[lost honda pro]

so, for those of you who are curious, or who havent seen the raw data, here is a pic. the top is your run-of-the-mill 4.0 log-style manifold, and the bottom is the '99-'01 manifold.

its really easy to tell how the small, thin plenum and unequal length runners (really short in the middle, REALLY long on the outside) are not as smooth or efficient of a system as the large plenum and nearly equal length runners of the newer model.

mine was $100 at the local junkyard (they sell em on ebay for $125) and $11 for the gasket.

bottom pic shows how unimaginably long our engine blocks really are (they're ridiculous!) gasket is 27" back to front... thats just crazy...

[SLO.XJ]

Have you finished? What were the results?

[lost honda pro]

yea, took like two hours... easy swap.

i did this along with a 2.25" intake pipe and a cone filter, and aside from the very slighty whistle (old filter), the results are good. the biggest improvement was throttle response, which is now very quick. engine smoothness also seems better, and the main point, fuel economy, seems better too (got like three days left on the tank, then ill let u know)

overall, easy, relatively cheap, and good gains. i recommend it.

[GOKUSXJ]

Hmmm interesting, good job.

[skyjacked94xj]

Fuel mileage??? whats the update...

[nascarnation]

Thanks for the info.
I'm going to do the same update on my 97,
Does anybody have suggestions for the exhaust - I'm looking for torque and mileage not hp & revs.

[XJ_Glen]

that is a very interesting swap. i can only imagine...

[HiMiles91XJ]

More changes are required on an older XJ, like a '91, right?

[skyjacked94xj]

Originally Posted by HiMiles91XJ

More changes are required on an older XJ, like a '91, right?

I am pretty sure on pre-96, you need a new power steering pump bracket

[alexrule123]

I did this swap on a 96 and it was easy, on a pre 96 you will need a 96+ power steering pump bracket

[je3per-xj]

I got one on ebay to put on my stroker for about 60 bucks. havent finished the build yet but when I do there will be pics and data. but Ive been told that putting that style maniflod on the older jeeps will give you about a 12 - 15 hp gain. the reason that they made those manifolds is cause when jeep stoped making the H.O. head (for emissions reasons I think) they lost hp and had to find a way to get it back and thats what they came up with

[Jmila1901]

You serious?!?! only two hours!!

[lost honda pro]

Originally Posted by Jmila1901

You serious?!?! only two hours!!

yea, you just pull the airbox, intake, TB, vac connections, and undo the 12 or 14 bolts.... the PS pump is a pain, but get a buddy with little fingers and it will go much faster

some of the vac lines will need to be rerouted, so have some spare hose and some smaller hose clamps on hands, but yea, easy swap.

[skyjacked94xj]

Originally Posted by lost honda pro

yea, you just pull the airbox, intake, TB, vac connections, and undo the 12 or 14 bolts.... the PS pump is a pain, but get a buddy with little fingers and it will go much faster

some of the vac lines will need to be rerouted, so have some spare hose and some smaller hose clamps on hands, but yea, easy swap.

SO did the fuel mileage ever go up?

[lost honda pro]

maybe a little, 3 MPG gains, but what do you expect?

it runs smoother and throttle response is better. couple this with an intake, bored TB, maybe a TB spacer, and u got a solid induction systen.