Where does my torque go after 4500 rpm?
10-31-2002, 11:26 AM
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Where does my torque go after 4500 rpm? I just installed a TR224 cam and I got it dyno tuned last night(I thought it was perfect for my setup). The car made good power for an A4 stock heads and normal bolt-ons. It put down 350hp & 388tq but the torque drops off fast after 4500. How can I flatten my torque curve? why does it drop off?
10-31-2002, 07:01 PM
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Re: Where does my torque go after 4500 rpm? Yeah it looks almost exactly the same but my numbers are a little lower. My horsepower peaks at 350 and my torque drops off to around 280 @ 6400. I have the same exact mods except for the drive shaft. I guess I should have paid more attention to that graph before I bought it. oh yeah I think that car is a six speed and my cam is on a 114lsa
11-01-2002, 12:15 AM
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Re: Where does my torque go after 4500 rpm? Are heads my only option? because that means new tranny, slicks, skinnies, rear, and a whole lot more money
11-01-2002, 12:46 AM
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Re: Where does my torque go after 4500 rpm? When you say “where does my torque go?” how much does it drop off?
Does your dyno look like the one below? (Picture is from Thunder Racing)
Link to TR224 dyno
John
Does your dyno look like the one below? (Picture is from Thunder Racing)
Link to TR224 dyno
John
11-01-2002, 02:31 PM
#7
Re: Where does my torque go after 4500 rpm? Some of the issue may be a perception issue due to the relationship between Tq, HP, & rpm.
TQ = HP*5250/rpm.
As you can see 300 HP at 5000 rpm produces more than 300 ft-lbs of torque where as 300 HP at 6000 rpm produces much less than 300 ft-lbs of torque.
If your rate of HP gain starts slowing as you approach and go past 5250, your torque numbers start falling even though HP may be increasing.
TQ = HP*5250/rpm.
As you can see 300 HP at 5000 rpm produces more than 300 ft-lbs of torque where as 300 HP at 6000 rpm produces much less than 300 ft-lbs of torque.
If your rate of HP gain starts slowing as you approach and go past 5250, your torque numbers start falling even though HP may be increasing.
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11-01-2002, 03:24 PM
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Re: Where does my torque go after 4500 rpm? Why is it that I did not lose torque through the A4 like I lost Horsepower. I am not complaining it just seems wierd that the car TR dynoed with the same mods but an M6 made just about the same torque curve as my A4, but then made about 50 more peak horsepower.
11-01-2002, 03:54 PM
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Re: Where does my torque go after 4500 rpm? Most of the difference is due to an A4's converter. An A4 dynoed with an unlock converter will have the torque multiplication from the converter at the lower rpms, giving the appearance of the engine making more torque. Likewise, an unlocked converter eats HP, typically 4-6%, and thus dynos lower total HP. To get your true torque curve, an A4 needs to be dynoed with the converter locked.
