Conveter RPM calculations
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Calculation for converter slippage??? Not a very useful tool since many converters are very different from each other. Like many other things, it all comes down to efficiency.
Very efficient converters will have far less slippage than very inefficient ones. (Assuming identical stall characteristics).
Stall isn't everything. Efficiency plays a big role. As does torque multiplication.
Did you know you could take two converters supposedly with identical stall speed, placed on identical engines, and get very different launch characteristics? Has to do with torque multiplication.
One might have a TM of 1.8, while another much better one might have a 2.5 TM.
Too many variables to rely much on a calculator. With converters (like most everything else) you need to compare apples to apples.
Very efficient converters will have far less slippage than very inefficient ones. (Assuming identical stall characteristics).
Stall isn't everything. Efficiency plays a big role. As does torque multiplication.
Did you know you could take two converters supposedly with identical stall speed, placed on identical engines, and get very different launch characteristics? Has to do with torque multiplication.
One might have a TM of 1.8, while another much better one might have a 2.5 TM.
Too many variables to rely much on a calculator. With converters (like most everything else) you need to compare apples to apples.
Top end converter slip is easy to calculate with Direct Scan.
For starters check if the defaults of 3.42 gear and 26.1" tire are set
if not then the data must be rescaled.
within a percent or two. (MPH * 47)/RPM will give you a coupling percentage.
Third gear....... BTW.
TurboBob
For starters check if the defaults of 3.42 gear and 26.1" tire are set
if not then the data must be rescaled.
within a percent or two. (MPH * 47)/RPM will give you a coupling percentage.
Third gear....... BTW.
TurboBob
Dave,
I posted this back in March so I kinda know where your coming from.
" Theres different ways to create stall, clearances between the fins (impeller/turbine) pitch angle of the fins etc. Also how the stator is cut efects stall and multiplication ratio. The more multiplication the harder hit to the tires and more torque to rear wheels. The trade off is that when the stator has this high ratio it stops multiplying the torque sooner. This hurts the second half of your 1/4mi /top end pull."
I was just looking for a way to see whatBob just posted and what others were getting in the traps for guys going 125 and above. Maybe I worded it wrong.
I posted this back in March so I kinda know where your coming from.
" Theres different ways to create stall, clearances between the fins (impeller/turbine) pitch angle of the fins etc. Also how the stator is cut efects stall and multiplication ratio. The more multiplication the harder hit to the tires and more torque to rear wheels. The trade off is that when the stator has this high ratio it stops multiplying the torque sooner. This hurts the second half of your 1/4mi /top end pull."
I was just looking for a way to see whatBob just posted and what others were getting in the traps for guys going 125 and above. Maybe I worded it wrong.
ChrisCairns
Senior Member
- Joined
- May 24, 2001
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Try this......
http://www.smokemup.com/auto_math/mph_range.php
And I have 8 ½ % slippage in mine....that's why I just put a borrowed converter in. Hopefully this one will be better.
Chris
http://www.smokemup.com/auto_math/mph_range.php
And I have 8 ½ % slippage in mine....that's why I just put a borrowed converter in. Hopefully this one will be better.
Chris
T-Dave,
with your new converter the "47" number can be calculated even closer
since your new converter locks so well.....take a bunch of sample points and average
them. Let me know what you find.
Curious about your old converter too.
Bob
with your new converter the "47" number can be calculated even closer
since your new converter locks so well.....take a bunch of sample points and average
them. Let me know what you find.
Curious about your old converter too.
Bob
- Joined
- May 28, 2001
- Messages
- 16,748
numbers?/
3.42 gear, 28" tire, 6000 trap rpm,132mph...
3.42 gear, 28" tire, 6000 trap rpm,132mph...
ChrisCairns
Senior Member
- Joined
- May 24, 2001
- Messages
- 2,197
Marty won't loan me any more. He says all I want is what I pay for...therefore I'm unreasonable and a spoiled little brat.
I have the borrowed one (it belongs to Steve M. from Boise, Idaho) in now...and it's tighter than my old one so I'm happy so far. We'll see tomorrow at the track how the top end does.
I have the borrowed one (it belongs to Steve M. from Boise, Idaho) in now...and it's tighter than my old one so I'm happy so far. We'll see tomorrow at the track how the top end does.
REDS HOT AIR
Buick Tweaker
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- May 24, 2001
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my 9-11 converter locked dont slip a bit
27" tire at 127 was 5500 rpm
27" tire at 127 was 5500 rpm
REDS HOT AIR
Buick Tweaker
- Joined
- May 24, 2001
- Messages
- 3,433
been noticing all you smart a*s replys to me ...
you can kiss off
cant help it your jealous
btw: this thread was for people at 125 trap speed or faster so dont think it involves you
you can kiss off
cant help it your jealous
btw: this thread was for people at 125 trap speed or faster so dont think it involves you
Bob.
Here's some data I took from a bunch of runs. When I refer to my stock converter, keep in mind that I have no "old" runs on it. The only runs I can find are with it in very new condition (about 3 months old and no more than 15 runs on it). AND my stock converter was a remanufactured D5 with some minor stall tweeking.
This could get a little long winded so hang in there
I found some really interesting stuff
I checked both converters, first the stock one.
REMAN D5
unlocked in the middle of 2nd gear yielded 55%
unlocked in 3rd at 80mph yielded 85%
unlocked in 3rd at 90mph yielded 90%
unlocked in 3rd at 100mph yielded 94%
locked in 3rd at 80mph yielded 93%
locked in 3rd at 90mph yielded 98%
locked in 3rd at 100mph yielded 100%
Now for the VIGILANTE. (These readings are at the end of it's second season of racing) (Always locked at WOT and about 80mph) (a couple seconds after the 2-3 shift)
unlocked in the middle of 2nd gear yielded 50%
locked in 3rd at 85mph yielded 97.3%
locked in 3rd at 95mph yielded 97.6%
locked in 3rd at 105mph yielded 97.7%
(the 10ths of percent differences could be attributed to measurement errors).
I did find some early Vigilante runs and it was rock solid at 99.7-100% through the above 3 parameters.
I was a little surprised that it was still up around 98% after two full seasons of beating the daylights out of it!!!!
I did find one run where I took an unlocked 3rd gear measurement at about 80mph and it was 77%%
Thought you might find some of this stuff enlightening.
As for the bee under Red's bonnett.... well, I'm not going there.
I guess if he knew me, he would know that jealousy is hardly a factor. I've reached the goals I set years ago, and that's the end of that.
REDS HOT AIR
Buick Tweaker
- Joined
- May 24, 2001
- Messages
- 3,433
anyone keeping in mind that soft tires such as slicks and dot slicks grow at them speeds ??
and anyone take in consiteration that scan tools other than direct scan dont pick up but every so often and its kinda hard to hit it on the money when traveling close to 130 mph
Dave you have nice stuff and i love the house but dont give you the right to act as a dic* head on the board.
anyone can seach your post and see all the smart a*s remarks you make to people..go figure i dont play that.
and anyone take in consiteration that scan tools other than direct scan dont pick up but every so often and its kinda hard to hit it on the money when traveling close to 130 mph
Dave you have nice stuff and i love the house but dont give you the right to act as a dic* head on the board.
anyone can seach your post and see all the smart a*s remarks you make to people..go figure i dont play that.
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