I've got '99 5.9l (gas) ram. I've added all the bolt-on's i can (full exhaust w/headers, underdrive pulleys, efan, 52mmTB, CAI, MSD ignition, and SCT programmer). Now I'm thinking internal stuff. Supercharger seems ifey because i'm at high elevation and when i move down to descent level where the air and gas is good i would have to modify the settings. For that reason I'm thinking about staying naturally aspirated. I read that the stock ration is 9:1 (roughly). What would be good level to raise it to? Does anyone have any experience in doing this? I'd like to get this going but don't really want to melt the engine either. When i do it, I'd like to do all internals at once (cam, port/polish, rollers, pistons/rods). Thoughts?

 

What are you wanting to do with the truck? A supercharger might need to be tuned if you move to a lower elevation but can't most of that be done with a computer tuner?

 

PCM is more adaptive than that. You would need a tune to run the S/C in any event, and simply going down the big hill won't upset the computer. It will notice things are changing, and compensate. If you go with a hemifever custom tune (365 bucks), you can get tweaks for free, that can be emailed to you, and loaded on the tuner. (should that prove necessary)

Bumping compression ratio has been a performance mod since the internal combustion engine first appeared on the scene. The question Novarider is asking becomes the most pertinent though. What do you want to do with your truck? And how do you drive it?

 

thanks for the info so far. When either option is done, I'd still like to use the truck to pull a boat or a camper and run around town a little.

 

in other words, i don't PLAN on track racing it. Just street bragging rights

 

LOLOL.

Ok, maybe go to 9.5, or 10:1. Keep quench area under control, and you still may be able to run regular gas. For a street driven vehicle, you don't really wanna push it much higher than that.

Big thing is, match all of your peripheral parts, intake, cam, valve size, to the rpm range you want most of your power at. For a potential tow vehicle, you don't want the beginning of your power band much higher than 1000 RPM. Pick your cam accordingly.

 

what is this "quench area" that you speek of? you kinda threw me off there. But you think 10:1 is as high as i can go and still be on pump gas?

 

Elevation effects N/A engines a lot more than forced induction engines. If it's tuned at high altitudes it'll be a little leaner at lower altitudes and make a little more peak boost, certainly not a problem, you're way overthinking this.