HPI Savage X SS 4.6, Duratrax Warhead EVO and Traxxas Revo 3.3 Hop Ups, Tricks, Tips, and Parts Reviews

One of the major steps I took when building this version of the BulletProof Savage was the conversion from the stock Savage X “easy access” differentials to the old school Savage Setup - a multi piece, Alloy Metal, differential which included the new Savage X SS alloy diff cups shimmed internally and externally.

The internal shims include thin shims and square shims to make the spider gears inside the diff cups mesh together better. Also, the new alloy diff cups from HPI do not flex! With the older versions of differential cups, they used plastic, which under stress would distort and compromise the mesh of all those spider gears. When that happens, they strip.

An ESSENTIAL step you MUST take if you want rock solid differentials is to shim for side to side clearance. This is BEST done with the alloy diff CASES as opposed to the plastic diff cases because the alloy cases don’t flex, don’t wear at the bearing races, and are generally more ridgid.

To shim the savage differentials, you need to get the hpi hellfire shims, which will take out the clearance between the crown gear and the pinion gear. You want them to mesh to where they are tight, but not crushing up against each other. One shim on the crown gear side and one on the cup side is what worked for me with the GPM diff cases. For you, it may turn out different…but that’s a start!

Here are some pics installed…to reduce weight, you may want to go with the diff cases only, using the plastic bulkheads. I got the gpm bulkheads for the bling factor (and I don’t think the bulks are vulnerable to bending).

Notice the thick piece of foam I have down in there between the bumper and the diff…this acts as a bumper for those hard landings when I happen to land on either end:

Here’s another shot of the savage differential, shimmed and installed:

After I totalled the last Savage, I got to work on ordering the latest and greatest new parts for my ongoing Savage Project. This build is the most solid one I have ever had the pleasure of putting together. This thing is solid as a ROCK now…

The details as to each and every savage hopup and mod that I have done to this truck are scattered throughout this website and labeled “Bulletproof HPI Savage X SS 4.6“.

I’m going to do a series of posts, all having to do with the Savage X, reborn as the HPI Savage X SS 4.6 (using the best parts from each generation of Savage that has come out thus far.

The first commentary I have is on the new Savage dual fiberglass disk brake system. BOY does this thing hold a tune well - they don’t fade, and they’re just as strong as the dual stainless steel system that came out a while back.

With the dual stainless steel system, my problem was that upon landing, I was bending the disks. That last crushing blow I made to it was when I landed upside down (having had no brakes to correct my in-flight pattern), I smashed the head of the engine towards the brakes, bending the brakes in, bending the engine mount/plate, etc.

Here are some pics of the new Savage X SS 4.6 Dual Fiberglass Disk Brake system, installed on the Bulletproof Savage

Notice below that the STOCK Savage X Brake Hub is too short to accomodate the new Savage X SS 4.6 Dual Fiberglass Disk Brake system…

I’m passing this knowledge on…just an fyi, not from me, but another rc fan out there:

Regarding Port size on a nitro engine, what’s the difference?

Smaller ports allow for greater intake velocity, good for low end torque, larger ports allow for more overall flow but a lower intake velocity, thereby reducing low end torque, and increasing top end power. As you will need to achieve a higher rpm with a larger port to match optimal intake velocity. Obviously undersized ports will limit power, but the same is true of over sized ports. You cant have both optimum torque and optimum top end, but you can achieve a good balance of both with proper sized intake ports.

In reguard to exhaust ports undersized ports will not allow all of the exhaust to leave the combustion chamber, whereas over sized ports will in effect lower exhaust velocity and not allow for proper scavenging of the exhaust, essentially you wont get all the exhaust out of the combustion chamber, thereby lessening power as the fresh fuel and air is smothered by leftover exhaust. Again, you must find a proper balance to allow for good flow, too big is just as bad as too small.”

Here’s the pic of the day - the guys in Hungary are fanatical about RC Monster Trucks, Buggies, and Truggies…and from the looks of this pic, Davzone is blazing the trail for Savage Owners over there. Check out this hopped up savage racer:

Photo of the day, this is “sportsfan’s” Savage X SS. Check out the battery level indicator and the swEEt body on that bad boy

This is what happens when you don’t have brakes to adjust the flight pattern (to bring the nose down!)…and land upside down from 20 feet in the air:

Damage Report:
1) Bent Motor Mount - I’m changing from this Nova Motor Mount to the Yeah Racing Motor Mount which has bolts and nuts to mount the motor to the mount at the motor instead of the nova racing design which screws directly into the aluminum at the motor.

2) Bent Engine Plate - This was a Savage X SS Engine plate, one of the newest. Welp, I broke it. HPI, get back to the drawing board! What I’m going to do is go to a thicker, one piece engine plate - hint, it’s 8 millimeters thick and HPI doesn’t make it.

3) Bent, splayed out stainless steel dual brakes - Look close at where the clutchbell mashed into the dual disk brakes LOL. These brakes bend easily anyway - especially if you land on all 4’s (which is the goal!) with the brake applied. My advice, don’t get the stainless steel brakes. They look cool, but they’re kindof noisy, they bend, and they don’t work that great for that long. What am I going to upgrade to? Hint, they’re red!

4) One Picco Carburetor - don’t know how, I guess from the carb smacking into the spur gear shaft, but the carb SLIDE got stuck wide open - so, I got a new picco carb off of ebay. Problem solved. Next time, I’ll rotate the carb a bit out from the spur gear shaft (or perhaps not land on my head?! )

Pic of the moment

Ladies and Gents, this is the setup you need for your HPI Savage X, Savage X SS 4.6 RTR, Savage 21, or whatever Savage you have…

Cure your differential stripping problem with this setup: