Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - Mechanical Advance Timing
View Single Post
  #45 (permalink)  
Old 10-08-2012, 12:44 AM
F-BIRD'88's Avatar
F-BIRD'88 F-BIRD'88 is offline
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,445
Wiki Edits: 0

Thanks: 2
Thanked 320 Times in 317 Posts
the stall of a 3000 converter is progressive relative to power input (Throttle)
yes the car will move fine with small throttle inputs. A torque converter is not a on off switch.

The max stall is not achieved untill full throttle is applyed from a stop assuming you have good traction.
The hyd coupling is loser at idle allowing a cammed up motor to idle easily in gear.

Overall part throttle low speed driving.: instead of hugging the 1300 to 2000 rpm range when driving from a stop at part throttle the engine rpm will hug the 2000 to 2500 rpm range on initial acceleration from a stop.
Heavyier throttle input results in higher engine rpm rise on acceleration, relative to throttle input.
Up to the point of full throttle. The car still move but the engine rpm is higher.
Once the vehicle reaches the desired steady cruising road speed, converter coupling is very near 1:1, much like a stock low stall converter. Engine rpm is very near normal. You only see the difference (higher engine rpm) when accelerating. It takes a few weeks driving to get used to a high stall converter, compared to a "stock" low stall converter..
Do not combine with low numerical gears. like 2.73:1 or 3.08:1.

GM th-350 and th400 torque converters.

A GM 13: converter stalls about 1300 to 1500 dehind a 350
a GM 12" converter stalls about 2100 rpm behind a 350.
A GM 11" converter stalls at 2800 behind a 350.
A GM 10" converter ( tight design) stalls about 3000-3200
a GM 10" "3500stall) stalls around 3500-3600 behind a 350
A GM 10" converter can be tuned to stall up to about 4500 behind a 350 ( race converter)
9" and 8" race converters can be tuned to stall anywhere from 3200 to 7000 rpm for a 350.
Race converters do no act like a switch and still drive well on the street as long as the gearing is agressive.

the same converter using behind a 300CID motr wil stal about 500rpm less
The same converter used behind a 454cid motor will show a higher max stall ( about 500-700rpm)
The max stall speed seen is relative to engine torque input.

If you want to know what torque converter you need, call the torque converter company.
B&M TCI, ATI Hughes. etc.
Ya get what you pay for.
A good 10" 3500 stall cost about $350-$450
A good full race converter cost $500 to $1200 (custom built)

if you ask the local trans shop what torque converter you need they will sell you what they have in stock want to sell you, not what you really need.

Last edited by F-BIRD'88; 10-08-2012 at 01:05 AM.
Reply With Quote