need help choosing torque converter - 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 09-12-2008, 04:57 PM
Registered User
 
Last photo:
Join Date: Oct 2006
Location: pennsylvania
Posts: 1,091
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
need help choosing torque converter

Hi
Well as I have posted before I have the wrong converter in my car,so as someone sugested I called 5 different manufactures ,gave them my car specs and have got 4 different answers,so I'm hopeing someone out there has about the same setup I have and give their thoughts.
92 chev 350
headers
re-curved,blueprinted HEI
edlebrock dual plane intake
holley 570 street avenger
isky 278-mega cam
234 duration@.050
106* libe center
.450 lift
rpm range-2500---6800
tranny beefed-up and shift kit
3.55 rear
29" tall rear tires
car weight---aprox 2600 lbs
The converter I have now is supposed to be 2200-2600 stall. If idleing in netral at 1000 rpm when I put it in gear it stalls the motor,I have to set the idle at 1600 and then when I put it in gear it drops 1000 rpm down to 600 and barely keeps running.
I called allstar performance (that is where it came from) and asked who makes their converters so maybe I could get it loosened up a little--guess what? made overseas was the answer
The manufacturers I talked to all agreed that it is too tight(not enough stall) for my car. BUT I got recomendations from a 2800 stall to 3500.
This is not a race car,just a hotrod street driven,but if I ever get it right I will go to the drags once in a while (probably 1/8 mile)
I can get a real good price on a 2800 from transmission specalities (they are in austin PA and build them in-house)but before I commit to anything I want to make sure I'm buying the right converter this time.
Thank you
Gary

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 09-13-2008, 07:18 AM
Member
 
Last photo:
Join Date: Feb 2005
Location: chillicothe oh
Age: 47
Posts: 1,445
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Due to the light weight of the vehicle and your cam specs I would pick a 3500 to 4000 stall converter.With the relitively light weight and mild engine this will probably stall real world at 2800 to 3000.If looking at a converters adv. rating a lighter vehicle will lower the rated stall speed, put the same converter in a heavier vehicle and it will stall higher. Same for power a converter that stalls say 3500 with 400 hp will only go 3000 or 2500 with 300 hp.(these are examples not exact figures).So lower power in lighter vehicle needs higher rated stall speed to get to the desired results.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 09-13-2008, 07:58 AM
Registered User
 
Last photo:
Join Date: Jun 2008
Location: NJ
Posts: 306
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
ok man im stumped, how do this things work? so your car wont move till it reaches 2500 - 3000 rpm? some one explain to me in laimen terms. right now i'm using a stock one in my 350. im using a wiend tunnelram two 450 carbs it idels at 1000 in park 800 when in drive. i have a comp cam 292 hyd cam. msd ing. system i have no problems the way it runs will it make it run faster? I really dont under stand how a high stall converter works?
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 09-13-2008, 08:18 AM
Registered User
 
Join Date: Apr 2008
Location: SoCal
Age: 45
Posts: 213
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by smrat
ok man im stumped, how do this things work? so your car wont move till it reaches 2500 - 3000 rpm? some one explain to me in laimen terms. right now i'm using a stock one in my 350. im using a wiend tunnelram two 450 carbs it idels at 1000 in park 800 when in drive. i have a comp cam 292 hyd cam. msd ing. system i have no problems the way it runs will it make it run faster? I really dont under stand how a high stall converter works?
In layman's terms - the torque converter's input shaft is connected to your motor. The output shaft is connected to your driveline which feels the weight of your vehicle and the torque addition of your driveline's gearing and your tires. So example - when the input shaft of a 3500 stall converter is spinning at 3500RPM or more then the output shaft will also be spinning at the same speed as the input shaft - minus a small percentage based on the efficiency of that converter. When the input shaft is spinning slower than 3500RPM than the output shaft will be spinning slower even more so than the input shaft. This difference where the output shaft is spinning slower than the input shaft when the input shaft is spinning slower than the torque converter's rated stall speed is the "slippage" which generates heat. But yes - a 3500 stall converter will still move your car at a lower RPM - but not as quickly of a take-off as with a stock converter. You'll just need to give it a little more gas. It does make a huge difference where your motor's peak torque is made. If your stock motor's torque peak is made at 3000RPM don't get a 4000 stall converter!
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 09-13-2008, 08:23 AM
Registered User
 
Join Date: Apr 2008
Location: SoCal
Age: 45
Posts: 213
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
My ride's torque peak is at 4000RPM - I have a 3500 stall converter. 500RPM below my motor's torque peak - but not over the peak!
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 09-13-2008, 09:06 AM
Registered User
 
Last photo:
Join Date: Oct 2006
Location: pennsylvania
Posts: 1,091
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
so how can U determine where your torque peak is ?
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 09-13-2008, 09:35 AM
Paul Marion
 

Last journal entry: 1935 Plymouth Pj coupe
Last photo:
Join Date: Aug 2008
Location: Tulsa Oklahoma
Age: 50
Posts: 29
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
need help choosing a torque converter

re: 3.55 rear > a bit lenient on the gear
car weight---aprox 2600 lbs > light least likely to feel the converter
The converter I have now is supposed to be 2200-2600 stall. I put it in gear it drops 1000 rpm down to 600 and barely keeps running.
I called allstar performance (that is where it came from) and asked who makes their converters so maybe I could get it loosened up a little--guess what? made overseas(American enginuity mass produced by non regulated,0 quality controlled slave labor) was the answer ...& they wonder why we have forecloseurs ...perhaps they should quit outsourcing our tech & mfg jobs, while peddlin' that disposable crap from overseas.
The manufacturers I talked to all agreed that it is too tight(not enough stall) for my car. BUT I got recomendations from a 2800 stall to 3500.
This is not a race car,just a hotrod street driven, I can get a real good price on a 2800 from transmission specalities but before I commit to anything I want to make sure I'm buying the right converter this time.
Thank you
You can't save money on a converter & expect results. Even if you get a good 3000 -3500 stall, it wont break loose as much as you would expect. Numerous companies offer them for less than 300.00. Even B&M's holeshot converter is a bit under budget for results. Their next product in line puts you back around that 3oo mark. You will still barely notice a difference. I personally have found that you have to spend 300 or more on a "quality built" converter to get any results. It's in the construction. More attention to quality. There must be over 10 name brands to select from. I personally have had good luck w/ TCI & Fairbanks (durability & selection/pr dollar) p.s. your tranny has to be working properly. via good frictions n steels,smooth functioning valve body,shift kit properly installed,correct amount of fluid,properly timed gov/kickdown/modulator etc. Once you've run a 3000-3500 for a while, you'll probably wish you could've spent excess of 5oo for a better built even higher stall configuration. They never seem to work as much as you expect them 2.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 09-14-2008, 12:09 PM
Registered User
 
Join Date: Apr 2008
Location: SoCal
Age: 45
Posts: 213
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by yragat
so how can U determine where your torque peak is ?
Download "Camquest" from Comp Cams' website. Accurate enough results I believe.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 09-14-2008, 04:37 PM
Registered User
 
Last photo:
Join Date: Oct 2006
Location: pennsylvania
Posts: 1,091
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I looked at comp cams "camquest" and it is a $15.00 dvd telling about their cams and how to choose one. I am very happy with the cam I have now ,so why did you suggest that? I'm looking fo the right torque converter,not a cam
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 09-14-2008, 05:25 PM
Registered User
 
Join Date: Apr 2008
Location: SoCal
Age: 45
Posts: 213
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by yragat
I looked at comp cams "camquest" and it is a $15.00 dvd telling about their cams and how to choose one. I am very happy with the cam I have now ,so why did you suggest that? I'm looking fo the right torque converter,not a cam
You can get a free download of camquest if you look better. Someone had posted the question about "how to you know your motor's torque peak RPM?" With that software you can get a decent guess. You need to know your torque peak's RPM to decide which stall of a converter you want in addition to other things particular to your ride. Your TC's stall too low is no good - too high is also no good. Cheap ones are no good, also. My good billet custom 10" - 3500RPM stall with anti-ballooning plates was $650.

Last edited by Sixtyninemercury; 09-15-2008 at 07:51 AM. Reason: wrong size TC - should be 10"
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 09-14-2008, 05:27 PM
Registered User
 
Join Date: Apr 2008
Location: SoCal
Age: 45
Posts: 213
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Here it is - http://www.compcams.com/camquest/default.asp
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 09-14-2008, 08:08 PM
Registered User
 
Last photo:
Join Date: Oct 2006
Location: pennsylvania
Posts: 1,091
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
NOW I found it! Thanks
acording to that chart,my peak torque is at 4500 rpm---so maybe I could go with a 3500 converter however,some of the info I put in wasn't exact like my weight is around 2650 and I had to choose between 2500 or 3000 and my cam is 234 duration and the one they put in was 235 and 249 . they recomended 1900 to 2900 stall converter I have a 2200 to 2600 now and its way to tight----so I guess I have to decide wether to go with a 3000 or 3500. bottom line---still don't know for sure
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 09-15-2008, 07:57 AM
Registered User
 
Join Date: Apr 2008
Location: SoCal
Age: 45
Posts: 213
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by yragat
NOW I found it! Thanks
acording to that chart,my peak torque is at 4500 rpm---so maybe I could go with a 3500 converter however,some of the info I put in wasn't exact like my weight is around 2650 and I had to choose between 2500 or 3000 and my cam is 234 duration and the one they put in was 235 and 249 . they recomended 1900 to 2900 stall converter I have a 2200 to 2600 now and its way to tight----so I guess I have to decide wether to go with a 3000 or 3500. bottom line---still don't know for sure
Did you enter the info as close as you could? The reason I'm asking is that the program told me my torque peak occurred at 4000RPM and it recommended a stall from between 2900-3900. You say your torque peak is at 4500RPM yet the program is recommending a 1000RPM less stall than mine? The higher your torque peak the higher stall. Maybe double-check what you input especially your heads' flow rates. My heads are RPM's - I went to Edelbrock's website and copied their flow rates directly from there. CFM flow intake and exhaust at .1", .2" .3" etc. Also I thought that you can enter your cam's detailed specs into the program so it gives you a better guestimation of your motor's power output. You could also post your ride's specs here if you want - weight (with you in it), trans, rear tire diameter, rear gear, motor - heads, cam, compression, intake, etc.

Last edited by Sixtyninemercury; 09-15-2008 at 08:02 AM.
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 09-15-2008, 08:35 AM
Registered User
 
Join Date: Apr 2008
Location: SoCal
Age: 45
Posts: 213
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Oops - I forgot you did enter your ride's specs on your first post. What about your compression and heads? Are you certain that the carb is set right? And your ignition timing as well? The reason I'm asking that is because a 2600RPM converter shouldn't stall your ride when idling at 1000RPM in neutral.
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 09-15-2008, 09:27 AM
Registered User
 
Last photo:
Join Date: Oct 2006
Location: pennsylvania
Posts: 1,091
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
The engine is a rebuilt 92 sb that came out of a chev pickup ,heads are stock Timing is 36* total and 14* at 1000rpm ,thats without vacuum connected I've had two really knowagable people go over the timing and carb settings and they (and everybody else) agrees that the converter is way too tight. The car is a dog off the line,will not break the wheels loose and its not even a posi,but after it gets going its a beast I can run it up to 70 mph in second and when I shift into third it chirps the tires.I did list all info on the first post,except I should add 200 lbs for my weight. on the comp cam download they let U pick one of their cams,mine in an Isky and I couldn't find one to match exactly. When I put it in gear its like the tranny is dragging the engine down--almost like an in&out box
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:
If you do not want to register, fill this field only and the name will be used as user name for your post.
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


Similar Threads
Thread Thread Starter Forum Replies Last Post
700R4 Torque Converter Flexplate Question fosterdl Transmission - Rearend 8 03-23-2008 12:03 PM
Torque Converter Question newbielike Transmission - Rearend 2 12-17-2007 05:53 PM
Torque converter question sam83k10 Transmission - Rearend 7 08-09-2007 07:23 PM
Torque Converter Failure - TH350 blown81 Transmission - Rearend 1 10-16-2005 11:41 AM
Torque converter, diesel vs gas pjd Transmission - Rearend 4 09-10-2005 08:52 PM


All times are GMT -6. The time now is 11:30 PM.


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.