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.21 bb

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SilentHunterKellen

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According to alot of message boards, people consider the .21 Nitro Star BB engine a big weak point in the savage. Now, Hpi states that the .21 BB puts out a massive 2.3 horsepower at 30,000 rpm. I find that to be unrealistic, but I want some feedback on owners who have the engine.
[move]-Kellen[/move]
 
I really can't believe that some people would think its a bum mill. It really isnt! I dont know about their claimed HP rating though. Actually, I think it paired up well for an RTR. No, it doesn't do wheelies like an RTR Maxx out of the box, but then again, the Savage wasn't meant to do wheelies. But if you put the .21 bb on the maxx I bet it would be flippin all over the place! Top speed isnt as high as the maxx either. 31mph on the Sav and 45mph on the Maxx. This is according to the latest Radio Control monster Trucks edition by Car Action. A little bit of spur/bell changing should close the gap. Not to mention, mine isnt/wasn't that slow either.

Either way, lb for lb and dollar for dollar, that mill is good for an RTR. And if you ever go to upgrade, mills like the Hyper 8 port and Picco .26 Outlaw are inexpensive and blow the doors off the competitors!
 
:stupid:

I've been waiting some time to use that smilie on the previous poster. :D

For a stock engine, the NitroStar 21BB is decent. But most people are looking for something more than decent. That is why there is such a competitive market for stronger engines. Çh®i§tiªñ makes an excellent point about proper gearing. A smart modeler will take a look at how his engine is running and regear as necessary to get what he wants out of the engine. The same holds true for this engine, properly geared you might see some bigger speeds. Properly geared you could guarantee wheelies. It is all in what you want.
 
Question....isn't the cooling head on the .21 bb by HPI really crapy or something like that...Don't they keep breaking on the same place ?
 
It does tend to break when it takes a landing directly on the cooling head. But then again most cooling heads will take some damage (small or large) when they are landed on. Cooling heads are not landing gear. That is why there are roll cages and other means to protect your engine.
 
Originally posted by TINY_MAXX
Question....isn't the cooling head on the .21 bb by HPI really crapy or something like that...Don't they keep breaking on the same place ?
Click to expand...

I believe alot of the earlier production savage's cooling heads suffered weaknesses. Alot of them messaged HPI on their boards complaining. HPI quickly fixed that. I dont think the Cooling head is made of billet aluminum like the .15FE engine. But hey, theres plenty of fins to make up for it.

And, the Savage was NOT meant to do weelies. I asked HPI why, and they said "it helps to improve acceleration and traction" and I agree. The rustler loses alot of traction when it pops wheelies. But the cool thing that I took advantage of is, I put a metal block on the end, so when it tries to wheelie, it doesn't but instead makes cool sparks. I dont know what kind of metal it is.

And for the .21 BB engine, I feel sorry for it. Traxxas kind of screwed HPI up the ass because of its new 2.5 racing engine. It is VERY powerful. Now, alot of R/C newbies are expecting alot from RTR engines thanks to Traxxas. I think the .21 should be enough power after watching some Savage videos-including EL's. As for the other Hpi engines, the .15FE is a good engine, speedy but didnt last very long. Damn.

And as Christian and Sky mentioned, gearing will make a world of diffrence. I've seen some drag movies with .21 BB with new spur gears and pinion gears, VS a Stock T-Maxx, and it Kept up with it.

31 mph on the Savage and 45 on the T-maxx
Click to expand...

I'm not convinced that the T-Maxx goes 45. I believe it hits the high 30's and probably hits 40. But 45...I dont know...my rustler barely hits 45. As clocked by a radar gun. and thats frickin fast. The T-Maxx has the same engine, and is like 6lbs heavier. The only variable is the 2spd. I'm not convinced.

And a message to savage owners: dont land directly on the cooling head!:hehe:
[move]-Kellen[/move]
 
Kellen,

There are easier ways to prevent wheelies than using a block of metal to create a remote controlled sparkler.

The first one that springs to mind is moving some weight forward in the RC to shift the center of gravity forward, making it harder to pull the front wheels up.

The method I prefer is in adjusting the suspension. Make the rear stiff to lessent the squat brought on by going WOT and soften the front suspensionto help the RC nose down a smidge...effectively transferring the down force to the front and allowing the RC to take off like a shot without making those nifty looking wheelies.
 

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