Reliably increasing power for tow capacity

[CobraMarty]

I'm partial to boost. I do like Golen for a crate stroker.

 

[joe_peters]

Well you can call BS all you want, I'm just telling you what the man said. And if you think about it, it doesn't seem all that far fetched. The 270/320 rating is for strictly stock components, stock intake, air box and filter, exhaust manifold, restrictive crossover pipe, cat, muffler, throttle body, and injectors.

Now, the 99+ intake was designed to make up a 15 hp deficiency when they redesigned the 4.0 for better emissions and it worked very nicely.

Now lets see what we could reasonably and conservatively expect to gain from each component:

-99+ intake-Maybe 5-7 hp maybe more.
-good exhaust header and upgraded cat, muffler, and 2.5" pipe-10-15 hp
-large throttle body and injectors- maybe 2.5-5 hp
-good cold air intake-2.5-5 hp

Without messing with anything else, that's a possible 20 hp on the low side and 32 on the high side, conservatively. I even think that with that strong of an engine, that just the better exhaust system alone compared to the stock system could go up as high as 20-25 hp if not more. The more powerful the engine, the better they respond to modifications, if they're well thought out and done properly. Especially in the removal of restrictions.

I've been turning wrenches for more than 35 years. I've gotten more with less. It seems very plausible to me. Have a great day.

99-Up Horseshoe Intake
Myth: According to that great wealth of information that is never wrong, the Internet says you'll get a 5-30hp gain thanks to the '99-up 4.0L's swooped, equal length runners and larger plenum volume.
Our Thoughts: While a free-flow intake manifold can deliver more power, it's only going to allow as much air to flow as the cylinder head and camshaft will call for. Upping the intake runner volume too much will cause the intake charge to lose velocity, killing low- and mid-speed power and torque. On a '98-earlier engine running a stock camshaft and unported cylinder head, it's wasted effort.
Claimed Gains: 5-30hp
Actual Gains: 5hp loss on Trasborg's '98 XJ (Project Mileage Master)

http://www.fourwheeler.com/how-to/engine/154-0911-jeep-4-liter-engine-myth-busting-true-lies/

 

[SolarBell]

This is unbelievably tempting. An M62 supercharger kit built for the 4.0, for a decent price.

http://denver.craigslist.org/pts/3979112907.html

 

[SolarBell]

This is unbelievably tempting. An M62 supercharger kit built for the 4.0, for a decent price.

http://denver.craigslist.org/pts/3979112907.html

So on further research this is the same supercharger kit that CobraMarty put in and documented on Cherokee Forum. Anyone with any comments or other opinions?

 

[CobraMarty]

That's a great price including a 'rebuilt' supercharger.
It's not me, I don't live in Utah.

 

[Warlock1]

99-Up Horseshoe Intake
Myth: According to that great wealth of information that is never wrong, the Internet says you'll get a 5-30hp gain thanks to the '99-up 4.0L's swooped, equal length runners and larger plenum volume.
Our Thoughts: While a free-flow intake manifold can deliver more power, it's only going to allow as much air to flow as the cylinder head and camshaft will call for. Upping the intake runner volume too much will cause the intake charge to lose velocity, killing low- and mid-speed power and torque. On a '98-earlier engine running a stock camshaft and unported cylinder head, it's wasted effort.
Claimed Gains: 5-30hp
Actual Gains: 5hp loss on Trasborg's '98 XJ (Project Mileage Master)

http://www.fourwheeler.com/how-to/engine/154-0911-jeep-4-liter-engine-myth-busting-true-lies/

I'm really surprised to read this coming from you Joe, you usually are spot on. Now with all due respect, the above quote is for a completely stock 4.0 of unknown mileage/power. I, on the other hand, was talking about a 4.6 stroker with higher compression and a bigger camshaft with a higher flowing intake filter, higher flowing intake pipe, a bigger bore throttle body, the higher flowing 99+ intake, larger lb per hr injectors, a higher flowing bigger cam, higher flowing exhaust header, higher flowing catalytic converter, and a higher flowing cat back exhaust.

Here is a key sentence from the above quote: "On a '98-earlier engine running a stock camshaft and unported cylinder head, it's wasted effort." Obviously, I was not talking about one of those engines. And , how did Chrysler engineers manage to do it?

Also, the Chrysler engineers were looking to make up 11 - 15 hp (I can't remember the exact number) from the redesign of the later 4.0's and not only did they get it, they exceeded the hp numbers they needed with the 99+ intake. I will take the Chrysler engineer's results over the results of an unknown engine any day of the week.

Here's a good question, who in the past has taken a stock 2bbl V8 engine (I'll leave it up to you on what make) and swapped on a better flowing 4bbl intake and not seen a performance gain? The engine is an air pump. The more air in and the more air out, the more power you will make.

With all of the above modifications, more air in, more air out , larger displacement, bigger cam, higher compression, more fuel, you're gonna tell me that a better flowing intake will not make more power, yea right!

I feel like either some people did not read my post all the way through or I am reliving a scene from Idiocracy, Lol!

Have a great day!