This can't be right (can it?)
#1079946
09/21/11 05:54 PM
09/21/11 05:54 PM
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Joined: Dec 2007
Posts: 10,542 BROOK PARK, OH
WILD BILL
OP
Senior Member of the Junior Dragster Club
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OP
Senior Member of the Junior Dragster Club
Joined: Dec 2007
Posts: 10,542
BROOK PARK, OH
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I'm using Wallace Racing Calculator to determine my Conv slip %
Using 132.66 mph/7000 Rpm at the line/ 4:56 gear ratio/ and the advertised roll out of my tires as 97"
I came up with 17.511 %
I tried varying the rpm and tire size a little figuring I might be going a little under what I think I see on the tack or thinking I might have to acct for tire growth but it still comes in as what I think is a way high slip percentage.
For some reason I was expecting somewhere around a 5 or 6 % number.
Can this be right?
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Re: This can't be right (can it?)
[Re: StrokerAspen]
#1079949
09/21/11 06:08 PM
09/21/11 06:08 PM
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Joined: Dec 2007
Posts: 10,542 BROOK PARK, OH
WILD BILL
OP
Senior Member of the Junior Dragster Club
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OP
Senior Member of the Junior Dragster Club
Joined: Dec 2007
Posts: 10,542
BROOK PARK, OH
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Yes, they are 31's but why are you using the diameter?
The calulator I see wants MPH, RPM, Gear, & CIRCUMFERENCE (inches}
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Re: This can't be right (can it?)
[Re: WILD BILL]
#1079951
09/21/11 06:13 PM
09/21/11 06:13 PM
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Joined: Nov 2007
Posts: 1,600 Alberta Canada
StrokerAspen
top fuel
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top fuel
Joined: Nov 2007
Posts: 1,600
Alberta Canada
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Quote:
Yes, they are 31's but why are you using the diameter?
The calulator I see wants MPH, RPM, Gear, & CIRCUMFERENCE (inches}
The calculator I am using works off diameter. Basically the calculator I am using takes the diameter, and uses the circumference based on the diameter.
31" X 3.1416 = 97.3896"
I have used this calculator to calculated quite a few cars and it has worked for me. I have had good luck with the Wallace stuff too though.
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Re: This can't be right (can it?)
[Re: WILD BILL]
#1079953
09/21/11 06:36 PM
09/21/11 06:36 PM
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Joined: Jan 2003
Posts: 16,925 NC
440Jim
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,925
NC
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Quote:
I'm using Wallace Racing Calculator to determine my Conv slip %
Using 132.66 mph/7000 Rpm at the line/ 4:56 gear ratio/ and the advertised roll out of my tires as 97"
I came up with 17.511 %
You are inputing gear ratio with a colon (4:56) instead of the proper way which is a decimal (4.56)
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Re: This can't be right (can it?)
[Re: StrokerAspen]
#1079954
09/21/11 06:41 PM
09/21/11 06:41 PM
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Joined: Dec 2007
Posts: 10,542 BROOK PARK, OH
WILD BILL
OP
Senior Member of the Junior Dragster Club
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OP
Senior Member of the Junior Dragster Club
Joined: Dec 2007
Posts: 10,542
BROOK PARK, OH
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Now I see what I was doing wrong
I was typing in 4:56 instead of 4.56 and that's what gave me the high slip.
Once I put in 4.56 I got 5.962 %
However, that said, I was starting to think that with the high slip that I was leaving some ET on the table and that a tighter conv would help get it to where it seems everyone thinks it should be running.
Now, I don't know what to think.
How do you know if you have the right (best) conv for your car?
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Re: This can't be right (can it?)
[Re: WILD BILL]
#1079955
09/21/11 06:49 PM
09/21/11 06:49 PM
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Joined: Nov 2007
Posts: 1,600 Alberta Canada
StrokerAspen
top fuel
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top fuel
Joined: Nov 2007
Posts: 1,600
Alberta Canada
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I would say 6% isn't too bad. What size is the converter? if it is an 8", maybe you could get a 9" converter built that will still get you off the mark the same. I would say everything is working well. There is a little simple math problem that gives you an idea. 1320/MPH = Optimum ET. 1320/132.5 = 9.962 An exapmle of one that ISN'T working to its full potential is My car But that's to be expected with a big loose converter and 3.23 gears. 1320/128 = 10.313..... I have gone 10.68. Is it a scientific math formula? No, I think it's a fluke that it works. haha. OR maybe it is and I don't know why it works. But it does. -Kenny
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Re: This can't be right (can it?)
[Re: Sport440]
#1079957
09/21/11 07:02 PM
09/21/11 07:02 PM
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Joined: Dec 2007
Posts: 10,542 BROOK PARK, OH
WILD BILL
OP
Senior Member of the Junior Dragster Club
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OP
Senior Member of the Junior Dragster Club
Joined: Dec 2007
Posts: 10,542
BROOK PARK, OH
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Calculated 60' for that pass was 1.383467
Actual 60' was 1.361
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Re: This can't be right (can it?)
[Re: VernMotor]
#1079959
09/21/11 10:06 PM
09/21/11 10:06 PM
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Joined: Dec 2009
Posts: 20,640 in a cattle trailer down by th...
Guitar Jones
Paddle faster! I hear banjo music!
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Paddle faster! I hear banjo music!
Joined: Dec 2009
Posts: 20,640
in a cattle trailer down by th...
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It's all math...and physics, math and physics. Why didn't I pay more attention in school...
"Follow me the wise man said, but he walked behind"
'92 D250 Club Cab CTD, 47RH conversion, pump tweaks, injectors, rear disc and hydroboost conversion. '74 W200 Crew Cab 360, NV4500, D44, D60 and NP205 divorced transfer case. Rear disc and hydroboost coming soon! 2019 1500 Long Horn Crew Cab 4WD, 5.7 Hemi.
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Re: This can't be right (can it?)
[Re: roadhazard]
#1079961
09/21/11 11:13 PM
09/21/11 11:13 PM
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Joined: Dec 2007
Posts: 10,542 BROOK PARK, OH
WILD BILL
OP
Senior Member of the Junior Dragster Club
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OP
Senior Member of the Junior Dragster Club
Joined: Dec 2007
Posts: 10,542
BROOK PARK, OH
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Quote:
I've seen a few of your recent posts Guitar Jones and wonder if we're brothers
No need to insult the guy Greg
And thanks
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Re: This can't be right (can it?)
[Re: Sport440]
#1079963
09/22/11 12:20 AM
09/22/11 12:20 AM
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Joined: Dec 2007
Posts: 10,542 BROOK PARK, OH
WILD BILL
OP
Senior Member of the Junior Dragster Club
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OP
Senior Member of the Junior Dragster Club
Joined: Dec 2007
Posts: 10,542
BROOK PARK, OH
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Doesn't sound like I'll be able to squeeze much more out of it then
On the other hand, that also means I can just put it away for the winter and NOT have to on it
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Re: This can't be right (can it?)
[Re: WILD BILL]
#1079964
09/22/11 12:24 AM
09/22/11 12:24 AM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
Doesn't sound like I'll be able to squeeze much more out of it then
On the other hand, that also means I can just put it away for the winter and NOT have to on it
Have you tried anything on the tune up Bill... its real close for the HP to weight(at that given time)
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