Converter slippage
Thread Starter
Burning Brakes
Joined: Mar 2004
Posts: 816
Likes: 1
From: Finland
Converter slippage
...what is the nature of it...
If i have 2 different converters, the other slips 5% and the other 10% with the same setup. Lets say the car has 400hp.
If I change from the 5% unit to the 10% unit:
1. is it like changing from 3.08 to 3.23 rear gears and getting more torgue to rear wheels?
or
2. is it just like loosing 20hp
or
3. is it something in between
or
If i have 2 different converters, the other slips 5% and the other 10% with the same setup. Lets say the car has 400hp.
If I change from the 5% unit to the 10% unit:
1. is it like changing from 3.08 to 3.23 rear gears and getting more torgue to rear wheels?
or
2. is it just like loosing 20hp
or
3. is it something in between
or
Last edited by Vesa; Mar 6, 2008 at 07:43 AM.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I'd say that they are poor quality converters. The higher the quality the more efficient (less slip) they have above the rated stall rpm speed.
I had a manually switch lockup 9.5 inch. above it's rated 3500 stall like 4000 rpm and above the total slip which is a loss of power at wide open throttle was only like 200-300 rpm behind my 427 ci motor.
On the other hand i had a car with a 440 ci motor and a 3000 stall junky converter. All the time that car drove 3000 rpm until it actually got going fast enough to exceed the 3000 rpm stall.
All the slip is going up in heat and it is not creating more rear wheel TQ.
So IMO it is worth buy the $700 and up Tc's
I had a manually switch lockup 9.5 inch. above it's rated 3500 stall like 4000 rpm and above the total slip which is a loss of power at wide open throttle was only like 200-300 rpm behind my 427 ci motor.
On the other hand i had a car with a 440 ci motor and a 3000 stall junky converter. All the time that car drove 3000 rpm until it actually got going fast enough to exceed the 3000 rpm stall.
All the slip is going up in heat and it is not creating more rear wheel TQ.
So IMO it is worth buy the $700 and up Tc's
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Gkull is right on that, the only thing I would add is this thought: The high stall converter is designed to work the same as slipping the clutch on a manual car, thats all it does. You can't just Dump the clutch at high rpm for a launch, you have to feather it in a little.
The converter does the same thing. But you don't want it slipping all the time, all that does is waste HP and make more heat. So, the Stall converter which locks up at a certain RPM, no more slipping, no more additional heat, and by the time you reach that RPM, you should be moving fast enough to not need to slip the clutch anymore.
Hope this helps
The converter does the same thing. But you don't want it slipping all the time, all that does is waste HP and make more heat. So, the Stall converter which locks up at a certain RPM, no more slipping, no more additional heat, and by the time you reach that RPM, you should be moving fast enough to not need to slip the clutch anymore.
Hope this helps
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
Converter 'slippage' can be due to some component in the converter being defective....like the stator not being able to lock in place when it needs to, etc...or it can be as a result of the design. High stall torque converters are designed to 'slip' at low speed and 'grab' at elevated speeds, so that you can launch well. They are...by design...inefficient UNTIL they get to that rpm. If you put a high stall speed converter in a car that regularly gets driven (other than for racing), be prepared to pay the price at the pump, with early wear on the engine, and with the discomfort of having to rev the engine to take off at every stop. They're great for racing, but nothing else.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Here is a good company. When I was buyiing my TC, vigilanty had a 6-8 week delay so I bought Art Carr Racing instead.
http://www.converter.com/vigilante.htm
http://www.converter.com/vigilante.htm
