Originally Posted by RockyMtnRay

Yay..another Tundra owner!

Glad you enjoyed my tales of conquest when towing a TM at flying altitudes.

Now, as for turbocharging or supercharging the Tundra engine. It's possible but you've to be extermely careful about doing it when the goal is increased towing power. The problem is towing demands boost durations measured in minutes (or hours) whereas a short blast of acceleration has boost time that's less than 10 to 15 seconds.

Firstly, totally and absolutely forget the TRD (Eaton) supercharger that used to be available through Toyota dealers and was warranted by Toyota if dealer installed. For one thing, TRD no longer sells these...probably because semi-confirmed rumor has it that Toyota was eating a heckuva lot of warranty claims for engines where the pistons and/or connecting rods had made an explosive exit through the side of the block. For another, this unit had no real intercooling...it used extra fuel injectors in the supercharger housing to spray fuel into the plenum in a not very successful attempt to reduce inlet air temperatures. Most of the time this worked for very short periods (under 10 seconds) to keep the engine from experiencing catastrophic detonation (the cause of those grenading pistons and C-rods) but not always.

There are two aftermarket forced air units available for Tundras...one is a strange turbocharger made by Squires Turbo System (STS) and the other is a centrifugal supercharger rom Speed of Sound (SOS) . Both run around $4000 (plus installation...around another $500 to $1000), both will likely totally kill your engine and drivetrain warranty, and neither has much in the way of solid documented user experience at TundraSolutions .

The STS turbo is very weird because it is waaaay downstream (actually under the truck) where the exhaust gasses have cooled enough to lose a lot (most) of their heat energy. Worse, its air intake is also under the truck where it will suck up all kinds of water and muck through the not-so-great K&N filter. I personally would not touch this system with a 10 foot pole.

The SOS Supercharger looks promising to me...it's properly intercooled and seems to have the right components. But AFAIK, no one has yet to install one and provide a detailed report back to the rest of us at TundraSolutions. But if I were to choose a supercharger and had no worries about being needing to pay for an engine and/or tranny replacement out of my pocket (about $8000 and $3000 respectively), this would be the one I'd go with. Potentially very good performance gains but also with potentially very high risk of engine/transmission damage.

In the meantime, the proven (and very low risk) mods that I have done...headers, low restriction muffler, and changing to 4.30 gears...have given me about the same usable torque increases (~25%) as I would have gotten from the very high risk forced induction solutions. Furthermore, I've gotten those gains for about $2000 less than any of the forced induction solutions would have cost if installation is figured in.

And there is still one more fairly low risk performance enhancement (a Unichip piggyback ECU) that I could install. The Unichip gets its performance gains (roughly 7 to 10%) by running the engine on much more aggressive timing maps and a much leaner (12:1 Fuel/Air instead of 10.5:1 F/A) fuel mix when the engine is in open-loop conditions (i.e. no feedback from the O2 sensors). Essentially the Unichip is getting these gains by cutting into the big safety margin that Toyota programmed into the stock ECU. One TundraSolutions member who does serious towing with a Tundra recently installed a Unichip...if he has no problems in this coming summer's towing season I may also put a Unichip in my Tundra. However, I'm also going to have to assess whether or not I really need to spend yet another $900 or so...it may be that the exhaust mods and regearing have already given me enough oomph for a great towing experience at flying altitudes. But then, I really hate to leave more power just laying on the table.