FYI, the 2006 CTS-V has an LS2, unlike the 2004-2005 CTS-Vs that came with LS6s. The 2006 CTS-V therefore, achieves power roughly equal to the LS6 with a different combination of parts. Specifically, it has a milder cam but more cubic inches (6.0 liter vs. 5.7 liter), fed by a larger throttle body through a lower cfm intake manifold. Overall the LS2 has more low end torque than the LS6 and the power delivery feelds more linear with no mid-range surge like the LS6.

The EPS cam when added to my LS6 results in a power curve almost identical to the stock LS6. This is evidenced by the fact that my rear wheel numbers (407 rwhp/393 rwtq) are almost indentical to the factory crank shaft numbers for OEM (400 hp/395tq). My car, as modified, feels almost like I just added cubic inches because it has more everywhere but no real change in how the power is delivered across the curve.

Finally, PatrickQ is familiar with my car since he speced it, tuned it, and dynoed it.

 

My bad, Google search for LS6 CTS-V dyno ended up with a 2006. That being said, your combo still ends up with more oomph than the LS2 and a stock C5Z06 graph I found, across the whole power band.

Thanks for the comparo, Darkman. It sounds like the EPS is heads and shoulders above the stock LS6 cam in every aspect. You're lucky to have Patrick in your back yard.

A few follow-ups to your config. What springs did you end up using, and would you consider this setup noisier under the hood than stock? You mentioned stock manifolds & upgraded cats, but axle-back is it still stock? The reason I ask, did it affect the idle/rev sound level or note? Does it sound near-stock with no lope? And last, any significant mileage changes (with right-foot under control).

 

My valve springs are Comp 921, which is a dual, but this cam is supposed to work well with beehives. I went with the Comp 921 based on their reputation for going many miles between changes. The engine does not have the sewing machine sound or random "ticks" that so many people complain about with LS engines.

The only change in the exhaust note at idle is the some additional bass note sound - almost like adding a subwoofer to a stereo that did not have one. From inside the cabin, it car sounds stone stock.

The idle is not particuarly choppy, but does have more "shimmer" than the stock LS6 cam. Unlike LS2s, stock LS6s do have a shimmer at idle.

The highway gas mileage is 26 mpg, which is 2 mpg better than stock. This is at 70 mph, measured for each tankful.

 

Bigger cams do make more power...BUT these little EPS cams run so well
with excellant street manuerisms. They are completely stealthy, have great
fuel mileage, and in a 346" as Darkman stated "slight shimmer"

 

Thanks guys, exactly what I'm looking for. I'll let you know what Patrick suggests.

LS6 cam & springs are headed to the F/S section as soon as I'm old enough.

 

Ok, after a few back-n-forths with Patrick I'm settled on a cam. His suggestion:

222 / 226 115LSA +3, .597 / .598 lift.
PAC 1518's, Untouched 243s, retainers, and locks. 6600 rpm limit.
SCR 10.5, DCR 8.20

He bumped up intake & down exhaust duration "because of the Vette's light weight and better than typical cat-back exhaust". He suggested the 222/226 would match the 218/230 in the lower RPMs, but would excel in the higher RPMs.

I've settled on avoiding the cost of head-work for now since the 243's are nice and tight. The remaining debate is over the target CR, and I'm leaning toward option 1.

1) Use Cometic .040" gasket for 10.9:1 CR, and switch to 91 octane. DCR bumps to 8.4.

2) Stick with GM MLS gasket for 10.5:1 CR and lower 89 octane.

I understand the two together would contribute up to 13hp in upper RPM. About 1.5% of HP across the spectrum, and 2 degrees of timing. This seems like cheap HP/$, with no P-to-V issues and little downside.

A few more questions on suggested tools for the job... Am I missing any?

- Balancer removal, Autozone/Oreilly loaner 3-arm puller
- Balancer installer tool
- Tim's tool for valve springs
- Valve lapping compound
- Old head bolt with V-grooves ground for thread chaser
- Tube of moly for ARP balancer bolt and the pre-03 ARP head bolts
- Tube of assembly lube for cam, rockers, lifters

Planning on linking up with JCTunes, but first a b4-dyno before snow flies.

Any other comments appreciated. Thx.

 

Sounds like a good choice. Some other tools/parts you might want to buy are listed below.

Gearwrench ( 10mm it gets used alot!)
Buy an ARP crank bolt so you dont have the torque to yield.

 

any update BartmanC5?

 

Funny you should ask today- great timing. I had an appointment this morning to meet my tuner at a dyno for a completely stock snapshot, and with his basic tune. They suddenly got busy so we needed to reschedule to next week. Something about freezing rain and then significant snowfall keeps the body shop guys busy.

Anyway my new stock parts (oil pump, lifters, balancer, gaskets) were ordered on cyber Monday. Tools are already here, along with ARP balancer & head bolts. Cam, springs, and gaskets are still to be finalized awaiting a discussion with Carl the tuner. I suspect it will be unchanged, but I value his opinions as I do Patrick's. I should have more progress next week and will post up when I do.

More "good news", I've picked up a coolant leak apparently at one of the water pump seals, so coolant slowly runs down the block and I have a few drips on the leaf spring. That will get resolved as part of this project, too.

 

Sorry to hear about the bad luck! Keep us updated! Have a great holiday!

 

I don't know what assembly lube You have or are getting but I've used a few different 1's through the years and the 1's in a tube I've used I have'nt been very impressed with ,,,,,,,,,,they don't mix with oil which they all say they do so I've started using the Lucas assembly lube in a bottle and that is the way 2 go IMO . It does mix with oil after a while as it is very sticky so it stays where it's needed plenty long enough and it does mix with the oil which adds 2 the oils viscosity and longevity and it has the sulfer and other ingredients beneficial for valve-train protection while breaking in . And the Zone carries it 4 like $4 .

 

I must say that even a stock LS1 (with axle-backs only) in an enclosed space run up to redline sounds sweet! I picked a stinkin' cold day to head to the dyno for the first time. And posi w/balding tires on snowy roads is a liability! In any event...

Run #1 (stock cold) - 297 hp / 304 tq
Run #2 (stock warm) - 305 hp / 311 tq
Run #3 (MAF recalibration, 27* timing) - 307 hp / 313 tq
Run #4 (24* timing) - 310 hp / 314 tq

My tuner Carl had enough time for his basic tune beyond the untouched readings. We'll do a full tune with wide-band and street data logging in the spring.

He suggested I throw a 160* or 180* thermostat into my parts list, to minimize heat-soak peak temps. He's in the "bigger is better" cam camp, but said the 222/226 would work for what I want. He runs a 600hp+ turbo truck spinning well past 7000, so I'm obviously on the tamer end of the spectrum.

His est for my project is a lower 360-370 rwhp, but still a big improvement over stock.

I'll attach runs #2 and #4 below. Carl noted some KR around 5800 in run #2. This was on a Mustang 1100S.


Appreciate the perspective. My tuner suggested Royal Purple Max-Tuff, also in a bottle. It's apparently sold in 2oz bottles but no one carries or special-orders it, only the 8oz for about $18. I would imagine anything is better than coating in plain engine oil.

Since the gaskets are being replaced as part of the cam swap, it's no big deal. However my headlight motor failed the same week, and that's more of a pain to rebuild. Oh well, the MN winter is probably 6 months, so plenty of time.

 

April update... I've put on about 500 miles on the new 222/226 cam after an early spring in Minnesota. A slight "shimmer" is a great description of the idle once warmed up. Exhaust is just a little louder than before, but remarkably similar note and sound through the rpm range. A little "sewing machine" sound can sometimes be heard at low speed, but usually sounds like a stock valvetrain. I ended up with OEM MLS gaskets and a Vararam.

The first 100 miles were still with the stock tune, and managed to keep the revs below 3500. I can safely say it performed nearly the same if not better from idle to 3000 rpm with zero issues. I think I gained some down low. 6th gear at 70mph has more oomph.

Got out to my tuner Carl around end of March and ... Wow. It comes alive right at 3500 rpm, pulling way stronger to the new 6600 redline, where the stock cam ran out of breath around 5200. In the cooler weather, a couple notables:

• Rolling on first gear, the tach jumps from 4800 to 6500 as the wheels completely break free. Never had that before.

• Second gear feels like I'm just on the edge of traction. That is how first gear felt with the stock cam. On a couple of concrete entrance ramps, the tires just slip all through second.

• Traction control engages on a hard shift into 3rd with a little tail wag. Never had traction problems in third before.

And yet still managed 34.1mpg on a 20 mile stretch of my route to work. I'm more than pleased with the outcome, but unfortunately need to go tire shopping now.

Carl said the Injector Duty cycle was around 94 or 95% on a cool day. If I calculate backward, that should be near 430hp at the crank. I'll be headed back to the same dyno shortly and will get an "after" snapshot for comparison.

 

A couple years old, but did you ever get that "after" snapshot? I'm curious to see what the new cam got you to.

 

Interested in this too. Nearly identical cam and Milled 317's for a 98.