regearing/ motor function

hey yall, i have a 00 2.7 auto prerunner and a 00 3.4 5spd TRD- both ends of the spectrum. i bought my TRD running 37s on it and wanting it to be a daily put my old 33s on from my auto because obviously 37s is a lot for a non regeared daily with big boy miles on it. I have put brand new driveshaft, whole rear axel, have a travel kit and new struts/shocks, heavy duty front cradle/upper control arm delete for my travel kit, and new clutch on er and have been doing a lot of research on regearing and how it works.. more power/torque to the wheels means less need for regear.. right?? i don’t quite get it. i miss my big tires. i’m selling my 37s (lmk if anyone is interested lol) to get 35s soon but am wondering if i should spend the money and hassel to regear my brand new factory diff lock rear end(im in MD and would have to spend a shit ton of $ and travel far) or if i will need to do this after getting a new motor/trd supercharger which im already planning on doing when my motor goes. What are your thoughts and experiences? put me in my place if this is stupid or unrealistic lol. i don’t do any crazy off-roading- just wanna be able to take my yota a few states away. but i don’t drive far for work ‍♀️ lmk ur thoughts and experiences. im just a girl tryna build a pimp ahh yoter help me out here .

 

So...you have two vehicles, right? Use the 00 2.7 as your daily and the 00 3.4 as your fun truck.
Regearing helps in several ways. It can put the engine back into the best power band for what you need, help with acceleration, correct for tire size changes, etc.
How did you fit 37s on an 00?

 

Yes.

Pictures requested!

 

as much as i’d love to use my prerunner as a daily, i don’t even have the title and it was deemed a total loss. its a parts truck essentially. runs and drives fine but no title back from MVA yet (after almost 5 months fk maryland) so it won’t be road legal for a while. i’ll post some pics. has 7 inches of lift and just rubbed slightly at full rotation after flattening the pinch welds a bit and cutting the front bumper flush with the fenders. (i bought the truck with the 37s on it) rode like shit ofc but it’s had a lot of love into it since then. i’ll put a pic of it with the 37s when i first got it and now with the 33s.

 

Unfortunately, your not going to find a lot of love for that Drop Bracket (DB) lift kit on here. Haters going to be haters. Don't be discouraged though. You can still get alot of information, and some support, on here. Ask me how I know.

I have a Fabtech 6" DB lift and 35" tires with 5:29 gearing on my 2000 3.4 TRD OR. I have done extensive work to my truck replacing all the bushings/bearings/ball joints underneath the truck. It drives really nice now. Like a new truck.

What you have can definitely be used as a daily. These things can drive pretty nice with a DB kit and big tires.

I think I would suggest 4:88 gearing for a daily. I went lower on mine because I like to go off the pavement. I have no opinion on driving with 35s on stock gearing. When I bought mine it had the lift and 4:88s.

In addition, I would suggest to replace your ball joints in the front end with OEM parts. Good piece of mind on an old truck especially when your rolling on 35s.

 

i appreciate ur response and much respect for the build as u speak of it, sounds pretty sick. as much as i appreciate ur humbling of receiving “love” on the lift, i bought it that way lol. i know DB isn’t the greatest which is why i upgraded the joints i needed to and accompanies it with new coil over lift aswell. definately not how i would have lifted it myself if i had the money/did the work myself. But as of right now i dont have any questions about functionality of my lift and components, although i haven’t been in the yoter shit for long i’ve spent hours researching every component of (my trucks) parts and have been replacing every part i can with either oem or the highest quality and function after market parts i can with the funding i have and what i already have on the truck at prime age of 18. At this point in time, regearing is not available to me due to cost and location. if anyone knows of a shop that won’t charge an arm and a leg for regearing within 2 hours of annapolis MD that would be super valuable info to me. i have no access to a garage nor have a butt ton of hands on experience, which is why my singular question was the comparison between motor strength and regearing and how they relate or not so relate to eachother, because i can’t find a lot about it. So if anyone can tell me anything about how motor size/power&torque accompany drivetrain function/gear ratios i’d love love it!!

 

How mathematical are you trying to get here?

The short answer is that the added power from a supercharger would reduce the need to regear, but with 35" tires regearing would improve drivability regardless of boost.

The longer, more mathy answer: Gears and drive wheels are essentially the same as levers (in the "simple machines" sense). Levers affect mechanical advantage by multiplying (or dividing) force applied and distance traveled.

Power from your engine passes through a bunch of separate "levers" before reaching the ground: the transmission, the transfer case, the differentials, and the tires themselves. All of those levers can be mathematically combined into one single imaginary lever.

Larger-diameter tires make the ground's side of the lever longer relative to the engine's side. The engine has to apply more force to its end of the lever to get the same force applied to the ground. The engine also travels a shorter distance (measured as engine rotations) for the same distance traveled on the ground. The result is sluggish acceleration but a higher theoretical top speed (theoretical because the engine might not have enough power to reach that speed).

Adding a supercharger means more power on the engine's side of the lever, which will offset some (probably not all) of the disadvantage caused by the larger tire. A supercharger will do nothing to correct for the change in distance traveled per rotation of the engine. That can only be done by regearing.

Of course, larger tires are also heavier and generally have more rolling resistance than smaller tires. When regearing, many people make the imaginary lever longer than stock on the engine side, which gives the engine an advantage in force but also means the engine travels a longer distance (rotates more) for a given distance on the ground. The result is quicker acceleration but a lower top speed.

Careful selection of gear/tire combinations will achieve the best balance between low-speed and high-speed drivability.

 

that’s the exact answer/information i was looking for. thanks so so much for the help. i’m glad im not entirely off in trying to understand this, with that info i will most likely save up a little to the point where i can get 35s after either more power or a regear (preferably regear as from the info i have gotten from you) rather than prioritize the bigger tire haha. maybe the 35s before if i know i’ll have the moola for reheat soon and wont be running them too long without it. trying to keep my trucks health a priority while still being able to build it how id like to. Id still love any more info anyone has about locations/logistics just cuz id love to learn as much as a can about it!! But this was a great second opinion and super educational!! thanks so much!!

 

Lots of folks here have used East Coast Gear Supply (ECGS) to buy pre-built differentials with the gears they want. They can ship you a diff ready to install. You'll pay a core charge that will get refunded when you send them your old diff.

You can avoid the core charge by sending your diff in advance if you have an extra or can live without your truck for a few weeks.

Keep in mind you'll need to get the front diff regeared to match the rear. Big tires are an expensive rabbit hole.

 

The supercharger is not the answer you're looking for. I found that out the hard way lol. Larger tires such as 35s load the engine up and with no intercooler to cool the charged air you will end up pinging on the highway which will kill your engine over time. Even with water methonal you will have engine performance issues. Too much load will make it hard for the engine to rev out. Knock sensors become active at 3k rpm and due to the high load the engine will aggressively pull timing making it hard for the engine to rev out. It's just overall not the right move. I highly recommend looking at ECGS. They are the easiest way to regear. Pre setup diffs with a warranty for a good price. I'd recommend 5.29 for 37s.

 

"http://www.grimmjeeper.com/gears.html" The gear ratio calculator is pretty handy albeit a bit unintuitive. 35's(34.5) with 4.56s is very close to stock gearing. 37's(36.5) with 4.88s are also very close to stock gearing.

https://www.youtube.com/watch?v=TyyuPt3A45I In this video the guy has 37s on 4.10s with a supercharger and auto trans. I'm skeptical but he claims the Supercharger made up for the tires .

 

I’ll speak from my own experience with 4.10, 35, and a SC. The short answer is no. You’ll end up spending more money to not run lean and some more on high octane gas. I’m not saying a sc won’t help, but solely putting all your eggs in the basket with a charger is not.

do it right with the correct gear ratio and add a SC. But what do I know, I’m stock.