[doc stang]

???at what point does a blower become too big for the engine.

i have a built, forged 4.6 in a 2007 gt, stroked to 5.0 liters
so displacement is halfway between stock gt, and gt 500.

Kb sells a 2.6 for the gt, and a 2.8 got the gt 500.
now whipple has a 3.4 and i think a 2.9.

???which to pick?

i was initially planning on twin turbo's but as the time draws nearer, i am becoming more worried about a protracted down-time for installation.

??? is my perception correct that - a twin screw would be a quicker, easier install?

the block is a teksid, the k-member is a bmr tubular, the exhaust is now a 3" granatelli manifold-back catless system. (stock manifolds, still)

suffice it to say that even if the stock twin turbo kit (still as yet to be decided on) went on a stock gt 4.6 perfectly . . .
my set up may be different enough based on the above, to really complicate /prolong things.

any other thoughts or suggestions would be appreciated

doc

[psycho bob]

you can put on the 2.8 Kenne Bell, but it's supposed to be for racing only on the 4.6. you should have no issues using twins that were made for the 4.6 as you still have the same block only bored. you might consider upgrading the turbos since you have already forged everything though. do you know where you want most of your power to come in. the KB vs. the procharger......the procharger will give you your power higher in the rpms as the KB will give it to you lower. the whipple is also a very good blower. my preference is the KB over the two.

[06RedfireGT]

If its a built motor it could easily take the 2.8, I say go for it.

[doc stang]

Originally Posted by psycho bob you can put on the 2.8 Kenne Bell, but it's supposed to be for racing only on the 4.6. why is this?, and would it be less of a problem considering the increased c.i.d? you should have no issues using twins that were made for the 4.6 as you still have the same block only bored. stroked , not bored. you might consider upgrading the turbos since you have already forged everything though. do you know where you want most of your power to come in. lower down, i dont like centri's the KB vs. the procharger......the procharger will give you your power higher in the rpms as the KB will give it to you lower. the whipple is also a very good blower. if i Do do a blower, it will be a twin screw, and the SIZE (thread title) will determine the brand my preference is the KB over the two.

doc

forged cp 12 dish pistons
forged eagle H beam rods
forged stroked crank.
stage III MMR p&p heads, with 1mm over on all valves
stage II mmr billet turbo cams, (unless i switch gears, and go for a blower)

i am torn between three companies for twin turbo kits, and am worried whichever i choose, fittment issues will lead to a prolonged down-time
i.e.:
it is a teksid block, on SHM mounts
it has a tubular k member from bmr, and these things may alter positioning, making even a well proportioned twin turbo kit not fit right.

also i already am running granatelli's 3" manifold-back, x-pipe, exhaust and mufflers, in a cat-less configuration. I feel this would be devalued by a single turbo, and want to be able to take advantage of this mod, with whichever power-adder i use.

doc

[doc stang]

so the question again, is how big of a twin screw to go with, if i switch gears . . .
keeping in mind it's a 5.0, midway between 4.6l, and 5.4l.

it is to be a daily driver, but i am looking for about 700-750 rwhp.

up to a point, the larger the blower the easier it will rach a given boost level, and hence hp goal. right?
if the screws are turning slower, it would seem like there would be less heating of the IAT, and better efficiency. right?

if seems, also, like this would help heat soak, since the blower isnt working as hard for a given output . . . right?
i dont have a thorough enough handle on all the terms like adiabetic effeciency, etc, to use them meaningfully (yet), but . . .
how large a twin screw could i put on the above motor with the above goals, before it becomes TOO large, or response, or streetability start to suffer?
doc

[05mustang_TT_charged]

2.6H will bolt right up and can run 24 psi. which is 700+ rwhp
2.8H should be coming out in a little under a month and supports 800+ rwhp