cptech

Hi Folks, wondering if what I want is reasonable......Looking for 600hp at the crank, 500hp to the tires.
Using a NA 6.0 LQ4 .030 over, right around 11 to 1 compression, stock LS3 821 heads with BTR .660 springs,
light weight valves, retainers etc... Haven't picked a cam or intake yet. Full length headers. Want a 7000 rpm
shift point. It's a semi budget build. I don't have the $$ for a stroker setup. My thinking is if i keep my shift points
at 7k, I can stick with factory rockers with the trunion upgrade and longevity shouldn't be an issue. I'm not concerned
about torque under 3500 as the car is 2780lb including the driver. The car has plenty of gear and converter. This will
be a street/strip car split about 50/50 between street and strip. I don't have the $$ to take it to the drags as often as
I'd like, so I'd like to be able to enjoy the car and go to the local cruise nights. Looking for a solid 10 second street
strip car.

Thoughts ??

RB04Av

Not likely.

A really well maxed out 37x inch N/A motor will make somewhere around 475 - 500 ft-lbs of torque at its peak, if it's set up to be capable of running on pump gas. (watered down cat pee) That's all the molecules of fuel that can be burned at atmospheric pressure in that volume without causing other problems.

To make 600 HP at the crank and shift at only 7000, your torque peak will need to be no higher than around 5500 RPM. You'd have to be making 550 - 575 ft-lbs of torque at that RPM to make 600 HP. It's just numbers: HP = torque × RPM ÷ 33,000 × (2 × pi). People usually shorten the last bit to 5252.11; comes out then to HP = torque × RPM ÷ 5252.11. Do the arithmetic (it's not really "math") and you'll see, the numbers just don't work out.

500 HP at the crank is not out of the question though.

At this point, consider what you can do to increase the CID.

98CayenneT/A

At that race weight you should have no problems running a solid 10.

ColeGTO

iTrader: (3)

The "math" tells us that to make 600 HP at 7,000 RPM, you will need to be making 450.18 LbFt at the same RPM.

I'm not gonna say it ABSOLUTELY isn't going to happen with a 369.6" engine at 11:1 and a 3.622" stroke, but the odds are against you with stock 821 heads. I think the more difficult challenge is an honest 500 RWHP with that combo.

Good luck.

spanks13

iTrader: (5)

Made 528whp to the tire through a 6000 stall powerglide with a stock bottom end LS3, LPE ported stock heads, Victor Jr and a Holley 750. Cam was a 239/251 on 110+2. Liked to spin to 7500, would shift at 7 and run it in the converter off the gear change. Compression was only 10.4:1 and ran on 91 octane.

Car ran 10.13@131, ~3200 pounds with me in it.

cptech

Thanks for the responses guys, I appreciate all the information.

Can anyone give me an idea of how much HP/TQ I'll gain having the heads ported ??
Maybe that's my best "bang for the buck" way to go for what I'm looking for. Plus, I figure
down the road I see a stroker which will take better advantage of the ported heads.

Thanks again.

RB04Av

Not much torque increase; it'll raise the peak torque RPM a good bit though.

Most stock heads on these motors have about 30 - 40 HP left in them that you can get out with a GOOD port job. Not, a billybob & cletus "hog em out" job; not a "gasket match" job; but, a GOOD port job. "Good" might include someone's CNC program for example.

SRT8.Acelleration

Change to trickflow 225s, sell the ls3 heads.... Look into solid roller camshaft and a real good valvetrain set-up.

NAVYBLUE210

cptech

Thanks again guys, I appreciate the information
@NAVYBLUE210 it's a back half car. Hooking up hasn't been a problem
in the past.