lift:
.590” / .590” (using 1.7 Rocker Ratio)

LSA:
117°

ICL:
115° (this advances the cam +2°)

Overlap:
-9°

.

 

Spinmonster 230/234 cam.

 

Thoughts.
i would keep factory rockers and upgrade to a bushing style trunion such as straub ,tsp, che, and keep lift. under .630". As said Cam Motion will custom for you. With a 222* Duration you could use a .365 lobe which would net .620" lift, however this would be an aggressive lobe even for their smooth profiles. I would go .355 lobe on Intake netting .603" and leave exhaust @ .345 =.587".
I would also use their .625" Beehive springs.
For your 6000 rpm limit, 222* of Intake Duration is plenty and +8* exhaust split as well.
I would set LSA @ 115*+3* but discuss with Cam Motion exactly what you want for
low speed driving manners.

Turbo6TA and I agree ~95%. and are just splitting hairs.

You do not want EITHER the spinmonster or the btr stage 2 based on your goals.

 

BTW ... Here are the cam specs for the OEM LS3 cam:

Duration:
204°/ 211°

Lift:
.551” / .525”

LSA:
117°

ICL:
120° (+3° Retarded)

Overlap:
-26°

 

And for valve spring comparisons:

OEM LS3
.550" Max Lift Single Beehive Springs
90 Lb Seat Pressure

Cam Motion
LS Premium .625" Max Lift Single Beehive Springs
135 Lb Seat Pressure

BTR
Platinum .660" Max Lift Dual Springs
155 Lb Seat Pressure
______________________________

Just remember ... the higher the spring pressure, the greater the wear on all the valve components (to include the cam lobes)

 

I recently did a build almost exactly like you're planning. Started with an LS3 though. I think you're selling yourself short by spending the money to port heads, bump C/R, port the intake mani, and add such a small cam. Nothing at all wrong with the mild cam suggested above. Just that you can employ a little bigger/more capable cam without much downside. And I'm not talking about even as big as the "stage 2" cams that just about all cam grinders offer. Also, I think you're selling yourself short by limiting RPM to 6K. I think most stock LS motors are redlined at 6.5K. I don't even think about shifting before 6.5K rpm. Closer to 7K before it gets done.

My rig has 350 ft/lbs of torque in by 1500 rpm. You're not losing anything down low vs a milder cam. It's so docile, I can pull it up on ramps just by modulating the clutch. No need to touch the acc pedal. Fuel eco is almost as good as stock on the highway. Couple mpg less in the city. Not saying it has stock like manners, but damn close. And I have 0 tolerance for an LS engine with less than really good manners. Been there, done it, don't want to go back. I spent 2.5 hours on the streets of Victoria, Tx having Pat Guerra street tune it. It wasn't bad before...just much better now.

In your shoes, I'd spend a few bucks and have Pat G custom spec you a cam. He has a detailed questionnaire that you need to fil out to really dial in the perfect cam for what you're trying to do. He takes the whole combo into account. That include your Vette, all mods, and YOU.

 

With this cam and your above mentioned plans you should be producing about(maybe more) 450 rwhp. I am looking at a very similar cam from Cam motion and plan on using in an A6 with shorty headers and no converter changes.

 

Going to the trouble to a cam swap and NOT doing a converter doesn’t make much sense to me. LS motors LOVE converters and a converter should be the first mod done on an A6 car.

 

Current I'm pretty committed to the Cam Motion Titan 2 using a .660 lift dual spring and Comp 1.8 roller rockers. Specs are:

Hydraulic Roller Camshaft
Mild Performance
Duration at .050": 222/230
113 Lobe Center Angle with a 110 Intake Centerline
Lift with 1.7 Rocker Arm Ratio: .595"/.587" (W/1.8 .630/.621)
Recommended Displacement: 6.0-6.2 Liter Engines
Cylinder Heads: Rectangle Port
Recommended Compression Ratio: 9.5-11.0:1
Recommended Headers: 1 3/4" - 1 7/8"
Recommended Stall Converter: 2400-3600
Recommended Rear Axle Ratio: 3.42-4.11
*Designed for factory style, or high flow aftermarket long runner intake manifolds.


For what its worth the TSP GM recommended almost exactly the same cam specs, just using TSP lobes .

 

Updates?

 

The total build took almost two years - car is a 2005 Z51, M6, 12k miles. DSOM color.

I did the TSP ported LS3 heads, Gwatney ported OEM LS3 intake, ARH 1 7/8 headers with cats, Cam Motion Titan 2 cam 222/230 113 +3, Com Cams 1.8 steel roller rockers, Johnson 2110 lifters, LS3/Z06 AFE cold air intake with a LS3 MAF sensor blade, "Vette-Air" cold Air intake scoop, std. speed ATI harmonic balancer, C5R timing chain w/stock gears (3 bolt), C6 LS3 NPP mufflers with a retro fit controller, and a bunch of TSP provided bolts, nuts, gaskets, etc. Pat G is doing the tune via email.

To help control speed I added painted/rebuilt C6 Z06 calipers with PowerStop Z26 pads and rotors. C7 ZR1 replica polished wheels with Michelin Pilot Sport 4s tires in 275/35/18 and 305/30/19 tires were also added.

A custom aftermarket stereo, speakers, subwoofer, back-up cam with full sound-deadening was also done. The B-pillar and tail/side lights were blacked-out. Front/rear black spoilers were added. All bulbs except headlights were upgraded to LED, headlights are this winter. Engine was "pimped" for shows.

A few thoughts on my build:
* Glad I did cats, once warmed they really cut down on the gasoline smell.
* in hind sight I would have done a MSD or FAST intake, used ones in good shape cost about the same as a used OEM LS3 with porting.
* Acdelco plugs solved a frustrating Service Charging System error when using NGK plugs.
* Dont go underdrive on Damper, my Service Charging System error really made me glad I didnt go underdrive.
​​​​​ * the LS2 MAF sensor is both ugly and limited in power production. Opinions vary, it tops out somewhere around 500 crank HP. Glad it was changed.
* The NPP mufflers when open are really, really loud, when closed much more muted, last like a base car when moving, louder at idle.
* The tune is critical! Pat G is a tunning legend, but I'm convinced that a mail-order tune should be a last option unless a very simple build. I convinced that a tuner need to see, drive and hear a highly modified engine. HPTunner log files are not the same as hands-on time with a car.
* Adding 1.8 rockers I believe made the cam "larger". There are lots of forum posts on this issue - concurring and disagreeing, but tuning the engine it just feels like the cam has 2 or 3 degrees of overlap instead of zero per cam specs with 1.7 rockers. Not trying to start a debate here, just my opinion.
* The NPP retrofit controller isn't as sophisticated as the OEM controller, the control valve starts opening about 3500 RPM, but not completely. Also, in some low speed driving the car gets loud as vacuum gets low. I'm going to add a small vacuum pump/reservoir to control the mufflers when my wife is in the car.

Here's a few pics:








And an engine compartment pic taken during the build:

 

Excellent Excellent. I'm curious as to what the intake and valve covers are covered with? Is that power coated. Also, can you post a video of what the Cam motion Titan 2 sounds like? How does it all drive...? Pull hard above a certain RPM, Dyno, track, etc?

 

Jim,

The car is an absolute thrill to drive. Lots of torque down low and the top end dosent let off till readline.

I wanted a "small" cam as I'm using OEM LS3 ported heads with big ports with a smallish LS2. Working to keep port flow up.

The intake and valve covers were all painted. This has been the big disappointment. The CAI is peeling badly and the valve covers dont match the intakes.

Vette Air did the painting and Carlos the owner has agreed to repaint them no cost. Now's just not a good time to pull all three off and send them on a two week journey. That's fall/winter activity.

I'll post exhaust sound pics and give more details soon.

Dave

 

Congrats on your results Dave!
Did you keep the stock Torque Converter?
What are your axle ratios?
How are the low speed, parking lot manners?
In for Dyno Results.