The Strongest Savage Diff Compilation.

[simplechamp]

I think the fact that an alloy cup is one solid piece is what makes the difference. With plastic cups it's a 2-piece design: a steel insert pressed into the plastic. That joint becomes a weak area and the plastic fails. Either the Nova or IRC cups should do just fine. 6061-T6 and 6082-T6 alloys are both very similar.

[JasonB]

I haven't had that problem with the plastic cups yet. Just took the back one out to inspect for wear and the cup still looks great inside and out.

[Jahay]

jason... what did you say you were running your plastic diffs in again with the plastic cup???

[JasonB]

Flux with a Castle 1520 motor on 6S. Punch at 60% I believe, and slipper locked.

[Jahay]

out of curiousity.. .what gearing do you run on the flux? with what wheels?

[JasonB]

Currently running 5.84" Badlands, with Gorilla tape on JConcepts 1/2" offset rims. Using 20/47 (~35mph) right now. Perfect speed for the tight makeshift dirt track that I'm running on right now in a patch of woods I found near a church. When I want to go fast, I drop in the High Speed Idler (~52mph); cop clocked me at 45mph on asphalt and 40 in the grass but I wasn't able to hit my theoretical top speed because the parking lot had curbs all over the place and I was . If I ever want to go stupid fast, I'll throw back in the stock motor, slap on my Road Rage's, and let her rip!

[Jahay]

thanks for that... i was 21/47 with the high speed idler... So basically the same... I still think it is undergeared! i run cool with that gearing! But it is plenty fast enough!

[Jahay]

Yep well... that nova cup seems a little out of reach... The IRC cups are still out of stock for the next month and i am getting impatient...

Im thinking:

Vorza plastic cup (hopefully it can handle 10s without flexing) ill use 30k rear and 50k front.
HotBodies Hard Steel Internals
Should i just use my existing savage cross shafts? or should i just buy some new ones specific for the diff cup???

edit.

I typed in the vorza diff cup no... and got this... Just confirming it is the same... So the only steel part on this is what the bearing sits on correct?
http://cgi.ebay.co.uk/HPI-trophy-3-5...f#ht_500wt_764


are these cross shafts stronger or more appropriate than the stock savage ones?
http://cgi.ebay.co.uk/HOT-BODIES-Dif...1#ht_500wt_764

[JasonB]

I'd say it's the same part. Look at this: http://www.hpieurope.com/piw.php?lang=en&partNo=hbc8019

Stock cross shafts fit fine and are ample strong, you may need to sand a few thousands off the length to get them to slide in easily. Don't take off any material until you do a test fit.

As far as the diff oil, the thicker you go, the quicker things will ware down inside . . . IMO. I'm using grease now; added benefit is no more leaks. The diff oil always seems to squeeze past the o rings and get all over the bearings, even with the green slime and new rings. Just been my experience.

[Jahay]

well it looks like my mate has some vorza diffs for me to have... they are stock vorza diffs so according to HPI should come with the hardened Hotbodies internals already supposedly! so i cna just bolt my ring gear on and a way i gO!!!! WWOOOP WWOOPP

Also jason.. regarding oil
i was always told that thicker oil, saves your internals. If you have low weight oil or just grease... these brushless systems can unload diffs very badly causing very hard wear on the gears. High weight oils prevents the unloading more so, so the diffs last longer... and thicker oil also has less chance of leaking out of the diff.
when i ran without any oil and just grease... i had really bad traction issues as my savage would just unload all the power to the inside wheels...
i am now going to try a different setup considering im going for 9s power...

50k rear and 60k front... see how that behaves..

[JasonB]

Originally Posted by Jahay

i was always told that thicker oil, saves your internals. If you have low weight oil or just grease... these brushless systems can unload diffs very badly causing very hard wear on the gears. High weight oils prevents the unloading more so, so the diffs last longer... and thicker oil also has less chance of leaking out of the diff.
when i ran without any oil and just grease... i had really bad traction issues as my savage would just unload all the power to the inside wheels...
i am now going to try a different setup considering im going for 9s power...

50k rear and 60k front... see how that behaves..

No one will argue that thicker oil means better traction. Just about every one has a different opinion on what weight fluid to run in thier diffs. My experience has been that the thicker oil wears out the gears quicker, and even 50K will blow by the o-rings. I started with HPI grease, then 7000 oil, then 50,000, and now I'm useing an inexpensive lithium grease. Having tried both oil and grease, grease is less maintenance for me which is a very good thing. Perhaps other's have had different experiences, I'm just shareing mine.

I could be wrong here, but the friction vs wear thing makes since to me because the higher friction caused by the thicker oil forces more metal on metal pressure between the gears resulting in a shorter lifespan. With grease, the gears are able to spin freely and don't grind eachother down as quickly. Works in my mind anyways.

I've driven both with Oil and Grease, and there is not enough of a traction difference to matter to me. If I did a lot of crawling, steep hill climbing, or racing, perhaps it would. One of these days, I'm going to lock both diffs, just for fun, but only on a temporary basis, because I know that will be torture on the rest of the drivetrain.

[thzero]

It would seem that with a higher vicosity oil that it would resist being pushed aside, therefore maintain lubrication and a small layer between the gears better than a lighter oil. Thus it would reduce the amount of metal on metal contact. But then again I'm not a chemist either.

Originally Posted by JasonB

I could be wrong here, but the friction vs wear thing makes since to me because the higher friction caused by the thicker oil forces more metal on metal pressure between the gears resulting in a shorter lifespan.

[Jahay]

i have just got the vorza diffs... i need to open them up and have a little look..

My 60k diff oil has just arrived, so ill use that in teh front and 50k in the rear....

Ill let you know how it handles and how badly the oil leaks out...

Ill use new o rings and plenty of green slime.

[Jahay]

I have been taking apart my vorza diffs... THEY ARE MUCH BETTER ALL AROUND OTHER THAN THE RING GEAR!

Remember the vorza stock internal gears are the HOT BODIES HARDENED STEEL INTERNALS... and there is an ever so slight difference in thickness.

I took plenty of pics to compare...
VORZA VS SAVAGE DIFFS (all vorza parts are on the left and savage on the right of the pics

Diff Mess


Firstly i will say that the vorza diff cup, although plastic... is extremely ridgid, and due to the design, actually has more material. So i have no problems using a plastic cup knowing it is this tough. You will notice this in the pics.

Notice in the pic below. The steel cap which allows the vorza cup to use an 8x16x5mm bearing.
Also notice the grub screw. This allows the use of a larger pin to hold the sun gears in place, dispersing the force over a larger surface area much better. (i snapped these pins often with the shorter savage pins. Pics will show this furthur down.






Spider gears are ever so slightly thicker. Maybe not noticeable on camera, but in person you can notice a slight difference. Also notice the longer axle pin! Also the washers that go behind the spider gears are twice as thick as the savage ones and are not flexible.




Sun gears... slight difference again.. .vorza on left... ever so slightly more robust than the savage.




AXLES - obviously there is going to be a differnce... but i believe the strength of both seems quite equal...
There is an obvious difference in length in the picture below...


But the actual internal thickness of the axles are the same!!! one is just larger than the other. I believe if i did carry out the LST Hub conversion on the savage (thanks to linc!) i believe these axles would work fit well with the lst CVD and i would most likely use the vorza cup... BUT if because the vorza cup is a little shorter than the flux cup, and the LST CVD falls out of the vorza cup upon turning, then i guess i will need to use an HD Savage cup rather than the SHD cup...

[Jahay]

RING GEARS

obviously there is going to be a huge difference... but more importantly, yes the BP gear fits tightly and all screw holes line up perfectly with the vorza cup





Picture of the BP Gear on the vorza cup with the vorza axle on left and SHD savage axle on right.





I just want to say thanks to everyone for the help. I will be using this diff setup in my 9s xxl flux and will report how well everything lasts.

if you have any questions... or things you want to point out... please do so... im not assembling these up yet as i am unsure as to what axle i need to use with the lst cvds....