TxSpeed heads and mild cam build
 

Fresh off the dyno. Vette is a 2013 M6 narrow body. Build as follows:
TxSpeed ported LS3 heads. They CNC port your heads, do a valve job, mill to spec, and set up the valve springs for $750. Hell of a deal. Absolutely not the best money can buy, but WAY less cheddar than a set of CNC ported aftermarket heads. They were milled .010 and installed with a .040 thick Cometic head gasket. Static C/R around 11.3:1.
CamMotion cam 226/234 115+4 with .620 lift on both sides. "0" overlap and very well mannered. BTR springs and pushrods. New Z06 lifters.
Gwatney ported and rod modded LS3 intake manifold.
Ported throttle body.
Powerbond 10% u/d crank pulley.
Kooks 1.875" LT's with 3" Z06/ZR1 non catted mids and Z06 mufflers.
Vararam CAI.

It made 507/459 uncorrected and 500/454 std on a Dynojet. It drives like a dream. Idle is a little choppy with little or no lope. No shake. I haven't gotten it to misbehave yet, but haven't driven it a whole lot either. We did Z51 sways and Z06 shocks along with everything else. Quite the transformation from before to after. My son did about 98% of the work. I set up the valve train.

My last two C6's were TVS2300 supercharged. Wanted to do something a little milder this time. Pretty pleased about now. Proof you don't need an ill mannered cam to make some really nice power gains.

strong #'s
I shipped my ls3 heads to texas speed the other day I got similar setup except mine is auto
I asked them to mill to 66cc and using .40 gaskets, cam motion 219/230 625/605 lift 115+5
who tuned it? I am thinking mail order tune. I am close to redline but damn dont want to spend $700 on dynotune

Yeah, I too had a problem shelling out 700 for an N/A tune with smallish camshaft. That's what LMR and another one wanted. Mine was done at Serious Horsepower in Houston for 500. Power is good. Drivability is good too.

Congrats. Motorhead glad you got your build complete and very solid numbers. I wish I would have gotten my heads milled just a little when I sent them to TSP but I didn't and the jacked up shop in Maryville, TN didn't want to make more power cause hell they couldn't cause they suck. LoL

"They couldn't because they suck". Now, that's classic !!! I need to get some tires on mine and take it to the track. I was cool yesterday and the run flats wouldn't even hold 2nd gear.

Nice numbers! I saw the other thread (BTR LS3 Cam) where you linked this. I have a 6.0 w/ LS3 top end in my '84 that put down 433/423 uncorrected and 420/410 STD w/ 220/224 cam and basically the same mods as you except for the ported heads/intake.

I too plan on doing the TSP port/mill/valve job in the future but I wanted to ask about the Gwatney intake rod/port job.

How convinced are you that the Gwatney modded intake actually boosted power and what do you think it is worth RWHP wise on your setup? I think I want to do it but I am just not sold on it, but I definitely don't want to spend $800+ on a Fast.

I think the cam I used would probably do 460ish rwhp with all the bolt ons on an LS3 powered M6 Vette. Let's say the heads are good for 20 (that's what TxSpeed told me to expect with their heads and a mild cam). The bump in compression ratio is probably good for 5-10 rwhp. That was "free" as I wasn't charged for the head milling and I had to buy head gaskets anyway. No extra charge for thinner ones. Smaller crank pulley good for a few. Again, no money spent as I wouldn't put the stocker back on anyway. Ported throttle body not much added hp, but cheap. "Supposedly better drivability and I'm all into to that. Vararam good for nothing on the dyno, but worth a nice bump in HP at speed.

So, all that said, I'm of the opinion it's worth 10 to 15 rwhp. About what the guys that port and rod mod the manifolds claim.

Do a google search for "rod modded LS3 intake manifold". Lots of stuff will come up on several different sites. I think it's worth $400.

Thanks for the response. I think I may just pull the trigger on the intake next. I have read about a few DIYers and other shops ruining them so it makes me a little skeptical. I also don't like it when companies/shops post up generic looking dyno graphs and are vague about their numbers. I have the Gwatney site bookmarked and have been trying to get some feedback from outside of their site. Thanks again.

Their own site says 5-10 hp from their modded intake. Don’t know if that is worth the cost.

The site says 6-12 rwhp on the radius rods alone and then they just post up a generic graph stating that they get a little more peak out of the porting but pick up power across the entire band without ever actually stating what they pick up. I would love to see an actual back to back done by a third party.

I think it will be worth it. It seems most of the ~500rwhp LS3 cars have some sort of intake work, either a Fast or ported LS3 manifold.

Obviously, if you are looking for every little bit of power you could justify the cost of the modded intake or the FAST. But for the other 95% of us, it’s a big price to pay for a minor increase.

I am at that point. I have all the other supporting mods, the manifold is the last thing I need to do before pulling the heads and cam.

BER is another option I sent them my intake for porting. My vette had around 90k miles and when I pulled off the intake it was coated in oil.
BER did an excellent job cleaning it up and porting. They have done back to back dyno tests with gains. Quite a few on the camaro5 forum
have done the gwatney intake and posted gains. I recently had my heads cnc ported from texas speed along with mild cammotion cam and 25%
underdrive pulley. Totally worth it I never had a traction problem when it was bolt-ons now I get to let off in 3rd gear it will break loose

I could have gotten 10 more hp from a bigger cam. 20 more hp from an even bigger cam. I've already had my last big cam though. I'm so not into the big cam thing. My build was centered around me trying to get a very smooth running Vette with good power from idle on up. I very mild cam was key. Fuel eco and reliability mattered too. So yeah, adding the ported/rod modded intake manifold that increased power without increasing buck, surge, and shake mattered to me. $400 didn't seem like a huge amount of money all things considered.

Always better to slightly undercam than slightly overcam.

That's frickn' awesome man!!! Do you have an idle video?!! I'm looking for 500RWHP for this summer and I'm going nuts trying to decide between a Heartbeat Blower and a heads and cam setup. If you can hit 500RWHP with such a mild cam then it definitely makes that option a lot more interesting to me than it was. What is your milage like as my car is a daily driver and I'm trying to compare N/A power to S/C for fuel consumption.

Pm me your cell # and I'll send you a clip. I have no idea how to post something like that on this site (or any site for that matter). I'm a pretty low tech redneck.

The fuel eco is slightly less than stock. I think it can be improved though. The car was bone stock before we did the upgrades. It might have had a tune as I've had three M6 C6 Vettes and this one seemed to be faster than the others before the mods. After the mods, I ran around on the stock (or maybe aftermarket) tune for several hundred miles. I didn't do any WOT stuff, but it ran just fine on the tune it came with. I bought the Vette with 45K miles on it. Mileage was actually a tad better than stock after the mods and before the current tune. Now, after the tune, it's slightly less. I think a sharp tuner could get that back. It was WAY worse after the initial tune. I complained about it and they did make some adjustments that did increase the mileage, but it still not as good, mileage wise, as the tune it came with.

Confusing? Yeah, I'm a bit confused too. It seems to get the same MPG going 65 as it does going 80. I pay pretty close to mileage and I've never seen anything like this. Vettes, trucks, sedans, doesn't matter. Usually, the slower you go, the better the mileage.

If you can swing the Heartbeat, do it and don't look back. My last C6 had the Heartbeat along with a mild blower cam and bolt ons. 664 rwhp on a mild 9.5psi. You could probably hit 500 at the wheels just adding the Heartbeat blower alone. Then, if you got a little crazy, you could add another 150 hp with just a mild cam and bolt ons. If you go the cam/heads route, you're limited to low 500's at the wheels. More than that and you're going to have to live with an ill mannered beast that will impress the car show crowd, but won't be any fun to live with once the new wears off.

Nice build

Nice power! I went with GPI's heads for mine and kinda regret not having them milled. But i was planning on doing a bigger cam down the road along with gears so i left them stock for clearance.