New intake manifold install write up done.

In my quest for more torque at low revs and better efficiency my research showed that the new intake manifold in newer Jeeps fitted the bill. These were fitted to XJ's, TJ's and ZJ's from mid 1999 to the end of production in 2002. You can use one from any of these models I have been told. These manifolds are good for 15 hp according to a Jeep engineer that told me that they had to come up with a way to bring the power back up after new emission changes cost them 15 hp. So that is why the newer Jeeps are not rated any differently than before. Of course though if you fit one of these manifolds to a earlier Jeep without the different emission you get a 15 hp boost!
I checked the volume difference between the two and it was 2600 cc's for the old and an impressive 4300 cc's for the new one. This is the mod to do if you need more torque down low for towing and to over come bigger tyres but not it you are a rev head!

Read my full write up on my site.

Ya read my mind! Was getting ready to post a few more q's about this very issue. I'll go hit your site & check it out as I'm in the middle of this right now.

Ok, looks like ya kept your old power steering pump and modified a your existing pump mount to clear the new intake - is that correct?
:anon:

GoJeep:

I gotta say...you have one of THE best XJ "how-to" and "mod ideas" sites on the web! thats a really sweet idea with the newer style intake manifold....I'm going to check out your writeup right now.
thanks for sharing!

CaptTrev

lunghd said:

Ya read my mind! Was getting ready to post a few more q's about this very issue. I'll go hit your site & check it out as I'm in the middle of this right now.

Ok, looks like ya kept your old power steering pump and modified a your existing pump mount to clear the new intake - is that correct?
:anon:

Click to expand...

Yes I was able to keep my pump but modified the fan bearing support which also supports the front of the pump. I ended up with a setup similar to the TJ one.

Excellent! I do appreciate the feedback. Trying to get this stroker built right the first time & hit yesterday to ask exactly the question ya answered.

You've got a newer XJ than mine but your swap gives me a 'plan b' to go to. Hopefully I won't run into unforseen problems keeping the non-HO accessories & pump - easier on the ol' wallet too.

I'll snap some pics of any non HO accessory mods required & post them.

:anon:

Great write up, thanks.

QUESTION: Can this be done on pre1991's? I am in need of a new TB and would hate to miss the opportunity for full intake upgrade.

BTT

Heard they bolt up but your port shapes are different. Just get a gasket from your model as well as from a new one and overlay them and see what the difference is. Might be able to do it while still in the shop
It might only take a little port grinding to match them!

Let me know what you find out as would like to know too. I would do it for you but as no XJ's before mid '94 exist in Australia I can't

You'd be best off going with an H.O. high port head.

Also the Renix TB mounts to the manifold w. 3 bolts, so you'll have to consider an adapter or a '91 or newer TB.