Trx-4 with or without lockers for max allround performance?

[Ola.]

I`ve got a modded trx, still running 2 speed and 2x lockers.
Considering building up a second car, a sport built for performance only, vs just keep on modding the one i`ve got to keep the lockers.

Because i`ve comed to like the lockers. Feeling ill might miss them on the sport, for both sidehilling and tight turns, they are often good to unlock. Especially the rear.

So for those of you that has experimented some, and built high performing trx`s...are the lockers better off left for the scale guys and just run some under/overdrive, or would the weight penalty maybe be worth it?

The 2 speed i can live without, and i`m allready running lightweight body without any scale features etc.

Complexity and price difference, isnt a problem.

[King Dork]

I’ve done a few cheap/free mods on my TRX4 Tactical. Removed the inner fenders and spare tire & rear “scale” parts (shed almost a pound and a quarter off of the body alone). I removed the stock battery holder and made a small battery platform out of carbon fiber that I mounted on standoffs just above the motor. I did the bumper mod front and rear, raised the sliders 8-9mm, and swapped the locking/unlocking diffs for lockers and ditched the extra servos. Truck looks much more aggressive and climbs much better. I left the 2 speed because I kinda like it. Myself personally found no reason to keep the locking/unlocking diffs for trailing or crawling. Stock esc and servo went out 2nd run so running a Hobbywing 1080 esc, stock motor, and “old” Hitec 5955 titanium gear steering servo that had been sitting in my spares box for over 10 years, on 1300mah 3s LiPo. Truck is really fun and predictable.

[AnimalHippie]

I like the diff lock option on mine but if I were building a comp rig. I would have them spooled and not have diff lock. Any weight above the springs you can get rid of on a Trx is good in my opinion. I'm not a comp guy. I just like running my rigs. Rock therapy! That's why they're still in my Trx. I like the 2-speed because I have a 27t motor and 9t pinion. Slow and torquey in first. A bit faster then walking speed in second. Just enough wheel speed to climb our sandy Florida hills. I would say it would still do good on comp level how it is now tho. I don't have OD/UD, but as soon as I can cough up $80 for some tiny gears. I'll be getting some. From what I've seen in videos and in person it makes a difference. Good luck! Can't wait to see a build thread on this one!

[OSRC]

I ran front spool/rear diff for quite a while. Works almost like dig, it's a nice option to have.

Sometimes you get in a situation where the rear wheels are pushing so hard they'll flip the rig or slide it off the line. Unlocking the rear axle lets the front do most of the work and takes the pressure off the rear. Many times I've unlocked the rear, let the front pull me into position, and re-locked out back and gotten up and over whatever I was crawling.

The TRX is so heavy, the tiny servo/cable is a minimal weight penalty.

Out of my 4 TRX's, 3 of them retained the rear diff lock, and considering adding it to my performance based Sport.

That's my 2 cents.

[Ola.]

Thank`s for you`re input guys.
As you say OSRC, the weight penalty is`nt all that much.. Even if i keep both diffs, it`s claimed to be 13gr pr servo, so maybe 50-60gr total with wires? And then the diff`s probably are a bit heavier than the spool?

[OSRC]

At the max guess of 60g, that's 1.8% of total mass using the weight of my sport (3246g) Going with 1 servo would be far less.

Not sure on the diffs vs spools, I imagine they'd be similar. Spool might even be a bit heavier since it's solid metal. It's down in the axle, so I'm not sure how much effect it would have. I have both laying around, I should measure.

EDIT: I was way wrong, spool is lighter, 27g vs. 32.5g with ring gears.

[Inspector86]

To be perfectly honest, if you want a comp rig buy a VS4-10. By the time you finish upgrading a TRX4 you will have the price of the VS4-10 invested and it will still not perform as well.

[crazee horse]

I'd leave as is. Locking diffs have there place, better to have and not use then to need and not have.

[Ola.]

Originally Posted by OSRC

At the max guess of 60g, that's 1.8% of total mass using the weight of my sport (3246g) Going with 1 servo would be far less.

Not sure on the diffs vs spools, I imagine they'd be similar. Spool might even be a bit heavier since it's solid metal. It's down in the axle, so I'm not sure how much effect it would have. I have both laying around, I should measure.

EDIT: I was way wrong, spool is lighter, 27g vs. 32.5g with ring gears.

Haha yeah, waay wrong

Thats it then, keeping the trx with the lockers instead of building a new sport, just doing some more minor mods to it.

[Ola.]

Originally Posted by Inspector86

To be perfectly honest, if you want a comp rig buy a VS4-10. By the time you finish upgrading a TRX4 you will have the price of the VS4-10 invested and it will still not perform as well.

Humm really, is it that much better?
I`ve seen some video`s, but didnt get that impression.
Most comments i`ve seen, claimed the opposite..

Gonna have to look more into it.

[Inspector86]

Originally Posted by Ola.

Humm really, is it that much better?
I`ve seen some video`s, but didnt get that impression.
Most comments i`ve seen, claimed the opposite..

Gonna have to look more into it.

You can't believe anything you read on Fakebook!

[Stormin2u]

On a comp rig I'd have both axles locked and use both under/overdrive gearing. It makes a huge difference on steering radius and removes any torque twist.

[Ola.]

Originally Posted by Stormin2u

On a comp rig I'd have both axles locked and use both under/overdrive gearing. It makes a huge difference on steering radius and removes any torque twist.

Good point, especially on torque twist. Never thought about that.

What about sidehilling? I would expect over and underdrive would break loose traction so much that it makes the car slide downward?
I even noticed mine sidehills better with open diffs, especially on low traction surface and ofcourse when steering at the same time.

[Greatscott]

I spooled up both lockers on my comp TRX4. As cool as the feature is, they got me into more trouble than they got me out of. One notable use for them is when you are climbing, when one back wheel has traction and is pushing you off to one side, you can unlock the diff and get yourself back on line.

[JatoTheRipper]

Originally Posted by Inspector86

To be perfectly honest, if you want a comp rig buy a VS4-10. By the time you finish upgrading a TRX4 you will have the price of the VS4-10 invested and it will still not perform as well.

Comparing a TRX-4 to a VS4-10 Origin isn't even fair. The TRX-4 has portals whereas the VS4-10 doesn't unless you are talking the new Ultra. And in that case I don't think it's fair to comment because I haven't seen one average person run a TRX-4 against the Ultra at this time. Portal axles offer the advantage of clearance, but they have the huge drawback of raising the center of gravity.

I also really like the remote, locking diffs for the dig-like use. And also unlocking them in less challenging places to actually challenge the truck.

[Inspector86]

Josh just published a youtube video that is relative to this thread about his TRX4/VS4-10 comp build. It is a VS4-10 chassis with TRX4 Sport portal axles. It is not my style but he gives a lot of good info on the setup and he talks about driving it in different conditions. And the truck is going up for sale soon if anyone is interested.

https://www.youtube.com/watch?v=DHWko0WgzQw

[farmjohn42]

Regarding the locking diffs, I find the rear axle locking/unlocking diff has value.
However, does a front unlocking diff have value vs being locked permanently? What are your thoughts?

[DirtMerchant]

If you're in a position where one front wheel is lifted on a climb, you can unlock the front diff to resettle it. You can unlock both diffs, really, and get that front end down, but line choice also plays a big role.

[OSRC]

Unlocking the rear makes quite a difference on climbs since that's where the weight is, the front I don't notice as much. I've kept it in all my trucks though, I usually have it open unless I need it. Less stress on the driveline if nothing else.

[ferp420]

when i built mine i spooled the front and have selectable rear
when its in low gear the rear axle is locked for crawling when its in high gear the rear diff is open for bashing