HPI BP Diff VS Cen GST DIFF !!!

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vios8820

vios8820

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well i have a cen GST diff brand new laying around ... i was going to upgrade my diff when my stock diff fails me ~ is better i goes for HPI BP or just get another cen diff and start custom ?

btw where is the cen diff mod ? izzit deleted already ?
 
based on gear ratios i vote for the HPI bulletproof diffs.

i sold my CEN diffs about a year ago.

They choke your top end. Plus you have to mod them. Bullet proof drop in & your done.
 
Plus the BP Hpi diffs are strong.

My torquey 1520 motor has been ripping my tranny gears apart, but upon inspection of my diffs they seem brand new. Just shim and lube correctly.
 
I put the BP diffs in my XL and haven't looked back. Haven't had had one issue yet and I've been running it hard. I'm really happy with them. I had blown a rear pinion before that with the stock ones.
 
ACCESSORIZE has 2 XL`s , one using CEN , and the other using BULLET-PROOF. So far the CEN`s are holding up better than the B/P!! The B/P still uses the "weak-link" aluminum diff cup, with the weak 10x16x5 bearing!! The CEN uses a STEEL end on their diff cup, and 8x16x5 bearings on both sides!! Anybody who has actualy looked at the two could tell which one is better! As far as gear ratio goes they are the B/P`s and CEN are the same!! I have seen the two in action and seen which have lasted. Those who argue about which is better must not have even looked at a BULLET PROOF or CEN diff, cause if they did this thread would not exist.
 
Very true regarding the bearing issue.. and this is something i would want to rectify at some point, and i cant remember who, either bank or frddy came up with a solution to the bearing problem.

I am not necessarily saying that BPs are better than CEN as i haven't used them but considering my applications using a neu 1600kv motor on 6s, i have been going through tranny gears and pinions but my BP diffs have been holding very strong with extremely litte wear compared.

I don't know if the CENs require extra modding or extra expenditure to work... but as a drop in swap, the BPs are doing very well.
 
Bank did that mod, and yes I believe the CEN's require modifications to work. The BP's are a drop in upgrade. I've have no experience with the CEN's but the BP's have done extremely well for me. Haven't even taken them out to look at them since I put them in, still working perfectly.
 
MikeK1981 said:
Bank did that mod, and yes I believe the CEN's require modifications to work. The BP's are a drop in upgrade. I've have no experience with the CEN's but the BP's have done extremely well for me. Haven't even taken them out to look at them since I put them in, still working perfectly.
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we both did the mod. both dumped the CEN diffs. both going with bullet-proof diff.

btw- the ring gear on the CEN diff is thick & meaty. the teeth on the CEN pinion are actually weaker, by design, than a stock HPI Savage X pinion.
 
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redneck said:
So far the CEN`s are holding up better than the B/P!! The B/P still uses the "weak-link" aluminum diff cup, with the weak 10x16x5 bearing!! The CEN uses a STEEL end on their diff cup, and 8x16x5 bearings on both sides!! Anybody who has actualy looked at the two could tell which one is better! As far as gear ratio goes they are the B/P`s and CEN are the same!! I have seen the two in action and seen which have lasted. Those who argue about which is better must not have even looked at a BULLET PROOF or CEN diff, cause if they did this thread would not exist.
Click to expand...

ummm I have seen the Cen bearing snap off that cup you are calling strong ..

BA post some pics here would yea.. I taught BA to make these diffs long ago. He turned it into a side biz and has seen more of these diffs then this forum has BP's

I now have BP's with a new mod I did up for 8mm bearings all around. Pics are in the gallery. I have not made a thread how to caz Fred wanted to make it..
 
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idk if i have the pics anymore but i will say this.

HANDS DOWN THE HPI BULLETPROOFS ARE BETTER.
the cens last fine in a nitro but when it comes to a flux, the pinions just cant take the heat.

yea pics are gone unfortunately.
i used to run cens before the b/p's came out. they were great until i decided to go brushless. once i did i stripped out 3 pinions, 2 ring gears and i blew the cover like bank said. the race that the bearing sits on sheard right off.

i will say you are correct about the bearing sizes but there are ways around it.
1. maintain them. check and replace
2. buy some boca ceramics (metal shielded ones) they are "cheap" and work great. i had well over 40 cycles run thru the same set of bearings in the truck and they still are super smooth. that includes bashing and racing. the whole truck had boca ceramics and i loved them. huge difference and still are going strong ( i was actually thinking of taking them and putting them in the ve8 but I'm thinking I'm just going to buy some new yellow lighting sealed ceramics from boca). hpi bearings in the diffs don't last more then a few cycles before they are close to total destruction.
 
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Baddasz_Savage said:
i will say you are correct about the bearing sizes but there are ways around it.
1. maintain them. check and replace
2. buy some boca ceramics (metal shielded ones) they are "cheap" and work great. i had well over 40 cycles run thru the same set of bearings in the truck and they still are super smooth. that includes bashing and racing. the whole truck had boca ceramics and i loved them. huge difference and still are going strong ( i was actually thinking of taking them and putting them in the ve8 but I'm thinking I'm just going to buy some new yellow lighting sealed ceramics from boca). hpi bearings in the diffs don't last more then a few cycles before they are close to total destruction.
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BA I have a new mod for this ... Fred wanted to make the thread for it so its not up yet..
 
even better! hop to it so everyone has a new mod to do to there trucks.
 
turning the cup in a lathe to make the 8x16x5 bearings fit is a mod that we have been doing for a while(used to do the#86922 gear also) but it weakens the diff cup. Warhead diff cups use the 8x16x5, but are hard to find in aluminum CEN pinions are weak, but they offer an optional H-D version now. BULLIT-PROOF`s are great,yes, but still use a weak diff cup, as compared to the CEN diff cup. Spider gears are also stronger in the CEN. don't get the wrong idea that we are CEN lovers, we all love the HPI SAVAGE !!
 
BA!!! get this write up please... this is one modification i will want to do on the next tear down!!! will be time for a boca bearing upgrade too... Stock ones are rubbish after 10 runs or so!
 
well as my buddy that borrows my account said all that you do is weeken the diff cup by doin that mod but if you get the cen they are X2 stronger every where but pion but thats why you get the hpi pinon they are identical and as far as gearing hpi copped CEN so shut it same tooth count for both adn i have seen him land on the rear end with the cen at wot after a jump nothin does that with the other truck with the hpi's and broke pinion
 
redneck said:
well as my buddy that borrows my account said all that you do is weeken the diff cup by doin that mod but if you get the cen they are X2 stronger every where but pion but thats why you get the hpi pinon they are identical and as far as gearing hpi copped CEN so shut it same tooth count for both adn i have seen him land on the rear end with the cen at wot after a jump nothin does that with the other truck with the hpi's and broke pinion
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they are not the same gear ratio.
HPI is 9/29
the cen is 9/26

ill state this again. hands down the hpi's are better. there are ways to fix the bearing issue. cen get the job done but the hpi's will outlast them.
 
I may be wrong but, I believe you can use the hellfire diff case which uses the 8x16x5 cup bearings, and then use the hpi bp diff gears on those cases, you end up with the BP gears and the better 8x16x5 bearings
 
B-Woo said:
how does the hellfire diff cups workout, any one tried them?
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I am using hellfire 7075 alloy cups in the mod I did for the 8mm bearing. they are in my Flux now and so far 100%
Unlike Cen the diff fluids work in BP's. Diff tuning is is #1 for me and why I dumped the cen when BP's came out.

Pics of it are in my gallery

Link to cups. you will also need 32 shims
They do take shimming skills to make them work. you cant just put the parts in the cup or it wont make it 10 feet b4 the internals granade
DSC_0141.jpg


Note the shims this is for all 6 gears to have correct mesh to each other. Again more advanced then shimming a diff to a bulk
DSC_0138.jpg



redneck said:
well as my buddy that borrows my account said all that you do is weeken the diff cup by doin that mod but if you get the cen they are X2 stronger every where but pion but thats why you get the hpi pinon they are identical and as far as gearing hpi copped CEN so shut it same tooth count for both adn i have seen him land on the rear end with the cen at wot after a jump nothin does that with the other truck with the hpi's and broke pinion
Click to expand...

Start by reading this.. Do you see what you said ? buy the hpi pinion for the cen and he broke the hpi pinion just a few lines appart... ummm make a point ? Also whats the shut it about> ? I hope that was not to a member and was a typo. thats shuts accts off as far as I am concerned..

we have had the CEN GST's snap clean off they are not stronger by any means look at ba's post above. they don't hold up to the flux. Nitro maybe, Flux no. I still have a set if you are a believer I will sell them to you a heart beat. 75 USD shipped to USA they are unused and modded for savage. PM me if you want them. I sold my used set for 80... They have been in a box for about a year now. Time to go as I'm not going back to them...
 
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Bank you got a link to the shims you used for those cups?
 
I'm sure i could just bring the bevel gear shafts down to my local homedepot and find some appropriate shims that way.....
But what was the size you did use bank.

Looks like it does take a bit of shimming, but that shouldnt be a problem anyway.

Thanks for those pics bank
 
not trying to argue with "friddy", but you said in the first response "plus you have to mod them, bullit proof, drop in and your done" so now your saying that HELLFIRE parts is the way to make the HPI diffs work, which also require "modification" to work properly in the SAVAGE. With this "MOD" , I also would agree that the HPI diffs are "strong" but they are not "drop-in and your done" as you tried to claim! The truth is that HPI has tried to improve on a product that was intended to be used in another application, and they have only improved it slightly. You agree that BULLIT-PROOF`s are not the only "upgrade" that is needed to make a reliable set of diffs! The CEN`s have worked better for me, and i have tried BOTH! At 50. each (canadian), the CEN "MOD" was very reasonable, ( had to drill 2 holes, WOW) unlike the HPI`s at 60. each ( plus the cost of HELLFIRE parts )
 
the only mods required is shimming correct? shimming isnt a mod anyway....

Redneck, how have the CENs held up in your flux so far? some people on MSUK say that they blew their diffs in a couple of standing back flips...
 
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