4.56 gears better than 4.88 if used a lot on the freeway?

[jeff88]

The MAF sensor calibrator unfortunately won't gain a whole lot of power. You might be able to richen a little bit to gain power while stock but it's not going to blow your socks off. I have a MAF sensor calibrator that I use on my engine but it's supercharged. The real culprit is atmospheric pressure and the lack of oxygen. At sea level, that's 14.7 PSI. At 8000 ft, it's only 10.9 PSI! That's a whole lot less oxygen in your engine making it much slower. Add 500 lbs of people and gear and it's getting even slower. Not much to be done about that.

I'm not expecting a 10 second car out of the calibrator just trying to be able to get up a damn hill! :lmao:
Seriously though, if I can just get a little more power so the trans isn't hunting all the time then it's a mod worth every penny to me. Plus I figure if I get a charger one day I'll need the calibrator anyway so it's one less thing to buy at that point if I already have it.

 

[Option01]

I wouldnt be too concerned about the higher rpm in 3rd gear for shorter period of times. It's not going to make much of a difference on wear. These engines can easily take it. I'm pretty sure I would have been disappointed with 4.56 gears.

I was in the same situation when upgrading gears, while I'm in there, I'll just throw in a front locker at the same time and be duel locked for those situations where I will need one. Well that day never really happened. It's purely subjective and in my case there wasn't any need for a front locker. These rigs are capable with a rear locker and honestly I dont put myself in situations where I need to be double locked since I solo overland most times and it's not the ideal situation to grenade the front end in the middle of nowhere. IFS doesn't play nice with a locked front if you are not careful. Hell, when I lock my front, going straight and turn slightly on dirt road you can feel the tension in the front end. You can accomplish a lot with a open diff or just a rear locker. If you are doing a lot of wheeling right now and consistantly getting stuck with open diffs, then I can see improving your rig by adding lockers to get you further down the trail. I never hit the limitations of my driving with a rear locker, even most of the time with open diffs.

I read multiple threads on being fully locked and most of them basically said the same thing, but I was wanting it and I tried justifying it. I suppose that's how you gain experience. At least I know that I dont need a front locker to support my needs now, though it was an expensive lesson which that could have gone into other upgrades. Your needs may be different though that warrant a front locker.

Skid plates/sliders/bumpers have saved my bacon more than my lockers.

Well, no offense but if you've got the supercharged/pully/injector and are still not satisfied with the performance then I'm not surprised that you would have been disappointed with the 4.56

Honestly, I think I'm overly concerned about high RPMs after driving a 95 Celica GT for 12 years. If you have any experience with the 2.2L 5sfe motor, you know it doesn't love high revs and yet the 5 speed gearing put it a 3000rpm at 65rpm. I did a lot of commuting in that car and was always exhausted upon arrival after the excessive noise/vibration so I guess that makes me a little gun-shy lol.

Regarding the lockers, I see what you're getting at. Having one in the front didn't necessary hurt anything but considering the risk of damage (if used) plus never actually needing it made it feel like a waste of money in hindsight. I agree that with good tires and rear locker, my 4Runner should be very capable but I do use it for overlanding in the snow and I would assume a front locker would be more useful in that situation and would be less stressed. I'm thinking it would help with getting through a difficult section of snow as long as I could do so going straight. I obviously don't want to grenade the front diff but I only do that kind of wheeling in a group so at least I wouldn't be stranded if something catastrophic did occur.

 

[Option01]

Limited slip in the front is also a good compromise...

Its funny because I actually started off planning to do a Truetrac LSD in the front. However, a friend added LSDs to the front and rear of his old Chevy truck as part of a substantial upgrade (big lift, huge tires, converted 2WD to 4WD etc) and once he got stuck in the snow, those LSDs acted like open diffs. Not sure what brand/type he had but my limited understanding is that LSDs need at least a little friction on both wheels to work so if one wheel is lifted or just spinning in slushy snow/ice, the other wheel will get zero power.

As I mentioned above, we do a fair amount of overlanding in the snow so that was my reasoning for doing a front locker. However, none of the guys in our group actually has one so I don't know if it will actually be as useful or as easy on the differential as I'm hoping for that kind of application.

 

[Option01]

This is the 4Runner mecca of Norcal for sure. Lots and lots of us around here!

I do plan to still drive it on freeways. I had a custom exhaust done a few years ago and it is pretty loud around 2000-2200 RPM. Increasing the RPM will actually make it quieter... and yes, the goal is aggressive. I hope to get this sucker on a 1/4 mile track when it's all done.

Oh dang! I just saw your signature... 325hp!! I'm curious to hear what kind of quarter mile times you can get with that.

 

[Option01]

Looking at the power/torque curve of the 5VZ-FE engine, it appears that at 65mph in 4th gear, there is almost no change to torque output when applying my new tires and a 4.88 gear ratio (thanks to the super flat section of the curve at those rpms). Thus, horsepower gets only a minimal increase from roughly 80hp to 85hp.

However, when you look at the same vehicle speed in 3rd gear, there are some much more substantial increases. Torque bumps up from 207 to 218 with the new tires/gears and horsepower jumps from 82 to 100. That's almost 22%!

I see now why so few people go with the 4.56 ratio. With such a flat torque curve, you really need to get those rpms up to generate more power.

**EDIT** Here's a zoomed in version marked up to better illustrate what I'm describing
<a href="https://ibb.co/rxRwBf7"><img src="https://i.ibb.co/fkzx3G1/Untitled.jpg" alt="Untitled" border="0"></a>

 

[gamefreakgc]

I see now why so few people go with the 4.56 ratio. With such a flat torque curve, you really need to get those rpms up to generate more power.

Tell me about it! That's been my fight from day one. My engine makes plenty of torque (~400 at the crank) but the transmission wants to drop the RPM down really low and make very little power. The O/D button on the shifter is your friend, don't be afraid to just keep it off and let it turn at closer to 3000 RPM. Also, keep ECT Power on non-stop, every day. It does make a difference. That's essentially what I'm after with the regear, making 4th gear closer to 3rd. I made this graph a while back to visually represent each gear and the top speed of each. Look especially at how the 5-speed transmission is geared and how much more torque multiplication it has due to shorter gears. The red line is our speed governor.

 

[Bad Luck]

Tell me about it! That's been my fight from day one. My engine makes plenty of torque (~400 at the crank) but the transmission wants to drop the RPM down really low and make very little power. The O/D button on the shifter is your friend, don't be afraid to just keep it off and let it turn at closer to 3000 RPM. Also, keep ECT Power on non-stop, every day. It does make a difference. That's essentially what I'm after with the regear, making 4th gear closer to 3rd. I made this graph a while back to visually represent each gear and the top speed of each. Look especially at how the 5-speed transmission is geared and how much more torque multiplication it has due to shorter gears. The red line is our speed governor.

That graph is awesome! What gearing is shown with the 5 speed transmission? What rpm's did you use for the top speed in each gear?

 

[Option01]

Tell me about it! That's been my fight from day one. My engine makes plenty of torque (~400 at the crank) but the transmission wants to drop the RPM down really low and make very little power. The O/D button on the shifter is your friend, don't be afraid to just keep it off and let it turn at closer to 3000 RPM. Also, keep ECT Power on non-stop, every day. It does make a difference. That's essentially what I'm after with the regear, making 4th gear closer to 3rd. I made this graph a while back to visually represent each gear and the top speed of each. Look especially at how the 5-speed transmission is geared and how much more torque multiplication it has due to shorter gears. The red line is our speed governor.

Awesome! Looks like the 5.29 ratio would give you something similar to the 5-speed without the overdrive gear. Would be interesting to hear from the 5-speed guys about how they'd feel driving without their fifth gear.

 

[Option01]

Just a thought before you go down the gearing rabbit hole, what is the condition of your spark plugs and is your transmission cable that is attached to the throttle body adjusted properly?

My 99 had issues initially when I bought it also. In fact I bought it cheap because it didn’t run well. Wouldn’t maintain gear going down the road and just struggle the high speed. The throttle cable wasn’t adjusted right, and the throttle only opened about 70%. The the trans cable was wrongly set. And the plugs were worn to about 3 times the gap they needed to be.

Wow, thanks again for this recommendation! I had some time to look under the hood today and sure enough, there was a good deal of slack in the throttle cable. It seems the rubber bushing where the cable connects to the accelerator petal was split/destroyed. I tightened the cable via the adjustment section near the throttle body but haven't had a chance to test it out on the road yet. Assuming everything runs okay, I'm now wondering if it's even worth the hassle of replacing the cable.

 

[Romeo1]

Wow, thanks again for this recommendation! I had some time to look under the hood today and sure enough, there was a good deal of slack in the throttle cable. It seems the rubber bushing where the cable connects to the accelerator petal was split/destroyed. I tightened the cable via the adjustment section near the throttle body but haven't had a chance to test it out on the road yet. Assuming everything runs okay, I'm now wondering if it's even worth the hassle of replacing the cable.

Called it! Mine had the exact same problem. I adjusted it for now. I have a new cable sitting on the bench whenever I get around to it.

Seriously though. Healthy plugs, good wires, clean air filter, throttle body and trans cable adjusted right make all the difference in the world.

 

[gamefreakgc]

That graph is awesome! What gearing is shown with the 5 speed transmission? What rpm's did you use for the top speed in each gear?

Oh, I forgot that part. It's 4.10 gears on the 5-speed. Max RPM is 5500. I realize that a 5-speed can rev higher but to keep the data consistent I used the auto redline limiter. There's absolutely no power above 5000 RPM when stock anyway.

 

[SaulG]

If you are gonna bust the diffs open anyway go with the 4.88's.. and you can use a locker in the front as you said in the snow..just have to be mindful of slip.
Just repaired locked Tundra that split front diff w/ARB it was ugly!!

 

[Option01]

So just a quick update. I dropped off the 4runner at the shop this morning and went with the 4.88 ratio. Thanks again to everyone who chimed in on this thread to share their suggestions and experiences. Now I just need to figure out how to properly break in the new gears in a short period of time!