I've done a bit of work to my KJ and it's turned out pretty good I think except my EGT's are insane. so it had me concerned. I've dont a bunch of reading on Lost jeeps and no one else seems to have seen this, but most people are not running a pyrometer and those that are running one only a few have it in the manifold. Some of the threads I've found are quite old. Here is one: viewtopic.php?f=5&t=62109 and another about what to expect for pre and post: https://www.lostjeeps.com/forum/phpBB3/ ... 495853ad60.
Good info but I'm sure my EGT's are too high, but why?
On country roads I'll see 800 at about 50- 55 mph.
On the interstate that goes up to 1000 - 1100 just to cruise at speed. To get to that speed I'll get to 1250 and that's taking it pretty easy. Up hills at speed are about that if I'm loosing speed and passing someone going quite slow just to merge into the next lane is the same thing. If I was pulling a trailer I could expect this, but I'm empty.
From what I've read I should maybe see 900 going up hill on the interstate.
My pyrometer is an Autometer kit with the probe installed right in the collector of the manifold.
The altitude here is about 4500 feet.
So now for my jeep configuration. I am running 33" tall tires. That's the number one issue that I could see. However I am geared a little slower than stock, so my RPMs are about 100RPMs higher than factory in top gear. So I have effectively re-geared for the wheel size change. There will be some extra weight from the rubber, but I though people were running 31" and 32" tall wheels here without re-gearing. The wheels I selected are pizza cutters so they are not fatty wheels. The whole reason for running this size is because I just manual swapped the Jeep and the overdrive is not as tall (.79 vs .67). Normally when people get higher EGTs from a wheel size change it is because they failed to re-gear, so that's why I'm hoping it is not an issue.
My jeep also has a 3" turbo-back exhaust without out a cat to restrict the airflow. That should help keep EGT's down.
I'm not rolling coal down the road and I'm getting 1000 at 10 pounds of boost. I am running a Yeti tune for full torque, but I doubt that it's the tune since everyone has had good experiences with him and ultimately I'm the one controlling the pedal. It might be able to be solved with a much more conservative tune, but I want to make sure I'm not missing something.
I' think I'm going to pickup a new air filter today, but I doubt that it will drop the EGT by 300 degrees if any at all. I'm going to also try to scrounge up another meter to verify the accuracy of my pyrometer.
I just rebuilt the engine so the intake has been cleaned, FCV is eliminated, EGR blocked, inconel exhaust valves installed and the pistons are ceramic coated on the crown. I have a 203 degree thermostat and I have never seen it creep up past normal running temp.
What your thoughts on EGTs, big wheels regeared and a tune?
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