PT4400 owners I have trap speed/RPM questions
11-21-2003, 03:19 PM
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PT4400 owners I have trap speed/RPM questions My current setup is a Yank PT4400 converter with 3.23 gears, TEA heads and a TR224 cam and I am crossing the ¼ mile traps at 6530rpm 
at 120.xx mph.
That RPM seems way too high to me considering the 3.23 gears I am running.
Is the high rpm caused by extreme converter slippage and is this normal?
If the converter were locked I should be crossing the traps at 5050rpm at 120mph with 3.23 gears and 5800 with 3.73 gears. 1500rpm of slippage with the 3.23 gears just seems too much to me.
What do you all think?
Thanks
John
at 120.xx mph. That RPM seems way too high to me considering the 3.23 gears I am running.
Is the high rpm caused by extreme converter slippage and is this normal?
If the converter were locked I should be crossing the traps at 5050rpm at 120mph with 3.23 gears and 5800 with 3.73 gears. 1500rpm of slippage with the 3.23 gears just seems too much to me.
What do you all think?
Thanks
John
11-21-2003, 06:57 PM
#2
Originally Posted by JNorris
My current setup is a Yank PT4400 converter with 3.23 gears, TEA heads and a TR224 cam and I am crossing the ¼ mile traps at 6530rpm at 120.xx mph.
That RPM seems way too high to me considering the 3.23 gears I am running.
Is the high rpm caused by extreme converter slippage and is this normal?
If the converter were locked I should be crossing the traps at 5050rpm at 120mph with 3.23 gears and 5800 with 3.73 gears. 1500rpm of slippage with the 3.23 gears just seems too much to me.
What do you all think?
Thanks
John
at 120.xx mph. That RPM seems way too high to me considering the 3.23 gears I am running.
Is the high rpm caused by extreme converter slippage and is this normal?
If the converter were locked I should be crossing the traps at 5050rpm at 120mph with 3.23 gears and 5800 with 3.73 gears. 1500rpm of slippage with the 3.23 gears just seems too much to me.
What do you all think?
Thanks
John
Tim
11-21-2003, 08:00 PM
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Me thinks its about right, Going back into the data file I'm almost positive that my finish line rpm was over 6000 with 3.42's at 113mph.
Do you have some kind of data logger?
LAter
Do you have some kind of data logger?
LAter
11-21-2003, 08:47 PM
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Originally Posted by Bob2of3
Me thinks its about right, Going back into the data file I'm almost positive that my finish line rpm was over 6000 with 3.42's at 113mph.
Do you have some kind of data logger?
LAter
Do you have some kind of data logger?
LAter
As per the question at hand, with both 3.23's in the stock rear and 4.11's in my 12-bolt, I get around 600-700 rpm of slippage with my TP4400. Take care.
11-21-2003, 08:58 PM
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Originally Posted by Bob2of3
Me thinks its about right, Going back into the data file I'm almost positive that my finish line rpm was over 6000 with 3.42's at 113mph.
Do you have some kind of data logger?
LAter
Do you have some kind of data logger?
LAter
Click link below for the data logged on the run.
ftp://members.aol.com/jnorris404/1114-3-run.htm
John
11-21-2003, 09:03 PM
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Originally Posted by RUQWIKR
Holy, moly, Bob you are alive!!! Email me directly with what's been up lately!
As per the question at hand, with both 3.23's in the stock rear and 4.11's in my 12-bolt, I get around 600-700 rpm of slippage with my TP4400. Take care.
As per the question at hand, with both 3.23's in the stock rear and 4.11's in my 12-bolt, I get around 600-700 rpm of slippage with my TP4400. Take care.
RUQWICKR - How do you measure slippage? Is it the difference in RPM between the converter being locked and unlocked?
600-700 rpm is a long way from 1400rpm.
Thanks
John
11-21-2003, 09:39 PM
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The way i have always done it is....mph x 336 x gear ratio = then divide by tire diameter. Then add conv slippage as per Yanks website.. A TP 4400 is what 5% slip? So yours is 5008 rpm without conv slippage..and 5250 with...It used to work with other combos i have had but seems like its off on this one.. 
Who knows?
Phil
Who knows?
Phil
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11-22-2003, 07:48 AM
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Correct me if I'm wrong, but you cant go by trap speed as actual MPH when crossing finish line. I have always heard that the MPH they use is an average speed that the computer gets from the last 2 sets of timers you go through at the track, which should mean you are going faster than the trap speed says on the time slip.
11-22-2003, 08:28 AM
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I do not know how your trap speed is measured in the 1/4 but you bring up a good point about the MPH.
I do not lift at the finish line of the ¼, I drive on through it. Also my ET streets and taller than my street tires so that makes the speedo read lower. In the data file above it shows 6445rpm at 119 when in reality I was going around 123 so my true RPM would be a max of 5200 with 3.23 gears and 26.5 inch tires with no converter slippage. It seems to me that I have at least 1200 rpm (or 19%) of slippage which seems high to me.
John
I do not lift at the finish line of the ¼, I drive on through it. Also my ET streets and taller than my street tires so that makes the speedo read lower. In the data file above it shows 6445rpm at 119 when in reality I was going around 123 so my true RPM would be a max of 5200 with 3.23 gears and 26.5 inch tires with no converter slippage. It seems to me that I have at least 1200 rpm (or 19%) of slippage which seems high to me.
John
11-22-2003, 08:45 AM
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I know in A-tap there is a option that measured the TC clutch I think? That will give you the rpm of slippage. And like Ruqwikr stated at the top of each gear was anywhere from 300-700 rpm difference
11-22-2003, 11:09 AM
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Originally Posted by Bob2of3
I know in A-tap there is a option that measured the TC clutch I think? That will give you the rpm of slippage. And like Ruqwikr stated at the top of each gear was anywhere from 300-700 rpm difference
Bob - You are correct about A-tap and EFILive being able to measure the TCC slippage. Good idea.
Thanks
11-22-2003, 11:32 AM
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I also have 3.23 gears, a Yank converter, and am crossing at 120 MPH. Looking at my Autotap files from last night, it appears that I'm crossing the line at about ~5825 or so. The last WOT entry is 5881 but I do drive through the line and then a bit further just to be safe.
Sure, mine is a 4000 and yours is a 4400 but it shouldn't make near that much difference at these RPMs. 6530 seems way too high. I think there's a problem.
Sure, mine is a 4000 and yours is a 4400 but it shouldn't make near that much difference at these RPMs. 6530 seems way too high. I think there's a problem.
11-22-2003, 11:48 AM
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Originally Posted by Colonel
I also have 3.23 gears, a Yank converter, and am crossing at 120 MPH. Looking at my Autotap files from last night, it appears that I'm crossing the line at about ~5825 or so. The last WOT entry is 5881 but I do drive through the line and then a bit further just to be safe.
Sure, mine is a 4000 and yours is a 4400 but it shouldn't make near that much difference at these RPMs. 6530 seems way too high. I think there's a problem.
Sure, mine is a 4000 and yours is a 4400 but it shouldn't make near that much difference at these RPMs. 6530 seems way too high. I think there's a problem.
I have gone over ATap log files from the past year and this converter has always had this much slip.
John
11-22-2003, 04:21 PM
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Originally Posted by JNorris
RUQWICKR - How do you measure slippage? Is it the difference in RPM between the converter being locked and unlocked?
600-700 rpm is a long way from 1400rpm.
Thanks
John
600-700 rpm is a long way from 1400rpm.
Thanks
John
11-22-2003, 09:48 PM
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Stephen,
I will call Mike on Monday.
This afternoon I logged the Torque Converter Slippage RPM at WOT in 2nd gear and sure enough the slippage rpm dropped from the time the gear started. (I could not check 3rd gear)
At the top on of 2nd gear the slippage RPM was between 700 and 800 rpm.
See link below for the data file.
ftp://members.aol.com/jnorris404/TCCSlip.htm
John
I will call Mike on Monday.
This afternoon I logged the Torque Converter Slippage RPM at WOT in 2nd gear and sure enough the slippage rpm dropped from the time the gear started. (I could not check 3rd gear)
At the top on of 2nd gear the slippage RPM was between 700 and 800 rpm.
See link below for the data file.
ftp://members.aol.com/jnorris404/TCCSlip.htm
John
11-23-2003, 10:07 AM
#20
U are having a problem,Either the trans is toas or the verter is toast.U shouid be crossing the traps at no more than 5200 MAX...(MPH X GEAR X 336 DIVIDED BY TIRE SIZE)Thats the way I've always done it too.
I ran 122 threw the lights with a TP4400/4.10/26in slick and went threw at 6500 and then I tested the VIG3800 and went 121 threw the lights at 6500 so IMO u are having some serious slippage.
If I had to guess u have a glazed lu clutch or a bad lu clutch that is not allowing u to couple which is causing the extra rpm but like Steven siad,Get in touch with Yank or check the trans...
Good luck
I ran 122 threw the lights with a TP4400/4.10/26in slick and went threw at 6500 and then I tested the VIG3800 and went 121 threw the lights at 6500 so IMO u are having some serious slippage.
If I had to guess u have a glazed lu clutch or a bad lu clutch that is not allowing u to couple which is causing the extra rpm but like Steven siad,Get in touch with Yank or check the trans...
Good luck