few questions

[wehswarriorS-10]

ok...i am debating on wether to buy a 70mm bbk tb....gibson headers....or bigger injectors for my 4.7...and on the injectors the accel ones you can get from jegs...will they work on my truck...it says for 5.0's, LS1's and more....just wondering and what would be the best hp gain....if i get headers i will do a full exhaust....no cats true duals, x-pipe....the works...but what would be the best hp gain is mostly my question

[BleedDodge]

Headers are for Chevies.

[neon_rt]

No cats is very illegal and the computer will know it and turn on the CEL. Bigger injectors is a waste of money unless you are making so much (75 to 100hp over stock) horsepower that the stock injectors can't keep up. If I recall right, some of the 4.7's have 4 cats and some have 3. The 4.7 usually doesn't gain a lot of power from exhaust mods b/c the stock exhaust is reasonably good. If you changed only the muffler to a low restriction one, you may gain 7-10hp. If you change everything you mentioned regarding the exhaust, you may end up gaining 15-20hp. After changing the exhaust, a cold air kit and possibly a computer change would probably be the best choice. Changing the TB with a stock computer can sometimes make the tuning off and cause a loss of power rather than a gain. Most aftermarket programming is designed for such mods and make them work better.

[BleedDodge]

Originally Posted by neon_rt

No cats is very illegal and the computer will know it and turn on the CEL.

That doesn't happen.

[neon_rt]

On the models with pre-Cat o2 sensors and post-Cat o2 sensors, if the cat is not working right, the CEL will come on with an associated code. There is a little device that you can plug onto the connector to fool the computer into thinking the Cat is working.

[wehswarriorS-10]

well i already have a flowmaster 40series exhaust with 3rd cat outta there, FIPK, superchip programmer, and a Poweraid TB spacer, so what would be my best bet, and also the HO version of my engine has 8lb bigger injectors, would a set of those make a difference or not???

[wehswarriorS-10]

oh and there are no precat sensors, i have a cat behind each manifold, an o2 sensor behind each one of those, and one before the 3rd cat and when i took that out, it didnt throw a code...

[Dakota00]

Dakotas came with either 3 cats or 1 cat depending on the years.

Headers on the 4.7 are pointless.
Redo the exhaust from the stock headers with 2.25" into 2 high flow magnaflow cats, then X pipe, and then 2 high flow Magnaflow mufflers into 2.25" tail pipes. Some guys have show as much as 20-25hp with this combo on the 4.7, with a PCM flash

Get a 68mm fastman TB, loose the Poweraid TB spacer. As it does shit for performance!!

Don't bother with the injectors as the 4.7 and the 4.7HO are not the same motor. Lots of different parts!!!

Remove the clutch fan will also get you about 5-7 more HP

[wehswarriorS-10]

already took it off...so go with the 70mm TB since i have a programmer to give it more fuel....and get some exhaust done, and im ohio right now and the trucks registered in WV (University of Northwestern Ohio Hi-Perf. student OOO-Rah...lol) so i dont have to worry about emmisions...so can i ditch the cats completely

[neon_rt]

I would think that HO cam and possibly HO ported heads would be next on the list. You won't need injectors until you start running out of fuel on the high end. Putting bigger injectors doesn't add power unless you are losing power b/c the old injectors have reached their flow capacity. As you reach full capacity, injectors lose their ability to increase the flow in a linear manner. When the duty cycle reaches about 85% there is not hardly any flow difference between 85-100% on most OE infectors, the computer is expecting the injector to flow more, but it doesn't and the mixture gets too lean. The Ford Motorsports injectors are known to flow linear almost clear up to the 100% mark. That is why you see some people replace their injectors with FMS injectors that are only one size bigger.

[wehswarriorS-10]

well....could i possibly go with some accel 20 pounders considering the stockers are 19...would that make any diff. and i am still wondering if the 70mm bbk TB would be of any help, says 7-10hp over stock and since i do ahve a programmer i would ahve the extra fuel to go with the extra air

[neon_rt]

If it were me, I would look for a dyno shop and get some A/F readings and power measurements before dumping a lot more $ into it.

[wehswarriorS-10]

well i dont really have any idea where to get on a dyno...the school has several...but you have to be taking the high-po engine class to use them...because they have to use them for class mon-thurs, and on fridays none of the teachers are there and u cant use them, so you cant just pull on them and use them, and i have no clue where one would be around me and i dont have high-po engines for a while....and im goin down to columbus this weekend and my mom and i are doing some christmas shopping at jegs..hehe so now do u see my situation better...lol so would the TB be my best bet??

[wehswarriorS-10]

ok...well i got my TB today and the A/F gauge and pod and put them all on...and the truck revs quicker and has noticeably more power and my gauge says that i am right on the money even when w/o im still a lil rich....so the superchips programmer gives just the right amount more fuel....whole setup works great, i would recomend it