Hi! I have a 2003 ford f350 4x4. It has a 5.4 and a manual 6 sp. The only thing that isn't stock is the exhaust. The cat is removed (by the prev. owner) and is dual 2.5" with a set of thrush mufflers.

I am looking at getting the SCT x3 tuner to help give me a little more ummphh, but I am leary if it'll give me anything worth while. all the research I have done really only shows the gains with an auto tranny (changing shift points). Is there anyone out there with a 5.4 and a manual tranny that can give me their real life opinions??

My goal is to try and catch up with my dad's '08 5.4 auto hp wise.

thanks guys!
Robert

 

you aren't going to get near 300 HP like your dads 2008 5.4 3v has.

you can expect about 15-20 extra HP with the SCT on your 5.4 2v


The SCT will help a ton, but as you said, it mainly helps the auto guys out more. Ford trucks typically see 100 HP drivetrain losses. About 115-120 HP losses with 4x4. Custom tuning can drop that to about 70 HP losses

 

An X3 with custom tunes will be your best bet. Buying a tuner with canned tunes is a waste and will not give you what custom tunes can. You will get the most gains on premium fuel (91-93 octane) however you can get some small gains on 87 octane. In stock form your truck does not allow WOT fuel enrichment which leaves power on the table and causes higher exhaust gas temps and possible detonation under heavy loads.

The stock ypipe on your 03' is a horrible design with two spots on the pipe which necks down to 1 1/2" from the nominal 2 1/2" around it. An SPD y-pipe will replace the necked down portion of the stock y-pipe which will help you get more power to the ground. A set of shorty headers will also help some but the tuner and y-pipe are the first things I would do. Regearing the truck is another option to increase performance but is also expensive. The only thing that is going to increase the flywheel HP over 300 with the stock long block is a forced induction system.

I'm not going to throw increase numbers at you because they would mean nothing. The only way you can get an accurate representation of power gains is to use a chassis dyno doing runs before and after the mods. (preferably all in the same day) You will however get a noticeable increase in power.

 

[quote=dkf;10799250]
The stock ypipe on your 03' is a horrible design with two spots on the pipe which necks down to 1 1/2" from the nominal 2 1/2" around it. An SPD y-pipe will replace the necked down portion of the stock y-pipe which will help you get more power to the ground. A set of shorty headers will also help some but the tuner and y-pipe are the first things I would do. Regearing the truck is another option to increase performance but is also expensive. The only thing that is going to increase the flywheel HP over 300 with the stock long block is a forced induction system.[quote]

The y-pipe and cat are not on the truck. As mentioned in my initial post, I have true 2.5 duals. This is the only thing that isn't stock on the truck. For what it is, it does a great job. But when I try and pull a 36' gooseneck with about 4 ton on it........(doesn't happen very often)

Talking to mike @ 5star, he states 15-25 increase in wheel hp. If I understood corectly that was with a good 87octance tune. If in deed I could get 25 whp out of the tuners, that'd be huge for a gasser. Just trying to see if anyone else out there has a manual superduty with a 5.4 and the sct x3 tuner.

I'm a dumb farmer and I know that dyno hp is usually different than real life, pulling power.

Thanks for the replies so far, keep them coming.

 

Anybody have an actual number on the hp increase from removing the y- pipe and/or cat from a 2 valve 5.4??

also, there is only 40 hp difference between the 2 valve and the 3 valve 5.4's if I'm not mistaken. If I can pick up 20 hp from mike's sct x3 tuner and 10 (prolly not actual) from the eliminated y-pipe/cat then I'm really knocking on the door w/ my dad's truck. Especially since mine is a manual and his is an auto(less drive line loss). His will always stay stock unless I buy him a tuner.

Thanks! Keep the advice coming!!!
Robert

 

With a Mustang, you see huge gains with better exhaust and tuning...but they have corresponding smaller/lighter components. Everything on these trucks is so overbuilt that I takes more up front to get similar gains to the wheels

To be honest, that 15-25 extra HP Mike quoted you was the result of tuning and your dual exhaust. Not separate gains. You aren't going to see a 10+ HP gain from putting new pipes on. Maybe if you had full length headers...maybe

And I'd ask Mike again, but those gains would be with a 92/93 octane tune. I recommend you get a 89 or 92 octane tune. The $0.20/gallon difference isn't too bad and you'll love how the truck feels like a new one

 

There is no company that makes long tube headers for the 5.4 in a SD. Its either shorties or stockers.

 

Ok I missed the true duals part.(Hope you have an X-pipe or H-pipe though)

If Mike says 15-25hp on X octane fuel, you will get it. Just be aware that those gains are usually not gains at the HP and TQ peaks, they are at given points throughout the rpm range.

For example say your stock truck make 100rwhp (rwhp= rear wheel horsepower) at 2200 rpm and the truck after tuning makes 224rwhp at 2200 rpm. That is a gain of 24hp at 2200rpm however you may only gain 8rwhp at the peak of the hp curve.

Some people think that the quoted gain numbers are at peak hp and tq and that is usually not the case. Just trying to explain things to make sure you understand.

 

very good point, thank you!

 

You may be able to use the F150 long-tube headers on the Super Duty. I purchased a set of OBX long-tube headers for my 2005 F350 5.4L 3V but have not yet tried to install them. They are high quality SS headers.

I purchased these headers:
OBX Headers 04-06 Ford F150 5.4L Long Tube 3" Collector | eBay



These are for the 1999-2003 F150 5.4L 2V:
OBX Exhaust Headers 99-03 Ford F150 Triton 5.4L V8 New | eBay



If they don't fit, sell them on Craigslist.