How much power can I safely add

[newmustangdude]

I recently bought a 2010 GT 4.6 with a Roush Supercharger and before making some mods interested in how much I can HP I can safely add. Also interested in going from 3.31 gears to something like 3.73 or 4.10 any suggestions. Thanks

 

[DieHarder]

A little tech background on PD superchargers if you're interested.

TECH - Department of Boost

www.departmentofboost.com

See 3v tech.

GT450-450HP Supercharger System - Department of Boost

Department of Boost - GT450-450HP Supercharger System

www.departmentofboost.com

Personally, I'd leave it where things are for the time being. At least until you replace rods/pistons there's not that much room to work with (~450hp is the safe limit). Higher than that you'll need a built/forged short block. IMHO Not worth bending a rod or worse windowing the block. That gets expensive, fast. The gear changes will make it quicker if that's what you want. If it were me I'd concentrate on improving handling as my thing is grand touring; vs 1/4 mile.

 

[07 Boss]

You can run up to 500 rwhp with conservative timing. I used to run 485 to the wheels for years and many trips down the dragstrip. I have since backed the timing off a couple of degrees because she is getting old.

 

[JC SSP]

Welcome from Florida.

Post some pics of your S/C Mustang.

 

[Dino Dino Bambino]

I recently bought a 2010 GT 4.6 with a Roush Supercharger and before making some mods interested in how much I can HP I can safely add.

Here's an informative video:

Since you have a positive displacement supercharger, your limit will be ~480rwhp & ~450rwtq. Even that's conditional on having an optimized tune, good quality fuel, and well-controlled IATs.
Only centrifugal superchargers will give you 500+rwhp while staying within the 450rwtq recommended limit.

 

[newmustangdude]

Here is a picture

 

[KLJ777]

i have an 06, with a MagnaCharger, Cams, long tube headers, Borla exhaust, 4:56 gears, aluminum Driveshaft, GT500Throttle Body and fuel pumps. My Tuner said 500 RWP is about as good as you can do with a stock bottom end.
My best is 11.97 at 117. I race her 4 times a year, but I think I am at the Max.

 

[KLJ777]

i have an 06, with a MagnaCharger, Cams, long tube headers, Borla exhaust, 4:56 gears, aluminum Driveshaft, GT500Throttle Body and fuel pumps. My Tuner said 500 RWP is about as good as you can do with a stock bottom end.
My best is 11.97 at 117. I race her 4 times a year, but I think I am at the Max.

Plus she still has Cold A/C and full interior.

 

[MrBhp]

I'm running quite a bit more than what is usually quoted as safe. I've never liked these "safe" numbers. Every engine is different as is every tune. My last time on the dyno I pulled 525 whp. I've since turned the boost up nearly 10 lbs. Back in the day I ran a high compression 302 in my daily. Today I hear said "don't go over 400hp, you'll split the block." Horse hockey. I was probably 500 n/a. I had two nitrous plates that totaled 500. Never hurt anything except the occasional bent rod. Never windowed a block. Never split a block.

However, with any kind of power adder that is using crankshaft torque, like your pd, is going to net lower horsepower per psi of boost. You are using power to make power. That's why I like turbos. And nitrous. No extra stress on the motor other than the actual power being produced.

I may have gotten off topic. I discovered a new cocktail. The Amaretto Sour. Dang. Good. And dangerous.

 

[whitmanink]

i have an 06, with a MagnaCharger, Cams, long tube headers, Borla exhaust, 4:56 gears, aluminum Driveshaft, GT500Throttle Body and fuel pumps. My Tuner said 500 RWP is about as good as you can do with a stock bottom end.
My best is 11.97 at 117. I race her 4 times a year, but I think I am at the Max.

im in ne pa as well.., im in denver (adamstown) ,, where abouts are you?

 

[Dino Dino Bambino]

i have an 06, with a MagnaCharger, Cams, long tube headers, Borla exhaust, 4:56 gears, aluminum Driveshaft, GT500Throttle Body and fuel pumps. My Tuner said 500 RWP is about as good as you can do with a stock bottom end.
My best is 11.97 at 117. I race her 4 times a year, but I think I am at the Max.

That's a nice set of mods, and I agree you are at the max for the stock connecting rods. The Boss 302 rods (same as Gen 2/3 Coyote rods) are a popular and inexpensive upgrade in a 4.6 3V.

However, with any kind of power adder that is using crankshaft torque, like your pd, is going to net lower horsepower per psi of boost. You are using power to make power. That's why I like turbos. And nitrous. No extra stress on the motor other than the actual power being produced.

Turbos also seems to be more forgiving on the stock connecting rods. Where 450rwtq seems to about a safe limit when the engine's supercharged, it's more like 500rwtq with turbos since you don't have the additional stress on the front of the crankshaft.

 

[AHaze]

Something I haven't seen mentioned yet is that there's no magic number where you jump from 100% safe to "ticking time bomb". A few engines have let go around your current power level while others have gotten lucky and pushed past all the usual HP and torque warning numbers, at least long enough to get dyno numbers and/or time slips. A lot of that "luck" is actually in the skill of whoever wrote the tune but some of it is just production tolerances of the pile of parts that happened to be combined in your engine. Assuming whoever tuned your car was reasonably competent, you are currently in the "it should be fine but no guarantees" zone. Every pound of boost and degree of timing advance past this point raises your chances of failure so how much risk are you willing to tolerate?

 

[JC SSP]

I have seen stock motors run to unbelieve lengths of HP/TQ power levels and I have seen newly built motors throw a rod on the first pass. Engine builder knowledge, attention to detail, machining process, quality parts and just plain luck all factor in...

In reality, whenever you add a power adder (S/C, Turbo, N2O) you increase the stress on the motor. That being said, of all in my humble opinion... nitrous seems to be the one that when installed & used correctly, yields a good amount of reliable power at the touch of button (figuratively speaking). When not in uses, the engine is not placed under a substantial strain until reactivated.

 

[MrBhp]

Turbos also seems to be more forgiving on the stock connecting rods. Where 450rwtq seems to about a safe limit when the engine's supercharged, it's more like 500rwtq with turbos since you don't have the additional stress on the front of the crankshaft.

Exactly. I've been preaching that for years. There's a reason why the vast majority of the fastest street cars are turbo powered. With N2O next.

In reality, whenever you add a power adder (S/C, Turbo, N2O) you increase the stress on the motor. That being said, of all in my humble opinion... nitrous seems to be the one that when installed & used correctly, yields a good amount of reliable power at the touch of button (figuratively speaking). When not in uses, the engine is not placed under a substantial strain until reactivated

Yes. The problem with nitrous is the finality of it. You have a couple bottles in the car, when they are empty, your night is over. I've ran two different nitrous cars. One of them I would occasionally hurt, but nothing catastrophic. The other one I ran on the ragged edge. I hurt it a few times. Also my fault. I was manufacturing racing fuel at the time and I used my car as the tester. I burned holes in pistons with that one. Too lean. I love nitrous. But it is addictive.

 

[Pentalab]

I recently bought a 2010 GT 4.6 with a Roush Supercharger and before making some mods interested in how much I can HP I can safely add. Also interested in going from 3.31 gears to something like 3.73 or 4.10 any suggestions. Thanks

Which Roush Supercharger ??

 

[Pentalab]

I recently bought a 2010 GT 4.6 with a Roush Supercharger and before making some mods interested in how much I can HP I can safely add. Also interested in going from 3.31 gears to something like 3.73 or 4.10 any suggestions. Thanks

How many miles on it ? Manual or auto ? Any other mods, like suspension or brake mods, LCA's, UCA. Stock 2 piece drive shaft or aftermarket 1 piece driveshaft ? Stock LSD or eaton tru-trac ?
What tires and rims ?

Is this gonna be a street car....or for drag racing, or both ? Or HPDE events, or road racing ?

 

[AHaze]

Which Roush Supercharger ??

Oh, yeah. I forgot they had the M90 kit for the 4.6. If that's what the OP has then there's probably 75 HP on the table before broken rods become a big concern. Could add a small N2O kit. Otherwise bumping it up that much is going to require a whole new forced induction setup.