Results 1 to 14 of 14

What stall convertors do

This is a discussion on What stall convertors do within the Automatic Transmission forums, part of the Drivetrain category; I see this question asked often, so I took this from one of our site sponsors website: http://www.fuddleracing.com/WhatConvertersDo.html 1. Higher ...

  1. #1
    Just me Y2KPewterSS's Avatar
    Join Date
    Nov 2006
    Location
    Broken Arrow, OK
    Age
    42
    Posts
    23,353

    Pewter metallic
    2000 Camaro SS

    What stall convertors do

    I see this question asked often, so I took this from one of our site sponsors website:

    http://www.fuddleracing.com/WhatConvertersDo.html

    1. Higher RPM Launches:

    Largely similar to "dumping" a clutch at a higher RPM, a higher stall converter allows your car to leave the line with more power hitting the wheels as you launch.

    Here are a couple of examples of how the launches change when you step up to a performance converter. Variables such as different brakes, tires, and gear ratios effect how the converter stalls, but these will give you a general idea.

    Example 1- Assume your stock stall is around 1600 RPM. Get into the car and hold your foot on the brake. Now at the same time you let off of the brake, stab the throttle like you are at the track. Keep a close eye on the tach. It will jump to about 1600 RPM and start climbing from there. If you moved to a 3200 stall, it would jump to about 3200 and start climbing from there. It gives you a huge punch by launching at a higher RPM and at an RPM that is more in the meat of your powerband.

    Example 2- Again, assume a stock stall of 1600 RPM. Now, in drive, hold your left foot on the brake as hard as you can. Now slowly rev the engine with your other foot. Notice that about 1200-1300 RPM the tires start to break loose. Now imagine that you have a 3200 stall. You could now spin the motor closer to 3k before the tires started to brake loose.

    2. Torque Multiplication:

    When an automatic transmission is launched, the torque converter actually multiplies the input torque. That multiplication is called the Stall Torque Ratio or STR. If you raise the STR, the amount of torque you have on launch also becomes greater. With a sticky tire, launches with a high STR can be down right brutal. STR

    3. Shift Extension:

    Most automatic cars experience a dead spot immediately after the 1-2 and 2-3 shifts. It will feel really strong all through first gear (with LS1's particularly at the top RPM because that is where LS1's like to be, high RPM's). Notice immediately after the 1-2 shift (and 2-3, if you get that high) that it seems to fall flat on its face for a couple of seconds. That is the dead spot and can feel like more than a couple seconds at the track. It feels weak until the RPM's get to where they should be, and the power feels like it comes back. With a stall converter, the RPM's do not fall like they do with a stock converter. Expect the RPM's to stay considerably higher after the shifts with a stall converter, completely getting rid of the dead zone.

    4. Reduced Weight: (Does not apply to stock style converters)

    A stock converter on an LS1 Camaro weighs 53 lbs. Our basic 245mm conversion weighs 30 lbs. While 23 lbs. of weight reduction does not sound like much, it is entirely rotational weight. The engine is now required to spin 23 less lbs. It now revs faster and considerably more freely.

    Example- Take a short pole with a 53 lb. weight at its end and one with a 30 lb. weight. Try turning the one with the 53 lbs. and turn it by hand. Now try the same thing with the other pole. The lighter pole is considerably easier to spin. The same is true for the engine. The lighter one is easier not only to spin faster but to start spinning.

  2. #2
    !!!!!!!!!!!!!!!!!!!!!!!!! ATCharming's Avatar
    Join Date
    Jan 2007
    Location
    Rockford, IL
    Age
    26
    Posts
    8,303

    Silver
    2000 Camaro SS

    awesome info!!! sticky it. ur a mod, i know u can do it.
    this was the best explanation i have read and i now fully understand what theydo... i always understood the concept of higher rpm launches and what not, but the whole dead spot explanation really cleared things up.

    if it is a 23lb rotation weight reduction, then why do stalls slightly lower RWHP? id assume they decreased drivetrain loss, therefore increased rwhp... theoretically, thats how it would work right? i dont understand that part...

  3. #3
    15sec stalled A4 TransAmy's Avatar
    Join Date
    Dec 2006
    Location
    Lake in the Hills
    Age
    33
    Posts
    729

    Shhh! There's a
    hooker in the trunk

    great info, im getting a stall soon and this was super helpful! now at least i have somewhat of a clue

  4. #4
    Junior Member
    Join Date
    Oct 2005
    Location
    Perth, Australia
    Posts
    3

    SILVER
    2003 Holden ute

    high stall with high hp

    My cammed LS7, stock 4le60 auto in a Holden ute breaks my M/T 275-17 street radials loose instantly when I nail it off idle. How will a higher stall help? It would apply even more torque to the tyres? Nobody on the Oz forum has been able to say how, just that it will help. Is it because I will have more throttle control with a higher stall? I am talking street not strip. Cheers.

  5. #5
    Member
    Join Date
    Jul 2008
    Location
    Decatur, IL
    Posts
    150

    red
    00 z28

    yeah i was thinking the same thing trabots said about the stall, i drive my car every day and never make it to the track, i want to get rid of the 1st to 2nd lag but dont want my car to come off of the line at 3000rpm when my girlfriend is at the grocery store...

  6. #6
    Senior Member qwkgto's Avatar
    Join Date
    Mar 2008
    Location
    OHIO"S only 9 second GTO
    Posts
    1,464

    Phantom Black Metalic
    2005 GTO

    to the last two guys on here above the stall will not help you with traction it raises your rpms at take off also when you are driving down the road and stab it flashes before it releases the power to the transmission ,basically it slips and then grabs so your car is at a higher RPM=more power sooner..you will need drag radials no question about that ,even for a street car and the UTE id say you need some better weight distrubution or some other form of traction helper as trucks are more prone to not hook up as well as cars.maybe some drag bags?are the utes IRS or leaf springs leaf springs are easily fixed.

  7. #7
    Member Racer X Vpr Klr's Avatar
    Join Date
    Apr 2006
    Location
    cal
    Posts
    164

    pewter metalic
    2000/WS6/TA

    torque converter

    that is excellent info and props to you 4 posting it ....

  8. #8
    Member
    Join Date
    Jan 2007
    Location
    canada
    Posts
    159

    black
    95 trans am

    stall help

    hello i have a tci 4l60e in my 95 trans am auto...I had the factory stall changed out to a 2200 stall..but am not happy with it as it requires alot of gas to get it to go..it just seemed more peppier and touchy with my old stall any idea what my factory stall is? I thought it was 1650 for some reason? ,y vehicle has many bolt ons and nitrough but thats it i do not want to do any internal work on it and I do not drag race it so is it ok to have the factory stall put back in and isisnt fine enough ? thankyou for any help

  9. #9
    Junior Member
    Join Date
    Feb 2011
    Location
    sylva, nc
    Posts
    2

    blue
    1999 z28 camaro

    what would be a good stall for everyday driving?

  10. #10
    dbl clutch'n like i shld WICKEDLS1's Avatar
    Join Date
    Aug 2010
    Location
    Oklahoma City, Oklahoma
    Posts
    1,807

    sebring silver
    Y2K SS CAMARO

    Quote Originally Posted by z28speed View Post
    what would be a good stall for everyday driving?
    i DD my 01 and im putting a 3400 yank in it in not too long. you can drive that around just fine. mind you it will decrease your gas mileage

  11. #11
    Senior Member Z28Thunder's Avatar
    Join Date
    Dec 2006
    Location
    Broken Arrow, Ok
    Age
    52
    Posts
    4,542

    Arctic White
    2000 Z28

    Quote Originally Posted by z28speed View Post
    what would be a good stall for everyday driving?
    I would not go smaller than 3500.. The 3400 Yank mentioned above is not bad as well.

  12. #12
    Moderator Firebirdjones's Avatar
    Join Date
    May 2006
    Location
    Arizona
    Posts
    12,552
    I run a 3400 fuddle in mine with a 2.1 STR. It drives nicely around town. I only lost 2 mpg around town driving, It went from 22 mpg down to 20 mpg if you are nice to it.
    If I get a little rambunctious with the throttle a few times on a tank of gas,,,my around town driving MPG can drop as low as 18.

    Highway didn't change (lock up) it still knocks down 25-26 highway)

    This is with 3.23 gears.

  13. #13
    Senior Member qwkgto's Avatar
    Join Date
    Mar 2008
    Location
    OHIO"S only 9 second GTO
    Posts
    1,464

    Phantom Black Metalic
    2005 GTO

    I would have to disagree all depends on the car,weight cam, what setup you have as well,too many variables,on FI cars a tighter stall is required I have a 3400 stall in my GTO,but i ran a 3000 stall for a long time. CALL YANK...I picked up 12mph in the 1/4 mile buy changing converters.. or some other reputable converter manufactor,this would be my info...no one stall is best for every given situation.
    mods: custom built twins, built 408 w/l92 stock GM heads,GM matching intake,drag bags,frame ties,aluminum drive shaft, performabuilt 4l80e,Yank converter,ohios fastest and quickest 04-06 GTO 9.52 at 144mph. 1.50 60ft on stock rear end and shafts/suspension,on drag radials.

  14. #14
    Moderator Firebirdjones's Avatar
    Join Date
    May 2006
    Location
    Arizona
    Posts
    12,552
    Quote Originally Posted by qwkgto View Post
    I would have to disagree all depends on the car,weight cam, what setup you have as well,too many variables,on FI cars a tighter stall is required I have a 3400 stall in my GTO,but i ran a 3000 stall for a long time. CALL YANK...I picked up 12mph in the 1/4 mile buy changing converters.. or some other reputable converter manufactor,this would be my info...no one stall is best for every given situation.
    I agree completely,,,,I just figured this was a given. Store bought converters off the shelf usually leave people with less than satisfactory results. They just don't work in every application.

    ALWAYS call a converter manufacture and have the converter built to the specs of the car.


LinkBacks (?)

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. acc performance torque convertors
    By 02transamce in forum Automatic Transmission
    Replies: 0
    Last Post: 09-07-2009, 12:53 PM
  2. Replies: 15
    Last Post: 07-02-2007, 02:49 PM
  3. Replies: 0
    Last Post: 03-14-2007, 06:30 AM
  4. WTT or SALE my new SLP dual dual muffler for your LS1 catalytic convertors
    By 2003Firehawk in forum Parts For Sale / Trade
    Replies: 3
    Last Post: 03-06-2007, 05:42 PM
  5. F/S 2002 Pair of Catalytic Convertors off SS
    By 7camaro7 in forum Parts For Sale / Trade
    Replies: 1
    Last Post: 02-25-2007, 10:48 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •