RockyMtC5

Decided I wanted a mild cam and head swap to get at least 400rwhp and a new top end for my '03 coupe with 53k miles. I bought it a year and a half ago, modded nicely but wanted more power after a year of ownership and wasn't sure how the engine was treated previously so decided to pull the trigger on a h/c build.

Dyno graph attached, very happy with the results. 405 rwhp and 370 ft/lbs. Torque is a bit low but it feels really strong above 3500rpm and SCREAMS all the way to 6800rpm. Went with PRC Stage 2.5 6.0 liter heads, 226/228 .600/.600 114 cam, new oil pump, timing chain, lifters, trunion upgrade, pushrods, etc for a fresh valvetrain. I wanted ported LS6 heads but turns out GM discontinued them so my builder suggested the Stage 2.5 6L heads, lower compression but they flow great and are great for high rpm and excellent for adding a supercharger in a year or two!

I am in love with the new setup. Idle sound is wonderful, nice lope and totally drivable around town. WOT sound is incredible and significantly louder all around, which I love! Just sounds a few notches meaner and drives the next level stronger than before, exactly what I wanted. All parts cost me about $2800, pretty good value for a nice bump in bad-assness

RockyMtC5

Anyone have any feedback or anything on my results? Anyone else using 6.0L heads in their build (with supercharger)? I'm not hitting the higher #'s I've seen here on builds with higher compression but wondering if anyone else has done similar build and then gone FI.....

I love it so far, and that's all that really matters but just wondering what you other h/c C5 folks think of this build....

Happy Thanksgiving everyone!

radar502

Well yes in fact I do , just did a top end on my 04 Z-16 ,Comp 54-111. custom Comp grind 230/236 595/595 112+4 got it off the forum new in box $200.00 cheap right ,ported the stock heads ,new oil pump timing chain B-Tooley 660 springs stock rockers . I had Comp. MAG. rollers 1.7.5 kit guide plates Etc.. would not run right so back to stock put those in the can junk Bryan Tooley said take those off put back the stock ones runs great now TX. Speed Molly push rods got Kools long tubs X-pipe GHLs on back ported T-body big after market air cleaner big plug wires about it for motor I think.. LMR in Houston tuned it ,It runs OK just not happy with the way they tuned it long story anyway 440 RWHP TQ around the same ,I think the ported heads gave it some more HP ,it peaks around 6800 and stays that way up till 7000 and I have to let off the gas weird the HP and the TQ just levels out and stays that way till I let off the gas .. around $15-$1800 in parts did the work myself ,have dyno sheet just not scanned into PC yet .. Will haul butt..

RockyMtC5

Mine runs great, I can cruise around town or fly thru country roads .... and can be heard for miles

Just wish the sun would come back out and melt the snow so I could take her out

JIMS SVT

Sounds like a good setup. I would've expected it to make a little more power than it did though. With a nice can and Ported heads you probably need more intake to take advantage of the rest of the combo. My old setup was a stock short block with stock 853 heads,ls6 intake and a ms3 cam which is a little bigger than yours. Also had eBay exhaust and it made 409/386 . It ran real well for what it was until it twisted a lifter on the cam. Them I redid everything. Good luck with your setup!

RockyMtC5

Thanks! It's right where I wanted it horsepower-wise but a little lower in torque than I was hoping for. I believe it's the 6.0L heads with lower compression that is the reason ......
I'm thinking about picking up a FAST 92 + LS2 throttle body to pickup 15-25 hp & tq. It's that or save up for a supercharger and be well over 500.

RockyMtC5

I'm obsessed with my car and can't stop thinking about what to do next! I am like this, have done it all my life (obsessions). I love my current build so far. The cam sounds awesome (nice lope but very drivable) and everything runs spotless. However, I feel like I should have gone FAST 92 intake and ls2 throttle body when I did the build because now I'm wondering "what could it have been?".

I'm definitely happy with my results, I wanted 400 rwhp and I got 405 rwhp. But like many here in the forums I have the mod disease and now I want 425+ rwhp and 400 rwtq. I think a Fast intake setup, properly ported (Mamo) with matching ported throttle body should probably get me close to, if not right at this goal. But this would not be cheap (more than half of what my I paid for my entire h/c build). I keep going back and forth, should I just get the best intake system and see what I can get to n/a. I've always wanted a n/a build and didn't want to go supercharger with the heat & stress and stronger risk factor (meth, fuel concerns, etc).

I thought about getting used intake and throttle body but then I'd still be spending over $1K for everything plus a tune so probably $1500 when its all done. With all new and ported I'm probably looking at close to $2K and $2300+ all said and done. For 20-25 rwhp and maybe as much torque, that's a lot of coin. But if I go cheap and get 10-15 hp then will it be even less worth it? I could go basic supercharger for twice what it would cost for a new ported intake setup but then I'd spend more on meth to prevent detonation and I'd worry about getting bad gas (I've gotten bad gas here before, in the land of 91 octane premium with 10% ethanol added).

So, I'm going to give myself a nice bonus for X-mas (business was good this year) and my obsession will require I feed additional mods so I'm probably going to go with the best intake system I can find. I've already reached out and heard back from Tony Mamo and we're going to talk in the new year! I may even get some of his heads some day, but since my PRC Stage 2.5 6.0 Liter heads have only a few hundred miles on them and I'm going to try to see what I can squeeze out of them ---> they are supposed to flow extremely well but they are lower compression so that's what I'm fighting. However, the crappy gas here makes me feel stock compression is probably best for me anyway……. just need to compensate for it with more go-fast parts

C'mon corvette forum members , let me know what you think! What did you do and lets run em' if you're here in the Rockies (once the snow and ice clears)!

RockyMtC5

RockyMtC5

Well I might be happening upon a Fast 90 intake with a ported LS2 throttle body and adapter harness. This should compliment my current h/c build very nicely!

Not sure if the intake is ported and I'll inspect it upon receipt, if it's not I will ABSOLUTELY have it ported before installing. The throttle body is V-Max ported, which I've been told is top notch so that's cool and maybe the intake is also (fingers crossed).

Any guesses where I'll be with the addition of this ported 90/90 intake system?

I'm hoping for 430/400 ….. but that's asking for a lot from my current 406/370 so we'll see

Turpid porpoise

I'd guess the manifold/TB combo might net 10-15 whp over your current setup but no way to really tell until you get it done and get it on a dyno.

RockyMtC5

I'd expect for 10-15whp unported.... hoping for 20-30 whp with a good porting & tune!

boostfarmer

Supercharge it and come down to AZ so I can stop it with my Evo! =P