01-21-2021, 06:17 PM | #1 |
Drives: 2021 LT1 10 speed auto Join Date: May 2013
Location: Connecticut
Posts: 2,343
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How much torque converter slippage at WOT near redline?
Any one know approximately how much torque converter slippage in RPMs there is in the A10 SS or LT1 cars ? at WOT over 6000 RPM. I have been doing a little digging to prep myself and my A10 2021 LT1 to get ready for a 1/4 mile pass.
I should be doing enough mods to trap 118 MPH and over. My set up will be with a 27.0 tall tire versus a stock OE tire diameter of 27.7 at 6200 rpm in 5th gear (1.52 ratio) I will be doing 118 mph. The program does not account for auto trans torque converter slippage, conceivably I could be going thru the traps at least 6400 rpm and I would rather not up shift or hit the fuel shut off. |
01-21-2021, 07:31 PM | #2 |
Drives: 2017 Corvette ZO6 & 2021 Camaro LT1 Join Date: Jul 2016
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I believe it will be pretty much locked up a 6200 rpm
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01-21-2021, 07:48 PM | #3 |
Drives: 15 SilveradoLTZ,162SSVert BlazerRS Join Date: Dec 2015
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Its not possible to measure this, However, at anything over 6K it should be locked up!!!!
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01-21-2021, 10:15 PM | #4 | |
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Drives: '21 Wild Cherry ZL1 Join Date: Aug 2018
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Quote:
At the very least rear wheel speed sensor can be extrapolated to driveshaft RPM, thusly driveshaft RPM can be determined via tire diameter & gear ratio, ergo transmission output RPM. |
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01-22-2021, 07:43 AM | #5 |
Drives: 2021 LT1 10 speed auto Join Date: May 2013
Location: Connecticut
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So no typical converter slippage at WOT at high rpm your thinking. I just cannot imagine it being like a manual trans and there is absolutely no slippage , but those are my thoughts and I thank you for yours.
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01-22-2021, 07:51 AM | #6 |
Drives: 2021 LT1 10 speed auto Join Date: May 2013
Location: Connecticut
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Your thoughts are making this way to complicated, I am not trying to measure torque converter slippage at WOT at high rpm, there has to be some and am trying to get some educated guesses on how much. Is it 100 rpm, 200 rpm, etc. The auto trans cannot be like a manual where there is no clutch slippage, so if your gear ratios and tire diameter calculate MPH at a given WOT rpm, I can only assume actual RPM at WOT is higher with a auto trans.
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01-22-2021, 08:06 AM | #7 | |
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Quote:
If not, you'd have to know more about torque converter characteristics, and probably be thinking more in terms of output/input as a % than fixed rpm numbers. Norm
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01-22-2021, 08:09 AM | #8 | |
Drives: '20 ZLE Join Date: Jun 2020
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Quote:
1/4 mile 6000 118 mph 84.28 tire circu. 2.73 gear I cal'd huge slippage so something's not right
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01-22-2021, 08:15 AM | #9 |
Drives: 2021 LT1 10 speed auto Join Date: May 2013
Location: Connecticut
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You are correct Norm, but as far as I know all automatic transmission converters slip , at WOT and at higher RPMs the converter will tighten up but still there is slippage. Also as far as I know any lock up feature is usually not operating when at WOT, not matter what gear you are in. My thoughts are even these very late model torque converters may be very tight at high rpm and at WOT but they cannot be totally locked up where there is no slippage in my opinion.
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01-22-2021, 08:24 AM | #10 | |
Drives: 2017 Corvette ZO6 & 2021 Camaro LT1 Join Date: Jul 2016
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Quote:
Redline is 6500 and 7000 won't hurt it. If you trap at 6200 it will be fine. |
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01-22-2021, 08:46 AM | #11 |
Drives: 2021 LT1 10 speed auto Join Date: May 2013
Location: Connecticut
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My concern , not worry , is a upshift by the auto trans, or hitting the rev limiter which I believe is at 6600 RPM . Not a good scenario for a max effort 1/4 mile pass. Trapping at gear ratio, tire diameter calculated 6200 RPM is not going to be actual RPM with a auto trans due to slippage I think.
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01-22-2021, 10:03 AM | #12 |
Drives: 2016 1SS NFG A8 Join Date: Aug 2017
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There is no converter slip on the A8/A10 transmissions since the factory converters lock at WOT in all gears. Aftermarket stuff doesn't lock till 4th/5th gear.
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01-22-2021, 06:51 PM | #13 |
Drives: 2021 LT1 10 speed auto Join Date: May 2013
Location: Connecticut
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That KingLT1 is certainly great to know, I thank you sir. Driving my 2021 LT1 for (just turned 1500 miles today) the past 2 months and have been doing enough WOT pulls , I came to the conclusion there isnt much torque converter slippage at high RPM, you just confirmed that and even better that the converter locks up at WOT in any gear. Today I did my first manual WOT shift very close to redline at the 2-3 shift and the trans does indeed shift quick, virtually no delay . All good to know if I decide to let it shift by itself or If I manually do it in manual mode.
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01-22-2021, 08:05 PM | #14 |
Drives: 2016 Camaro 2SS Join Date: Apr 2017
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If WOT, let the trans do the shifting.
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