It is possiable to get to 340 rwhp with out ported heads on a allen kit. The blower can support up to around 380 rwhp. How much have you done to your allen? Are you running the fmu? ditch the fmu. I don't have cams but I am saving to get them.
This is my personal recomendiation If you want to turn it past 6k you should rebuild the motor with a forged internals and cobra oil pump with forged billet oil pump gears. ASK EEC dock why. Here is what I would do.
1 1 inch raised spacer top from A_train
2 have magnum powers port your blower and espicaly on the inlet. I noticed on
my PI motor with the spacer the manifold pressure droped in the upper rpm which
meens a restriction on the inlet and the blower could not flow as well to keep up.
3 If you can afford it I would get renegade racing to port the heads.
4 If you don't want to go forged and won't spin the motor past 6k rpm I would get
a crower hot street stage 2 cam. It should wake it up just make sure to get a set
of comp cam valve springs. STAY AWAY MODMAX products espicaly springs.
patriot heads are having sever quality controol problems with valve seats droping
out destroying motors.
5 get a 75 mm throttlebody and gasket port match the opening behind it to 75 mm.
The allen opening is only 67 MM.
6 make you own custom air intake pipe. It will allow much more flow than the
plastic piece that allen gives you. I had to bent my fuel rails down If you use 3
inch mandrel pipe you might not have to do it. The best way to do this is to
purchace a 3 inch 90 degree mandrel tube along with a 45 degreen one also and
work with a chop saw fiting till It fits well then have it welded and jet hot coated.
7 If you have not don this do it. Get a screw in lightning air charge temp sensor and
have the manifold drilled and tapped just ablove runner 2 or in the top of the
runner. You might have to have a bung welded in. Make sure it dose not interfer
with the fuel rails. The sensor will ajust for high tempetures protecting the
engine from detonation due to high act.
8 Get a 90 MM lightning mass air meter and get a mass air meter adpter from
9 you will need a set of 36# hr injectors. 30 won't be enough and 42 could give you
10 Have sct dyno tune your car. Make sure only "the man" tunes the car.
11 I think that this helps but you will have to send the manifold back to allen for
them to do the machine work on it. On the 5.4 trucks the intercooler brick has
a 3/4 opening in the center compared to a 5/8 for a 4.6. allen can modify your
brick and manifold. don't have them tap the manifold for the lact sensor.
They like to put it inbetween runner 2-3 in a dead air area.
12 If you have the mechanical intercooler pump
take that off and throw it as far as
as you can. Get a lightning intercooler pump from frpp. It flows 17 gpm. I
recomend that you have the bottom fitting on the resivor tank drilled and
tapped for 5/8 pipe which 3/4 heater hose fits on perefectly. This allows more
coolant to flow throught the intercooler brick improving heat removal.
13 Get a saleen or equivalant improved heat exchanger. You might be able to
source a used cobra one from somebody that has upgraded to aftermarket for
cheap. If possiable mount a couple of small fans on the heat exchanger to
improve cooling between rounds at the track.
14 I would not change gears in your stang because 3.27 in a stang are about 3.55
in a bird.
here is a picture of my dyno graph and below the picture there is a link to a video of my bird with all the mods.
right click and save as.
my allen video