which way should i go?

[MaxxXJ]

i have a 2000 4wd with the 4.0 automatic and 231 transfer case, no lift just 235/75 mud terrains, and open/open diffs i want a hp/ torque increase and keep my mileage the same if not better

so which way should i go?:

a drop in filter like for example a K&N or airaid or should i do the airaid or another cold air intake? seems like alot of people dislike the cold air intakes. i know on my other vehicle it didnt do anything but give me more intake growl

should i keep the stock header or should i go with a performance header?

and i know a smaller dia pipe like the stock 2" (after cat) gives more backpressure for better torque, but will i lose or gain going to 2.5 cat back? from what i've heard the flowmaster 40 series sounds pretty good

and from what i've read the throttle body spacer is all hype.

anyone else got any ideas how to pull a little more hp/ torque w/o going turbo or NOS just simple bolts on?

[FlexdXJ]

The way i see it that if your jeep is gonna see mud i'd keep the airbox and do a drop-in.....................oh i already did that. Talyn has a pretty sweet box made for a cone filter on his jeep you might get one of those if you are gonna run a new intake.

The stock exhaust is 2.25 all the way back. I would say go to a 2.5 and go with a header instead of the stocker or something like that. I want to build a stroker for mine so i'm just gonna stay with my 2.25 dynomax cat-back and stock header or exhaust manifold whatever the hell it is until then.

[MaxxXJ]

its not going to see any deep mud... nothing deep enough to submerge the motor anyway, if it goes mid door i might get worried a little bit...it will mostly see dusty trails and lots of sand from the beach.

[FlexdXJ]

i would probably stay with the air box in that case too. I could see an "open" filter getting dirty very quick in those situations too.

[wolfpackjeeper]

go with a drop in. You can smooth the tube out if you want. Look into different header options, there are several out there.

The spacer is a waste of time, so is the cold air intake. The exhaust is not a bad idea, but you will NOT see performance out of a flowmaster, you will get noise. And I think they are annoying sounding as well. Go with a magnaflow or dynomax. A Hi-flow cat is a great idea, once again magnaflow or random technologies. Get a new down pipe made too.

[Boostwerks.com]

The spacer is a waste of time, so is the cold air intake. The exhaust is not a bad idea, but you will NOT see performance out of a flowmaster, you will get noise. And I think they are annoying sounding as well. Go with a magnaflow or dynomax.

Wow. Someone who agrees with me for once lol.

[urban yan]

The spacer is a waste of time, so is the cold air intake. The exhaust is not a bad idea, but you will NOT see performance out of a flowmaster, you will get noise. And I think they are annoying sounding as well. Go with a magnaflow or dynomax. A Hi-flow cat is a great idea, once again magnaflow or random technologies. Get a new down pipe made too.

Lately, I've been annoyed with my magnaflow.... who knows... maybe I find it noisy because I'm getting old lol. Now if you excuse me.... I have to yell at some kids to get off my lawn.

[j99xj]

You could do a stroker and change the gear ratio to a higher one (lower numerically).

So in your case you could go from 3.55:1 to 3.07:1.

Since a stroker will produce more torque on its own, you can get away with installing taller gears.

A stroker will burn more fuel just because its a larger engine, but if you reduce the rpm's its turning (by installing 3.07s) you can sort of "cancel out" the fuel economy loss.

The only downside is that it will perform like your stock engine in all but wide open throttle situations where the stroker would make more horsepower regardless the gear ratio.

Of course a stroker isn't a simple bolt on but its far less complex than a turbo/nos setup.

[Talyn]

Spacer is worthless on the 99+ intake manifold. The most you can do for external bolt ons is bore the throttle body, larger exhaust (2.5" max), exhaust header, and some cold air intake.

If you are going to be going through a bunch of mud I would stay with the stock box and do a drop in. Either K&N or I think Amsoil may make one. When I got my 2000 I put rusty's intake with a 5x9" K&N and I noticed a lot better throttle response.

The one that FlexdXJ is made by S&B. It is a box that is open in the front allowing more cold air in and less engine bay hot air. I still intend to seal it to the from of the bay more and open some more cold air points. I would not recommend this unit as it needed quite a bit of modifications to fit. The hood wouldn't even close if left unmodified.


and i know a smaller dia pipe like the stock 2" (after cat) gives more backpressure for better torque, but will i lose or gain going to 2.5 cat back? from what i've heard the flowmaster 40 series sounds pretty good

Back pressure is bad all around. What is important is keeping the speed of the exhaust gasses up to promote scavenging. And yes, flow masters don't flow all that well and sound like crap.

[REDXJ4FUN]

a drop in filter, 60mm tb cat back i like the one from jegs has a great tone. and good plugs are all simple and effective and cheap

[DanMan2k06]

Has anyone invested in a flowmetrics throttle body? They're like $375, but make a 65mm and 68mm one. Think of the throttle response good lord.

[hubs97xj]

Does anyone buy the $400 throttle bodies? I'd consider regearing before I spend that much on a valve.

[MaxxXJ]

should i go with headers? what kind should i go with? it looks like banks has the best setup from what i can see at 465 but i wonder what kind of power increase im looking at.

[urban yan]

To be honest with you.... bolt-ons will eat your money and still leave you wanting for more power. I have a hot-jet coated banks header, 2.5" custom cat-back (including 2.5" cat), AFE stage 2 intake, 62mm TB, and 3/8" TB spacer. I'm afraid to add the cost of all those goodies, but I'm willing to bet they're pretty close to the cost of a low-buck 4.5L stoker (which would produce more power).

If I knew how to build motors or if I had buddies that could help than I would definitely go with a stroker build first.

[REDXJ4FUN]

well starting with bolt ons is a good start since once you go to a stroker you will need those parts aswell. for most people the prosses of building a stroker is a little much if they just to gain some pep. a 60mm tb and the other stuff are proven to provide so good pep and be easy on the wallet.

[seanyb505]

Do a search on APN header if you go that route. You can get one shipped for 140 or something. Its the same as the banks.

[DanMan2k06]

Does anyone buy the $400 throttle bodies? I'd consider regearing before I spend that much on a valve.

Apparently, otherwise the company wouldn't be around?

[hubs97xj]

I haven't seen any that only make throttle bodies for the 4.0 Jeeps, so yeah, I would expect most to still be around. <shrug> I don't recall seeing more than a few folks running aftermarket TBs, and I believe most had come with the CAI/chip/TB package that the big box Jeep stores sell.

[Talyn]

A stock 4.0L will not benefit from a larger throttle body that 62mm or 63mm. I wouldn't even run anything that that on your standard stroker. There are many people running a bored throttle body, much more than the few running the Cai/chip/TB package by Edge.

http://www.strokedjeep.com/ does bored throttle bodies. Cheap too and good quality work. He also radius the IAC ports so you don't get that annoying whistle.

[wolfpackjeeper]

I bored mine myself. Did no more than take the bottom section out, I think it runs out to 60mm. Worked fine on my stroker.

[DanMan2k06]

I have the 62mm bored one, just curious if a few more MM would make a difference. Here's a pic/link...

http://www.fbthrottlebodies.com/products.htm

http://www.fbthrottlebodies.com/images/photos/jeep66mmtop.jpg

[Talyn]

I spoke with Dino a while back about the 65mm tb on his stroker and he advised against going larger than 63mm on a stroker. The throttle would be difficult to control and you would see no gains other than a very touchy gas pedal (really it should be called an air pedal, its not a diesel, but that's off topic)

[wolfpackjeeper]

I prefer the term "Throttle"

[Talyn]

That works, but I think it should be called the air pedal

[MTBracer367]

Does anyone buy the $400 throttle bodies?


wrangler guys :laugh: