RCBasher.com - HPI Nitro MT Info and Mods

Nitro (ni-tro) -prefix: Nitrate; Nitrogen; Containing the univalent group NO₂

HPI Nitro MT

I've got some "real" content coming (detailed information to go with the pictures), but in the meantime, check out the pics of my NMT in various stages of its life if you'd like. The oldest pics are at the bottom, newer as you scroll up. I'll detail the 125cc tank swap, brake-disc-up-front swap, and big-block engine conversion, as well as other mods when time permits.

HPI Nitro MT - Big-Block Conversion

My NMT was a lot of fun with the .15CV-R, but it needed more power. I tried and Epic .18 for about a week, but thanks to a VERY dusty, sandy track I toasted that engine. Lots of dirt got past my filter and into the engine. Time for a new powerplant!

I had an old OFNA Force .21 engine with a Savage 21 head available (borrowed), so why not drop it into the NMT? It was pretty simple, actually. I used the big-block mounts, drilled new holes in the chassis to match up with those mounts, rearranged the throttle servo for slide-carb operation, swapped to the MT2 slipper setup, put the brake mechanism in front of the spur assembly, and did a little trimming on the body. Done! Fortunately my drilling was spot-on, because with holes rather than slots, there's no room for mesh adjustment or gear changes. It works great with the gearing I've got installed though, thanks in part to large power in a smallish truck.

It wasn't long before I had to return that engine to its owner, but by then I had a spare GS .21B01 out of a Storm RTR 1/8-scale buggy that ran great so I dropped it into the NMT. It had torque to match the Force 21, but the GS engine could actually rev, something the Force would never do. Ahhhh, now THIS is FUN!!!

Great acceleration and nice top-end, can't beat it! I'll probably slot the chassis at some point so I can do some gearing changes, though. Sometimes it's nice to run regular 2.2" tires rather than the big Masher 2000s, but the gearing is a bit short for them. Acceleration is great, but it tops out pretty fast.

Obviously a big-block in an NMT requires a different header and pipe, so I used a stock Savage header for the quick turn forward and put on an RB 086 pipe (my favorite!). To cope with the added weight of the 125cc fuel tank and the big-block engine, I threw some GS Storm 1/8-scale buggy shocks on the NMT as well, with the stock GS springs up front and soft OFNA blue springs out back. Works great! Somewhere along the line I added a Hitec 625MG steering servo and Pro-Line Masher 2000 tires, too.

HPI Nitro MT - O.S. .15CV-R, 125cc Tank

I sold my original NMT to a friend so I could buy a new Savage in January of 2003. Well, I missed the NMT so much that in the fall of 2003 I traded my RC10GT tub-chassis roller for an NMT roller from that same friend a few months later, got it together, and dropped in an O.S. .15CV-R engine. A little more torquey than the Fantom, but not quite the same rev-ability. Great engine, though! I also bolted on an OFNA #30280 125cc fuel tank for longer run times and powder-coated the chassis and pipe just for fun.

HPI Nitro MT - Fantom FR.15 Engine

By this time I destroyed my original, anemic .15FE engine thanks to a runaway, and installed a surprisingly-powerful and high-revving Fantom FR.15 engine. Also by this time I had switched to Pro-Line Masher tires to help ease landings and for more ground clearance (some body trimming was required), and added an HPI tube header, RC10GT Factory Team pipe and throttle return spring. BIG performance increase! I even considered installing a Wasp .12 engine, but never did.