Kraton Speedy's probably OCD Kraton Build

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Kraton Speedy's probably OCD Kraton Build

Speedy!

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  1. Kraton 6s
Anybody do any diff tuning/testing? I know a lot of people say they just put in 50K/500K/30K or something like that for F/C/R, but did you test to get there or just used it because someone else recommended?

I put 30K in the front to test and I can't tell a ton of difference to be honest. My Kraton seems to want to steer wide (over steer) under anything more than a tick of throttle input and I thought maybe a bit thicker fluid up front would help, but so far not really. I wanted to test this before jumping straight to the EXB LSD diffs.

Maybe I should drop in the EXB LSD center diff first to see what that does? This thread is pretty quiet on responses so I may need to post these questions out in the forum.
 
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Speedy!

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Well, since it was like a 10 minute job I dropped the EXB LSD center diff in and left the BLX front with 30K and rear with 10K in the truck. Some quick testing suggest this is WAY better than the open center diff. It still over steers a bit under throttle but not as bad, and turns very tight off throttle. Thicker fluid may be a cheaper/easier way to achieve the same thing in a BLX center diff but I kinda like knowing it's LSD for some reason.

Next up I'll drop in the EXB front and rear diffs and see what that does.

For reference while my front BLX diff was filled pretty well from ARRMA the center diff really needed a bit more fluid and had a very slight leak as well. The screws holding the diff together weren't as tight as I'd like them to be.
 

Speedy!

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More testing with the diffs and here's what I've done so far:

With all stock BLX diffs I upped the front to 30K fluid. This helped some, but not as much as I'd hoped. It still felt like the truck would turn wide under throttle and still a bit too much diffing out under hard power where the front tires would lift some.

Added the EXB LSD center as it comes from ARRMA. This seemed to help quite a bit and may be a good budget upgrade for someone with a BLX Kraton looking for better handling. Turning improved probably 30% under throttle and 60% off throttle in terms of turning radius. Under power WOT handling improved as well as the front is more planted now, however a side effect is that the rear can be a bit more lively under WOT power. This is starting to make sense as the center is more locked up with the LSD so more equal power going front and rear even when the front is lifting. So now the front is unloaded, the rear is digging in, so the rear acts like a pendulum and can start to want to swing. Some counter steer handles it fine and kinda made it more fun to drive for me.

Now I'm swapping in the front and rear EXB LSD diffs as they come from Kraton. I bought all three EXB diffs from Jenny's pre-assembled and only opened them up to check fluid. All three needed fluid topped up.

kraton_lsd_swap.jpg


There are A LOT of screws and they all start to look the same pretty quick. To keep things going back where they're supposed to I got in the habit of putting the screws back where they came from as I worked.

kraton_keep_up_with_screws.jpg


It's also nice when upgrades work as well as expected. The rear mud guards are doing a great job of keeping junk outta the rear suspension, and the taller side guards keeping the inside clear as well. However after a good rip in a gravel area, the mud guards took a beating. At least it wasn't the rear suspension bits. I'm likely going to add some small aluminum plates to protect this area better.


kraton_blasted_guard.jpg


The painted white letters didn't fair as well. Two bashes and they're pretty much toast.


kraton_worn_tire_letters.jpg


And, the Mrs. got me a few things for Christmas. These MIP hex wrenches are a bit pricey for what they are, but WOW are they high quality and fit fantastic. No stripped hex heads gonna happen now. My only complaint is for what they cost, the size should be etched on them rather than a decal you have to apply yourself :/ Got some upgraded bearings and some LP Backflip tires to play with as well.

kraton_christmas_2021.jpg


I like the raised letters on the LP Backflips better than the standard ones. Here they are side by side. I painted the wheel on the standard set.


kraton_bf_lp_vs_reg.jpg
 

Speedy!

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Well, the verdict is in, and for me the EXB LSD diffs are a HUGE upgrade to the BLX diffs I was running. I'm running all three as come from ARRMA with max effect front and center and min effect rear with 10/100/10 fluid. If what others say is correct, this would be similar to 50/500/30 fluid in the BLX diffs for reference.

I just got back from some testing and WOW what a difference. I tested on asphalt and very short grass. I'm super happy with the upgrade. The only caveat to my experience vs others may be that I never ran much more than stock fluid in the BLX diffs. I did try 30K in the front and it helped a smidge but not a ton. I enjoy drifting the truck and now I can do that pretty easy and if you're reasonable on the throttle coming out of a corner it plants and goes. Over cook it though and it will want to spin a bit but in my case the front will grab just as it starts to over rotate and I'm back under control. I also don't jump my Kraton 30 feet in the air either, so not sure if that makes any difference.

If I were trying to do this on a budget, I'd go with the EXB LSD center diff and up the fluid in the BLX diffs, but getting the whole diff assembly including case from Jenny's was pretty cost effective plus you get the added benefit of the stronger gear set as well.

I also did the servo mod with the 9/16" lock rings and replaced the steering bushings with bearings. This really improved steering so thanks @Monster Dork for reminding me to drop those in while I had it all a part. I'd guess turning radius improved at least 50%. So much in fact you have to be ready for the outside tires to bite and flip the truck on it's lid :)

Something for other new folks that may find this thread....All of the diffs I've looked at (BLX and EXB) all had one shim on the bearing to keep the ring gear tight to the pinion. I checked my BLX diffs out of the box and they were all tight with this configuration. However when I was disassembling things to install the EXB diffs I noticed a bit of looseness in the BLX diffs. I'm assuming these wear a bit on break in and that's when that second shim becomes a good idea. I don't think I could have even gotten it in there out of the box, or at least not without some foul language to go a long with it, but after they were run a bit I think it'd fit in there nice and snug. Something I'm gonna keep an eye on with the EXB diffs.
 
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Speedy!

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Built some shields for the mud guards out of aluminum plate. Hopefully this will help with the rocks eating up the mud guards.

kraton_mudguard_shields_1.jpg


Hit them with some self etching primer and paint.

kraton_mudguard_shields_2.jpg


Screws hold them in place fine, but I added some JB Weld around them as well to seal them up.

kraton_mudguard_shields_3.jpg


They wrap around to protect the bottom of the suspension as well.

kraton_mudguard_shields_4.jpg
 

Speedy!

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Next up will be some body mods. Gonna do some re-enforcement and lights. I've worked out the heads and tails but am having to do something custom for running lights. Hopefully that pans out, working with @3d-rc.myshopify.com on that one.

I wanted to control the lights from the Tx and the SLT3 only has a momentary button, so I grabbed a DX3 for cheap. It's a decent upgrade over the SLT3 for someone like me that didn't want to get in to a $100+ Tx. I like that it has battery level info so I know when it's getting close to done and the steering and throttle adjustments are much more granular over the SLT3. Plus the A/B button can be programmed to turn lights and other things On/Off. I thought the little $20 BT upgrade for the Spektrum Dashboard mobile app, but seem reviews on that app are iffy? I'm primarily interested in monitoring motor temps, rpm, and vehicle speed if anyone has info.

kraton_led_1.jpg


kraton_led_2.jpg


spektrum%20dx3%20and%20lights.jpg
 

Speedy!

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We don't get a lot of snow here, so when some fell I had to get out and play in it. I quickly learned WD40 and a shop sink are your friends after something like this.

kratorious_snow.jpg


Let the snow melt out of the truck in the shop sink, hit it really good with some compressed air, then gave it a once over with some standard WD40 and good as new.
kratorious_snow2.jpg
 

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Bud, coming along nicely. Like the videos, nice work there. I used to hang on the Challenger and LX forums for a bunch of years. It was surprising to find you on this side of the mods world, even if only recently. I'm having a blast with these things as well. Tinkering is cathartic and it takes me away from my day ( night) job stresses.
My last Mopar was a 15 Challenger SRT I custom ordered, I miss that car but life and demands change, still rocking a couple of Cummins 1 ton duallies for the heavy lifting (44'TH), one is a sporty 5.9 and the other is a 6.7 workhorse.

Make sure to lube up your Bearings, water can trash em pretty quick if not maintained. I'm using some Dupont dry Teflon spray for after wet sessions, I find WD-40 attracts dirt.
I'm looking at getting the dashboard for my DX3 transmitter as well. I haven't dug too deep into the reviews yet but I'm gonna give it a shot anyway.
Great information on this thread, it seems that your getting some solid advice and experience in a really short time.
Welcome to the zany side of performance rigs.👍
 

Speedy!

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Yeah I wish I'd gotten one of these sooner. Tons of fun and cheap compared to what I'm used to LOL.

What bearings do I need to keep lubed? I've got some graphite I can use temporarily until I get some dry spray. Only bearings I've seen so far were the ones I put in place of bushings in the steering and the ones in the diffs but the diffs are covered in grease.

For $25 I may try the dash board deal as well. If it showed me only motor temp it would be worth it.
 

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Yeah I wish I'd gotten one of these sooner. Tons of fun and cheap compared to what I'm used to LOL.

What bearings do I need to keep lubed? I've got some graphite I can use temporarily until I get some dry spray. Only bearings I've seen so far were the ones I put in place of bushings in the steering and the ones in the diffs but the diffs are covered in grease.

For $25 I may try the dash board deal as well. If it showed me only motor temp it would be worth it.
Pictures for ya below. There's two at each wheel, and your bell crank. The motor and diff bearings can get wet but unless you're submerged I think you fairly safe. I'm new to this as well but from a logic perspective I think those are the ones that'll get wet pretty easily. They're the ones I service most often if I get into a random puddle in the field or morning dew down here in FL. Lube the stock shafts, and all your pivot points after each run too. Keeps the suspension moving freely.

Screenshot_20220112-135931_Chrome.jpg

Screenshot_20220112-140113_Chrome.jpg

Screenshot_20220112-140021_Chrome.jpg
 

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Its pretty straightfoward. After you do the first one youll fly through it.
Here's my mess...
Shimming the hub bearings, bellcrank, and installing GPM c-hubs on a new build. Waiting on new hexes but I figured I'd give this a shot.🥃

20220112_204255.jpg

20220112_204303.jpg
 

Speedy!

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First parts failure, or worn out part perhaps. Running the Kratorious last night, heard it make a strange bzzzzzt sound and no more go. Took a look at the pinion had moved forward on the motor shaft and the diff gear ate the top off the set screw. Had to carefully drill on the set screw to uncover the hex, then eased it out. I thought I could just put in a new set screw, but the pinion gear itself is pretty worn and VERY loose on the motor shaft so I'm on the hunt for a replacement.

Vehicle has about 30 packs through it now and I honestly expected the Copper Head 2 tires to be the first things to wear out, not a pinion gear.

20220113_171431.jpg
 

JPWarrior_KRX

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  6. Typhon 3s
First parts failure, or worn out part perhaps. Running the Kratorious last night, heard it make a strange bzzzzzt sound and no more go. Took a look at the pinion had moved forward on the motor shaft and the diff gear ate the top off the set screw. Had to carefully drill on the set screw to uncover the hex, then eased it out. I thought I could just put in a new set screw, but the pinion gear itself is pretty worn and VERY loose on the motor shaft so I'm on the hunt for a replacement.

Vehicle has about 30 packs through it now and I honestly expected the Copper Head 2 tires to be the first things to wear out, not a pinion gear.

View attachment 192727
The one thing I make sure to redo after taking delivery of a new rig, is to go through and loctite everything that has torque on it. If the pinion has bad wear than this has been going on for a minute, make sure the spur gear is good(probably is). There are higher quality pinion and spur gear sets made from companies like Integy, Castle Creations and such that will outlast the Arrma supplied gearsets.

On a side note, I snagged the BT chip for the dashboard app ( $14.95). I updated the firmware and everything connected up pretty easily. I got the phone mounts well, another $18.00. My S21 Ultra fits in it even with the phones case but the access button is centered on the right side of this phone so I have to shift the phone slightly the the left so the clamp isn't pressing it. Seems to hold it fairly firmly.
 
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Speedy!

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Cool let me know what you think of the app. I've heard the firmware update can brick the Tx then I heard the firmware is only for the BT chip? So not sure.
 

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Cool let me know what you think of the app. I've heard the firmware update can brick the Tx then I heard the firmware is only for the BT chip? So not sure.
I may be assuming this wrong, but I thought the firmware was for the chip. It's been sitting in my LHS for a while.
Will report back once I get this build done...
 

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Got it all set up and gave it a brief run. Works as advertised. There's a slight delay in the data but it's not a big deal. It's not like you'll be staring at it all the time. If nothing else it will be good to record the data for comparison set ups.
 

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The original Kraton body will be the one I beat on since it's my least favorite so I did the drywall tape/shoe goo deal and added some skids. Just in time as it seemed my Tx got out of throttle calibration somehow and 75% throttle limit was actually 100% (??). Needless to say it went on the roof in short order at full throttle. Bummer. Not sure how the calibration got jacked up but I recalibrated and solved the issue.

The shoe goo thing is kind of a PITA and messy for an OCD type like myself, but seems to work well. Some people do the entire body, but I focused more on the areas where I figure stress would be the greatest, like corners and close to the body posts.

kraton_body_shoegoo.jpg


kraton_body_armor.jpg

I also dug through my old box of computer parts from back when I built them quite a bit and found a pretty decent 40mm fan that came from a server class power supply I believe. Zip tied it to the motor as a test and it seems to lower temps at least 20°F with no heatsink like @SrC recommended. He states the motor case is a heat sink and based on my testing I'm inclined to agree. I'll eventually get an aluminum mount for the fan, but for now the zip ties and a bit of window screen repair as a grill are working fine.

Fan is 40x40x20mm and moves about 11cfm at 12V so a bit less at 7.4 but it's whisper quiet.

motorfan2.jpg
 
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