Too much air? *new member*

[xcodyxj]

So Id like to start off with a warning that i am a new member to this forum
so cut me some slack if my first thread sucks


I have a 97 Sport and have been saving money and planning a build for a long long time.
I would like to improve performance as its something im able to do for the most part in the garage before I make it big and tall.

I have got my sights set on a cold air intake, rifled TB spacer, and a 62mm TB for the intake. CAI because why not, the TB because of the "choke point" in the system theory. The spacer because (in laymans terms) the simple fact that it gives the airflow more room to bend into the manifold, more volume and the rifling just sounds like a good theory as well.

Im not looking for anyone to knock those down Ive seen alot of builds do just that and boast about horsepower gains. im not expecting 30+ but any gains without a loss in fuel mileage and cleaning up the engine bay sound good to me.

I also have a header to Muffler, high flow exhaust build im figuring out the specifics on starting with the banks revolver header. I want the exhaust to sound mean, not be falling apart like mine is currently, and flow better

Heres where I need help, Ive been reading alot about the 99+ manifold swap and im wondering if i did that in conjunction with the rest that i am planning if its gonna end up losing me a noticeable amount of torque in the low end RPMs.

I want to gain some horsepower and still maintain good fuel mileage since im currently driving the jeep daily but I obviously dont want to lose all my low end power.
I still havent figured out my injector situation if i do the swap but i wont be doing any 24 Psi or anything just something to keep me from running lean and more efficient than stock.

Does anyone have any real world experience with doing all this in conjunction? Im just looking for some advice on how to get the most out of my 4.0 while still maintaining driveabilty. Im not an engineer (yet) Im a kid with a jeep and a laptop that works in a Pep boys, so any advice would be greatly appreciated.


And YES once i fix my nissan up, porting, polishing and a stroker kit will all become an option for the XJ .:repair:

 

[Demonoid369]

The spacer because (in laymans terms) the simple fact that it gives the airflow more room to bend into the manifold, more volume and the rifling just sounds like a good theory as well.

Im not looking for anyone to knock those down

Sorry to burst ya bubble but all of us are gonna tell you that a spacer is snake oil, it doesn't do a thing, even JP magazine proved it. The only time a spacer helped was when engines where throttle body injected, it gave more time and such for the fuel to mix with the air before going into the cylinders

 

[SolarBell]

Throttle body spacer on a fuel injected vehicle is a waste of money. Take the money and put it toward a 99+ intake. You won't notice much if any drop in low RPM HP. Chrysler designed that intake to make up for the 5HP loss incurred from the late model federal emissions package so it's free gain on earlier models.

You will need to do the exhaust in combination with the intake to see the full potential. A simple high performance cat back exhaust will get you almost all of the gains. Good tone as well.

I would suggest a good air oil separator between the CCV and intake. Less oil in the air increases the effective fuel.

I would actually not be surprised to see the intake changes with the new exhaust and AOS to net you 25 HP.

 

[SolarBell]

Oh, and increasing the airflow efficiency will not make you run lean. The PCM won't allow it. The only time you need to get larger injectors is if you increase engine displacement.

 

[Johnnie Walker]

Do not waste time with the TB spacer.
Pick up a set of either Chrsyler 703 injectors (831_xj sells refurb sets for a good price) or Ford Yellowtop 19# injectors.
99-up intake
Aftermarket exhaust, etc.

 

[streetxj]

Eliminate the throttlebody spacer. I tried that mod on a 2000 XJ 4.0 and it just worsened the throttle response.

Here are the mods that made a good difference on my 96' XJ 4.0.

2003 4.0 intake manifold.
Gibson stainless header GP400s.
Crimped section of the down pipe replaced with a smooth pipe.
Bosch 703 fuel injectors.
62mm throttle body from Leigh Performance (Jeff)
Stock intake system with shoe horn/venturi tube removed, K&N panel filter (changing to AFE pro dry s soon), Extra large cutouts made to the intake tray beneath the filter facing the ECU.
2.5 inch Thunderbolt high flow catalytic converter.
2.5 inch Aero Turbine (AT2525) muffler.
Dynomax 2.25 inch tail pipe with 2.5 inch stainless tip.

Other mods for sh&ts and giggles:
180 degree thermostat.
Taylor ThunderVolt 8.2mm spark plug cables.
JEG's Performance ignition coil.
Accel cap and rotor
champion RC12LYC spark plugs

 

[Dr. Dyno]

Eliminate the throttlebody spacer. I tried that mod on a 2000 XJ 4.0 and it just worsened the throttle response.

Here are the mods that made a good difference on my 96' XJ 4.0.

2003 4.0 intake manifold.
Gibson stainless header GP400s.
Crimped section of the down pipe replaced with a smooth pipe.
Bosch 703 fuel injectors.
62mm throttle body from Leigh Performance (Jeff)
Stock intake system with shoe horn/venturi tube removed, K&N panel filter (changing to AFE pro dry s soon), Extra large cutouts made to the intake tray beneath the filter facing the ECU.
2.5 inch Thunderbolt high flow catalytic converter.
2.5 inch Aero Turbine (AT2525) muffler.
Dynomax 2.25 inch tail pipe with 2.5 inch stainless tip.

Other mods for sh&ts and giggles:
180 degree thermostat.
Taylor ThunderVolt 8.2mm spark plug cables.
JEG's Performance ignition coil.
Accel cap and rotor
champion RC12LYC spark plugs

That's a nice set of mods and I agree; buy an '00+ intake manifold and don't waste your money on a TB spacer.
__________________________________

1992 XJ 4.6L "Poor Man's" Stroker
202rwhp @ 4700rpm (248bhp)
258rwtq @ 3400rpm (311lbft)
1/4 mile: 14.63 @ 94.4, 3450lb curb
AX15, NP231, D30/D35
Jeep Performance, Jeep Tech, Junker to Stroker

 

[Rainman]

look at a electric radiator fan install.
have done just about every thing you have mentioned, stand alone that was the best bang per buck mod i have done, in terms of freeing up horse power.