Power Adders: Best Bang for your Buck

[CherBear]

So I have noticed quite a few of you guys have done some engine mods to your Cheros. I am thinking of doing some myself.
So i would like to know what mods have given you the biggest performance increase for the money?

 

[Sherman_thetank]

My vote, the tried and true cold air intake and exhaust, they are pretty cheap and helps it breath immensely.

 

[wolfpackjeeper]

exhaust is a good thing to upgrade. Skip flowmaster, they suck. However the cold air intake is a complete and total waste of time. Better off spending that money elsewhere. By insulating the stock airbox and moving to a high flow flat filter you can get the same games.

BEST bang for the buck is the stroker. There is really no substantial way to add a lot of horsepower to the 4.0 without going internal. Especially if you are due for a rebuild anyway. You can build a stroker for not much more that a basic rebuild, and end up with much more power.

However, this may all change once Bryson gets a good turbo kit out there for the 4.0.

 

[CherBear]

Amen, already have a Cold air, working on the exhaust soon. Does seem to be a pretty decent combo. How about after that, like a Jet Chip or a bored throttle body? New plugs? Anything else like that?

 

[old_man]

Historically horsepower doesn't significantly change with out either a change in displacement or in the cam. Everything is just nibbling at the edges. Boring the throttle body only really helps if you run wide open. It is the same as simply pushing down on the throttle more except at WOT.

Probably the best mod for anybody with over 50k on the engine is to run a can of BG44K.

A good second step for lowlanders would be to run a high altitude CPS or modify their own. This nudges the timing forward a few degrees.

A MAP adjuster can help dial the best F/A ratio if you know what you are doing and have the tools.

Performance means different things to different people. Above I was talking pure horsepower. As far as driveability, gears are probably the thing that would make most people the happiest.

 

[Mr_Random]

Amen, already have a Cold air, working on the exhaust soon. Does seem to be a pretty decent combo. How about after that, like a Jet Chip or a bored throttle body? New plugs? Anything else like that?

Those are just nickle-and-dime 1/2hp at a time upgrades. The Jet chip will require premium gas (if you get the stage two) in order to feel it, and the bored throttle body will help for sure, keep good old champion truck plugs in there, nothing else will help. I'm sure an MSD will help, but not for low end, what most people don't realize is that it doesn't kick in until upwards of 2000RPM. HEI would be nice, but once again, 1hp only.

So, you can do all that for probably 15hp, and, I'd say around $500, or you could do a good stroker for three times the gain and only twice the price?

 

[wolfpackjeeper]

I kind of lump all that stuff into the "supporting mods" category. I consider power adders to be things along the lines of cam changes, internal displacement mods, and forced induction/nitrous.

Jet chips have mixed results it seems. The bored throttle body will move more air, but it will be a throttle response type of mod rather than a true increase in horsepower. Coupled with a new cam and head work it would be great. New plugs are regular maintenance, however if you need them when you switch to better ones you can be tricked into seeing gains.

Nitrous is probably the best bang for the buck out there, but it comes with a bunch of risks. Using a wet system instead of a dry one can minimize those risks, but I would probably still keep it below a 100hp shot unless you can tune it.

 

[badron]

Late model intake manifold.
For offing and DDing a long crankshaft not cheep but a good bang-per-buck.
Then bigger poop pipe
For the !/4 and just showing off NOS and/or forced draft induction and any or all the above.

 

[slcpunk74]

I'm sure an MSD will help, but not for low end, what most people don't realize is that it doesn't kick in until upwards of 2000RPM.

You sure you know what you are talking about? Not trying to be rude just making sure your not feeding the bull.

 

[Sherman_thetank]

I kind of lump all that stuff into the "supporting mods" category. I consider power adders to be things along the lines of cam changes, internal displacement mods, and forced induction/nitrous.

Agreed, I'm assuming that is not what he is referring to though, but if so, nitrous is the cheapest and can do wonderful things.....like make you walk home :dunce:

 

[ehall]

How much bang? And how much buck?

There is a lot you can do to free up lost horsepower in any engine. The basic operation of a four-stroke is: pull air and fuel into the cylinder, compress it, ignite it, and then expunge gasses. Only one of those strokes produces power, and the other three consume power. By consuming less power in the engine itself, you allow more of the existing power to be used by the wheels, which is where stuff like high-flow intake and exhaust really comes into play--allow air to be pulled in more easily, and exhaust to be expunged more easily, results in less power being wasted on the engine operation. Other mods like fuel injectors that atomize the fuel more, larger active spark (from coil, or bigger gap on the plugs) that ignites the fuel and air mixture more evenly, advanced timing that ignites the mixture a little sooner, etc, can also produce slight improvements in creation of power.

In the end there's no replacement for displacement. If you want to actually make noticeably more power, you need a bigger explosion on the one stroke that matters.

 

[REDXJ4FUN]

I have a basic system for all of my cars and trucks, first off is a good tune up with upgraded stuff then a good air filter and depending on the car i do a whole airbox setup. then its on to the exhaust. anything much after that is either needed after another part is bad or it realy gives me great bang for the buck such as the punched out TB. the 60 does a great job and the 62 is just a little better even on a stock motor.

 

[Mr_Random]

You sure you know what you are talking about? Not trying to be rude just making sure your not feeding the bull.

No personal experience, pro engine builder told me that, so I trusted his word...

 

[seanyb505]

Regearing. Going from 3.07 to 3.55 with stock tires made the most difference before going the stroker route.

 

[urban yan]

If you have the loot = stroker+regear

 

[CSaddict]

Forced induction will net the most bang for the buck. Nitrous is cheap but the refills add up fast.

 

[Dr. Dyno]

You can gain ~30hp (flywheel) over stock with external bolt-on performance mods, maybe a further ~15hp with a ported head, and another ~15hp with a performance cam and raised CR. If you want more than 250hp at the flywheel you'll need to take the stroker route.
If you're going to internally modify the engine at all with a ported head/cam, you might as well rebuild the bottom end into a 4.6 stroker while you're there.

 

[Darky]

Four Wheeler mag just did a test where they took a stock TJ and dyno'ed it at 126.4hp@4474rpm and 176lb-ft@2385rpm.
After a lift and tires it lost 4 horses and 13 lb-ft. Then they installed a JBA header, Airaid CAI, and TB spacer. That brought power up to 148hp@4850 and 213lb-ft@2365. The header along gave them 6 hp and 33lb-ft. All in all, for about $500 they gained 22hp and 37 lb-ft of torque with just intake and exhaust. So yeah, bolt ons are definitely worth it. I think I have a new plan for basic engine mods in my Jeep...

 

[wolfpackjeeper]

my next mod on the 4.7 will be head work and a new cam. After that: Blower

 

[Boostwerks.com]

Forced induction will net the most bang for the buck. Nitrous is cheap but the refills add up fast.

Bah. You wouldn't know.

I reccomend getting a couple of the big ones...