LS3 - Is 550whp all motor feasible?
 

So after a custom cam and TSP longtubes, my car made 470hp/440tq at the wheels. Next I'm throwing on a CAI and getting the heads ported to try and hit the 500 number. If that's all it takes to hit 500, what gains do other mods add? What would I see with a FAST intake and ported throttle body? People seem to say the FAST isn't worth the money unless you get a cam and ported heads. What if I do have a cam and ported heads? Am I going to lose bottom end torque with the intake?

After 500, I'll be looking into all of the little mods. What else should I consider?

I know people push 600+ with FI. Do I face any longevity issues pushing it as far as it can go NA? And it seems like people break axles on these cars somewhat frequently. What's up with that? Bad production run, too sticky tires, the fact that the factory launch control is set to 4k?

Gpi max head cam package seems to be the most power I've seen N/A from a stock bottom end ls3

You can do it, yes.
In a car as heavy as the 5th gen... meh. Go too big on the cam and you're losing power under the curve, and drivability really suffers.

how fast are you going to spin the motor? if you spin the motor above 7K the fast 102 may be better but a rod-mod intake manifold is difficult to beat when staying under 7K rpms.

check this out for more info and the flow test: https://ls1tech.com/forums/generatio...ast-102-a.html

also, if you're going all-motor why not consider itb's? expensive yes but the gains appear to be pretty damn good

edit: as for the loss of low-end power/torque you can swap in a shorter (numerically higher) rear gear and get back some of the lost wheel torque due to the cam and other mods

I'm mostly staying under the stock rev limit. I like the look of ITBs,
but is there no air filter?

you'd have you make your own filters or a plenum set up that you can put a filter on the end of. they do look really good lol

but!

if you're sticking to under 7K RPM i would get a rod-mod manifold

Just stroke the motor and it will be much easier.

I've thought about it, but if I'm going to drop the money on a stroker kit + labor, I might as well go for forged pistons and rods. And at that point I'd expect to pay upwards of $10k.

Mast Medium bore LS7 heads
MSD atomic airforce intake manifold
102mm throttle body
ARH special order 2" -> 1.875 -> 1.75 stepped longtube headers
2.75" or 3" exhaust (z28 npp works)
PMAS 120mm cold air intake
ZL1 or LS7 injectors
flex fuel sensor
wide band sensor
fuel rails for MSD intake
ZL1 fuel pump or better
e85
Proper valvetrain (cam, valves, x ratio rockers)
reduced ratio pulley
normal maintenance/seals/gaskets
3 bolt timing chain + gear w/ the cam

if done right, you have a shot at squeezing 600whp.

What are you trying to accomplish ? Is it a DD ? Are you just chasing a number? If you want to go fast in the 1/4 a 3800 pound car is going to need a lot of RWHP and the right gears and be able to hook up . If that is you goal ,a little spray go's a long way and is dirt cheap.

^^^yes!!!! A little spray^^^

Yes it is possible to get 540-550 rwhp naturally aspirated if you change to the LS7 set up with 2.5-3.0” exhaust,fuel system,intake set up with a dyno tune etc. The most I ever seen with the LS3 set up with full bolt on’s and a custom camshaft was 470-475 rwhp. You could always try a nitrous set up when it is controlled it is safe to use.

alot of cylinder head, compression and camshaft yes.

Well you can achieve most by doing a great bolt on set up, get near 480 then add good heads, intake and cam it for 75-7800 shifts. You can achieve well over 550 with a good 13:1 compression on E85 if available or a good fuel like C85 or CHP for the track (like $70 for 5 gallons) If your limited to 91 then 11.5:1 will have to do and sacrifice a few big ponies. great thing about the aftermarket heads is valve angle for added piston to valve clearance. I will be chasing 530 cam only and 9s for my goal when I go that route.