Lock up or no Lock up

Could anyone explain to me the pro's and con's of lock up and non lock up when people are talking about transmissions. I have seen things like lock up only on overdrive etc etc

please explain

Vic

Think of lockup as a clutch in a manual transmission car that doesn't slip and non-lockup as a slipping clutch in a manual transmission car.

The lockup converter in theory provides a direct connection between the engine and the automatic transmission to help improve gas mileage.
[addsig]

A converter that is not locked up will develope more torque, but will not allow as high of trap speed.


_________________
------- Work in progress -------
392 stroker crate engine
Race prepaired AOD with low gear ratio gear set. (2.84 1st)
3,000 rpm converter
3.73 gears
17x9 Cobra Rs, with 255/45/17 BFG KWDS tires
AFR 185 heads

<font size=-1>[ This Message was edited by: 392Bird on 1/23/03 7:39am ]</font>

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2003-01-22 19:35, 392Bird wrote:
A converter that is not locked up will develope more torque, but will not allow as high of trap speed.
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>

hmm, interesting dyno chart. What gear is the pull in? Lock up only occurs in 1:1 or OD, right? I dont understand how you get nearly 200 lb.ft of torque difference just from a lack of lock up. Can you educate [img]/phpBB/images/smiles/icon_confused.gif[/img]

<font size=-1>[ This Message was edited by: 67stang on 1/23/03 7:50am ]</font>

Torque converters are really neat things. They have the ability to allow the trans to come to a complete stop, yet still keep the engine from dying. The neatest thing about them is the fact that torque is multiplyed by the torque converter. Basically if you apply 100 lb-ft to the torque converter, you will get more than that out of it (depends on the torque multiplication factor...different for most converters). Some converters can double, even triple the torque output, at the expense of speed. The stator inside the converter redirects the fluid coming from the turbine back into the turbine again which creates more force on it, this is how the torque is multiplied.

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2003-01-22 23:06, mavman wrote:
Torque converters are really neat things. They have the ability to allow the trans to come to a complete stop, yet still keep the engine from dying. The neatest thing about them is the fact that torque is multiplyed by the torque converter. Basically if you apply 100 lb-ft to the torque converter, you will get more than that out of it (depends on the torque multiplication factor...different for most converters). Some converters can double, even triple the torque output, at the expense of speed. The stator inside the converter redirects the fluid coming from the turbine back into the turbine again which creates more force on it, this is how the torque is multiplied.
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>


I completely understand how a converter works. What I have never seen is a non-lock up showing nearly 200 lb ft more at the rearwheels than a lock up... and that is what I would like some explanation of.

I am going to purchase a street/occasional strip AOD, and I find the dyno sheet very interesting. If it is correct, than a non-lockup converter would be the one to have for the street. Lots more torque sooner than the lock up. Any more opinions?