torque converter for light weight car - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Transmission - Rearend
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 10-07-2003, 02:15 PM
Member
 
Last photo:
Join Date: Oct 2002
Location: Lexington, Kentucky
Posts: 122
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
torque converter for light weight car

Hey all,

I am building a T-Bucket and was contemplating the torque converter to go behind the 200R4 Tranny. I have been told to buy an approximately 2200 rpm stall converter to keep the tranny from pulling so hard at idle (800 rpm). The bucket will weight approx. 1800-2000 pounds completed. I talked to techs at TCI about it and they didn't get the idea that the stall would need to be increased due to weight and lack of braking power. I won't have any power brakes and don't want to have to put it in neutral every time i stop. Any suggestions?? does anyone have any equations that would help.

Thanks

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 10-07-2003, 06:09 PM
Frisco's Avatar
Glad To Be Here
 
Last photo:
Join Date: Nov 2002
Location: Canton, North Carolina
Age: 73
Posts: 2,244
Wiki Edits: 0

Thanks: 0
Thanked 8 Times in 8 Posts
Re: torque converter for light weight car

Quote:
Originally posted by tnoftsger
Hey all,

I am building a T-Bucket and was contemplating the torque converter to go behind the 200R4 Tranny. I have been told to buy an approximately 2200 rpm stall converter to keep the tranny from pulling so hard at idle (800 rpm). The bucket will weight approx. 1800-2000 pounds completed. I talked to techs at TCI about it and they didn't get the idea that the stall would need to be increased due to weight and lack of braking power. I won't have any power brakes and don't want to have to put it in neutral every time i stop. Any suggestions?? does anyone have any equations that would help.

Thanks
First a few comments.

The torque converter will go in FRONT of the trans not behind it as you posted.

You shouldn't have any problem with a stock torque converter (approximate stall is 1400 RPM) with the idle RPM in gear set at your posted 800 RPM. If you have a fairly 'hot' cam that doesn't make power until 2500 RPM or above, then you will need a higher than stock stall. This will enable you to get into the power band quicker.

Keep in mind that the lighter the vehicle, the converter will begin pulling at the lower RPM range that is advertised for it.

i.e. I use a TCI Saturday Night Special torque converter. The advertised stall is 1800-2100 RPM. My Model 'A' truck weighs 2660 lbs. The stall is about 1900 RPM. The same converter, engine, trans, rear gearing, etc. in a 3200 lb. vehicle would be closer to the advertised 2100 RPM.

Call TCI back, as well as Hughes and Coan. Give them your engine, cam, trans, rear gears, rear tire diameter, vehicle weight and ask for their suggestions as to what torque converter to use.

Last edited by Frisco; 10-07-2003 at 06:16 PM.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 10-08-2003, 07:38 AM
Member
 
Last photo:
Join Date: Oct 2002
Location: Lexington, Kentucky
Posts: 122
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Thanks Frisco, I realize that the converter will begin pulling a little earlier due to light weight, but how much and how early?

The T-bucket will be powered by a 383 stroker i built and Desktop Dyno marks it at 410 ftlbs @ 2000 which is as low as it calculates power. It looks to be making 390+ just off idle. Is there some math that will calculate the change in stall due to weight? And is 3200 lbs what most converters are rated for?

Thanks again for the reply
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 10-08-2003, 08:14 AM
Frisco's Avatar
Glad To Be Here
 
Last photo:
Join Date: Nov 2002
Location: Canton, North Carolina
Age: 73
Posts: 2,244
Wiki Edits: 0

Thanks: 0
Thanked 8 Times in 8 Posts
Converters are rated for an RPM range where they begin to transfer the rotational force to the trans. This is based more on fluid dynamics and pressure.

The vehicle weight plays a part as to when this transfer takes place. Obviously, simple physics tells you that more force is required to initially move a heavier object.

The converter manufacturers need much more info to properly determine what stall speed to suggest to an individual. One thing I should have mentioned is the type of driving you will be doing. Street/strip will require a different converter than for strip only.

Go to: http://www.coanracing.com/SpecSheet/SpecSheetDB2.asp

If you don't wish to call them, send them an e-mail request. They should have an online request form for that. Give as much info on your combo as you can. It (the info) all factors in to what you need.

By the way, it would be a good idea to run a separate trans cooler, even if you use a stock converter.

With a 383 I'd personally run about a 2400-2600 RPM stall.

However, I'm more into street performance than just cruising.

ENJOY!!!

Last edited by Frisco; 10-08-2003 at 08:30 AM.
Reply With Quote Quick reply to this message

Recent Transmission - Rearend posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -6. The time now is 10:01 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.