almighty15
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Lmao.... you don't want a G320 or G340 going over 17,000rpm
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Why not?...almighty15 said:Lmao.... you don't want a G320 or G340 going over 17,000rpm
Because it wrecks the bearing... I've talked about it on the Losi 5ive forum...Ice_2k said:Why not?...
I run with people who have 32/34c OBR reeds and the TTO's have never gone over 19,000rom in the real world.Ice_2k said:Well, I never owned one of these engines so I can't say for sure, but that's what OBR is claiming. Both on the website and confirmed to be directly by Sean, via email. I have the stock 32cc and it goes to ~17.000rpm, so I'm guessing an OBR-built Zenoah with reed case should go over that pretty easy....
Well, the discussion began with 17,000 19,000 is quite different, especially since you mentioned running on grass. Running on tarmac with tarmac tyres would probably increase that top rpm a bit more.almighty15 said:I run with people who have 32/34c OBR reeds and the TTO's have never gone over 19,000rom in the real world.
That's weird as it directly contradicts what sean o'neill told me on email, I just rechecked my emails. He said the reed case fm g320 revs significantly higher than the normal fm g320.almighty15 said:They might very well hit 20,000rpm when under no load, Reed engines do also loose top end rpm over the none versions due to the reed valve design.
Getting back to your original question, I tested my Dunerunner today and it hit 40mph at about 17,000rpm. My gears are 29-31-26-24. Replacing the A&B gears would get me to about 44mph, altough to be honest it already seems too fast for such a big rig.almighty15 said:In theory and sticking to a single speed what could a TT powered by a ported G320 get up to?I've heard you can swap the first 2 gears around to get silly top end but at the expensive of bottom end torque? Something a G320 should cope with much better then the stock engine?
Would 45mph+ be possible?
What about gear ratio's with the best drive?
Have you looked at the 35/25 gears?Ice_2k said:Getting back to your original question, I tested my Dunerunner today and it hit 40mph at about 17,000rpm. My gears are 29-31-26-24. Replacing the A&B gears would get me to about 44mph, altough to be honest it already seems too fast for such a big rig. Hope this helps.
No, what for? I have plenty of top speed and already can't put the power down in low revs, so I don't have any use for either higher or lower ratios.talunceford said:Have you looked at the 35/25 gears?
An engine builder saying a more expensive product is better then a cheaper one......Ice_2k said:That's weird as it directly contradicts what sean o'neill told me on email, I just rechecked my emails. He said the reed case fm g320 revs significantly higher than the normal fm g320.
I did the math on stock gears turned around for top end and with XB wheels at 15000 rpm it will do 43mph, not sure how big the TT wheels are over the XBs but you can expect some good speedphreerider said:tire choice is an element to consider, maybe 45mph more like 40, more be would be deluxe custom and alot of something else.
he G320 still has a 28mm stroke, to say it favors torque more then a 30.5 is not really true at all. rod speed will be much lower then the 30.5 and would favor high reving more then the 30.5 would. what it doesn't favor is high compression as the compressed gas is spread over 38mm rather then 36.phreerider said:its a description of how mill speed is realized at crank level. G320 favors torque. by choosing a shorter stroke motor like 230/270 with stock rod the motor can turn faster. so motor choice is a factor for hi speed as well... its just an example
he G32 still has a 28mm stroke, to say it favors torque more then a 30.5 is not really true at all. rod speed will be much lower then the 30.5 and would favor high reving more then the 30.5 would. what it doesn't favor is high compression as the compressed gas is spread over 38mm rather then 36.phreerider said:its a description of how mill speed is realized at crank level. G320 favors torque. by choosing a shorter stroke motor like 230/270 with stock rod the motor can turn faster. so motor choice is a factor for hi speed as well... its just an example
I can see the flappers getting in the way at high speed and probably not opening fully to allow this but this is just a theory that comes up I have no full proof as to why the top end won't be as good.almighty15 said:I run with people who have 32/34c OBR reeds and the TTO's have never gone over 19,000rom in the real world.They might very well hit 20,000rpm when under no load, Reed engines do also loose top end rpm over the none versions due to the reed valve design.
This makes 20,000rpm all the more unattainable in the real world.
it favors torque because of total mass/area of larger piston. doubtful it revs higher AND produces usable power because of same reason. the increased compression and less mass of 30.5 seemingly better balance for both high crank speed AND torque. the bigger volume of gas(32) produces better torque at lower crank speed, at extreme crank speed the reaction is all spin. yes the shorter crank should swing things faster but the mass (i'm guessing) is going hold it back but has higher torque earlier in the power band. i havent looked at dyno graphs and certainly have not done the numbers. it has alot of new parts in the lower end to balance and not sure of actual hi rpm crank speed and usable power, i;ll check a graph and seeGTi_Leo said:I did the math on stock gears turned around for top end and with XB wheels at 15000 rpm it will do 43mph, not sure how big the TT wheels are over the XBs but you can expect some good speedhe G320 still has a 28mm stroke, to say it favors torque more then a 30.5 is not really true at all. rod speed will be much lower then the 30.5 and would favor high reving more then the 30.5 would. what it doesn't favor is high compression as the compressed gas is spread over 38mm rather then 36.
I think you may be reading to much into piston weight and RPM, sure the G320 engine might have a larger piston but its only 2mm larger, it also has a larger bearing meaning the hole for the wrist pin is larger which will shed some weight.phreerider said:it favors torque because of total mass/area of larger piston. doubtful it revs higher AND produces usable power because of same reason. the increased compression and less mass of 30.5 seemingly better balance for both high crank speed AND torque. the bigger volume of gas(32) produces better torque at lower crank speed, at extreme crank speed the reaction is all spin. yes the shorter crank should swing things faster but the mass (i'm guessing) is going hold it back but has higher torque earlier in the power band. i havent looked at dyno graphs and certainly have not done the numbers. it has alot of new parts in the lower end to balance and not sure of actual hi rpm crank speed and usable power, i;ll check a graph and see
I'm sure a G340 might be a bit different then the G320 they as a +2mm stroker to it so it might mess around with things a little bit. I only compared the G320 and 30.5 , it doesn't seem like OBR has any graphs for the 340 so my guess is its going to be similar to the 30.5, more torque but less high revving power.phreerider said:no worries, i looked at the graphs and very surprising it has power well into hi rpms, definitely differnet animal, i was guessing it had more mass total to balance , kinda like big block not allowing more spin. very powerful balanced build
reduced i guess it would rev even higher!
we all get chatty when we love it and want more than just knowledge , its the understanding that allows discernment. good stuff , prolly will get a 320 , esp. since i looked at the graphs!
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