When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Just got a 2011 C6 Z06 with 37k miles.
Love the car the way it is but prudence dictates getting my head(s) examined
I'm gonna pull the heads and inspect/rebuild, then reinstall with a bit lumpier cam and rocker trunnion upgrade.
Looking for cam recommendations, my target is 550 whp or so.
I just dyno tuned a 2013 Grand Sport LS7 convertible 2 nights ago. It put down 530 rwhp with a BTR "Stage 2" cam and headers. That cam has a nice idle lope and great driveability. That can plus an MSD intake manifold you should hit your 550 rwhp goal. Or you could always choose a more aggressive profile for even more than 550hp. But there are typically trade offs with some driveability as your valve overlap increases.
I'm going with the BTR stage 2 V2 package (BTR springs, ti retainers, and pushrods) and the BTR trunnion upgrade.
Don't want headers on this car.
Not swapping the intake. Richard Holdener did a test years back with LS7 stock intake vs Atomic and the gains don't seem worth the money to me.
I can always add it later if I change my mind.
Was thinking of dyno testing it before and after, but I'm taking it easy on it until I get the heads up to snuff. Haven't spun it above 5k and I'm trying not to. It sure wants to spin, though, it's almost cruel to the motor not to... cruel to the driver for sure.
It would suck if I lunched the motor when I've already decided to err on the side of caution and do the heads.
If you don't care about drivability, your goals are easily had. Cam it enough to get there. Boom...done. That's been done a time or two. Stock exhaust is going to hold you back a bit. Stock intake mani is a bottle neck too. Ported heads, ported aftermarket intake manifold, bump in static C/R and you're there even with a mild cam.
I just did a cam and heads and put down 555rwhp and 523rwtq. I bumped compression slightly and i am on stock intake and tb. I went with a tsp 2.2 cam. Drives great and has a healthy aggressive idle. I will be adding an msd intake and 103 tb later.
After some research I realize my goal is a bit unrealistic with only a cam without severely impacting low RPM performance (street manners). Since the heads may need work anyway, I've been reading about alternative bare heads with smaller CC volumes. The cam kit comes with springs, retainers, stem seals, and pushrod guides. All told it may not cost much more than fixing the stock heads. Spending $1200 for the MSD Atomic intake seems like a reasonable investment at that point.
It all depends on the condition of the valve guides in the heads when I pull them off the motor.
Are there any shops porting the factory heads with decent improvements?
I just did a cam and heads and put down 555rwhp and 523rwtq. I bumped compression slightly and i am on stock intake and tb. I went with a tsp 2.2 cam. Drives great and has a healthy aggressive idle. I will be adding an msd intake and 103 tb later.
Just got a 2011 C6 Z06 with 37k miles.
Love the car the way it is but prudence dictates getting my head(s) examined
I'm gonna pull the heads and inspect/rebuild, then reinstall with a bit lumpier cam and rocker trunnion upgrade.
Looking for cam recommendations, my target is 550 whp or so.
Thanks
Joe
At 37K, would just check the valves, and leave the rest of the motor alone.
Problem with the LS7 in not the motor, but the intake manifold instead. Hence where the motor runs out breath, since the intake manifold can not supply enough air all the way to red line.
So motor will pull hard to 5.5K, then pretty much goes flat after than to its 7K rev limit.
The short bus is there is not enough room under the hood for an intake manifold that will breath correctly to 7K for the LS7 in the C6, so better off with a super charger instead. In regards to SC, we are not throwing a lot of boost at the motor, but instead enough that the motor does breath correctly to 7K.
So with just headers and stock cam, put a ruler on the above graph that the motor pulled up to 5.5K, then draw that line up to 7K, to get an idea of what the motor can make in stock form. To add, yes cam on a LS7 N/A motor will make more horsepower, until is runs in to the intake breathing problem around 5.5K again.
As for how to solve the Breathing problem of the Ls7 past the 5.5K revs with the motor N/A, need to look no farther than the SB4 motor (which is built on a LS7 block). https://www.mercuryracing.com/conten...ne-Catalog.pdf
I always go to Richard Holdener's You tube channel when I have questions about a particular combo.
The stock intake manifold is not as much of a restriction as you think.
With better heads and a stiffer cam, it makes power to 6500 RPM, although 20 less (at the 650 crank HP crank level) than the Atomic.
I appreciate what a blower does for a health NA motor.
I've got a C5 Z06 with a Procharger making 600 WHP with 10 PSI boost.
I've got a G37X with a Vortech making 405 AWD HP with 8 PSI boost.
Both motors are otherwise stock and have great driveability with stock low end power building to a stronger than stock midrange and a screaming top end of at least 150% stock power.
i went with a reworked set of stock castings on this build. I am very happy with my set up. You can get to 550rwhp with good driveability if you don't go crazy with your cam selection. My last set up hit 545rwhp with full bolt ons including a ported intake and it had great manners. A good tuner is a must when doing a cam. Do your research on tuners in your area. See if you can get a ride in a car your shop has done recently with the power levels you are looking for.
Race Proven Motorsports package is the best available package out there.
I've been having a conversation with them since last week. Turns out there's a really great shop 35 minutes from me, RPM.
I'm formulating a plan with them.
Just got a 2011 C6 Z06 with 37k miles.
Love the car the way it is but prudence dictates getting my head(s) examined
I'm gonna pull the heads and inspect/rebuild, then reinstall with a bit lumpier cam and rocker trunnion upgrade.
Looking for cam recommendations, my target is 550 whp or so.
Thanks
Joe
What do you want to do with it? If your goal is to get that magic who number, your build will be very different than if your goal is autocross times or something else.
It's a street car. I doubt I'll track it. I tracked bikes for a decade and I'm tired of all the ancillary work and money to do that, plus I'm not as young as I used to be. Might track my C5 but I'd need wheels, tires, and lots of time to do it.
My goal is for it to be as fast as my 600 WHP 01 Z06. That car is peaky, engine makes decent power down low but at 4500 RPM WOT it gets really fun all the way to 6500 RPM or more.
I don't want to push a stock LS7 bottom end that hard so my goal is a wide flat torque curve and peak WHP around 550.
As such I've decided I'm going to inspect/rebuild the stock heads, replace at a minimum the exhaust valves with Manleys, possibly replace the intake valves with GMPP ti replacements or maybe stainless depending on what I hear back from RPM.
Then it's getting the Magnuson TVS2300 Heartbeat blower kit. A light puff maybe 5 PSI.
Research indicates that a TVS2300 rotor based SC pulleyed to pruduce 5 PSI max boost should result in a serious torque (over 525) from 2500 to 6500 RPM.
That's my goal.
I've been having a conversation with them since last week. Turns out there's a really great shop 35 minutes from me, RPM.
I'm formulating a plan with them.
Thanks to all.
Joe
Yeah RPM shouldnt be too far from you if you are in Malvern PA. Prob 40 mins to RPM
Yeah RPM shouldnt be too far from you if you are in Malvern PA. Prob 40 mins to RPM
Took a deposit to RPM for the Magnuson Heartbeat SC kit the other day.
Also, local shop that's gonna rebuild my heads got me Manley sooooper duty inconel exhaust valves.
Woo Hoo.
I added a Heartbeat to my previous C6 grand sport. With a mild blower cam, bolt ons and 9.5psi, it did 664/612 at the wheels. Pretty sure it was over 500#' just past idle. Unless things have changed, the Heartbeat will come with a 96mm blower pulley. You'll probably need to pulley down a notch or two to hit your goals. The pulleys come in 3mm increments. A 93mm pulley would probably get you there. A 90mm damn sure would.
If you have E available, doing a flex fuel setup would be ****. You need to upgrade the fuel pump and injectors anyway. Might as well do it right.
The kit for the LS7 is different than the one for the LS3. LS7 heads have different intake port shapes (requiring different runners) and the heads flow more than LS3 heads.
The powder metal rods in the LS3 are a little more trustworthy than the ti rods on the LS7 so a little restraint is prudent when boosting the 427.
For the LS7 Heartbeat kit it does not need injectors or fuel pump, the OEM is more than adequate.
It's designed for a target of 5 PSI boost. I'm interested in longevity, so I'm starting with the supplied pulley. If I'm not satisfied the pulley and injectors/pump can be swapped later.
I've done a few WOT pulls in 2nd and 3rd to 5500 RPM and it's a lot of fun as it is... I just want more, along with peace of mind.
Last edited by scudzuki; Aug 3, 2023 at 09:43 AM.
Reason: typos
C6 Z06 cam
