Originally Posted by Extreme_RC

The 800-73 doesnt seem to lack any torque in my 127mm Ramtec setup, 17lb thrust at 4800 watts on 12s is not too shabby.

How many amps??

115A, pretty nice balance point and I wouldnt call it inefficient either

that sounds really good ...was that on the test bench? thats a lot of thrust for the watts and amps .

Yeah, that seriously got my attention, tell me more

Here it is running with my 2+ year old 5000mah 30c packs, someday I will plug up new packs, every time I think about it I run out of 5000 and 6000's!

You can see my packs sag out and stabilise at 16lb thrust at 4500 watts, not bad eh

Extreme RC's 127mm CNC Alloy Ramtec Fan with our new 5075 inrunner! (2 min 44 sec)

That's similar to the scorpion DynEmax set up so not bad at all. The thing about the Ramtec we have found is that in the air it seems to take longer to get on step, it must be something to do with the blade pitch. We ran one with a Big Screamer and it produced 20lbs of thrust but pulled around 190 amps, once on step it was good but even with ample thrust tube diameter it just lacked low end thrust compared to the Dynamax, Schubeler HST and Turbax.

Originally Posted by Extreme_RC

Here it is running with my 2+ year old 5000mah 30c packs, someday I will plug up new packs, every time I think about it I run out of 5000 and 6000's!
You can see my packs sag out and stabilise at 16lb thrust at 4500 watts, not bad eh

Not bad at all, thanks.

Funny as others have found the ramtec faster in the air, and it certainly was reported as such back when running OS91's in the glow days.

Originally Posted by bri6672

That's similar to the scorpion DynEmax set up so not bad at all. The thing about the Ramtec we have found is that in the air it seems to take longer to get on step, it must be something to do with the blade pitch. We ran one with a Big Screamer and it produced 20lbs of thrust but pulled around 190 amps, once on step it was good but even with ample thrust tube diameter it just lacked low end thrust compared to the Dynamax, Schubeler HST and Turbax.

Bri, this is the motor I saw the 160 amps on I mentioned in the other thread.

I would think the Big screamer motor was more efficient, prolly not a good test motor after reading this

IINM Marks using a custome motor?

Decent numbers no doubt

Mark have you tested it on 14s yet?

Regards

Originally Posted by Extreme_RC

Funny as others have found the ramtec faster in the air, and it certainly was reported as such back when running OS91's in the glow days.

I'm no expert but my guess is that it might have the equivalent of a higher pitch. Takes more to get in step but moves more air when it does?

No I am using the 800-73, I had been pushing het for a 45 or 50mm inrunner for a looong time now, was so happy when they sent me the samples to test!

Yes have run it on 14s, still using my old 5000 packs, the results were 141.4A and 7100W for 20.9lb thrust. With some big packs behind it we will see a good 22lb at 160A I reckon. Temps were a non event, in the alloy housing the motor runs really well.

what kv 800-73 ?

Should be the 590 KV

We have tested the big screamer in both fans, once on step the Ramtec is great and has good top end performance but just lacks the low end power. The Dynamax seems to be more balance with a good blend of low end and top end, the higher pitch is moving more air when on step but it takes longer to get there. This is all real world expierence not hypotheticals, if I haven't tested it myself I don't comment on it! Maybe Extreme Rc's stators are making a difference??

thats what i was thinking too ,back in the day i played with longer stators on the turbax and larry and i felt that it helpd with thrust and speed.im sure his alloy shroud has less startors than a Ramtec fan ,and they may be shaped different. the 590 kv could account for the lower amps...i think he just has a great set up there ,those are great thrust to amp numbers.