99 to 01 intake swap to an older xj

[bscg2000]

Who has done an intake swap from a 99 to 01 to an older xj? Specifically an intake off of a 2000 to a 92. I need help with modifying the vacuum lines to fit and where they are supposed to hook into the intake! It is driving me nuts that I cant figure it out. Thanks in advance

[XJ Wheeler]

Looking forward to seeing the answer. I've got a 01 intake to put on my 92.

Sent via messenger pigeon. I talk, he types.

[Cheromaniac]

Sorry to take so long to reply but I've had a busy week at work and I've been coming home too late to get photos.
I did an '01 XJ intake manifold swap into my '92 XJ nearly 7 years ago and I also swapped in the '01 XJ PS pump, mounting bracket, and tensioner at the same time. Dealing with the vacuum lines was pretty straightforward actually and I didn't need to use any new materials. I just rearranged the existing lines and extended two of them (the fuel pressure regulator and the evap. system lines). I've attached a couple of photos to help you. The wiring harness for the MAT sensor also needed to be extended.
I was very happy with the result (2hp/4lbft/1mpg gain) and this was my dyno run after the swap:

http://www.angelfire.com/my/fan/HP_TQ.jpg

[4.3LXJ]

200 hp on a 92? Not bad

[Mudderoy]

As I recall extending the sensor wiring was the only modification between the squarish 98 intake to the 99+ intake.

[Infidel Edition]

...
I did an '01 XJ intake manifold swap into my '92 XJ nearly 7 years ago and I also swapped in the '01 XJ PS pump, mounting bracket, and tensioner at the same time...

I was very happy with the result (2hp/4lbft/1mpg gain) ...

The 2000 intake ... only resulted in a couple hp?

I was reading in the Hesco Adjustable Fuel Pressure Regulator that they're touting 4 hp just by changing the regulator. and 7 - 10 with a higher flow TB.

So I was hoping that swapping the intake, brackets for the PS Pump / and pump, Fuel Pump & higher pressure regulator and going 2.5" exhaust back no cat.
But to justify all that work, I'd want at least 10-15% gain over stock (190 hp). so like 210+

...and maybe on the next rebuild, swapping out the cam and adding a higher performance ignition system.

:confused:

:stars:

[Infidel Edition]

~ or are you talking 200 at the wheels vs. off the engine?
as I understand, I'm at 190hp off the engine, but like 140hp at the wheels

[4.3LXJ]

I remember seeing a youtube vid of a dyno test. They claimed 15 hp with that swap

[bluedragon436]

I'm trying to find out whether I want to run a gasket from my 97 or go to a 99+ gasket when I do my swap over?? I picked up a new TB gasket so that I can install my Bored TB, and have all new O-rings for my injectors.. as I have new 4 hole injectors to install... figure I'll install my new injectors as well as my Bored TB, at separate times on my current 97 manifold.. that way I can make sure all will run smoothly and correctly, before I change all the parts out.. plus I am wanting to pick up a new exhaust manifold to swap in at the same time I do the 99+ swap, to replace the cracked factory manifold, but also get a bit of an upgrade @ the same time..

[Cheromaniac]

I remember seeing a youtube vid of a dyno test. They claimed 15 hp with that swap

That guy had also changed the injectors before the "after" dyno test so the baseline dyno might have been lower than it should have been due to bad injectors. A claimed 15hp gain with just an '00+ intake manifold swap is extremely optimistic given that the '00-'01 4.0 XJ was only rated at 193hp/231lbft (3hp/6lbft more than the '96-'99 models).


or are you talking 200 at the wheels vs. off the engine?

As per my sig,. it's 202hp at the rear wheels and 248hp at the crank.


The 2000 intake ... only resulted in a couple hp?

Yup but keep in mind that the '00+intake was designed for improved low/medium rpm torque, better gas mileage, and lower emissions, not for HP.


I was reading in the Hesco Adjustable Fuel Pressure Regulator that they're touting 4 hp just by changing the regulator. and 7 - 10 with a higher flow TB.

He he, yeah, if only that was true! Might be possible if your engine's running lean and needs a higher fuel pressure. Otherwise I'd call it BS.



So I was hoping that swapping the intake, brackets for the PS Pump / and pump, Fuel Pump & higher pressure regulator and going 2.5" exhaust back no cat.
But to justify all that work, I'd want at least 10-15% gain over stock (190 hp). so like 210+

With a true cold air intake, 62mm throttle body, '00+ intake manifold, header, and 2.5" catless exhaust you might see a HP gain ~15%. Even then, the stock fuel pump and fuel pressure regulator would be up to the job so don't waste your money on changing those. I still have those stock items feeding a 4.6L stroker, never mind a stock 4.0L engine.
The stock ignition system is also up to the job so don't waste your money "upgrading" that either.

[bluedragon436]

With a true cold air intake, 62mm throttle body, '00+ intake manifold, header, and 2.5" catless exhaust you might see a HP gain ~15%. Even then, the stock fuel pump and fuel pressure regulator would be up to the job so don't waste your money on changing those. I still have those stock items feeding a 4.6L stroker, never mind a stock 4.0L engine.
The stock ignition system is also up to the job so don't waste your money "upgrading" that either.

What header you thinking would be best to run to have the ideal flow?? (I only ask cause my stocker is cracked ((GO FIGURE))...).. and running the stock downpipe?? to a catless 2.5" exhaust.... running what muffler setup, so you don't get too much drone/raspiness or anything??

[Cheromaniac]

There are several makes of header on the market but I'd recommend one that has a 6-into-2-into-1 pattern with a 2.5" collector. An exhaust shop can fabricate a 2.5" mandrel-bent downpipe for you.
You'll need a chambered muffler to keep the drone down but if you're going catless, you could replicate my set-up with a Flowmaster 2.5" chambered muffler where the cat normally sits, and a Magnaflow 2.5" straight-thru muffler directly behind it. The sound is deep and sporty with no rasp and no drone.