HPI Hellfire, soon to have an Axial .28RR Spec 1

[Defiantspaz]

I have read some people don't think the a-arms are strong and that the stearing servo is junk.

I can say that the first run of Hellfire A-arms were very weak, BUT HPI found out this was an issue and redesigned then to be much stronger. If you have the older style just contact HPI and they will send you a new set, FOR FREE! I broke my first a-arm about 5 tanks into the break in. Called HPI and they sent me a new set, all 4, of lower a-arms at no charge.

The strearing servo, ya, JUNK! Stripped out in 5 minutes of running the truck. I was kinda confused because it is the exact same streaing servo used on the Savage X RTR. I would think that the Savage would put more stress on the servo than the lighter Hellfire, but who knows.

I upgraded to the JR XS3 pro radio and used the JR Z590M as the throttle servo and a JR Z650M as the stearing servo, so the quality of the stock radio gear is no longer a concern to me.

The K4.6 HO is really a good fit for the Hellfire. I noticed that the truggy would spin the tires pretty bad with the stock gearing so I installed a 17T HPI racing CB and the Hellfire has much more traction coming out of the corners and much higher topspeed. As good as the K4.6 HO is I am looking to get more power into this truck. I was looking at the STS D28M, but after the hassle of the RB modded STS D30M's carb I am going to get the new Axial .28RR Spec 1. My friend has an Axail .28 Spec1 and loves it, so the RR version should be a better mill.

Mods to my Hellfire RTR are Integy MSR7 shocks, Hellfire SS rear drive hubs, JR radio gear, Sway bar set, Axial beadlock rims with Axial oversized Terrarizer tires, rear wing and 17T CB.

I plan on getting the alloy chassis supports, upgraded shock towers and the lighter spur gear. I havn't had any trouble with any other part of the Hellfire. The truggy handles very well and is balanced. The Hellfire with the 17T gearing has no problem out running my friends Savage XSS with the K4.6. I have no idea exactly how fast it is but it just screams weather it is on pavement, gravel or dirt.

Some parting pics:

 

[Memnoch]

Looks great. Man is that thing w-i-d-e with those rims on it!

 

[Revo-World]

nice HF you have there

 

[X25]

How do you like the HF give us a run down on it if you would please. Also it is a very nice looking HF

 

[Defiantspaz]

OK first off you need some history about the state of RC's in Uncasville CT. Anything new is completely unheard of in my area. If Tower Hobbies wholesale sells it then my area has it, BUT thats it. No STS, no Novarossi's, no RB concepts. If it is new and hot it isn't in my area. When I did the race truck Savage I got all kinds of funny looks, no joke either. When the guys at the track saw the RB modded STS 30 they didn't know what it was. Everyone in my area has either an O.S. engine, OFNA or a Wasp.

Well I wasn't going to buy a truggy, just browsing Savage parts, and the owner of the LHS asked if I was interested in it. I told him no, he continued to tell me how great truggies are. My responce was "then why is it still here?". The owner of the HS is a cool guy, he just wanted to sell one and get it on the track so other people can see how good truggies are. Eveyone who looked at the Hellfire thought it was a junk MT with a single speed transmission. I bought the Hellfire RTR for $350.00.

First thing you will notice it how crazy detailed the manual is. It covers everything from what each shock hole will do to the handleing to how to setup your clutch shoes to suite your engine's output and your requirements.

In stock form the Hellfire is very durable aslong as you have the updated lower A-arms. Mine sat in the HS for some time so it was the first gen A-arms. I had one break and HPI sent me a set of the updated ones for free. The stock stearing servo is crap, mine stripped very quickly. These are the only parts to break on the Hellfire so far.

The stock radio meh, get a good FM radio. I went with the JR XS3 pro and love it.

The stock gearing is too short 13T CB and 52T SG. the truck would go OK but it really didn't match the powerband of the K4.6 HO. I messed around with CB's until I found the setup that made the best use of the K4.6 HO's power, what I ended up with was a 17T CB and 52T SG. I know this is a huge jump in gearing but trust me the truck has no trouble with accelleration at all. The 17T also really woke up the top end speed as you might guess. Stock the Hellfire would pull about even with a Savage XSS until the Savage got well into 2cnd gear and then the XSS would pull away. With the 17T the XSS is never out front, never. The truggy actually accellerates better with the 17T CB which is usually not the case.

The suspension is amazing on this thing. I can't explain how many adjustments there are, something like 200+ different combos. You can actually make the car handle for the way you drive, not adjust your driving to make the truggy handle. My Hellfire is setup for a really tight track right now so it has alot on the brakes stearing put into it. I love that I can go from full throttle stearing to full brake stearing if needed to suite the track. The stock shocks are top notch except that they still use the clips for preload. I bought Integy MSR7 piggyback shock and really like them.

The K4.6 HO is actually a very strong mill, it just needs the right gear combo. It pulls very well with a broad powerband and it screams up top. It is only a 3 port engine but it seems that the ports were well thought out and placed just right. I am still running the stock pipe so i might be able to get more out of the K4.6 HO with a better designed pipe combo.

The layout of thge chassis is very well done. Everything is made of high quality and the fit & finish it top notch. The Hellfire is a really stiff truggy, the SS version has alloy supports instead of the plastic RTR ones so that thing must be like granite.

The stock tire were ok for all around use. I had the Axial beadlocks and Terrarizers on my race Savage and swapped them to see how the Hellfire would respond to them, needless to say they never made it back to the Savage. I am getting another set of Axial beadlocks with Axial Cubes tires for the Hellfire and then the Savage can have it's rims and tires back.
I will rate everythin from 1 to 10, 10 being best.

Quality = 8.5, Slight deduction for the servo and lower A-arms.
Radio = 2, Get a new one if you get the RTR, the only good deal is the standard 6v flat pack.
Handleing = 9, I don't know of anything that is perfect so I never give a 10, but this thing is close. except for the lower A-arm.
Engine = 8, I give the engine an 8 because with the right gearing it really goes. The wrong ratios will kill even the most powerfull engine powerband.
Brakes = 9, braked are really good, sometimes too good.
Durability = 8, again the only two things to fail were the lower A-arm and the servo.
Fun factor = 9.5, breaking stuff isn't fun, but after you get the detail right this thing is a hoot.

If I missed anything just ask away, I'll try to answer any questions you guys have. I love this truggy. It handles everything I throw at it and just keeps on motoring. The new Axial will push the Hellfire to the next level. I'll keep you guys updated when I get the Axial .28RR Spec 1 installed and broken in.

 

[Defiantspaz]

Looks great. Man is that thing w-i-d-e with those rims on it!

I love the offset Axial built into the beadlock rims. With the tires out so far the stability is awesome at high speeds and the turning hasn't suffered at all.

 

[Jaret2007]

Top Speed with those Gears

Hi, I just finished building a Hellfire SS kit and I spent hours trying to find out if it was possible to use a 52t / 17t gear combo instead of the 52t / 13t one that came with the kit. Thank - you for posting the changes you have made.

Do you have any idea of the top speed the hellfire now with the 52t / 17t gear combo? Or can you at least give me an estimation?

 

[Defiantspaz]

I never really radar'd the Hellfire but it has more topend than a Savage XSS, which the box states 46 MPH for the XSS.

I'd guess a solid 48 MPH for topspeed with the 17/52, now this is a guess based on my race Savage with RB mod STS D30M, Savage XSS and Traxxas Jato 3.3R.