The unofficial Losi Tenacity DB Pro thread by Alex.M. and slick2500.

[smirkracing]

@parcou thanks for your advice. I received the tekno driveshafts. However, there seems to be a slight issue... first off, the instructions say " a very small amount of material may need to be removed where the outdrives exit...", but they don't really specify what they mean. Here's a pic of the instruction sheet:

Second, when I reassembled the gearbox, one of those plastic 'housings' that goes on the outside of the outdrives is totally bound up. Here's a pic (since I am sure that description did nothing for anyone):

The only solution I see is hitting the entire inside of the problematic housing with a dremel and removing maybe 1mm (or less) of material all the way around the inside of the housing such that it doesn't bind up the outdrive. Before I do that, I wanted to check with the experts on this thread... I can't be the only one experiencing this issue. Is this what the instructions mean when they refer to a small amount of material needing to be removed?

Thank you!

 

[parcou]

@parcou thanks for your advice. I received the tekno driveshafts. However, there seems to be a slight issue... first off, the instructions say " a very small amount of material may need to be removed where the outdrives exit...", but they don't really specify what they mean. Here's a pic of the instruction sheet:
View attachment 300376


Second, when I reassembled the gearbox, one of those plastic 'housings' that goes on the outside of the outdrives is totally bound up. Here's a pic (since I am sure that description did nothing for anyone):

View attachment 300375

The only solution I see is hitting the entire inside of the problematic housing with a dremel and removing maybe 1mm (or less) of material all the way around the inside of the housing such that it doesn't bind up the outdrive. Before I do that, I wanted to check with the experts on this thread... I can't be the only one experiencing this issue. Is this what the instructions mean when they refer to a small amount of material needing to be removed?

Thank you!

Hello

I had the exact instructions and did not need to remove anything from the driveshafts. They were a perfect fit for the Losi DB Pro. I read this thread fully years ago when I did mine some time back do not recall anyone needing to for the DB Pro...maybe it is needed for other rigs they fit.

Been so long since I did this I forgot. The plastic was an issue. Just forgot...sorry. I have happy to go with the alumin inserts flex was part of the issue with the rear, so the inserts were perfect.

Needed and used these here:
https://www.amazon.com/gp/product/B..._asin_title_s00?ie=UTF8&psc=1#customerReviews

Technically, the stock plastic "should" work as you see it did on the other side. Few options. Plastic is not perfect, so you could mil out a bit of material and test. Option #2 I can see you mine I am not using to see if three is a difference and/or fits better.

 

[smirkracing]

Hello

I had the exact instructions and did not need to remove anything from the driveshafts. They were a perfect fit for the Losi DB Pro. I read this thread fully years ago when I did mine some time back do not recall anyone needing to for the DB Pro...maybe it is needed for other rigs they fit.

Been so long since I did this I forgot. The plastic was an issue. Just forgot...sorry. I have happy to go with the alumin inserts flex was part of the issue with the rear, so the inserts were perfect.

Needed and used these here:
https://www.amazon.com/gp/product/B..._asin_title_s00?ie=UTF8&psc=1#customerReviews

Technically, the stock plastic "should" work as you see it did on the other side. Few options. Plastic is not perfect, so you could mil out a bit of material and test. Option #2 I can see you mine I am not using to see if three is a difference and/or fits better.

@parcou First, thank you so much for offering to send me your spare plastic parts. That's very generous of you. Luckily, I won't be needing anything.

I took your advice and milled out some material from the part that didn't fit correctly. It was a 5 min job, 4 min of which was spent finding the right bit for the dremel from my toolbox.

For anyone else who ends up going this route, there's a *tiny* raised seam or ridge on the inside of the plastic part in the photos that @parcou and I shared. The seam is probably .1mm high and .1mm wide. It goes all the way around the inside of the asymmetric plastic housing. With any small grinding attachment on your dremel, you can remove this seam in a minute or two. You could probably do it with sandpaper and your finger, actually, as long as your finger was small enough to fit.

This is an easy fix for several reasons:
1. the seam is on the inside of a circle, so you don't need to measure, or even have a steady hand really. Just spin the part slowly in your hand and your grinder will take care of the seam. It doesn't matter if you drift up or down, as nothing in that section of the part is meant to touch anything else.

2. There's no penalty for grinding off a little more material than you need. This particular part is seated on the bearing on the outside of the diff, and the seam is nowhere near that section of the part. So whether you clear the outdrive by .1mm, or .5mm, or even more, it really won't matter much. You would really have to make a great effort in order for this to go wrong (or perhaps use the wrong tool, like a saw).

Thanks for the great advice! I'm past this problem and moving on.

 

[smirkracing]

I was lazy about buying new diff fluids and used what I had on hand... so in case you were curious, here's a set-up that sucks. Don't copy this!

Rear: 7k
Center: 30k
Front: 1k (estimated effective weight - this is just stock from factory, but judging from other diffs I serviced, all oil leaked out and it is likely an open diff)

For reference (and I'm sure the experienced folks know this but I hadn't experimented before), with the above set-up, the vehicle is tail-happy. The 30k oil in the center, which I did not think was too heavy, is in fact WAY too heavy and causes the rear wheels to have power all the time. So if you give the vehicle any aggressive throttle input, the rear end breaks loose and spins around. On high traction surfaces, the car is fast but spins out easily. On grass, the car feels slippery.

Separately, the 7k oil in the rear diff is too heavy compared to the almost-empty front diff (which I did not refill) so the vehicle pushes a lot more than it used to. My turning radius is much later than I recall it being before I messed things up.

Having all three diffs mostly empty was far better, in fact.

I am going to pull everything open and swap the front / rear diffs so the front has 7k and will have maybe 3k, and I'll reduce the center diff down to 7k. That should be pretty close to the stock set-up.

 

[parcou]

I was lazy about buying new diff fluids and used what I had on hand... so in case you were curious, here's a set-up that sucks. Don't copy this!

Rear: 7k
Center: 30k
Front: 1k (estimated effective weight - this is just stock from factory, but judging from other diffs I serviced, all oil leaked out and it is likely an open diff)

For reference (and I'm sure the experienced folks know this but I hadn't experimented before), with the above set-up, the vehicle is tail-happy. The 30k oil in the center, which I did not think was too heavy, is in fact WAY too heavy and causes the rear wheels to have power all the time. So if you give the vehicle any aggressive throttle input, the rear end breaks loose and spins around. On high traction surfaces, the car is fast but spins out easily. On grass, the car feels slippery.

Separately, the 7k oil in the rear diff is too heavy compared to the almost-empty front diff (which I did not refill) so the vehicle pushes a lot more than it used to. My turning radius is much later than I recall it being before I messed things up.

Having all three diffs mostly empty was far better, in fact.

I am going to pull everything open and swap the front / rear diffs so the front has 7k and will have maybe 3k, and I'll reduce the center diff down to 7k. That should be pretty close to the stock set-up.

The Losi DB Pro is a fun rig once you find your sweet spot for each person's bash style. 7/15/5k works great for me. I bash in dirt or very dead low patchy grass/dirt. This setup gives me drift ability to keep the front pulling with a nice power slide in corners. I also use Spektrum AVC, where I have all 3 AVC settings perfectly tuned for this rig. Pure fun....

Make the change and enjoy!

 

[Maxx. D]

I only run on 2s, but I’ve now gone through 2 rear Tekno stub axles. Pretty annoying, I do mostly track driving and some bmx tracks. I also have the scte 3.0 steering rack but now it’s got a lot of play similar to the stock rack, does anyone else have the 3.0 steering rack and after awhile it’s seems to ware out for you? Thinking of getting the new exotek steering rack 2.0. Anyone try it yet? How do you like it, pretty expensive so would like to hear some feed back.

 

[parcou]

I only run on 2s, but I’ve now gone through 2 rear Tekno stub axles. Pretty annoying, I do mostly track driving and some bmx tracks. I also have the scte 3.0 steering rack but now it’s got a lot of play similar to the stock rack, does anyone else have the 3.0 steering rack and after awhile it’s seems to ware out for you? Thinking of getting the new exotek steering rack 2.0. Anyone try it yet? How do you like it, pretty expensive so would like to hear some feed back.

FWIW I feel the exotek is a needed install. There is too much slop in the stock. I did it for the DB as well as the Losi Lasernut. Costly but one of the few items I called a miss by Losi and a good upgrade.

 

[YourConfused]

I only run on 2s, but I’ve now gone through 2 rear Tekno stub axles. Pretty annoying, I do mostly track driving and some bmx tracks. I also have the scte 3.0 steering rack but now it’s got a lot of play similar to the stock rack, does anyone else have the 3.0 steering rack and after awhile it’s seems to ware out for you? Thinking of getting the new exotek steering rack 2.0. Anyone try it yet? How do you like it, pretty expensive so would like to hear some feed back.

I have the exotek steering rack and I wouldn't purchase it again due to not being able to tighten screws without also locking the steering. With loctite it get about 20 minutes of run time before the rack falls apart. But honestly the majority of the vehicle is no better, and that's why mine just sits on a shelf.

I'm currently looking for another rc that uses 90/105mm shocks so I can replace the stock shocks with something more durable. Those damn e-clips that hold the pistons on are Super annoying!

Anyone know a durable upgrade for shocks, maybe something from a Tekno or TLR vehicles? Most of my stuff is 1/8 scale or mini in size so I don't have another off-road 1/10 scale to compare parts to.

 

[Hypnotoad]

I just tore mine down completely and cleaned everything, changed the shock and diff oil and even added a red rear taillight that fits in the space on the wing mount. Looks factory. Also changed all of the outdrives on it. They were getting chewed up, but I will say they held up surprisingly well considering I run it on 4s with a 2400kv motor. Three years strong with this buggy.
One more thing, I have two DB Pros. Fox body is the one I use and the Lucas Oil one is a shelf Queen that has never been run and is completely stock.

 

[Maxx. D]

I have the exotek steering rack and I wouldn't purchase it again due to not being able to tighten screws without also locking the steering. With loctite it get about 20 minutes of run time before the rack falls apart. But honestly the majority of the vehicle is no better, and that's why mine just sits on a shelf.

I'm currently looking for another rc that uses 90/105mm shocks so I can replace the stock shocks with something more durable. Those damn e-clips that hold the pistons on are Super annoying!

Anyone know a durable upgrade for shocks, maybe something from a Tekno or TLR vehicles? Most of my stuff is 1/8 scale or mini in size so I don't have another off-road 1/10 scale to compare parts to.

Do you have the 2.0 rack or the old one?

I use hpi vorza shocks and they work great, I’m sure you could mount up any 1/8 buggy shock.

 

[YourConfused]

Do you have the 2.0 rack or the old one?

I use hpi vorza shocks and they work great, I’m sure you could mount up any 1/8 buggy shock.

I'm not sure which version I have but I bought it about 1.5yrs ago. What's the difference between the 2 versions?

I tried shocks from my 8ight buggy but they were too large, same as my Tekno and arrma Kraton shocks. I was actually looking at some Traxxas shocks that might fit. I think they are from the 4x4 slash.

I attached a pair of mini b socks to the front bumper just for fun. Looks kinda cool. Overheating the center differential solved with a big fan, and replaced hubs with aluminum to help dissipate bearing heat. I also got aluminum beadlocks for the Hyrax tires, so if I can get the shocks to stay together I might actually have a fun vehicle again.

 

[parcou]

I'm not sure which version I have but I bought it about 1.5yrs ago. What's the difference between the 2 versions?

I tried shocks from my 8ight buggy but they were too large, same as my Tekno and arrma Kraton shocks. I was actually looking at some Traxxas shocks that might fit. I think they are from the 4x4 slash.

I attached a pair of mini b socks to the front bumper just for fun. Looks kinda cool. Overheating the center differential solved with a big fan, and replaced hubs with aluminum to help dissipate bearing heat. I also got aluminum beadlocks for the Hyrax tires, so if I can get the shocks to stay together I might actually have a fun vehicle again.

View attachment 317460

View attachment 317461

Are you sure you installed their steering bellhousing correctly? I have one on my older Losi DB Pro and also added one a few months back for a used Losi Lasernut U4 I purchased.

Their installation has to be exact...!! Use thread-lock and be certain you do not over-tighten the screws they state specifically not to over-tighten.

My first for DB Pro I did have to source some more of the small bearings either they were wrong or missing. The package for the U4 had all the pieces.

I certainly see a difference in the slop over the stock which was really bad. I would also advise as an added item to shim up the hex for the tires.

Overall both are good rigs but both out of the box suffer from a lot of slop. Reading this entire thread reveals all the slop issues. Once buttoned up on the slop, she is great!

 

[Maxx. D]

I'm not sure which version I have but I bought it about 1.5yrs ago. What's the difference between the 2 versions?

I tried shocks from my 8ight buggy but they were too large, same as my Tekno and arrma Kraton shocks. I was actually looking at some Traxxas shocks that might fit. I think they are from the 4x4 slash.

I attached a pair of mini b socks to the front bumper just for fun. Looks kinda cool. Overheating the center differential solved with a big fan, and replaced hubs with aluminum to help dissipate bearing heat. I also got aluminum beadlocks for the Hyrax tires, so if I can get the shocks to stay together I might actually have a fun vehicle again.

View attachment 317460

View attachment 317461

The Hpi vorza shocks are a bit long in the front but if you use the outer most holes they fit nicely. Sounds like you have the older version steering rack as the new one came out recently. I fit the Lasernut Center diff mount which is made of aluminum and has a built in heat sink, it also weighs a lot less too.

 

[formfactor]

Nope. It's the DB pro cage and body mounted up to my Typhon for U4RC racing. Wanted a bad ass IRS rig for the class we run. I'll grab some other pics of what I did...
View attachment 76782Boom

Started this thread from the beginning, up to here so far. I really want to do this to my TLRT! That looks epic!

 

[BigDirtyUnko]

Hi everyone! I got a DB Pro a little over a month ago and kind of went crazy with it.

Here's how it sits now! Along with a few pics from the build process.

I made a chassis protector out of thermoplastic sheet. Its the same material that Kydex pistol holsters are made of. Its easy to trim with tin snips and can be heated and formed with a butane torch. I also wanted rear shock dust guards and the easiest way I found to attach them was by making a rear A-arm skid plate with a large front lip.

I added Exotek front/rear transmission cases, GPM center diff case, Tekno front/rear axles, Exotek chassis braces, RPM front/rear A-arms, Exotek steering assembly, MX28 Badlands on 17mm hubs and adapters, receiver box, motor fan, front fender dust guards, and SCTE front bumper (thats why I have the hack job on the front skids).

I saved the patterns that I used for the various skid plates so my next step is to redo the chassis skid plate to get rid of the cutout for the RPM piece that's left over. I also want to add a longer lip to the front diagonal sections so they don't get hung up on landings.

Other than that I'm messing with gearing. I got a pinion set and started with a 13T with the MX28s. It was too slow so I went up to a 14T. After this weekend's run I'm looking at bumping to a 16 or 17T and monitoring temps. I am running 3S.

Edit: Forgot to mention that many of the mods were directly from folks that shared what they did on this thread, so thank you for that!

I have a few questions that I'm hoping some of you could help me with.

I need stiffer springs. I have found LOSB2959, the front spring set that comes with 4 different stiffnesses. It seems like the same set for the rear, LOSB2963, has been discontinued. Does anyone have any recommendations for a stiffer spring tuning set? Another option I have is to disassemble the stock shocks and try to find something that works at my LHS based on spring diameter and length.

I can't find any upgrade options for the center dogbones except for the MIP with pucks. Does anyone know of any current options? I can't find the Tekno ones mentioned earlier in this thread. Aside from the MIP my current replacement options appear to be GPM's "#45 hardened steel" or stock Losi.

Lastly, anyone having problems with their Proline 17mm hubs cracking? After my first run on them all four are cracked. It looks like they had overpriced aluminum ones which are no longer available.

Thanks!

 

[parcou]

Hi everyone! I got a DB Pro a little over a month ago and kind of went crazy with it.

Here's how it sits now! Along with a few pics from the build process.

I made a chassis protector out of thermoplastic sheet. Its the same material that Kydex pistol holsters are made of. Its easy to trim with tin snips and can be heated and formed with a butane torch. I also wanted rear shock dust guards and the easiest way I found to attach them was by making a rear A-arm skid plate with a large front lip.

I added Exotek front/rear transmission cases, GPM center diff case, Tekno front/rear axles, Exotek chassis braces, RPM front/rear A-arms, Exotek steering assembly, MX28 Badlands on 17mm hubs and adapters, receiver box, motor fan, front fender dust guards, and SCTE front bumper (thats why I have the hack job on the front skids).

I saved the patterns that I used for the various skid plates so my next step is to redo the chassis skid plate to get rid of the cutout for the RPM piece that's left over. I also want to add a longer lip to the front diagonal sections so they don't get hung up on landings.

Other than that I'm messing with gearing. I got a pinion set and started with a 13T with the MX28s. It was too slow so I went up to a 14T. After this weekend's run I'm looking at bumping to a 16 or 17T and monitoring temps. I am running 3S.

Edit: Forgot to mention that many of the mods were directly from folks that shared what they did on this thread, so thank you for that!

View attachment 340511

View attachment 340512

View attachment 340513

View attachment 340514

View attachment 340515

View attachment 340516
I have a few questions that I'm hoping some of you could help me with.

I need stiffer springs. I have found LOSB2959, the front spring set that comes with 4 different stiffnesses. It seems like the same set for the rear, LOSB2963, has been discontinued. Does anyone have any recommendations for a stiffer spring tuning set? Another option I have is to disassemble the stock shocks and try to find something that works at my LHS based on spring diameter and length.

I can't find any upgrade options for the center dogbones except for the MIP with pucks. Does anyone know of any current options? I can't find the Tekno ones mentioned earlier in this thread. Aside from the MIP my current replacement options appear to be GPM's "#45 hardened steel" or stock Losi.

Lastly, anyone having problems with their Proline 17mm hubs cracking? After my first run on them all four are cracked. It looks like they had overpriced aluminum ones which are no longer available.

Thanks!

Love the build

The DB is a great rig once the bugs are worked out and the diffs internal gears, spider gears, etc although they corrected it on some version not mine…. Lyon look good!

1. I have been happy with the stock springs but took some time to get the front/back setup to work the way I like. I have a Lasernut U4 and it has the same shocks but the springs are stiffer, only difference. I did buy the Lasernut used so not sure if those were stock or not…those springs would work if I knew the part number.

2. Never had an issue with the center diffs. Yes, I did replace the driveshafts as you did so it would not eat out the diff outdrives. Center drives has been fine stock for me.

3. Hubs cannot say. I have the Exotek hubs with the stock hex size

 

[BigDirtyUnko]

Love the build

The DB is a great rig once the bugs are worked out and the diffs internal gears, spider gears, etc although they corrected it on some version not mine…. Lyon look good!

1. I have been happy with the stock springs but took some time to get the front/back setup to work the way I like. I have a Lasernut U4 and it has the same shocks but the springs are stiffer, only difference. I did buy the Lasernut used so not sure if those were stock or not…those springs would work if I knew the part number.

2. Never had an issue with the center diffs. Yes, I did replace the driveshafts as you did so it would not eat out the diff outdrives. Center drives has been fine stock for me.

3. Hubs cannot say. I have the Exotek hubs with the stock hex size

Thank you!

I took a look at the Losi parts diagram for the Lasernut. It references LOS233013 for the springs but it says they are for all of the Tenacity line. But in the links to parts for this model I found LOS234042, Spring Set Ultra 4. They don't appear in the parts links for the DB and they appear to be specific for the Lasernut. At just $9 I'm be willing to order it and see what happens. Thanks for the tip!

https://www.losi.com/product/spring-set--ultra-4/LOS234042.html

 

[parcou]

Thank you!

I took a look at the Losi parts diagram for the Lasernut. It references LOS233013 for the springs but it says they are for all of the Tenacity line. But in the links to parts for this model I found LOS234042, Spring Set Ultra 4. They don't appear in the parts links for the DB and they appear to be specific for the Lasernut. At just $9 I'm be willing to order it and see what happens. Thanks for the tip!

https://www.losi.com/product/spring-set--ultra-4/LOS234042.html

Good research. I would take the risk as well. I wish I could know what I have on the U4. I did swap them on the DB and U4. I was curious how the DB would feel but never ran it before I swapped them back.

 

[BigDirtyUnko]

I got the U4 springs in and they are definitely stiffer. The part number is LOS234042.

They are same length and diameter but appear to be made of a very slightly thicker wire with a looser coil. The U4 springs are on the top and DB springs on the bottom.
Front:

Rear:

Any lastly I have a question for you all. What does changing the attachment point here do? I know that adjusting the link length will change camber but I can't figure out what moving this up/down 2mm does. Thank you!

 

[parcou]

I got the U4 springs in and they are definitely stiffer. The part number is LOS234042.
View attachment 341152

They are same length and diameter but appear to be made of a very slightly thicker wire with a looser coil. The U4 springs are on the top and DB springs on the bottom.
Front:
View attachment 341153

Rear:
View attachment 341154

Any lastly I have a question for you all. What does changing the attachment point here do? I know that adjusting the link length will change camber but I can't figure out what moving this up/down 2mm does. Thank you!
View attachment 341155

Now, this is great!!!!

I will save that part number for my knowledge. I'm glad it worked.

I do not understand all those changes with moving those screws. I do have a Typhon TLR, although it is different. Their PDF manual explains how changing all those positions affects the rig..., which would give some knowledge.