Arrow Racing GTR .21 Engine Thread
#1276
Almost done with break in on my GTR plus. Thing is a beast. Just want to make sure I got this mid range setting down. If I back it out 2 turns from flush so that its pointed at 2 o'clock, isn't there 50% chance that its actually pointed at 8 o'clock? I may be over thinking this but since the screw head "points in two directions" how do I know its pointed at 2 and not 8?
#1277
In my lunacy I had myself thinking that I was turning it all the way in (similar to the high speed setting) then backing it out 2 turns etc... Either way, great little engine. Has a ton of bottom already. Scared to see what happens when it really settles in.
#1281
Try.....the os speed....v spec crank on my arrow 5 ports.....it increases the low end and it's responsiveness significantly.....but must be on a os 2060...........power everywhere......
with the arrow pipe.....rpm....max out pretty quickly......
with the arrow pipe.....rpm....max out pretty quickly......
#1284
edit...
see it here
http://www.vpprousa.com/engines.html...category_id=85
Based off the O.S. Mugen Ninja JX-21 BO1A V-spec engine. (Compare to OS 21VZ-B Speed & Ninja JX21 B01A)
see it here
http://www.vpprousa.com/engines.html...category_id=85
Based off the O.S. Mugen Ninja JX-21 BO1A V-spec engine. (Compare to OS 21VZ-B Speed & Ninja JX21 B01A)
#1285
Seems the new arrow 2103 pipe resembles the Ofna 086 in shape....did anyone else have some time on the new pipe? How did it run? I'm trying to find a replacement pipe for the 086 but something built stronger.
And the pipe wouldn't get dented easy.....mine over 3 races....and still looks brand new......super hard pipe.
#1287
This engine is vspec based. So I used os 2060.........it is ok....smooth very good runtime but the low end is sluggish.
Engine was 3 port before. New is 5 ports....so the 2060 didn't work too well anymore.
Once I changed over to the Arrow pipe......it changed the low end dramatically. .....power everywhere. Only problem my runtime drops 1 min ++.....used a 7 mm venturi. ....haven't try a smaller one yet.......now engine freaking stable.....no mysterious flameout.....which I suffered in previously but only one or two occasion.
Engine was 3 port before. New is 5 ports....so the 2060 didn't work too well anymore.
Once I changed over to the Arrow pipe......it changed the low end dramatically. .....power everywhere. Only problem my runtime drops 1 min ++.....used a 7 mm venturi. ....haven't try a smaller one yet.......now engine freaking stable.....no mysterious flameout.....which I suffered in previously but only one or two occasion.
#1288
Tech Apprentice
Joined: Apr 2012
Posts: 56
well heres the scoop. i had a arrow gtr 21. was running it today and could put a tune on it at all. so i pulled it out after first race to see what was wrong and found the case to be cracked right along the casting seam at the bottom of engine. thought that was odd. any one else have this happen??? please help
#1289
but........the breaking....of case have many. ....reasons. one main issue is the chassis flex.....it only have issue in excessive....flex.
Not just the issue of crankcase. ...but other known causes are like smash clutch bell bearings......main bearings go off....fast....the big scratch where the clutch bell sits......conrod breaking......all this caused by chassis flexing.
Not just the issue of crankcase. ...but other known causes are like smash clutch bell bearings......main bearings go off....fast....the big scratch where the clutch bell sits......conrod breaking......all this caused by chassis flexing.



