oquela

I just built my first rc truck-a Tamiya Blackfoot Xtreme. I did the full bearing upgrade. I want to upgrade other parts without completely destroying it. I want it for basic bashing around grass and dirt, but mostly some street/pavement runs.

I've noticed it's not going to break any speed records with a stock silver can 540, but I'd like to go a bit faster. The recommended speed hop ups are a sport tuned black 540, and a 20t pinion, but I've read the difference between the silver and black 540 motors is minimal. (I've also read that going brushless can damage the gears, which I do not want to do-besides, some of these brushless set-ups are worth more than the truck itself.)

1) recommended motor that will speed me up, not damage the gearbox, and won't break the bank?

Next, I'd like upgrade tires (since the included ones have already lost their little "spikes."

2) which tire ( tire size/rubber composition) should I be looking for? What about tire foam inserts?

Finally, I know that oil filled shocks/springs are recommended and improve the suspension/ride.
3) Which size shocks can I fit on this without modifying the body? Are other longer shocks recommended (with modifications)?

Any help would be appreciated.

The Mad Modder

I don't know where you heard that a brushless system will damage the gearbox, but it won't. The BFX has one of the strongest RC truck gearboxes built in plastic. The weakest link in the BFX drive-train while stock are the drive shafts, which will still handle a mild brushless system. There are upgrade cv type shafts you can get for it that are supposed to be stronger and I've heard the the shafts from an ofna evo will fit.

1.Tamiya's dirt tuned motor will give you more speed than the sport tuned(black can) one. Unfortunately there isn't a great selection of brushed motors available because many companies are switching over to making brushless motors only.
http://www3.towerhobbies.com/cgi-bin...?&I=LXMVR1&P=0

2.Any 2.2 truck wheels and tires will fit. Don't get ones made for the front wheels of a 2wd, though, since the way the bfx is designed regular 2.2's fit on all 4 corners.
For my bfx, I have Imex J-hawgs on it. They have great traction, but they're a bit on the heavy side. For one of my higher speed trucks I use Proline dirt hawgs, which are smaller in diameter(about 4"), but are lighter and get good traction as well.

Whether you need foam insert or not depends on your tire. Some are thicker and can support the truck without inserts(like the stock tires and the j-hawgs) tires with thinner sidewalls , like the dirt hawgs, need foam to support them, but they work just as well as thicker tires and they don't weigh as much. Both the dirt hawgs and j-hawgs come with foam inserts.

http://www3.towerhobbies.com/cgi-bin...&I=LXDU11&P=ML
dirt hawg

http://www.imexrc.com/servlet/the-28...G-TIRES/Detail
j-hawg

3.Stock size shocks are touring car sized. I think 1/10 buggy front shock may fit if used on the further out hole on the arm(looking into that for my truck). There are shock tower extenders available that will allow you to use 4" truck shocks. GPM makes an aluminum one and xtreme racing makes a carbon fiber one. The Xtreme racing one is made in USA, while the gpm one is chinese.

Sorry for taking so long, but not many post in this forum anymore.

oquela

Mad Modder,
Thanks for the quick reply. It is MUCH appreciated. Got a couple more questions:

1) I was told tires/wheels shouldn't be glued (the manual said that,) but my rear wheels are spinning inside the tires when I punch it from a dead stop. Should I glue? If so, is it a couple of drops or all the way around?

2) I really like the dirt tuned motor. Had never heard of it! Thanks for the recommendation. I will def. get one. Which "mild" brushless motor rating (kv) would you recommend?

3) Thanks for the shocks info. I had no idea what the other holes on the lower arms were for! Another noob question: How does the suspension quality change as the shocks become less vertical/more slanted as they're mounted closer to the wheel on the bottom arm outer holes?


Again, all the info is much appreciated! Thanks again!

The Mad Modder

1.Tamiya recommends that you don't glue the tires because they sort of act like a slipper clutch to protect the transmission. In the bfx's case, though, the trans is very strong and gluing the tires won't hurt anything. You generally glue all the way around both sides of the tire. Also, if you ever do chrome wheels, scrape the chrome off in the grooves the beads fit in.

http://www.youtube.com/watch?v=6ux4J...07C14604294014
(note: horizon is promoting their own brands in this video. Isopropyl, rubbing or denatured alcohol will work fine to clean the rim and tire bead.)



2.Well the dirt tuned motor is a relatively new motor that Tamiya makes. As far as brushless goes something around 13t or 3300kv will be faster and a good deal more powerful than even the dirt tuned motor while still being mild enough for the stock bfx to handle.
I've had good luck with Novak's systems.
http://www3.towerhobbies.com/cgi-bin...?&I=LXWLW9&P=7

3.Well, the further out holes were actually made to let the truck ride a little lower, but using them would allow you to use slightly longer shocks an remain at the same ride height. Front buggy shocks(at least the evader's) are about 25mm longer than the stock car shocks the truck uses so using them would only lift the truck a little bit if you use the further out setting. Again this is just what I think from specifications I've looked up, I haven't tried it yet.

Using the shock tower extensions would allow you to use 4" truck shocks and doesn't require any modifications.

Shock performance is actually not affected too much by the angle they're mounted at. They are affected more by where they are mounted on the suspension arm. The closer in to the chassis they're mounted, the softer they'll be and they won't have as much control over the wheel movement. The closer to the wheel they are, they will be firmer and the shocks can control wheel movement better.

That's why Ford moved the shock absorbers in the rear of their newer f-150's closer to the wheels. It helps the shock to control the wheel movement better which leads to better performance.

oquela

Thanks Mad Modder,
just installed the Dirt tuned motor, a 20t pinion, and have just finished ordering oil filled 65mm shocks (stock size upgrade.) I'm gluing the tires as we speak.

Your recommendations are much appreciated!

The Mad Modder

Glad to help.