ZJ: Leach headers installed!

[TOOLman]

It's been a long wait, but it was definitely worth it. In early November last year, I ordered my exhaust system from Kolak. It arrived in January, after some minor trouble with customs. A few weeks later I managed to get an appointment with the Jeep service shop I've used. They called after half an hour and told me that they couldn't do it, since a piece of pipe was missing. They couldn't even figure out how to install the Turbo City air tube...

This morning, and friend and I started working on it. Even though I was nursing a bad hangover, everything went pretty smoothly, except that we had gotten the wrong size for some U-bolts. It turned out to be impossible to find the right size in my old home town, so we used the big ones as a temporary solution.

Then came the moment of truth... I turned the ignition key and the engine came to life with a nice, deep rumble. A bit louder than I had hoped, but not as loud as I had feared. I don't think there will be any problems with the authorities over loudness. There is an annoying drone at highway speeds, much louder than I'd prefer, and when I step on it, it really roars. At low RPM's, she sounds quite a lot like a V8 now.

But the really amazing part is the performance gain. It's like having an entirely new engine! Even with the 31's, she really moves now. And mileage has increased quite a lot. I don't have any exact numbers yet, since I've only driven 60 miles or so, but the average MPG went up noticeably even in that short distance.

When we examined the old exhaust manifold, we found out why she had been so tired and thirsty lately. A big crack at the bottom Y :(

Although my friend did all of the welding, it was really nice to be able to do at least part of the work myself. I can definitely recommend this setup for anyone who wants more power out of their 4.0!

Many thanks to dave, Agent00ZJ, and TaylorZJ for their help and advice. Here's to ya: :beer::beer::beer:

[boxcab]

Then came the moment of truth... I turned the ignition key and the engine came to life with a nice, deep rumble. But the really amazing part is the performance gain. It's like having an entirely new engine!

Great to hear that your odyssey has at last come to an end. It is a difference, isn't it? It just seems to roll along easier, as if level ground is going downhill. I'm going to try tweaking the exhaust tip location to see if I can decrease some of the drone at low speeds. Nick suggested that moving the tip to just beyond the rear bumper face can help. Right now mine (Angelus down-turned tip) is farther back than stock, but not beyond the face of the bumper. I have noticed that the system is louder when cold, which seems odd. But now we have an audible tach! :judge:

[Agent00ZJ]

Te placement of the rear tip can make a big difference is sound in the cabin. Try to have it at leat 1/2" to 1" beyond the rear bimper to avoid resonance in the cabin. Also, of course, make sure all the bolts are tight and welds are good (double check after some driving).

[TOOLman]

Here's a pic from the installation, when we had just got the headers on. Too bad those beautiful headers are completely obscured when you get the intake manifold and all the connections back on...
http://albums.photopoint.com/j/View?u=1375911&a=10264858&p=45388519&Sequence=0&re s=low

[Agent00ZJ]

They are real purty, aren't they? :D Nice pic. Good job.

[dave]

Right on! Congrats! The 70 will quiet down a bit over time. And you'll get used to it. :)

I'll let you know "next time" I'm in the neighborhood. Have to catch up with those virtual beers. ;)

[TOOLman]

I replaced the wrong sized U-bolts yesterday and re-tightened everything. Wow - what a difference. It's now very quiet, practically like stock, but with a nice, deep rumble. Not even too loud at WOT.

And dave, if you show up here, I promise you the beers won't be virtual :)

[TaylorZJ]

Toolman, those look great! Glad to be of some help and thanks for the beer! BURP! Its not bad manners, just good beer! Also, when or if, did you change out the motor mounts, especially the driver's side?? From your picture it looks like the original and the driver's side can start showing signs of cracking from 50K miles and up. Sorry, I should have posted this with my tips earlier, as it is a good time when everything is out of the way......RT

[TOOLman]

I've had the ZJ for a little over a year, and I haven't replaced the mounts. I didn't know that there was a problem with them. I took a cursory look when I had everything out of there, but I didn't see anything that looked wrong. But as I said, I didn't look very closely.

I did the install on a Saturday in my old home town (pop. 7,000). There is no Jeep dealer there, so I doubt that I could've gotten a mount even if I had discovered a problem. I'll try to take a look anyway. The ZJ is scheduled for a 120,000 km service next week, so I can ask the mechanic to take a look, too.

Thanks for the tip. I hope there's nothing wrong, 'cause I'm not too anxious to do that all over again... :)