F-Type ( X152 ) 2014 - Onwards

Torque Limiter

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Old May 30, 2018 | 01:46 PM
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Default Torque Limiter

I'm trying to figure out why my car has torque limitation programming in the ECU. I have a 2017 Base 340, which has a maximum torque of 332 ft/lbs. According to Wikipedia (https://en.wikipedia.org/wiki/ZF_8HP_transmission - best source I could find), all F-Types use the ZF 8HP70 transmission, which has a maximum torque of 700 ft/lbs.


I can't go over 700 ft/lbs, so the tranny is limiting the measly 322 that I have? HUH????



Could someone who understands these things please educate me?
 
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Old May 30, 2018 | 02:28 PM
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Originally Posted by FullChat
I'm trying to figure out why my car has torque limitation programming in the ECU. I have a 2017 Base 340, which has a maximum torque of 332 ft/lbs. According to Wikipedia (https://en.wikipedia.org/wiki/ZF_8HP_transmission - best source I could find), all F-Types use the ZF 8HP70 transmission, which has a maximum torque of 700 ft/lbs.


I can't go over 700 ft/lbs, so the tranny is limiting the measly 322 that I have? HUH????



Could someone who understands these things please educate me?
It’s a marketing gambit. You gotta pay for an S or P400 to get the extra power.
 
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Old May 30, 2018 | 02:38 PM
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Your transmission is RATED to hold 700 Nm of torque (not lb-ft). The engine you have is only tuned to produce 332 lb-ft (451 Nm) and isn’t limited by the transmission calibration from a peak torque perspective.

Interestingly enough, going to the S or P400 will only net you 339 lb-ft (460 Nm) of torque even though you’re gaining 40-60 bhp because they only limit you on the top end between the different V6 trims.

Note: 700 Nm of torque = 516 lb-ft which is convieniently the max torque on the V8 models.
 
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Old May 30, 2018 | 03:05 PM
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Thanks for the Nm lb-ft correction. Ooops!


I was just thinking about a tune and had heard that the torque limits were put in to save the transmission, and worried that the tune might be giving me more torque that the tranny could handle. Then I found out that all of the F-Types use the same transmission and thought - if it can handle a SVR, it should be able to handle a tune!
 
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Old May 30, 2018 | 03:06 PM
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Originally Posted by Stohlen

Note: 700 Nm of torque = 516 lb-ft which is convieniently the max torque on the V8 models.
Similarly, the ZF 6S-45 manual has a max rating of 340 lb-ft even though we know it can handle 425.
 

Last edited by Unhingd; May 30, 2018 at 03:08 PM.
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Old May 30, 2018 | 03:49 PM
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One thing to consider about the VAP tune is what you really feel is not the increase in peak torque as much as a much flatter torque curve. With the tune you get much more torque down low, point being you don't have increase the max torque to get a significant benefits.
 
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