LS3C5Z

Hello all! I'm new here, although I've had my 02 Z06 for a couple of years. I'm going back to NA, found a really nice Katech forged LS3 shortblock to drop in in place of the LS6. To keep this fun, I'm going to see who has the closest guess on WHP results on a Superflow dyno. Car will be professionally tuned after build so I should get accurate numbers when I pick up the car next week.

Specs:

-LS3 shortblock built by Katech, all forged/balanced internals. Equipped with Katech oil squirters under the piston to keep things cool.

-Stock 243 heads, stock LS6 intake (I know, I know. Leaving alot on the table. Going to better head/intake is a winter project...) Then again these heads shouldn't have the oiling issues of the LS3 heads.

-Comp Cams XE-R 224/232 cam, 918 springs

-Vararam

-LG Street headers, high flow cats, Corsa Touring catback

-McLeod RST Dual-disc clutch, 14lb lightweight aluminum billet flywheel

-RPM Stage IV MN12 trans. Stock gearing.

-Stock rear end, 3.42 ratio.

-315 Michelin PS2 in rear.

So any guesses on final numbers?

Also, anybody out there running a similar setup?

THANKS!

LS3C5Z

Oh and one more thing- motor is stock displacement.

Z/YA

iTrader: (36)

I would diffently pick up at least a stock set of Ls3 heads an intake. The Ls6 is going to really choke that motor. I had a bone stock Ls3 in my 2000 Z28 an made 465rwhp an 430ish tq (can't remember the exact TQ).
I just did a LS3 swap in a C5 two weeks ago with ported LSA heads an Lingenfelter GT-11 cam, Borla headers an it made 551rwhp an 499TQ.

bww3588

iTrader: (49)

465 at the wheels bone stock?

Maybe with some fudging on the dyno because your telling me that the stock ls3 makes 535 at the crank.

LS3C5Z

Thanks! Two good reasons for not going with LS3 heads right now:

1-time
2-money

I'm in Germany as well so LS3 heads are a bit thin on the ground and I want the car done next week. It's been down hard for over a month in the summer in prime driving weather so I'm focused on getting it up and running, it's in storage over the winter so I can do some research and shop around for exactly what I want.

Those are great numbers you made for a NA motor with LSA heads, I'd be happy with power like that. Part of the reason I went with the LS3 is so I can use a set of the big-bore heads down the road. I'll be selling off the 243/LS6 intake combo as well so should make back some of the cost.

Anyway- back to the original question. Numbers?

LS3C5Z

Yeah I find that a bit hard to believe as well.

bww3588

iTrader: (49)

420 ish

87silverbullet

iTrader: (11)

I also can't see an LS3 making 550 rwhp and 499torque with just a set of LSA heads and a GT11 cam. That cam only measures 215/231 631/644 lift on a 118 centerline.

Plus the torque don't add up. LS3 strokers don't make that much torque, let alone a stock cube one. That dyno is broken for sure. Here is a quote from a member of his LS3 418.


Here is the thread.

https://ls1tech.com/forums/dynamomet...5-eps-cam.html

LS3C5Z

OK you're the first one to make an actual guess rather than just tell me to get LS3 heads or spout inflated numbers from a stock LS3. We'll know mid-week how close you got. I'm hoping for a bit more but will just be happy to have the car back on the road while the sun is still shining.

djfury05

iTrader: (30)

437rwhp

LS3C5Z

See now *that's* a guess!

cybernco

I'll guess 440 RWHP if you use a competent tuner. I really enjoyed the Comp Cams XE-R 224/232 cam; I ran it in my LS2, but never had that set-up dyno'd. I can't wait to see your results.

LS3C5Z

Thanks man! It will be tuned by the guy that tunes the Callaway team race motors over here, so I think he can handle my little street motor

I've found some clips of cars running with that cam, I really like the sound and feel of it. I want some chop but nothing crazy.

The short block was built by Katech for a GT4 car, it's forged with all the tricks so it should be a real solid bottom end for a high-winding street motor. I'm hoping that not even I can kill this one.

I'll keep you posted on results.

COPO9560

415 rwhp. Two factors - probably hard to get a good LS tuner in Germany, second is unported heads & intake will limit upper range flow. Hope you do better than my guess.

LS3C5Z

OK you've got the lowball guess! Heck you may win. Like I said, this is to get the car running with the parts I have on hand. Big heads and intake to follow on this winter.

My tuner is not going to be the limiting factor. I have faith in his abilities.

Keep 'em coming!

LS3C5Z

Current average of all guesses is 428whp...

futureuser

iTrader: (1)

415 with a lot of room to grow with all those nice forged parts.

Che70velle

iTrader: (6)

I'm in at 432. Sounds like you have a great tuner.

LS3C5Z

Thanks man! Yeah I've got a solid base to build on. Will watch the forums for LS3 heads/intake for sale. Will have LS6 intake/243 heads up for sale at the same time.

BTW- *NICE* build thread on that 69 Camaro. That thing really hauls the mail.

redgto4u

iTrader: (8)

Checking in..I'll be doing the same thing for the same reasons.