What STR do I want?
What STR do I want? I am looking at getting a circle d 4C stall. Its supposed to be 3800-4000 speed. I have bolt-ons and will be adding 3.73s at the time of the converter change. I have been doing some reading up on stall torque ratio and I am still undecided on what would be best for me. We like to do a lot of dig racing, but mostly I only get to do short 25mph punches with most people around here. (Lots of slow cars) Anybody got any suggestions?
There's probably a limited range of available STRs given
the stall speed and diameter you want.
I think you will have zero traction in 1st gear regardless
of what you choose. This is one reason I went with a low
STR on my build (3.42s).
The two things a low STR will give you are a better fluid
coupling at low slip (I cruise at 1500RPM at 30MPH in 3rd,
climb grades at 2000RPM on a 3500/2.0 converter) and a
broader range of torque multiplication. A higher STR has
less RPM between paddlewheeling and fully coupled. In
my opinion a low STR is more street friendly, thrust is
pedal-proportional.
But I don' tknow if this enters into it, 3800+ is not what
I'd pick for the street.
How are you planning to hook up 3.73s and a (say) 2.5:1
multiplication off the line? I've been unable on 3 brands of
regular tire and ET Streets. Spin all through 1st and the
lower half of 2nd, with less gear and less (2.0) STR.
the stall speed and diameter you want.
I think you will have zero traction in 1st gear regardless
of what you choose. This is one reason I went with a low
STR on my build (3.42s).
The two things a low STR will give you are a better fluid
coupling at low slip (I cruise at 1500RPM at 30MPH in 3rd,
climb grades at 2000RPM on a 3500/2.0 converter) and a
broader range of torque multiplication. A higher STR has
less RPM between paddlewheeling and fully coupled. In
my opinion a low STR is more street friendly, thrust is
pedal-proportional.
But I don' tknow if this enters into it, 3800+ is not what
I'd pick for the street.
How are you planning to hook up 3.73s and a (say) 2.5:1
multiplication off the line? I've been unable on 3 brands of
regular tire and ET Streets. Spin all through 1st and the
lower half of 2nd, with less gear and less (2.0) STR.
As Jimmy said a lower str will drive much nicer on the street and most of the time out run a higher str due to traction issues. They will also mutiply torque for a longer period of time. On a bolt on car with a converter change alone you see see a drop in et of .6-.8 tenths in et. The lower str will also run cooler because the coupling phase is so much better. Fluid shear inside the converter is where the heat is made. A 3600 is very driveable with little difference in daily driving but when you whack it look out!!!
Greg
Greg
__________________
FTI COMPETITION CONVERTERS AND TRANSMISSIONS
"IT'S NOT CHEATING, IT'S THE COMPETITIVE EDGE."
1-866-726-8358
info@ftiperformance.com
FTIPerformance.com
FTI Converter build sheet
FTI COMPETITION CONVERTERS AND TRANSMISSIONS
"IT'S NOT CHEATING, IT'S THE COMPETITIVE EDGE."
1-866-726-8358
info@ftiperformance.com
FTIPerformance.com
FTI Converter build sheet
Is the STR the same for all converter companies? Can the STR be numerically correct by some measuring system? Does, say a Yank 2.0 Str the same as a Vig 2.0 STR, Edge 2.0 STR, Performabuilt 2.0 STR all the same? If it can then one can compare different TQ's by efficancies, if not, a lot of trail and errors can be found before a person can pick whats best for them
In theory doing all the math 3000 stall with a 2,0 str should be the same with any company. This is however not always the case.
__________________
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
my 3200 with a 2.4 hits hard off the line and i have been fighting traction issues ever since i got it.
Last edited by 01ssreda4; Jan 3, 2009 at 12:15 PM.
Trending Topics
I was planning on going with a 4k stall with a 2.5 str. I was hopin that some 275/40/17 et streets would do the trick to hook, but if that's going to continue to be a problem, seeing as how I already spin like a bitch, I may go 3600 with a 2.0 str. Anybody have any suggestions on where I should get a converter with those specs?
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'
Brett Foote
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?
Pouria Savadkouei
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
The yank ss3600 is a 245mm converter with a 2.5 str. They have one that is a 3200, but I only plan on stalling this thing once, unless I go big on it and make it a full out drag car. I'm just wondering if a 3200 would do the trick.
The converter I mentioned above is a 2.16 str.It is one of our best sellers for DD cars.
Greg
Greg
__________________
FTI COMPETITION CONVERTERS AND TRANSMISSIONS
"IT'S NOT CHEATING, IT'S THE COMPETITIVE EDGE."
1-866-726-8358
info@ftiperformance.com
FTIPerformance.com
FTI Converter build sheet
FTI COMPETITION CONVERTERS AND TRANSMISSIONS
"IT'S NOT CHEATING, IT'S THE COMPETITIVE EDGE."
1-866-726-8358
info@ftiperformance.com
FTIPerformance.com
FTI Converter build sheet
