Yank Converter Stall Torque Ratio, Stall Speed Information
05-16-2010, 02:25 PM
#1
Yank Converter Stall Torque Ratio, Stall Speed Information 
The stall torque ratio is the multiplying effect the converter produces on engine torque between the engine and transmission
on the initial movement of the vehicle, i.e. A stall torque ratio of 2.0 on a 400 ft. lb. engine will produce 800 ft. lb. at the transmission
input shaft on launch. So the higher the stall torque ratio, the higher the torque and harder the initial launch will be. This means sticky
tires will be required to maintain traction on the higher stall torque ratio converters (2.2 and above). Due to the new manufacturing process,
Yank Converters have a higher efficiency than the competitors. Don’t let the stall torque ratio be the only deciding factor on your converter
selection and feel free to contact Yank with any questions.
("*" denotes stock converter)
Last edited by Yank; 05-16-2010 at 02:38 PM.
05-16-2010, 07:30 PM
#2
Issues with my Yank Converter...... Had my set-up (mods in signature) at the Tuners last night to tune in a 200... N20 shot. N/A it made 400 RWHP which the Tuner said was way low compared to similiar set-ups on LF402s he had tuned on the same dyno. Anyway we proceeded to tune in the N20 shots on my Nitrous Outlet Plate going from 100 to 150 to 200 and each one seemed to be under what the advertised HP should be. Last run we made 569 RWHP and 525 RWTQ on the 200 shot which = approx 170 HP. At that point the Tuner did a slippage test on the converter using RPM, (6100?), 3rd Gear which is 1:1, my 3.42 gears and 26 inch tires. Based on his calculations we should have been showing approx 130 MPH vs. the 113 showing on the Dyno. Based on those numbers he indicated I was experiencing between 16-20% slippage and was blowing through the converter. Anyway my Converter is a Yank which I purchased for my N/A set-up and sent back to Yank in 2009 for re-configuration for the N20 set-up. Along with the slippage the lock-up is also malfunctioning chattering really bad when going down hills and in and out on the Hwy. My Tuner disabled it last night which greatly improved the drivability on the Hwy. Anyway this is not a bashing thread at all because I also need to mention the transmission also went earlier this year (replaced with Performbuilt Level 3) so who knows what impact that could have had on the Converter even though we flushed everything. My 2 questions are these. Firstly, I want to purchase a new converter to handle the nitrous and be streetable as I drive my car all summer. I certainly have no issues purchasing another Yank but I also understand Vigillante has triple lock-up clutches on the lock-up and need to understand why that is a benefit or not. Second, and ultimately most important, how accurately using my signature data and the Dyno numbers can someone pick the right stall for me the first time out because I don't want to do this twice. Appreciate any feedback or assistance...
Last edited by CanadianEh!; 05-16-2010 at 09:06 PM.
05-16-2010, 09:29 PM
#4
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Had my set-up (mods in signature) at the Tuners last night to tune in a 200... N20 shot. N/A it made 400 RWHP which the Tuner said was way low compared to similiar set-ups on LF402s he had tuned on the same dyno. Anyway we proceeded to tune in the N20 shots on my Nitrous Outlet Plate going from 100 to 150 to 200 and each one seemed to be under what the advertised HP should be. Last run we made 569 RWHP and 525 RWTQ on the 200 shot which = approx 170 HP. At that point the Tuner did a slippage test on the converter using RPM, (6100?), 3rd Gear which is 1:1, my 3.42 gears and 26 inch tires. Based on his calculations we should have been showing approx 130 MPH vs. the 113 showing on the Dyno. Based on those numbers he indicated I was experiencing between 16-20% slippage and was blowing through the converter. Anyway my Converter is a Yank which I purchased for my N/A set-up and sent back to Yank in 2009 for re-configuration for the N20 set-up. Along with the slippage the lock-up is also malfunctioning chattering really bad when going down hills and in and out on the Hwy. My Tuner disabled it last night which greatly improved the drivability on the Hwy. Anyway this is not a bashing thread at all because I also need to mention the transmission also went earlier this year (replaced with Performbuilt Level 3) so who knows what impact that could have had on the Converter even though we flushed everything. My 2 questions are these. Firstly, I want to purchase a new converter to handle the nitrous and be streetable as I drive my car all summer. I certainly have no issues purchasing another Yank but I also understand Vigillante has triple lock-up clutches on the lock-up and need to understand why that is a benefit or not. Second, and ultimately most important, how accurately using my signature data and the Dyno numbers can someone pick the right stall for me the first time out because I don't want to do this twice. Appreciate any feedback or assistance...
05-16-2010, 10:41 PM
#5
Very good info here. hes really not bashing them at all but he saying to them please help??? SOmething is wrong and it needs to be addressed. 200 shot should make close to 200 but What KIT ARE YOU USING???? SOME KITS SAY 200 BUT IN REALITY IT AINT NEAR 200??
05-17-2010, 06:07 AM
#6
CanadianEh!
Give us a call
at 775 826 9955
We can help you understand whats going on and give you some tuning ideas.
You can not get a correct reading of converter slip on the chassis Dyno so do not belive in the numbers you have, the time frame and RPM in not correct for true converter slip testing.
To be done correctly you must use a constant torque input at max. RPM for regulated time period.
Give us a call
at 775 826 9955
We can help you understand whats going on and give you some tuning ideas.
You can not get a correct reading of converter slip on the chassis Dyno so do not belive in the numbers you have, the time frame and RPM in not correct for true converter slip testing.
To be done correctly you must use a constant torque input at max. RPM for regulated time period.
I have 2 ST3500 converters in 2 LS1 F-bodies still going strong. Trending Topics
05-22-2010, 04:55 PM
#13
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After a long absence from patrolling this board and modding my car I now have the itch again. Back in the day I had a ST3500 put in which I forgot the stall torque ratio for it was 2.5 right? Pretty loose converter for the 3.23 rear I have. Thinks it's time for some changes 
05-23-2010, 08:20 AM
#15
After a long absence from patrolling this board and modding my car I now have the itch again. Back in the day I had a ST3500 put in which I forgot the stall torque ratio for it was 2.5 right? Pretty loose converter for the 3.23 rear I have. Thinks it's time for some changes
Any info you need call us.
Thanks for coming back to LS1TECH
05-23-2010, 07:10 PM
#16
Great info Dave.
To the person measuring slip and tuning on the dyno - As Dave said,that slip % is totally wrong going on the dyno.It can be measured on a load dyno though. Also your car has to be tuned with either the converter locked,on a full load dyno or at the track.Locking the converter can put those HP gains up alot higher.Keep in mind though that these converters are not really designed to hold a nitrous shot like that on the lockup clutch.
To the person measuring slip and tuning on the dyno - As Dave said,that slip % is totally wrong going on the dyno.It can be measured on a load dyno though. Also your car has to be tuned with either the converter locked,on a full load dyno or at the track.Locking the converter can put those HP gains up alot higher.Keep in mind though that these converters are not really designed to hold a nitrous shot like that on the lockup clutch.
06-02-2010, 07:39 PM
#19
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I have a convertor question regarding stall. So I order a convertor that's a 3600 stall, I up the horsepower from 500 to 700
will the stall speed increase?
will it lose efficiency/have more slippage close to the rev limiter?
will the stall speed increase?
will it lose efficiency/have more slippage close to the rev limiter?
06-03-2010, 07:29 AM
#20
Call me and we can discuss
at 775 826 9955
Dave or Mike