View Full Version : increasing engine performance at altitude

August 10th, 2004, 07:05
I've been looking into mods to increase performance of my 2000 4.0L. I live at 6000 ft. I've looked at all the usual intake and exhaust mods. Here is the deal. I've seen articles on the new 4.0 HO changes. They basically say than the improvements made to the newer HO intake/exhaust are good. I can bolt stuff on, but won't see as much improvement as older engines. Meaning less improvement for my dollar spent. I can't find any hard numbers for newer engines. Also at 6000 ft., I loose 20% air/power. So to me that is the same as saying my intake/exhaust moves 20% less air mass, so it's not as restrictive. Does that make sense? Am I going to see any real improvement modifying my intake/exhaust or is it all just snake oil? Can I make any real imrovements short of supercharging? The point being is that I have less air to move to start with at altittude. When I wheel it's usually up to 10,000 ft. Any input is appriciated. Thanks

Dr. Dyno
August 10th, 2004, 07:16
Any bolt-on performance mods are only going to have a minor effect. If you want a noticeable performance gain, your only real choice is forced induction (supercharger or turbo). Another alternative is to build a stroker.

August 10th, 2004, 09:24
Your funny Dr. Dyno. Do you have a standard response that you just insert? LOL I've looked at you stuff, seen you post. You have great info. Wish you had a 2000! That's kind of my point. I could spend $1000 on upgrades that "might" get me to sea level performance. I would still be in the same boat with a stroker, but yes it would be a bigger motor. Forced induction is the only real answer, but a costly one. My motor has 100K on it. I have always figured on sorme kind of upgrade in he future. Are there any mild superchargers out there? Simple ones that could just get me back to sea level? All the stuff I've seen are maxed out 5-7 psi modified engines. How about maybe 2-3 psi?

August 10th, 2004, 11:52
I live in the Springs. A cold air intake is useful. You aren't going to get massive improvements, but it makes a difference at our altitude. Also focus on low gears, and less on I-25 performance.

I have a '97 and my engine used to ping unless I at least used mid-grade gas. I just run 85 now with no pinging.


August 10th, 2004, 12:19
I was thinking of a 62mm TB. At least I'm going to bore mine sometime soon. Looking into all this stuff, and looking at my options, I don't have as many as I thought. I mean I was going to do an intake, but with AC and ABS I don't have very much room. Nay, What's up local? I don't think I have a sports car, but I've always been real happy with my 4.0. The recent addition of 32's with 3.55 have definitely dropped the performance. I want to swap my axles before I regear, but who knows when that will be. Maybe I will rethink that stratagy.