What ratio to trick GV-1 to 2200 Headspeed?

[erniefritz]

OK all you smart math Helifreaks out there... i'm running a GV-1 and it only lets me go to 2100 HS. i run 2000 HS in idl1 and 2100HS in idl2. if i wanted to actually get 2200HS out of my machine in idl2 while the gov still thinks it's 2100 , What gear ratio would i put in the GV-1 to trick it?

I know that this actually puts the motor out of the RPM band and really screaming, but i thought it would be nice to try just to see..

I was thinking it would be 8.9 ???

[Mercuriell]

Gee teach - that's too hard for a Friday afternoon - anyway:

If the GV-1 wants to limit HS to 2100, with an 8.5 ratio this will be a motor speed of 17850 as HS x GR = MS.

So if the GV1 is going to limit them little magnets whizzing round to 17850 we need to tell it what GR will make real-life HS of 2200

As GR = MS/HS this comes to 17850/2200 = 8.11 n'est ce pas ?

Better get the 'ol tacho out Ernie :lolol

[Finless]

Dang... ya beat me to it... I was just going to tell him to change the gear ratio!

Good job John!

Bob

[erniefritz]

nope , Didn't work on 8.11 ratio , seems we went the wrong way..... ??? Engine RPM way too low... , if i want 2200 HS the engine needs 18700rpm.... i think the gear ratio needs to be higher like my first guess...

Hypethetically - if i tell the GV-1 the gear ratio is 10:1 and i want 2100HS it's gonna let the motor spin to 21000rpm and that's where it will want to keep the engine...

tell me if you think this is right , i'm going to try it this weekend. If i want 2200hs at 8.5:1 which is what we run , the engine needs to spin 18700 , now take 18700 motor rpm divided by 2100HS which is what the GV-1 is limited to gives me 8.90 ratio

so what this means is if i put a 8.90 ratio in the gv1 and a hs of 2100 , the gv-1 will let the engine spin to 18700 , that is where the gv-1 thinks 2100HS is. but since we are running 8.5 ratio at 18700 , this = 2200 HS

Sound good? Anyone else have an idea... I'm flubbing my way thru this , but i'll let you know how it fly's and what i come up with.... :wink:

[Mercuriell]

Depends whether the GV-1 limits head speed to 2100 by calculated HS or an actual measured maxiumum engine speed - as my calculation didn't work I guess the former is correct in which case your calculated ration might work - tacho rules :lolol

[MarkD]

The GV1 measures engine speed if installed right so set the main gear to a lower tooth ratio to get a higher head speed

[erniefritz]

Mark , are you saying that going from 8.5 to 8.1 is going the right way? ,my HS got lower when i went that way...???

lets assume i put 1:1 ratio on the GV-1 and a HS of 2100 , it's going to limit the engine RPM to 2100 rpm because 2100 rpm on the engine at 1:1 is 2100 HS , now at 2:! it's going to let the engine spin to 4200 rpm because the gov only reads the engine rpm and at 4200 rpm at 2:1 that is where 2100HS is... keeping along the same lines , if i tell the GV-1 8.9 ratio and 2100 hs , it's going to spin the engine at 18700 , but really at 18700 that's 2200hs.....????

I guess the only way to find out will be to try it tomorrow and tach the head..... I'll let you guy's know how it goes... :wink:

[tcast305]

erniefritz,

You will need to set the gear ratio on your GV1 to 8.9, at that ratio the GV1 will be looking for a motor RPM of 18690 to maintain 2100 RPM headspeed since you told it you have a 8.9 to 1 gear ratio (2100x8.9=18690).

So when the GV1 is governing your motors RPM at 18690 due to the ratio that you put in, your actual headspeed will be 18690/8.5=2198.82RPM (close enough to 2200RPM :D ).

Now I don't own a GV1 so I dont know if it supports that setting of a gear ratio of 8.9.

Thanks.

[erniefritz]

yep, I thought i was right. the GV-1 supports 8.9, just going to try it to see how it does... I have the NEU 1515/2.5 in my 600E and run a 2320hs at 100% , just thinking what 2200 would do for the 600Nitro , i know it will be way out of the 50 Hyper's power band but if you don't try you don't know.... i just want to make sure i don't run it too lean.... :glasses2:

[erniefritz]

That was it guy's..... 8.9 gives 2200 HS , 8.7 gives 2150 HS , that's if you have 2100 as your HS in the GV-1 , the machine runs best between 2000 and 2100 HS tho , 2050 seems the best.... 2200 is just too much , the machine is lightning fast but the engine is way out of it's RPM band....