Power Upgrades for my Runner?

[UFG8R Runner]

So, when I put the 275/60R20's on my Runner, it definitely lost a good bit of power— particularly at interstate speeds. Even in some of the relatively small hills in North Florida on I-75, the Runner has to double-downshift on cruise control to maintain speed at 80.

I make no claims of being an engine expert or engineer, but doing the quick math shows that my tire diameter is about 4.5% larger, which means that my speedometer should be off by about 4.5%, AND and my cruising RPM's at equivalent speed should also be down 4.5% (someone correct me here if I'm wrong).

Now, all of that said...it presents a conundrum. These larger tires have a greater rotational inertia, push more air due to their increased width (60mm larger front end footprint pushing wind), and my RPM's have dropped 4.5%— what I would assume is a very important amount on a V6 not known for stump-pulling low end torque. If anything, adding this greater rotational inertia, weight, and wind resistance should require MORE RPM's to keep equivalent power.

Now, let me be clear: I am not complaining. I really, REALLY like my Runner. I love the way my truck looks, and I think it was worth it— but I still would like to do something to add more power and cut down the gear hunting.

I've thought about gears...possibly 4.10's. Or maybe 4.30's, but I'm concerned they'd really hurt gas mileage on the interstate. Perhaps re-gearing would get the engine a bit higher into the torque curve to compensate for the effective gear reduction from the larger tires. The problem here is that I hear gears are a BEAST on the IFS front end...and I would have to really research to find a truly qualified shop in Florida to do the swap.

SO, FINALLY, Here is where I'm hoping to get some weigh-in: has anyone done any power upgrades they think actually helped? If so, was the cost worth it? Anyone try the URD MAF module, or anything else? Do you guys think I'm on the right track with gears? Any other thoughts?

 

[TOYSTRY]

I wish you the best of luck.....I could use some addt power myself but haven't seen anything worth spending the money on (my TRD CAI was a waste of $$$ btw).

 

[harper7]

So, when I put the 275/60R20's on my Runner, it definitely lost a good bit of power— particularly at interstate speeds. Even in some of the relatively small hills in North Florida on I-75, the Runner has to double-downshift on cruise control to maintain speed at 80.

I make no claims of being an engine expert or engineer, but doing the quick math shows that my tire diameter is about 4.5% larger, which means that my speedometer should be off by about 4.5%, AND and my cruising RPM's at equivalent speed should also be down 4.5% (someone correct me here if I'm wrong).

Now, all of that said...it presents a conundrum. These larger tires have a greater rotational inertia, push more air due to their increased width (60mm larger front end footprint pushing wind), and my RPM's have dropped 4.5%— what I would assume is a very important amount on a V6 not known for stump-pulling low end torque. If anything, adding this greater rotational inertia, weight, and wind resistance should require MORE RPM's to keep equivalent power.

Now, let me be clear: I am not complaining. I really, REALLY like my Runner. I love the way my truck looks, and I think it was worth it— but I still would like to do something to add more power and cut down the gear hunting.

I've thought about gears...possibly 4.10's. Or maybe 4.30's, but I'm concerned they'd really hurt gas mileage on the interstate. Perhaps re-gearing would get the engine a bit higher into the torque curve to compensate for the effective gear reduction from the larger tires. The problem here is that I hear gears are a BEAST on the IFS front end...and I would have to really research to find a truly qualified shop in Florida to do the swap.

SO, FINALLY, Here is where I'm hoping to get some weigh-in: has anyone done any power upgrades they think actually helped? If so, was the cost worth it? Anyone try the URD MAF module, or anything else? Do you guys think I'm on the right track with gears? Any other thoughts?

I've tried most that's out right now and the gains were minuscule.
Headers :toilet:
TRD intake :toilet: Sure is pretty and loud
Muffler :toilet:
Your on the right track with gears ,at least til a supercharger is released.
The problem is ...this ain't no chevy with lots of gearing options. The rear diff is a brand new 8.2 and Nitro just came out with 4:56's three or four months ago to fit it. No other plans for other sizes at the moment that I heard of and I've been in contact with Just Diff's and East Coast Gear for the last month.

The front diff is the same old 8" clamshell design from the past 10 years so no problem with parts.

Your on the right track with gears at least until a supercharger comes out.

That being said, I've been in touch with Chase at ECGS and they are building me a 3rd member and clamshell with 4:56's and ARB lockers at the moment. Waiting for a new 3rd member from Toyota to come in to work with.

I'm running 33's now so a little mpg will be lost but not too much at 70mph and below and even better mpg's around town.The low speed torque should be greatly improved however so it's a tradeoff on the mpg's. Should take away the constant 4th-5th gear hunt that we endure with the 33's .I plan on going to 34's soon anyways as they will be geared very close to stock.

 

[UFG8R Runner]

Wow Harper, great post. Very informative. So just to be crystal clear— there is currently no option for 4.10's on a 2010+ 4Runner?

I was moving in this direction, fully expecting that there would be several brands of 4.10's to choose from.

4.56's will be quite low for my 90% on-road needs (but would be AWESOME off road!). I can't wait to hear your feedback after you build yours up with the ARB and 4.56's— that thing will be a BEAST.

 

[jspagna1]

Just my observations concerning the topic at hand.

I have a 97 4Runner that I bought new. Well we know how much power the 3.4 V6 had that year. Here's what I did to that truck to get more power out of it short of adding a supercharger on it.

K & N CAI
Cut away carpet behind the gas peddle
Took the slack out of the throttles cable.(quicker starts/full throttle)
Removed trailer hitch (less weight)
Took off running boards (less weight)
Removed roof rack (less wind resistance)
Changed to highway all season tire (less weight & rolling resistance)

With only 183 HP, not sure how much of a power gain?
******************************************************************
Now for my 11 4Runner, they only things I have done:
Replaced air filter with a K & N Drop In Filter.
Notched out a piece of the carpet behind the gas peddle.

The only other ideas I can think of is shaving weight from the vehicle somehow.
I don't want to remove the trailer hitch on this truck because it will be obvious that it's missing. I don't want to remove my running boards as my family would not be able to get into the truck. And a CIA I think would be a waste of money as TOYSTRY has already said.
My 11 4Runner is strictly for comfort and a nice ride for those long family trips we will be taking. You can tell I'm 15 years older than when I bought my 97 4Runner!

So depending on your situation, you can try any of the things that I have done in the past. But I think changing the gears on your rig will definitely hurt your MPG's.

 

[UFG8R Runner]

jspagna— thanks for your feedback.

Again, I'm going to go back to my comment about not being an engineer or engine expert...but I wonder if a reasonable gear ratio adjustment will hurt my MPG's at interstate speeds? In other words, an adjustment that gets the RPM's back to factory (or just above factory) levels at highway speeds.

Here's why I question whether it will detrimentally affect MPG's: if the truck is constantly shifting to maintain power, then it isn't in an appropriate torque curve. Wouldn't that mean it's "lugging" and not optimally efficient?

I don't know the answer. But it goes back to the failed theory of many people who buy a 4 cylinder Ford ranger to tow a 4,000 lb trailer, and then realize they get the same 12MPG they would have in a V8 towing that trailer because the engine is lugging.

Just a thought...I really don't know the answer.

 

[1engineer]

jspagna— thanks for your feedback.

Again, I'm going to go back to my comment about not being an engineer or engine expert...but I wonder if a reasonable gear ratio adjustment will hurt my MPG's at interstate speeds? In other words, an adjustment that gets the RPM's back to factory (or just above factory) levels at highway speeds.

Here's why I question whether it will detrimentally affect MPG's: if the truck is constantly shifting to maintain power, then it isn't in an appropriate torque curve. Wouldn't that mean it's "lugging" and not optimally efficient?

I don't know the answer. But it goes back to the failed theory of many people who buy a 4 cylinder Ford ranger to tow a 4,000 lb trailer, and then realize they get the same 12MPG they would have in a V8 towing that trailer because the engine is lugging.

Just a thought...I really don't know the answer.

Let me see if I can shed some light on your challenge. I will try to keep formulas or laws out of it.

You have made changes to your 4Runner that have affected your "drivability." You have added larger diameter tires that are heavier and added to the unsprung weight. This change will hurt you worse around town by constantly having to accelerate this additional weight and not so much on interstate. You have also added wider tires. This will hurt you everywhere due to higher coefficient of adhesion, aerodynamic losses (spidertrax spacers) and higher rolling resistance. The larger diameter tire changes the final drive ratio. You have also added weight to your vehicle with your other mods. This is what you have done, correct?

Now, let's assume that it took you "X" horsepower to go 70 mph on level ground with your stock unmodded 4Runner.
After the mods, it takes "X" + "Y" horsepower to go down the same ground at same speed, where "Y" is additional power required due to mods.

Now, you first mentioned you want to get back the torque you lost. Next you mentioned you don't want to lose the mpg efficiency. You will be breaking many laws of physics if you can figure that one out lol. You see, those mods you made requiring additional power will still be there. You are not willing to get rid of them. Changing gearing will get you back the torque, depending on the ratios. It will not magically give you free power you need to overcome the losses incurred by the mods. A supercharger will give you the power but no efficiency gain there either.

What you have done (and are witnessing by the added downshifting) is moved your vehicle's power requirements higher up the power curve (not torque curve) and the additional shifting is required to meet this power demand. Now if we were talking about how fast you got to 70 mph we would be talking about torque curves. Changing final drive ratios could keep your RPM lower but the power demand is still there. Hope this helps explain and your truck looks great!

 

[UFG8R Runner]

Another great post, thank you 1Engineer. This is why I love this forum.

Informative on all counts, and it sounds like the best option for me at present is some revised gearing (if available, that is). I think you've stated the case that there is no "free lunch" on power...and seeing as how there is no supercharger available yet— and I wouldn't want to void my warranty if there were— then it looks like I should look for gears (if they exist). I am willing to take a reasonable hit on MPG's for a bit more power...I still dream of V8's.

Anyone notice how many "ifs" there were in that last run-on sentence? :toilet3:

Thanks all for your contributions. If anyone has had a positive experience with any power mods, please let us know— I'm still interested in anything that WORKS!

 

[UFG8R Runner]

Uh....Oh

And Antman: Please continue to work on that Cold Fusion mod with 1Engineer so we don't have to suffer the indignity of a power loss to accompany all of our totally awesome upgrades.

Thanks!

 

[03_4x4Runner]

I think it would be a lot cheaper and easier to just put a smaller lighter tire back on it.

 

[UFG8R Runner]

Yea.............no.

This is America, and we always want something better. I love the way my truck looks, I love the added ground clearance, and I wouldn't change a thing.

As much as I love it, I want to make it even BETTER— which is why it's time for a few more ponies under the hood, a little better gearing, or both.

And to be clear, are you suggesting that Antman and 1Engineer would have trouble with a cold fusion mod? CHALLENGE! :banana:

 

[philsey]

Drive it in "S", and wait for the URD S/C. They've had the prototype running since last July (I think). Can't be too far off. Harper will have the first one, he probably already has his deposit down.

 

[4Run4YourLife]

Drive it in "S", and wait for the URD S/C. They've had the prototype running since last July (I think). Can't be too far off. Harper will have the first one, he probably already has his deposit down.

URD told me that they plan on releasing the FJ SC first, then the 4Runner.

 

[smilycook]

It would be cheaper to simply slow down a little. You will save money on gears and your mpg goes up.

Note that the power needed to push an object through a fluid increases as the cube of the velocity. A car cruising on a highway at 50 mph may require only 10 horsepower to overcome air drag, but that same car at 100 mph requires 80 hp . With a doubling of speed the drag quadruples per the formula. Exerting four times the force over a fixed distance produces four times as much work.

 

[1engineer]

It would be cheaper to simply slow down a little. You will save money on gears and your mpg goes up.

Note that the power needed to push an object through a fluid increases as the cube of the velocity. A car cruising on a highway at 50 mph may require only 10 horsepower to overcome air drag, but that same car at 100 mph requires 80 hp . With a doubling of speed the drag quadruples per the formula. Exerting four times the force over a fixed distance produces four times as much work.

So what would be my mpg difference going from 25 mph to 50 mph? According to your statement ( or what you are implying) if you slow down you save gas correct?

 

[phillyd2]

This thread reminds me of the ago old human condition of everybody wanting to go to heaven but nobody wants to die.

 

[Antman]

In my world, it's much simpler. I want more power? I cut a huge hole in my airbox and convince myself that the following happened:

1- more power
2- better sound
3- improved fuel economy
4- satisfaction because it was free

Who's going to argue with me, myself?

You should try my world. It's great!

 

[1engineer]

Contrary to popular belief, I love mods. I don't mod my 4Runner much because it suits me fine the way it is. Back when I was a mere lad I modded the hell out of my vehicles though. My mountain bike on the other hand has been modded a lot. You guys think the TRD wheels cost a lot at $400.00? Go price a Crank Brothers mountain bike 29'er rim. $550.00 - apiece. How about upgrading your rear gearset to Shimano XTR? Or hydraulic dsc brake upgrade to the Elixer taper bore master cylinder? Anything to get me going and stopping better. Anyway, I digress. I do like mods but I try to look at both sides of a mod (advantages/disadvantages) before doing it. I also like the mods for efficiency and performance more so than pure looks. Function before form I always say.

 

[UFG8R Runner]

As a point of clarification, I would like to state that I never said I wanted or expected more power with no correspondent decrease in MPG (but it would be cool!). This thread starts and ends with desiring more power.

I did, however, say that I questioned how much MPG I would lose if I were to keep the vehicle from lugging as much at interstate speeds. 1Engineer gave a concise and well stated explanation of the tradeoffs we can expect.

Of course, I would be asinine if I didn't hope to achieve this added power in the most efficient possible manner, from both a cost and MPG perspective. But I would sacrifice a bit of MPG for a little more pep in it when I step on it.

This thread is also about making something better— not simply about power. I'm not interested in removing the mods I love in order to get the power I desire...I really love my Runner in its current form, and as with so many others on this forum, I love the process and fulfillment of incremental improvement. I hope to continue to improve the truck to perfectly suit my needs and desires, and I'm willing to make the cost commitment to reduce my compromise in other areas (notably, power, performance, and looks).

Which brings us back to the original question— if anyone has done anything they truly believe has added power (and believe it was worth the investment), I'd love you to weigh in.

:snacker:

 

[03_4x4Runner]

You can do what I am doing. Wait until they put a V8 in the 4runner again and buy it.