DIR Return Create A Forum - Home
---------------------------------------------------------
CycleKarts GB
HTML https://cyclekartsgb.createaforum.com
---------------------------------------------------------
*****************************************************
DIR Return to: Tech Forum
*****************************************************
#Post#: 11761--------------------------------------------------
Torque convertors and RPM
By: Ade Colmar Date: October 24, 2024, 5:24 am
---------------------------------------------------------
Since joining the forum a few weeks ago I have been madly
researching all the ins and outs of cyclekart building. I’ve
been enjoying the research hugely and a big thank you to
everyone who posts and helps spread the word and the knowledge.
I’m beginning to believe (fear) that the area with the greatest
technical mysteries is the torque converter (and its interaction
with the engine) and I’m looking for more insights on this. My
understanding at present is that the driver (engine) pulley
sheaves respond purely to RPM, whereas the driven pulley sheaves
respond only to the rear axle torque resistance (load). As the
Vee formed by the sheaves is acute, then the clamping forces on
the drive pulley are quite significant, so extremes of clamping
forces are to be avoided to prevent unnecessary power losses (as
much as 15-20%).
This brings me to my question: High RPM and high axle load give
the greatest clamping forces, therefore the greatest losses.
Therefore, is what you really want from the engine high torque
at moderate RPM? This avoids the engine pulley being maxxed out
on diameter (high rpm) and still allowing some interaction
between the driver and driven pulleys. This is a little at odds
with governor removal on engines. I understand that 3600rpm is
unnecessarily low, but would resetting the limit on a suitably
tuned engine to around 4500rpm not be more effective? Setting
the max RPM at around 4,500 may loose say 1BHP, but is that
minimal additional horsepower actually useable, or is it just
lost in belt friction?
Ade
#Post#: 11763--------------------------------------------------
Re: Torque convertors and RPM
By: Phaeton Date: October 24, 2024, 12:46 pm
---------------------------------------------------------
[quote author=Ade Colmar link=topic=1561.msg11761#msg11761
date=1729765495]
Setting the max RPM at around 4,500 may loose say 1BHP, but is
that minimal additional horsepower actually useable, or is it
just lost in belt friction?
Ade
[/quote]
Or is driver weight more important?
*****************************************************