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Thread: Tacoma Regear or Supercharge?

  1. #1
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    Default Tacoma Regear or Supercharge?

    I am a new owner of a 2012 Tacoma. As some of you may know I am building the Tacoma as an overlanding rig. After discussing gearing in some other threads gearing-and-255-85-tire several Tacoma owners have elected to gear 4.56 or 4.88. This gearing gets the 4.0L in the 2500-2700rpm range,at 75mph, where the 4.0L develops about 175-190 ft lbs of torque. This seems to be the sweet spot for the 4.0L.

    I like to run 85mph across the flatlands of Kansas and Nebraska which at 4.56, or 4.88 gearig, puts my engine speed above my self imposed limit of 2600rpm.

    I found a dyno curve of a TRD supercharged 4.0L. The Dyno curves appear to turn the supercharged 4.0L into a low end torque machine. Essentially a supercharged 4.0L develops 270 ft lbs of torque at 2000 rpm. (see curves below)

    My question, what is the opinion regarding supercharging instead of regearing? Could I have the quiet, low reving, economies during flatland highway travel at 85mph while kicking in the supercharger when the torque and power is need to climb grades, at altitude, while towing the Chaser?

    I'd also like to hear the experiences of TRD supercharger users regarding maintenance and reliability of the supercharger.

    Here are the dyno cuves I found on TacomaWorld.com and CustomTacos.com

    Tacoma '07 Dyno Curve.jpg1GR-FE SC with Longtubes copy.jpg

    RPM curves of various gearing options:
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    2011 Rubicon JKU, Mango- Hemi-ized and built for the rocks
    2012 Tacoma DC SB OffRoad- White- Expedition minded rig
    2013 Adventure Trailer Teardrop Customized Front Storage
    2011 Adventure Trailer Chaser- SOLD March 2013

  2. #2
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    Another great thread on the subject:
    http://www.expeditionportal.com/foru...ger-or-regear?

    Its obviously aimed at the 1st generation Tacoma's but the logic is the same, my today would be identical to those I posted last summer. Still happy as a clam with my TRD SC and no reason to re-gear.
    Kurt Williams
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    Your original outfitter for OME - ARB - AA - Safari - Helton - Engel - Since 1992
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  3. #3
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    Default More questions

    Quote Originally Posted by cruiseroutfit View Post
    Another great thread on the subject:
    http://www.expeditionportal.com/foru...ger-or-regear?

    Its obviously aimed at the 1st generation Tacoma's but the logic is the same, my today would be identical to those I posted last summer. Still happy as a clam with my TRD SC and no reason to re-gear.
    Thanks for the reply and the link. I read the thread. Many say "re-gear" and don't give much reasoning behind their decision. (Cruiseroutfit excepted.) I was hoping for a little more technically backed debate.

    Folks seem to be regearing to 4.88 to put the engine in the torque range of 175-190 ft-lb range (2400-2700rpm) at 70-75mph. If this is true, why is the supercharger being dismissed when it acheives the same torque at 1700-1800rpm? Cost, maintenance issues, need lower gearing on the trail, gears are easier to install, etc.?

    My Tacoma is an overland type build and DD. My guess is that 80% of the time will be spent on highways, roads and unmaintained roads. 20% of the time will be spent on trails, with only a small portion of that on truly technical terrain.

    WHY isn't a supercharged engine that has the ability to produce tons of low end torque, as needed, desired over regearing?

    Loads, speed, and power applied being equal, does a supercharged engine running at 2,200 rpm burn less fuel than a normally aspirated engine running at 2,700 rpm? Or is it simply, that for an engine to move a particular load, X, requires Y amount of fuel to be burned, regardless of engine rpm?

    Don't get me wrong, I'm not against regearing. (after all I have hemi in the Jeep and it's geared 5.13) I'm simply in the process of trying to figure out what is best for me, doing my due diligence, looking at all my options, and thinking out the build before I get too far down this path.

    Thanks for any light you can shed on the subject.
    Last edited by mvbeggs; 01-23-2012 at 05:23 PM.
    2011 Rubicon JKU, Mango- Hemi-ized and built for the rocks
    2012 Tacoma DC SB OffRoad- White- Expedition minded rig
    2013 Adventure Trailer Teardrop Customized Front Storage
    2011 Adventure Trailer Chaser- SOLD March 2013

  4. #4
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    Well, for one thing the torque multiplication on a gear swap happens in the rear diff so the transmission and T-case are spared the extra stress. With the SC, the torque boost is coming at the engine, everything behind it is stressed. The engine itself is stressed. I can't say how much of a real world problem that is with the stock drivetrain. I would guess the 6 spd would handle it better. It is certain to need more maintenance and attention. If you are just using it for cruising, with common sense, it may be a nonissue. The problem really is your requirement for 85 mph and 2,600 RPM with a 4 liter engine, on a rig that still has to be trail capable. Too many divergent variables for calculus. You may need to resort to quantum physics (or maybe metaphysics LOL).

    There is another possibilty that might be worth checking into, and that is an add on overdrive. I ran one on another rig for many years without issues. The one I had was a Gear Vendor OD. I had 5.36 gears in that rig and could easiy do 70 on the hiway. I have no idea whetter there are any applications for the 05+ taco.

  5. #5
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    For an overland rig I want to keep the drive train as reliable as possible. Re-gearing the diffs would effect the total stock configuration of the drive train the least so I would go that rout.Seems like adding more stuff means you have added more things that can maybe fail, witch would require you to need to bring more spare parts(more wight).How easy is it to find belts and pulleys for these? Like you asked above I would question how the SC would effect you fuel consumption. After all the idea is to travel long distances to see and explore cool stuff, these trucks don't have the largest range already so taking even more away means bringing more fuel(more weight). If I had to choose between 70mph and the possible loss of reliability and range with the SC to run 85mph, I would just drive slower overall it wont take that much longer to get there.
    On the other side the TRD SC is Toyota. And if it were installed on a new truck I would hope that it would carry the same reliability as the rest of the truck. (That is why you got a Toyota right?) I could see that if driven with a soft foot that the extra fuel needed to keep up with the SC could be kept to a minimum.

    All in all the added power is great if you can still keep the reliability and range. But if you compromise those on a overland rig then no amount of added power is worth it.
    Gordon

    1997 FZJ80 40th and locked "Oh my god I finally did it!"
    My FZJ80 Overland Build

  6. #6
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    Quote Originally Posted by NM-Frontier View Post
    ...On the other side the TRD SC is Toyota. And if it were installed on a new truck I would hope that it would carry the same reliability as the rest of the...
    That is kinda where my thoughts lie on the system, I've seen far more issues with aftermarket r&P setups (most often install error) than I have with TRD SC's, in fact I can't really think of an instance where the modern TRD SC's have left anyone stranded. The belts are available at any Toyota dealer and I suppose you could match it up easy enough aftermarket, I carry a spare behind my seat along with the other belts. Other than that there are no real maintenance issues to speak of. Re-do the oil ~120k, beyond that?

    Likewise a good gear install can be equally as trouble & maintenance free.

    I think it really comes down to a budget and the intended returns. The SC isn't going to give you the low speed crawl abilities off-road particularly in 4-low, and the gears are not going to get you the top end up a canyon
    Kurt Williams
    Cruiser Outfitters
    Your original outfitter for OME - ARB - AA - Safari - Helton - Engel - Since 1992
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  7. #7
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    Default More-

    Downhill, glad to see you got in on this!

    Lots of good points here. As many of you have pointed out, mechanical reliability is #1.

    Like cruiseroutfit mentioned, I also assumed the TRD SC is a Toyota factory engineered and integrated product for the Tacoma. Toyota's extension of the factory warranty for a "dealer" installed SC tended to reinforce that assumption.

    Replacement belts really don't concern me as I carry spares anyway. I could lump a pulley into the spare parts bin as well.

    Driving slower on the highway isn't a problem when it's just me and the wife. The problem arises when I'm traveling with others that can run 85 down the highway. I don't like to be the slow wagon in the wagon train.

    The near vertical torque curve on the TRD SC dyno chart really caught my attention. (i.e. 85% of the total torque made before 2000 rpm) I started thinking the SC might be an answer to my 15-16mpg, 2600rpm/85mph highway cruise speed, trail capable, vehicle. (withouth having to resort to downhill's suggested quantum physics solution. ) If the drivetrain is up to the task, it sure would be nice to be able to fly down the highway < 2600 rpm.

    I'm not worried about not having the low speed crawl, in 4LO, afforded by lowering the gearing. I don't think this rig will see that much technical terrain. That's what the Jeep is for. The Tacoma will be used more for hunting type trips. I do need the Tacoma to be able to run high altitude passes pulling the Chaser.

    Cruiseoutfit, what is your setup? (i.e. vehicle, tires, armor, gearing, etc.) What kind of gas mileage are you getting?

    Thanks for everyon's input.
    2011 Rubicon JKU, Mango- Hemi-ized and built for the rocks
    2012 Tacoma DC SB OffRoad- White- Expedition minded rig
    2013 Adventure Trailer Teardrop Customized Front Storage
    2011 Adventure Trailer Chaser- SOLD March 2013

  8. #8
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    In an Apples to Oranges example, I have a local Jeep Rubicon that I look after from time to time, they installed a SC without regearing, then went about adding bumpers, taller tires, winches and every other gizmo they could find. Then they wondered why it was sluggish on the highway, got lousy gas mileage and kept throwing computer codes even with a programmer.

    Your SC would be better tuned to your Tacoma so maintenance and compatibility would not be a problem, but unless you know and weight everything you will possibly add to the truck in the future (plus the additional wind drag), your projections of RPM and speeds and fuel mileage are going to be shortsighted. As mentioned the stress on the rest of your drivetrain is going to become compounded with the growing need for RPMs of the SC, you will begin to have to really weight any additions to the truck versus your goals.

    The gears would put less stress on fewer drivetrain parts, and if you go to an even lower ratio like the 4.88s then you could always add a taller tire or (kind of more weight) to bring you down to the numbers you are trying to hit, so almost an excuse to add more stuff
    00 Jeep Wrangler 4banger
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  9. #9
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    I think you'd have to burn high-octane fuel with the SC. I'm a fan of re-gearing. My previous rig was a turbo diesel and I always locked in the speed limit, wagon train be damned.

  10. #10
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    Quote Originally Posted by mvbeggs View Post
    Or is it simply, that for an engine to move a particular load, X, requires Y amount of fuel to be burned, regardless of engine rpm?
    This is what I would consider the more accurate statement... There's no such thing as free power. You might be turning more rpm's with lower gearing, but you're not going to need as much pedal. That said, the supercharger does add good low-end torque. Sorry for not helping.
    -Mark
    '03 2.7L 4x4 Tacoma & '06 Xterra 4x4

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