looking for a safe pulley size for everyday driver
 

I brought my lightining a month ago. I took it to the dragway to get base line run.The truck was stock accept for glass packs. It turned 98 mph in the 1/4 mile. Today with superchips tune and k&n filter kit I got 100 mph. My next mod is the crank pulley. Superchips has a program for 4 or 6 pound pulley.So I am trying to get feed back from all of you experts. Should I be safe with the 4 pound or am I going to go all out for the 6 pound. Please help me make up My mind . Thanks

The 6-pounder will produce more torque earlier so it provides really quick throttle response. The down side is that you are really over spinning the Eaton at higher RPM’s. Over spinning causes excess heating of the intake charge and robs some HP on the high end. The net result is the 6-pounder produces better (peak) dyno numbers but quarter mile times are right in line with the 4-pounder. They make quick-change pullies so you can switch back and forth in a few minutes.

Oh, I run a 4-pounder on mine.

Thank you! I was leaning to the 4 pounder. Should I change thermostat to a lower temp like 180 and or plugs to one lower heat range? And should I be concerned about blowing a plug?

Most tuners recommend going to a cooler plug. I’ve used NGK TR6’s and Denso IT22’s. Both work well. The NGK’s are inexpensive and require more frequent replacement while the Denso’s are expensive and last much longer. Plug changes are a PITA on these motors. I run the stock thermostat but many put in cooler ones looking for the ability to add another degree or two of timing. My 04 never needed it. I have run as high at 19 degrees advance on my street tune without any detonation. I am currently running at 17-degree advance just to be a little more conservative. You might want to check out the Diablo Predator tuner as a future tuning option. It provides way more flexibility than a chip, allows for live data streaming of OBDII, and doubles as a code reader. Another thing to keep in mind is that most feel that a trip to the Dyno (with AF readings) is a must after adding a pulley and chip/tuner. If the Air/Fuel ratio is lean you can have catastrophic engine failure. I consider a Wide-Open-Throttle (open loop) A/F between 11.8 and 12.3 safe. I installed a wideband O2 sensor and meter on my L so I can monitor the A/F myself whenever I add mods. Widebands are available from Dynojet, AEM, and a couple other manufacturers. Ford made a change in the later heads (I think it was in 2002) to eliminate the plug problem. What year is yours?

My truck is a 2000. I have the superchip tuner (1715). It has a program for the 4 pound pulley but does not have any adjustments for a/f. I am assuming they set it at a safe level. I hope.

I wouldn't go over the 4lb. due to the grade of gas always changing. And the heat built up.

Yes, that tuner includes conservative tunes that aren't adjustable.