I have a 3rd gen Tacoma with a Swift full camper. Stock tires but would like to step up slightly in size. The power is inadequate both from a dead stop and highway. Downshifting to 4th and even 3rd on the interstate is often necessary. The orange virus tune helped a tad but not IMO as much as the forums raged about. My main question is how much would a regear help? I can see some value with dropping first gear lower but above that can it do anything that shifting behavior would not do(manual trans)? Would $2,200 (local quote for g2) be spent better elsewhere? Should I just rev the hell out of it and get over it? Assuming a catback exhaust and intake would improve it nominally.
To regear or not
- Thread starter Frstnflt
- Start date
rubberlegs
back country campers
Have you weighed your truck/camper? This would not affect highway power much, but would affect from a dead stop.
Ace!
Gone Traveling
Re-gearing provides more torque, so it can be of great benefit, possibly at all speeds (your RPM will be higher at any given speed). I've regeared one or two vehicles and it was money well spent. I'm considering it for my full-size that has 4.30 gears. If you do go off road it is also a great time to add a limited slip or locker since the differential is already open. You can add a limited slip to the front differential, a TrueTrac. It is gear based and does not give the feedback that clutch-based limited slips do in the front. They are very driver friendly and provide a great deal of traction over the open differential.
I am surprised that you think it is inadequate. I have a 2016 Tacoma (v6) with a Fleet Flatbed (heavier than your Swift) and have no issue with power. It is no sports car, but can keep up with traffic with no issues. I can cruise at 80 on the flat interstate (although I don't), maintain at least 60 up the steeps grades to the Eisenhower tunnel on I-70.
One thing to realize is that the 2GR-FKS is a modern high revving engine, peak power (278hp) is near 6000rpm and peak torque is near 4500 rpm, so expect to be revving high when you are pushing it. It takes some getting used to.
One thing to realize is that the 2GR-FKS is a modern high revving engine, peak power (278hp) is near 6000rpm and peak torque is near 4500 rpm, so expect to be revving high when you are pushing it. It takes some getting used to.
If peak torque is at 4500, then that is where you want to be when climbing up hills. It might not be right at the max efficiency for that engine, but it might close! If a regear helps you you be at around that RPM more often, then that's a good idea.rando said:
FYI, many a Honda S2000 and Miata spend most of their time well above 4000 RPM, and run many hundreds of KM/miles that way. High revving engines really don't mind it.
ntsqd
Custom User Title
If you do go off pavement I would caution against anything like a K&N air filter, in any form. Contrary to what their marketing might imply those are not used in desert racing except by those who are sponsored by them. And for good reason. They allow grit past them. I've experienced this first hand, it is not some internet legend. Nothing that I tried, the usual tricks for sealing an air filter like greasing the rubber seals etc., would stop it. Moved to a paper element and the grit stopped.
It does take some getting used to sustained reving of an engine to what for an older V8 would be near redline.
I've re-geared two trucks and drove one that had been re-geared prior to my buying for 125k miles. I consider the proper axle gearing for the use and tire size to be one of the most important mods that can be made. Some sort of rear Traction Adding Differential should be considered while the axle is opened up. This is probably the second most important mod for off pavement travel. A TAD in the front comes with some undesirable complications, I wouldn't do it under a truck intended to carry a camper unless you plan to go rock-crawling with the camper.
It does take some getting used to sustained reving of an engine to what for an older V8 would be near redline.
I've re-geared two trucks and drove one that had been re-geared prior to my buying for 125k miles. I consider the proper axle gearing for the use and tire size to be one of the most important mods that can be made. Some sort of rear Traction Adding Differential should be considered while the axle is opened up. This is probably the second most important mod for off pavement travel. A TAD in the front comes with some undesirable complications, I wouldn't do it under a truck intended to carry a camper unless you plan to go rock-crawling with the camper.
Having driven a few vehicles that love to rev, I like this topic! Granted my current 8.1L does not like nor need to rev much, however here is what I dug up on this engine:
http://www.exploringoverland.com/overland-tech-travel/2015/8/20/the-new-tacomas-new-engine
https://en.wikipedia.org/wiki/Toyota_GR_engine
http://www.toyotareference.com/guts/tacoma16_engine.pdf
This post is informative as it points out that from 2300 RPM up the engine has good torque with about a 10% bump up centered around 4800. The BSFC Map appears to show max efficiency around 2000 RPM when under load, and a huge high efficiency range from 1200 to 3600 RPM when not (I think that is what it is showing).
https://www.tacomaworld.com/threads/2016-tacoma-dyno-torque-hp-crve.391512/page-6#post-11154522
FYI, stock Miata's are quiet happy at 4000 RPM at highway cruise getting 35 mpg doing so. The flat roller 347 stroker I stuffed into my Miata was cammed to come alive over 2600RPM and redlined at 8200, and cruised at 3K at 75mph. It got 30 mpg while doing that.
http://www.exploringoverland.com/overland-tech-travel/2015/8/20/the-new-tacomas-new-engine
https://en.wikipedia.org/wiki/Toyota_GR_engine
http://www.toyotareference.com/guts/tacoma16_engine.pdf
This post is informative as it points out that from 2300 RPM up the engine has good torque with about a 10% bump up centered around 4800. The BSFC Map appears to show max efficiency around 2000 RPM when under load, and a huge high efficiency range from 1200 to 3600 RPM when not (I think that is what it is showing).
https://www.tacomaworld.com/threads/2016-tacoma-dyno-torque-hp-crve.391512/page-6#post-11154522
FYI, stock Miata's are quiet happy at 4000 RPM at highway cruise getting 35 mpg doing so. The flat roller 347 stroker I stuffed into my Miata was cammed to come alive over 2600RPM and redlined at 8200, and cruised at 3K at 75mph. It got 30 mpg while doing that.
craig333
Riley's Human
That'd be hard to get used since my Jeep redlines at 3000 and the diesel even less 
JHanson
Senior Member
Frstnflt,
You actually answered your own question.
As you surmised, installing higher numerical diff gears would give you some extra pull in first gear with your manual transmission. Beyond that, all it's going to mean practically is that in each gear the engine will be turning slightly (depending on how drastic you go) higher rpm. So you might wind up in a situation where you might be doing, say, 70mph in 6th gear at 3,000 rpm, where with your stock gearing you'd be doing the same speed at the same rpm in 5th gear. But so what? The engine doesn't care what gear you're in.
Furthermore, both your fifth and sixth gears, IIRC, are overdrive gears, and thus slightly weaker than the 1:1 or "underdrive" gears. Pulling a load up a hill the transmission is better off in the lower gear. The simple fact is, as was mentioned, these engines produce their highest torque (not to mention horsepower) at absurdly high rpm, and you need to keep the engine up in that region to get the best power.
Also, remember that a higher numerical ring and pinion is weaker than a lower one. It's been argued ad nauseam how much this affects durability and reliability, but the indisputable fact is that a 4.56 r&p is weaker than a 4.11 r&p, and a 4.88 or 5.29 are weaker yet.
If you plan to install taller tires the equation shifts a bit, and re-gearing will compensate somewhat for the added diameter. But you'll still be weakening your diff, and compounding that stress with the added rotational inertia and mass of the larger tires.
You actually answered your own question.
As you surmised, installing higher numerical diff gears would give you some extra pull in first gear with your manual transmission. Beyond that, all it's going to mean practically is that in each gear the engine will be turning slightly (depending on how drastic you go) higher rpm. So you might wind up in a situation where you might be doing, say, 70mph in 6th gear at 3,000 rpm, where with your stock gearing you'd be doing the same speed at the same rpm in 5th gear. But so what? The engine doesn't care what gear you're in.
Furthermore, both your fifth and sixth gears, IIRC, are overdrive gears, and thus slightly weaker than the 1:1 or "underdrive" gears. Pulling a load up a hill the transmission is better off in the lower gear. The simple fact is, as was mentioned, these engines produce their highest torque (not to mention horsepower) at absurdly high rpm, and you need to keep the engine up in that region to get the best power.
Also, remember that a higher numerical ring and pinion is weaker than a lower one. It's been argued ad nauseam how much this affects durability and reliability, but the indisputable fact is that a 4.56 r&p is weaker than a 4.11 r&p, and a 4.88 or 5.29 are weaker yet.
If you plan to install taller tires the equation shifts a bit, and re-gearing will compensate somewhat for the added diameter. But you'll still be weakening your diff, and compounding that stress with the added rotational inertia and mass of the larger tires.
On flat highway at 65-75 somewhere between 1800 - 2200rpm in 6th/5th. The gearing is tall in 6th, but the auto downshifts quickly for hills. Heading up a steep hill on the highway (the passes on I-70 for instance), you will quickly drop down to 3rd/4th and be at 5000 rpm, but it will hold 65 no problem. The 3rd gen Tacoma has about 20% more power than the 2nd gen (and better fuel efficiency to boot), but that power is at a higher rpm. I don't think regearing is going to buy you much.cwdtmmrs said:
Also an intake and exhaust will primarily just make it uncomfortable (loud) to drive at high rpm without any real gain in power.
So Cal Adventurer
Senior Member
- Joined
- Nov 7, 2017
- Messages
- 368
Best Explanation of gearing i've read in a log time, and spot on!JHanson said:
Is this the Jonathan Hansen that gave me a copy of his Outdoor Photography book (which i still proudly have) when i met him in AZ with Scott Brady 10+ year ago???
Big tall bald ugly Kevin (that raced the baja 1000 in an 80 series) and was copartner in Baja Overland before it became a buzzword.
The weight isn't much of a factor on the flats as you are not accelerating or pushing the weight up hill. I think wind resistance is the primary issue on the flats - not that the Cd is all that good with the double thickness cab over.
Keep this in mind if the plan is to go larger with the tires and regear. One kind of negates the other. The larger diameter tire acts like a an OD gear slowing the engine speed for the same road speed with the same gearing.
Playing around with an online gear calculator to see where you would need to be to maintain stock like feel with larger tires.
https://www.crawlpedia.com/calculators.htm
The ring and pinion calculator is a good way to see what you have, input the new tire size you want to run and it will suggest the ratio to compensate for the increase in tire size. Meaning it's going to behave like stock, but not really add too much extra torque over what is compensating for the larger tires. I'd suggest if you want more power (at the expense of highway cruise RPM) to take what the caluclator says for larger tires and step up to the next higher numerical ratio available. If it say recommends 4.10's, go to 4.56's, or if it recommends 4.56's, jump to 4.88's.
Like others have indicated the higher numerical ratios do have some strength issues as the pinion gear looses teeth at the numerical ratio increases. But, sticking with good quality gears and professional setup should keep things lasting.
One thing not really discussed (I'm surprised too) is the aero drag from these campers. I noticed it big time with mine. I'm running a 5.3 Vortec in my K5 with a FWC and it made a huge difference in mileage and power. Pre-camper the 5.3 pushed my K5 around Colorado with 4.10 gears and 35" tall tires without too much issue. I was averaging 15-16 MPG on the highway too. I put the camper on and I noticed aero drag requiring more throttle to overcome the wind. Throw an uphill grade and it got worse. My tire size was great for keeping my cruise RPM lower even with the 4.1's, but the RPM was low enough I was almost 1000 RPM or better below peak torque. It caused sooner downshifts to maintain speed and keep the RPM closer to peak torque.
I've felt the drag when driving into the wind to be so much I had to downshift to 3rd and leave it there until the winds calmed. What this means is if you do plan on re-gearing, use a gear calculator and go the next gear up from the target to gain a little torque on top of the tire size change.
I could use to move to 4.56's in mine to compensate, but I'm going to install a 7.4L big block to overcome the lack of low end torque from my 5.3. The peak torque is lower and comes in sooner so it will limit my need to spin the engine to the moon to build the torque needed to get the truck/camper rolling down the road. Granted swapping engines isn't a realistic idea on a late model Toyota, but bump in gearing will help a lot. You will continue to rev the engine too the moon though.
Playing around with an online gear calculator to see where you would need to be to maintain stock like feel with larger tires.
https://www.crawlpedia.com/calculators.htm
The ring and pinion calculator is a good way to see what you have, input the new tire size you want to run and it will suggest the ratio to compensate for the increase in tire size. Meaning it's going to behave like stock, but not really add too much extra torque over what is compensating for the larger tires. I'd suggest if you want more power (at the expense of highway cruise RPM) to take what the caluclator says for larger tires and step up to the next higher numerical ratio available. If it say recommends 4.10's, go to 4.56's, or if it recommends 4.56's, jump to 4.88's.
Like others have indicated the higher numerical ratios do have some strength issues as the pinion gear looses teeth at the numerical ratio increases. But, sticking with good quality gears and professional setup should keep things lasting.
One thing not really discussed (I'm surprised too) is the aero drag from these campers. I noticed it big time with mine. I'm running a 5.3 Vortec in my K5 with a FWC and it made a huge difference in mileage and power. Pre-camper the 5.3 pushed my K5 around Colorado with 4.10 gears and 35" tall tires without too much issue. I was averaging 15-16 MPG on the highway too. I put the camper on and I noticed aero drag requiring more throttle to overcome the wind. Throw an uphill grade and it got worse. My tire size was great for keeping my cruise RPM lower even with the 4.1's, but the RPM was low enough I was almost 1000 RPM or better below peak torque. It caused sooner downshifts to maintain speed and keep the RPM closer to peak torque.
I've felt the drag when driving into the wind to be so much I had to downshift to 3rd and leave it there until the winds calmed. What this means is if you do plan on re-gearing, use a gear calculator and go the next gear up from the target to gain a little torque on top of the tire size change.
I could use to move to 4.56's in mine to compensate, but I'm going to install a 7.4L big block to overcome the lack of low end torque from my 5.3. The peak torque is lower and comes in sooner so it will limit my need to spin the engine to the moon to build the torque needed to get the truck/camper rolling down the road. Granted swapping engines isn't a realistic idea on a late model Toyota, but bump in gearing will help a lot. You will continue to rev the engine too the moon though.
JHanson
Senior Member
Wow, that would be me, although I don't recall you being ugly!So Cal Adventurer said:
Technique aside, that book is about as outdated as can be these days. I believe I discussed something called "film."
knoxswift
Senior Member
Late to the discussion but I can add that this is one of the best Gear Ratio calculators out there on-line:
http://www.grimmjeeper.com/gears.html
If they don't have your trans you can enter your own numbers.
This calculator was dead on perfect for when I did my re-gear in a 2nd Gen Tacoma. (Tacoma with 33' tires, Manual Tras and an Eagle FWC).
My 2c re-gear if changing tires and go slightly higher on the RPMs when doing so from stock. Also quite frankly Toyota should of had a 4.10 option in these newer trucks (Stock tire size) but I think EPA/MPG is why they don't have more aggressive gearing...
http://www.grimmjeeper.com/gears.html
If they don't have your trans you can enter your own numbers.
This calculator was dead on perfect for when I did my re-gear in a 2nd Gen Tacoma. (Tacoma with 33' tires, Manual Tras and an Eagle FWC).
My 2c re-gear if changing tires and go slightly higher on the RPMs when doing so from stock. Also quite frankly Toyota should of had a 4.10 option in these newer trucks (Stock tire size) but I think EPA/MPG is why they don't have more aggressive gearing...
Most truck manufacturers have moved away from deep gearing in the axles in favor for higher gear count transmissions. 6-speeds are the norm when 4-speeds used to be for automatic transmissions. Now the 8-speed is getting more common and 10-speeds are right behind them. GM (what I'm used too) dropped 4.10's in half tons many years ago and made 3.73's the normal when you wanted a "towing" gear ratio. With the 6 and 8 speed transmissions now, GM has dropped to 3.42's as the deepest gearset you can get in a 1/2 ton truck.
Why? Normally the 6, 8 and 10 speed gearboxes are coming with deeper gearing in 1st, 2nd and 3rd. By combining deep 1st gear ratios and a mild axle ratio like 3.42's they still are getting a similar ratio to the older stuff with a lower numerical first gear and higher numerical axle gear. The bonus is better gear splits that keep the high revving engines working in the right RPM range for optimum torque. Then once the truck is up to speed, the lower numerical axle ratio allows for an even lower cruise RPM to sip fuel.
It's not uncommon to see the new GM 1/2 tons with a 6 or 8 speed transmission cruising at 65 mph with the engine RPM below 2,000. The downside is the need to make multiple gear downshifts when the need for more power is required. 6 to 4 downshifts are the norm and if you aren't ready for it kind of surprising when the engine goes from 1700 rpm to 5000 rpm as quick as you can snap your fingers.
Why? Normally the 6, 8 and 10 speed gearboxes are coming with deeper gearing in 1st, 2nd and 3rd. By combining deep 1st gear ratios and a mild axle ratio like 3.42's they still are getting a similar ratio to the older stuff with a lower numerical first gear and higher numerical axle gear. The bonus is better gear splits that keep the high revving engines working in the right RPM range for optimum torque. Then once the truck is up to speed, the lower numerical axle ratio allows for an even lower cruise RPM to sip fuel.
It's not uncommon to see the new GM 1/2 tons with a 6 or 8 speed transmission cruising at 65 mph with the engine RPM below 2,000. The downside is the need to make multiple gear downshifts when the need for more power is required. 6 to 4 downshifts are the norm and if you aren't ready for it kind of surprising when the engine goes from 1700 rpm to 5000 rpm as quick as you can snap your fingers.
ntsqd
Custom User Title
As an aside, I've never understood why over-drives. Why not make top gear 1:1 with deeper 1st gears and taller axle ratios? End up in the same place, but now top gear doesn't have the parasitic losses of extra bearings & gears under load.
CVT's are really what it will come down to. Infernal Combustion Engines run the best when they are tuned for one RPM. As soon as you ask them for a power range or band efficiency and economy of operation decrease. The wider that band, the less efficient the engine is within that band. To say nothing of when operated out of that band.
CVT's are really what it will come down to. Infernal Combustion Engines run the best when they are tuned for one RPM. As soon as you ask them for a power range or band efficiency and economy of operation decrease. The wider that band, the less efficient the engine is within that band. To say nothing of when operated out of that band.
