lsevenl

iTrader: (5)

I'm trying to figure out the best way to get a reliable 550rwhp na. Without going too extreme on a cam, what is the best way to achieve this? 427? That seems to be the route i'm going to take.

Currently i'm running a 346, TEA Ls6 stg 2.5 heads, F13, Kook LT 1 7/8, Magnaflow, K&N Fipk, NW & F.A.S.T. 90mm. I put down 443/397 through this setup. I imagine I can swap the heads ,headers, and intake over. With a 427, what size cam would be needed to reach around 550rwhp?

Are there any other recommended setups for this power level?

Z'mnypit

iTrader: (58)

Your defiantly going to need some more displacement. 550hp isnt out of range NA but its going to take some mods to do it. I would think in a 6speed car, with the following your goals could be achievable:

402/ 408/ 422/ 427
Stage III heads
a cam along the lines of: 25x/26x 6xx/6xx
the fast setup
the correct fuel setup
& all the bolt ons,

you should be really close then. If you have a A4 car its going to be a little more difficult.

Race Car Driver

You'll need a bunch more cubes to make 550rwhp n/a. A friend has an ARE 427 with 11:1 and great alum. heads and makes 560 rwhp.

Patrick G

iTrader: (14)

Your heads may be holding you back from hitting the 550 rwhp mark once you add cubes. You seem to have all the right components, yet your power is average. To exceed 550 rwhp, you'll need above average power.

Right now you're at 1.28 rwhp/cubic inch. At 427ci, you'll need close to 1.30 rwhp/ci to be in your ballpark and as you know, the hp gains are a little tougher to get (from a hp/ci standpoint) once you start adding displacement. I'd suggest getting your FAST intake ported and your TEA heads massaged (to accomodate the larger bore and additional cubes) to get you there.

Beast96Z

iTrader: (21)

Either have your heads sent back to TEA for the Stage 3 upgrade for big bores, or get some AFR 225's. 402's have made the 550 rwhp mark, but the 427 might make it a little easier. You have to figure in the cost of the sleeved block if you want the 427, which is where most people opt for the 402.

lsevenl

iTrader: (5)

thanks guys, good info.

Would the headers in 1 7/8 hold me back as well?

Patrick G

iTrader: (14)

Those headers will work even better on a big motor than they will on your current motor.

Ferocity02

iTrader: (60)

The headers will be fine as said. I am planning on getting some 1-7/8" stepped to 2" for my 427. The heads will turn out to be restrictive in the higher RPM range. As for a cam, you will probably want something in the 25x/25x with a lift in the mid to high .6's to feed the cubes. The NW TB and FAST intake will work well. What block are you planning on using?

snketr

iTrader: (3)

A buddy has a 415 in his 01 Vette. He put down north of 550 on the dyno last year. It's and automatic. He had TEA heads if I remember right.

RussStang

I have to ask. What would it take to reach 550 rwhp on stock displacement? I know currently people are brushing the 500 mark on "street" motors, but has anyone gone much higher in an all out race configuration? Would it be possible to hit 550 if the engine was bored over and destroked to reach stock displacement with a more oversquare engine? I would think this would help to run a bigger valve and get the heads flowing better at the elevated rpms that will be needed to make this happen. This is just a theoritical, before everyone starts telling me it is a dumb idea. Anyone have any experience on this, perhaps with a race engine that needed to be kept a certain displacement?

JL ws-6

iTrader: (50)

550 could be made on a 346 motor.. if you don't mind running 14 to 1 compression, and probably a single plane intake setup, best heads you could find, and don't mind spinning te motor to 8000+ rpm. Would an overbore/short stroke motor do it? Yes, probably easier due to the bigger valves, but the thing is gonna be peaky on teh power curve though.

Just not a sensable option for that power level IMO. If you want that, go bigger cubes.

Patrick G

iTrader: (14)

Yes, you can make over 550 rwhp with a stock displacement naturally aspirated 346, but don't expect is to run on pump gas or be a daily driver. As mentioned, you'll need to turn it WELL over 8,000 rpm which will require much better flowing heads, a sheet metal intake, solid roller cam/lifters/rockers, and at least 13.0:1 compression. All that's gonna cost some big bucks.

550rwhp is much cheaper and easier with additional cubes. You can have a daily driver that runs on Super Unleaded and you can drive it anywhere when you increase displacement. That's the reason GM chose the 427 route with the new Z06. Same reason why Dodge is running so much displacement on the Viper.

RussStang

I know it wouldn't be cost effective, or street friendly. Just wanted to hear some opinions on how guys on here would do it. I heard pretty much what I expected, but thanks for the input.

z98

Sorry, no N/A motor putting down 550+ is gonna pur like a kitten.

You need a nice big lopey cam, preferably a solid.

lsevenl

iTrader: (5)

I guess that was the wrong choice of words. Going to a 427 anyways is prompted by my extreme nature I guess I just didn't want to go with the largest, must unstreetable cam.

davered00ss

iTrader: (4)

Only way to get that N/A is Bigger cubes. Stroker motor.

Brian Tooley Racing

iTrader: (13)

I would contact the guys at East Coast Superchagers, they built a 441? cu in engine with our Stg 3 LS6 heads and made right at 600 RWHP. That is the most I have heard of with our LS6 heads. And yes, your ports, chambers and valves would need to be upgraded. Or, you can run the heads you have on that size engine and it would be a TORQUE monster.