Ok members, I was wondering what the diff was between the 4.6 engines, lower half only. I mean are they built stonger with diff components to handle the higher output for the Cobras compares to the GT? I would assume so, but what is the diff? How much HP can the GT engine realistically handle without rebuilding the lower half? I'm looking into a complete turbo kit for my GT that will put 480hp to the rear wheels. You can see it here it's the stage 2. I have a lot more research before going foward, so I thought I'd start here. These may be no brainer questions to some of you, but I have searched without coming accross any good info.

 

Can't really answer that question for you with 100% certainty, but I definately think you would have to go with forged internals. Also, not from personal experience just from what I have read, I would take a look into other companies to get your turbo setup. I haven't heard many good things about TDC. Look into www.turbochargedpower.com they are pricey, but I've heard alot of good things about their kits. Either way, whichever route you go, I think there will be some bottom end work needed.

 

You will hear different opinions on this one. I have been told by a couple of tuners in my area that about 400 to the wheels is the limit. That only was for S.C.'s. Not sure about a Turbo. It also factors in other components such as clutch, transmission, etc.

Most people say that it's all in the tune. With a power adder, you have to support all the other additional needs such as injectors, pump, etc. There are a lot of factors involved.

My thoughts are that no matter what type of bottom end you have, subjecting a car to higher pressure/heat will eventually result in pre-mature wear of components.


Todd

 

Up until the '03-'04 Cobra the only differences were the Cobra block was aluminum compared to the GT block which is cast (GT block is stronger but heavier - but both blocks are considered nearly twice as strong as a 5.0 block). SHM says both type of blocks are good for 800+ hp. The Cobra & GT had hyperutectic pistons and had identical powdered metal cast rods (the weak link). The GT has a cast crank and the Cobra has a forged crank. Even though the Cobra crank is forged - I've never ever heard of a cast GT crank failing. Now the '03 - '04 Cobras have an all forged bottom end - pistons rods and crank.

As you can see the weak link in the bottom end is the rods as long as you have a safe tune (for the pistons). Forged pistons can handle a bad tune alot better than cast pistons - as well as really high hp levels. With a good tune 480hp is certainly attainable - but the rods will be the weak link. T&J ( www.modularfordpowerhouse.com ) has built and tuned many a 480hp car and a few of them were tuned on a stock longblock. They don't recommend it though.

 

i'm not going to beat a dead horse...

it will be WORTH your money to build your motor. after beating on it for awhile, it will eventually take its tool on a stock bottom end. plus, turbo's love lower compression. for lower compression, you have to change the pistons. if you are going to do that, you might as well do everything else....

Good Luck!!

 

From what I understand, Turbos are easier on the motor than a s/c. If you want to gain 100hp more to your wheels, you have to increase your hp by 120 for s/c and about 105 for turbo, since you need more hp to run the s/c.
I want to also let you guys know that I'm not upping the hp to race it every day, It will still be my everyday driver, but with more *****. The kit on TDC's site has a boost control, so I won't be beating on the engine all day long. It's more for the times when those punk *** kids pull along side, I just don't want to spank them, I want them to cry...

And RTM, this kit comes with everything needed for the top end. Injectors, fuel pump etc.

 

even still, you are going to push over 450hp. that will not last long on a stock bottom end, even with a boost controller. you are still going to run that 450+hp eventually. i personally don't think it will last long at all.

 

Heck...no offense MD, but there's no way that a stock bottom end would last as a daily driver. If you are going to spend the thousands it would cost to turbo the 4.6, why not spend a bit more and protect your engine with good forged components?!? Not to mention the fact that 450+ RWHP would twist a stock GT vert into a pretzel LOL

This is an interesting conversation but I doubt that you would ever actually do it anyway RT. If you had that kind of money, you would have bought a faster car in the first place and it sure as hell wouldn't be your daily driver. No offense dude, I'm just sayin' [sm=smiley2.gif]

 

Mike, no worries, no offence taken.

You make several valid points... But this is why I'm asking the questions here.

I just want to make one point clear, I didn't buy my car because it is fast, I bought it because I love Mustangs and I fell in love with mine when I saw it at the dealer. Money is not an issue, I bought this one and not a Cobra, Roush or Saleen because I like this one. I will be upgrading and modding my engine as time allows, and a turbo is where I am heading. I'm just looking for good info on the 4.6 and what it's capable of...

 

Tim, most members said it here...the difference is the forged internals. If it were me, I would build up the bottom before I did a Turbo, if even to be on the safe side. The reason Ford racing put forged internals on the S/C Cobra, should be enough reason to do it. I think you need the forged internals to take the beating.


Didn't you and I have this conversation at the Gas station??? HAHA!