teej281

if youre running N/A get domed pistons for more compression. flat tops wont get you the compression you could have because of the 4v cylinder chamber is really large.

darkstarnes

I have not seen those for the 4.6l if you could please direct me where to find them... I am more interested in the domed than flats (of course.)

teej281

They dont make them really, you just gotta call a company you wanna deal with and see if they can make them. They probably have the means to make them and have made them before, they just dont make them in batches like the flat tops and dished.

JC316

450HP on a NA 4.6L 4v.... No way will it happen. If you could do it with H/C/I every cobra guy here would. Only thing even remotely close is some guy claiming he adds 100HP with a carb swap on a 4V and I highly doubt him.

teej281

JC, its actually been done multiple times before. High compression, ported heads, cams, intake manifold.

JC316

I should have added for cheaper than a supercharger and actually still drivable. Any of them still run on pump gas?

teej281

I know there are some in the low to mid 4xxrwhp range on pump gas.

SVTeeshirt

a little high, 425whp is more accurate, im shooting for anything over 400..

a litte high but i've seen them run high 10s all motor stock with a little over 400whp.

Buy C heads:
"First, it is a common misconception that B heads do not flow too much. The reason B heads aren't the n/a head of choice is that their intake ports are too large and this results in low velocity. Velocity is needed to overcome the increasing cylinder pressure brought on by the piston moving up at the start of the compression stroke...low velocity causes the a/f charge to be forced out the open intake valve. The C heads have smaller ports that flow just as much or more CFM as the larger B ports. Because the ports are smaller and the air/fuel charge velocity is higher, the C heads provide more mid-range and peak power. Even when used on FI engines they make less power than all three 4.6 C heads" N/A SVT

The only way anyone will see more than 450whp is most likely through a big bore motor with cobra R Heads and intake, i've seen the intake alone going for $2400 (N/A that is).



yeah i think 450 is a bit high of an estimate though.

darkstarnes

I think 400whp is high numbers for a N/A... can any one forward me to a thread or video showing those numbers with a N/A? and I still want to be on pump gas.

SVTeeshirt

NazMan @ SVTP has a 4xxwhp car that ran high 10s stock. 9s on the bottle.
Theres another guy making 380whp on the stock shortblock.