[powersrj]

I was just wondering if anyone knew how much a stock 05+ gt can hold as far as horsepower.

[Garhfer]

I wouldn't put anymore than 450 rwhp on a stock bottom end

[Drgnracin72]

they have been prven to over 500 hp, also please put you threads in the correct section

[El_Cangri]

Sniper Tuners have a 05 GT with a ATI Procharger D1sc supercharger hittin 577 h.p and 511 trq. with just #60 injector, twin in tank pumps and dull exhaust done between other simple things...

Sniper Stang

[TheUNZippee!]

A stock bottom end in the 05 up 4.6 will safely handle 450 hp as Garfher stated. You can put more on it, but if you drive like I do, which is beating the shit out of your engine with a heavy foot, eventually the bottom end will fail. Typically the first thing to go on our engines are the rods. So before ever putting more than 450 rwhp on mine, I will be replacing the rotating assembly (crank, rods & pistons) with stronger stuff. Remember that just because you talk to a guy who may have 550 rwhp who says he has had no problems, doesn't mean jack shit. Just because they are all the same engine, doesn't mean they are the same. You can put 550 horse in to 20 stock 4.6es that are exactly the same, drive them hard, and some may come apart, and some may not. Know that if you go over 450 rwhp, and drive the car hard, you are running the risk of having the rods come apart, which is usually catastrophic, ruining the block along the way.

[powersrj]

ok, that sounds like some good advice ha

[Regency 2007]

Stoc Mustang GT's with the Whipple 10psi HO kit run strong and stay strong when they hve a good coservative tune. I have seen several of them in memphis that are putting down 475rwhp and have absolutly no problems/risks

[06RedfireGT]

10 psi is the max. any more than that and there is a good chance of throwing a rod and toasting your block. if you want more than 10 psi gotta upgrade the internals.

[dblindberg]

Correct me if im wrong but if you run 50psi and get 450hp and if you run 5psi and get 450hp, you are putting the same stress on the engine! The engine rods, heads, and cylinders can handle loads of pressue, its when the engine fires that the real stress is produced. Thats why we have physics guys, your net outcome of power is in HP, you dont drive down the street talking about your PSI!!!!

[forensicsteve]

putting down 475rwhp and have absolutly no problems/risks

You hear all sorts of numbers. Heard of people grenading at 420 rwhp and others lasting several seasons at 550 rwhp. There are too many variables to cover. Whatever the number, there is risk, so I don't agree with the above statement. The risk increases as the number increases. I am planning on engine rebuild very very soon but until then, every day I start the car without mishap....is a good day!

[kmjsmith]

so...if im too understand db's philosophy...a engine that is N/A pumping out say 400 horse with bolt on mods... is under the same stress as a engine with a huffer and spraying to make 400 hp??

[forensicsteve]

Big difference between 400 hp and 450-480 rwhp (500-520+ hp)

[kmjsmith]

im just using a number out of the air...same senario with 480 horse then...

[forensicsteve]

The threshold most posters are talking about is 450 rwhp (around 500 hp) for stock internals. I'm no expert but I don't think anybody is getting much more than 400 hp n/a, if that.

[kmjsmith]

you are right there...all im trying to determine is if a engine goes under the same stress no matter how you make the hp.

[Emay]

Forensic is right, you can't come out and say the same stress is present at 50psi as 5 psi. Logic immediately tells you that at 50 lbs, you have to compensate for more air, with more fuel, requiring damn near 110 fuel and hence, a far stonger combustion within the cylinder. You can't make that kind of charge conservative.

People will always push the envelope, it's inevitable. Those that do, will break, it's not a question of if, it's a question of when. As mentioned, people are destroying motors at levels below 450, others are getting away with it at 500.

The question you have to ask yourself is this, do I want to buy a $25,000+ car, spend 6 to 7 grand charging or turboing it, to grenade the motor and have a very expensive paper weight in the garage. Is the power worth that?

For those that are pushing the limits, here are photos of the internals in our 4.6 motors. These show just how weak this motor really is.

Block Vented piston and half of a rod up under the intake. Check that hole out..



These are of rods 1 and 5 out of an 07 gt.. They simply bent.. the known weak link. Car only posted 435hp 438tq at 8psi. Check out the piston skirt damage that occured.

[kmjsmith]

enough said.....for me anyway.

[dblindberg]

Maybe im just not getting this but lets get this right.

we all want a turbo/supercharger system running as low of a PSI number so that we can get more out of it sooner or later. A car running 6psi generating the same horsepower at the crank as a 12PSI engine (forget Fuel ratios) is the same stress on a engine. If PSI was a measure of power we wouldnt care about the HP number but the fuel/air ratio with PSI. Think about it, a stock motor pushing 500hp is going to blow some time or another, yes ford quality will allow for some to go faster then others but they will all fail sometime, might take 5 years. WHO KNOWS!

So lets get deep into this. Lets say we have three identical motors (I mean IDENTICAL)

Motor 1: 200 Shot of NOS...motor will blow sooner or later due to stress

MOTOR 2: 12PSI Supercharger running 500BHP will blow sooner or later

MOTOR 3: 6PSI Twin Turbo running 500BHP will blow sooner or later

Motors dont care what you are using to get the power, they dont care how much fuel is in the chamber when they ignite, When that explotion takes place it generates pressure from the explotion not the induction.

Here is something that will help you all out

The mathmatical break down of HP
1 hp = 33,000 ft·pound-force·min−1 = exactly 745.69987158227022 W

When you introduce more air into the engine you allow for more fuel to be added. Fuel by itself will not ignite but requires oxygen. This is where fuel/Air ration comes into effect. The effeciency of the power adder is shown by its PSI but the failure of the engine comes from the BHP.

Next time you are free take a air hose and fill a water bottle with 12 PSI of pressure, wont break. Add the right amount of fuel and ignite it and the bottle will never look the same. The pressure comes from the explotion of the fuel, not the forced induction!

[dblindberg]

One more thing...Do any of you know the pressure generated in a single cylinder during max power.

Try 1,600PSI to 2,000 PSI...MORE HORSEPOWER THE MORE PRESSURE AT DETINATION...thats how you bend your rods and blow your engine!

[Drgnracin72]

its all in the tune