Renix vs HO

Quick quesiton, maybe not such a quick answer...

I'm lookign at an 89 project to replace my 96 project that litterly did not get off the ground.

In deciding what to keep from the 96 before it goes off to the bone yard I'm debating on whether or not to grab the 4L HO and the computer. Both the Renix and HO have quite a few miles (300K on the Renix) so either would need a rebuild before too long I assume.

I know there are fans of both engines but what specifically do people like and dislike between the two?

I understand that the computer is one of the main differences but much of my background is related to 60's and 70's Buicks, no computer to worry about back then it either ran or didn't. If it didn't you checked fuel and spark...

Eh, the difference goes far beyond that. The entire computer/fuel delivery/ignition system is different. Renix has a better torque curve, and is slightly more reliable while harder to troubleshoot.

HO has more horsepower, but its power is at a little higher RPM, easy to troubleshoot but nto quite as reliable.

Renix gets better gas mileage.

Don't try and "upgrade" a renix rig to HO stuff, its not worth your trouble.

cal said:

Don't try and "upgrade" a renix rig to HO stuff, its not worth your trouble.

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True in certain ways...

Dont try to swap out the RENIX computer with the one from your HO. However, the intake, exhaust, and head would be good things to swap over. Use all RENIX sensors (the TPS will have to be modified, or an adapter purchased). That would be good for a good performance increase.

If it were me, i would strip about everything off of the HO to have for spare parts, and build a stroker using the RENIX block and HO top end (if it has the 7120 head). The stuff you wont ever use (like the computer, sensors etc) sell them on here, craigslist, or ebay and make a little bit of cash. Most of the other stuff can swap into the RENIX no problem (body panels, interior, axles, tc etc .. etc..)

Muad'Dib said:

True in certain ways...

Dont try to swap out the RENIX computer with the one from your HO. However, the intake, exhaust, and head would be good things to swap over. Use all RENIX sensors (the TPS will have to be modified, or an adapter purchased). That would be good for a good performance increase.

Click to expand...

While I thought about that, I am on the working assumption that if someone was ready for that kind of project, they would not be asking these questions

(That was not picking on you OP, everyone has to start somewhere!)

While not ready for a project like that it does sound like something that I would want to plan on in the future... I'll pull the head and intake (header is shelled so will pick up a new one when I need it).

This is exactly why I posted this question because I knew that I would end up wishing I had kept something that I didn't. I like the thought of the Renix having more torque, HP is nice but I plan to wheel this and want some low end grunt too.

No worries Cal, I am just starting in this jeep thing, had a XJ Chief while I was in Ft Campbell but it was the wife's and I never really got to play with it (had the GM V6 in it and was a real dog).

Save the transmission and transfer case, too.

The Renix aw4 has a 21 spline output, the HO is 23 spline output. Most of the upgraded transfercases available are 23 spline.

I have 5 XJ's, 90', 94', (2)96's, and a 00'. They are all 4.0/AW4/NP 231/D-30(90 is a disco)/8.25(90 was swapped).

I have never had any issues with any of my XJ's other than regular maintanance. I prefer the 90 over the rest but I'm fond of the 96 model year as well (both of my trail rigs are 96's).

RENIX is simple and reliable. You do not need a scanner to troubleshoot, just a volt-ohm meter and the RENIX FSM. My RENIX is my daily driver.

I see little or no difference in the performance between a HO and the RENIX, they drive the same to me.

xjtrailrider said:

I have 5 XJ's, 90', 94', (2)96's, and a 00'. They are all 4.0/AW4/NP 231/D-30(90 is a disco)/8.25(90 was swapped).

I have never had any issues with any of my XJ's other than regular maintanance. I prefer the 90 over the rest but I'm fond of the 96 model year as well (both of my trail rigs are 96's).

RENIX is simple and reliable. You do not need a scanner to troubleshoot, just a volt-ohm meter and the RENIX FSM. My RENIX is my daily driver.

I see little or no difference in the performance between a HO and the RENIX, they drive the same to me.

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X2, my well maintained / slightly modified RENIX (90) hauls, and snaps you in your seat when you get on it.