Adding a supercharger to a 1999, tips and suggestions wanted

I'm thinking of adding a supercharger to my 1999 Tacoma TRD v6 4x4 5-speed w/188k miles to improve highway towing. Do I need anything other than the supercharger (bigger injectors, 7th injector, firmware update, etc..?) and does anyone sell refurbished supercharger kits? New would be too much $$. All tips and comments are welcome!

I bought my truck new in 1999 and it still runs great, but I'm starting to tow more on the highway. The trailer is light but like a parachute and to maintain 70mph I'm either 3/4 throttle in 5th gear, or over 3000rpm in 4th gear. In 4th gear it pulls it fine, but spending hours at a time over 3000rpm doesn't seem good for the service life. My hope is that by boosting lower RPM torque I could tow in 5th gear without feeling like I'm killing it.

 

I added my supercharger pretty recently and would definitely recommend the 7th injector kit. I was running pretty lean without it. If you're keeping the stock pulley that should be enough but if you're sizing down a higher flow fuel pump would help too.

I picked up a used supercharger and then found an oil change and rebuild kit on eBay. The install instructions are available online so get a copy and make sure you have all the parts before starting. All in I think I paid about $2400 from nothing to running supercharger with the 7th injector kit.

 

Adding a supercharger for towing is going to put more stress on your motor. These chargers in particular are notorious for having terrible low end performance without serious fuel upgrades and tuning. As long as your fluids are in check you can run this engine at 5000 all day and it will be fine.

I would recommend a stock sized pulley and a water/methanol kit. You don't need extra fuel with 3-4 lbs of boost, the only issues are high intake temps and detonation which is specifically what water/meth was designed for. Additionally, with a higher end meth kit (progressive) you'd be safe all the way to 10 lbs of boost if you suddenly developed the "need for speed."

The 7th injector kit is a safer, more novice friendly (and more expensive) version of a meth kit. It basically uses extra fuel in place of water/methanol to cool things off.

You should be able to find a used charger for under $2,000. They pop up here once a month or so. People here seem to ask a lot for them. Don't budge, paying over $2,000 for one of these things is a waste. You could turbo for the same cost and have better gains.

 

Thanks guys for the replies. After weighing all my options, and considering the age of this truck, I've ruled out the supercharger. I'm debating on just letting it run 3100 RPM while towing and seeing how it does, or swapping it for a Chevy Colorado diesel. I really wish Toyota offered a diesel in the USA, I'm concerned the chevy won't hold up as well as my Tacoma has, but the diesel for towing is really attractive.