| Re: New Manny Tranny on hills [message #195328 is a reply to message #195321] |
Thu, 10 January 2013 00:23   |
George Beckman
Messages: 1085
Registered: October 2008
Location: Colfax, CA
Karma:
|
Senior Member |
|
|
| robertmcw wrote on Wed, 09 January 2013 18:49 |
Would a Variable pitch converter (creates a 6-speed transmission.) help in the mountains?
Robert
|
I have the switch-pitch and it is indeed handy. One of the good features is that the "regular, not switched" stall is lower than the original torque converter. Our stock converters have a stall of about 2200. (Lock the brake and step on it and the RPMs go to 2200.) When not switched mine is more like 1700 RMPs.
When I switch the converter the stall is more like 2600+. This can jump you back onto a good torque range without shifting. The thing to remember is automatic transmissions have cooling lines in the radiator for one reason. Torque converters produce a ton of heat because they slip. The more they slip the more heat is produced. I never keep my trans in switch for more than a minute or two. I have never seen the heat going up quickly but I also know it is way hotter in the torque converter than in the pan and there is probably a lag between real heat and the gauge.
When I have a tough hill, I like to run my 455 between 2700 and 3200. It is a good engine and seems to pull well in that range. At that RPM I know the converter (not switched) is about as locked up as it will get. But it is slipping. Hills make the temp go up.
Lug an original converter down to 2100 and it is beginning to slip big time. Trans heat will follow. Run it at 2100 on a hill long enough and I think you will be looking at a new transmission. It just cannot dump the heat quick enough.
'74 Eleganza, SE, Howell + EBL
Best Wishes,
George
|
|
|
|
GMCforum
Search
Help
Register
Login
Home
