Author Topic: What is the optimal RPM for a 2.4 at highway Speeds?  (Read 1221 times)

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kingpin71

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What is the optimal RPM for a 2.4 at highway Speeds?
« on: November 04, 2008, 06:54:44 PM »
I was just wondering where my 2.4's RPM's should be for the best performance and fuel economy. I just dont feel right cruising around at 2900.

Mr_Random

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Re: What is the optimal RPM for a 2.4 at highway Speeds?
« Reply #1 on: November 04, 2008, 11:39:43 PM »
the 2.4 is a DOHC engine, right? Stick or auto? Depending on which one, I don't think that should be too high of a number for a DOHC engine...

Offline aw12345

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Re: What is the optimal RPM for a 2.4 at highway Speeds?
« Reply #2 on: November 05, 2008, 05:09:26 AM »
My little 2.4 starts making power above 2500 rpm , 3000 is pretty good. For power on hills I often wind it up over 4000 and on some sandy gravely climbs I had it a 6000 to get me to the top. That little motor likes to rev.
I would say anywhere between 2500 to 3000 is good, for better milage around 2500 seems to work well. That's where I used to get the best milage on the highway
2006 Jeep Wrangler TJ SE
2004 Jeep Wrangler TJ SE

Mr_Random

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Re: What is the optimal RPM for a 2.4 at highway Speeds?
« Reply #3 on: November 05, 2008, 11:51:38 AM »
My little 2.4 starts making power above 2500 rpm , 3000 is pretty good. For power on hills I often wind it up over 4000 and on some sandy gravely climbs I had it a 6000 to get me to the top. That little motor likes to rev.
I would say anywhere between 2500 to 3000 is good, for better milage around 2500 seems to work well. That's where I used to get the best milage on the highway

Do you have a stick or auto? I would think auto runs marginally higher rpms at the same speed as manual...

do the PT turbo swap, then you wont have to deal with high rpms again! haha

kingpin71

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Re: What is the optimal RPM for a 2.4 at highway Speeds?
« Reply #4 on: November 05, 2008, 03:46:58 PM »
I have the 6 speed.  Running down the highway at 70 it is about 2500 rpm, but with a headwind in 5th I need to pull around 3000 to keep it around 70ish. 

What is involved with the PT turbo swap?  About how much will the parts cost?

Offline aw12345

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Re: What is the optimal RPM for a 2.4 at highway Speeds?
« Reply #5 on: November 05, 2008, 04:10:12 PM »
You need the whole engine and computer flip the exh manifold rig up an inter cooler and make new motor mounts
I might eventually do this. For now it works fine for me its not always easy to keep up with the 6 cyl jeeps in the mountains but generally manage to do so
2006 Jeep Wrangler TJ SE
2004 Jeep Wrangler TJ SE

Mr_Random

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Re: What is the optimal RPM for a 2.4 at highway Speeds?
« Reply #6 on: November 05, 2008, 05:08:37 PM »
actually I think the purpose of the adapters being sold was to allow the 2.4 to use the stock pt gear and computer, but I definately could be wrong.

Offline aw12345

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Re: What is the optimal RPM for a 2.4 at highway Speeds?
« Reply #7 on: November 05, 2008, 05:48:47 PM »
Airsierra made an adapter to move the turbo from the back of the engine to the front, In its stock setup you have to butcher the firewall for clearance his setup flips the exhaust manifold and moves the turbo forward is a very nice solution to the clearance problem. It's better to use the whole engine so you have the lower compression and you don't have to mess with reflashing and fiddling with the timing and fuel map
2006 Jeep Wrangler TJ SE
2004 Jeep Wrangler TJ SE