I am not a 3.4 expert but based on the below diagram if you remove the compressor and run a shorter belt the belt tensioner can not work as it was designed. The tensioner moves up to increase tension in the loop made by the AC system. No AC, No loop. I can not think of and easy way to go back and forth. In some cars you can do what you are talking about (Just buy a smaller belt) In other cars you have to buy the idler replacment for the compressor. If your bearings in your Compressor are in good shape the idle replacment would be the same as what you have HP and MPG wise.

 

he is not really looking for any big gains in power or mpg and has said so, i have seen at least 1mpg improvement when a/c is unplugged, to some thats good enough to do it. when i drive my son home i use 15 gallons, thats 15 miles which saves almost a gallon, thats 3.75, i make that drive 25 times a year, it all adds up. thats what im hearing. im also hearing tig say that its a wast of time and effort and to do it is foolish, i dont see it that way and if i wasnt old and dont care what tig says i would be insulted. tig,,, lighten up, this is the second time that i have seen. 94,,, learn to take each post as help and ignore the offensive parts. i can start deleting suff if the op wishes for me to clean up his thread. i would rather not.

 

Unplugged and bypassed is two different things. Unplugging the compressor is easy and free, bypassing the compressor isn't worth the effort and cost. That's my opinion anyhoo. And since a picture tells a thousand words, that diagram Gorn posted shows that he will NOT have enough belt tension when bypassing the compressor with a shorter belt. A slipping alternator or other accessories at higher rpm's and greater loads should be soon to follow.

 

Craby, you don't have to unplug the compressor in the winter. Just switch the dial on your heater to split upper and lower vents. This will not engage the compressor like defroster will. On a daily driver the defroster comes in handy on rainy days with high humity. They should call it the defogger, In the dead of winter when there is no moisture in the air it adds nothing to the "defrost/de-ice" process

 

My latest (and other past) experience proves otherwise. The weather was cold and snowy toward the end of last week. Saturday, it got into the mid to upper 30's and rainy. Stepping in with wet and snowy shoes, gave plenty of moisture inside the car. Rain (humidity) in the changing cockpit air almost instantly put a layer of blinding dew on the inside windows. The defrost setting which cycles the A/C cleared it right up. This happens to me plenty of times over the winter, and I doubt I'm the only one.

 

dont get no snow here, my car is kept inside so no foggy windows to start with. the smaller the engine the bigger the impact on mpg a 6 cly might see 2mpg.

 

Key word is should, but doesn't mean it will. I got my 3.4 with the ac removed and bypassed with a shorter belt and I've yet to have any issue.
Not sure what size belt they used, hopefully come time to replace it I can still read the part numbers.

 

That picture is on an angle. If you look at it straight, it has plenty of angle. Ill go up front in the engine bay and pull the throttle back and the tensioner still works as it should. The angle, plus the direction of the spin from the torque, still presses down the tensioner.

 

Thank you, you do seem to understand the most of what I try and do. And I am ignoring tig now. His comments dont appear to me since I put him on my ignore list. So you guys might see it, but I wont. So everything should be fine now. Thank you.

 

Hey! I was about to post the picture up. HAHA. Anyhow, I kept all my a/c stuff since I will want it in the summer. If anyone does want to know the belt number, just message me. Ii kept the box for future reference. If you want a video showing no issues as well, I can do that. Bbut for now, here is my picture. Again, I had to take the picture on an angle, so you cant see just how much curve and tension is on it. But like I said, the angle is enough combined with the direction of spin from the torque that it will push down the tensioner and not slip.