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Lumpy Torque Curve. Normal?

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Old Mar 27, 2011 | 02:55 AM
  #1  
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Default Lumpy Torque Curve. Normal?

I did a dyno run after flashing a new tune (Brenspeed) that was updated for the new mods. Numbers were 291 @ 5400/308 @ 4400 (275/294 previously). I noticed that the torque curve was rather lumpy and would spike and flatten for a few hundred RPM. Is this normal? Tuning? Or am I retarded? Thanks guys.
Old Mar 27, 2011 | 03:11 AM
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what are your mods?

LT's with cat delete? if so, ensure the rear O2's are turned off
Old Mar 27, 2011 | 03:13 AM
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BBK CAI, BBK 62mm TB, Shorties, Dynomax Ultra-Flo Welded muffs, 91 tune.
Old Mar 27, 2011 | 12:04 PM
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Check for air leaks on your Cai and TB. That can cause wierd spikes


Not bad numbers otherwise for relatively unmodded. How was your A/F ratio?
Old Mar 27, 2011 | 12:15 PM
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Originally Posted by Tylus
Check for air leaks on your Cai and TB. That can cause wierd spikes
No leaks. I checked everything before I pulled.


Originally Posted by Tylus
How was your A/F ratio?
Not sure. I haven't put a wideband on it yet. Although she did like being "2% richer".
Old Mar 27, 2011 | 12:16 PM
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No it's not normal at all. Your torque and HP curves along with your AF ration should be as smooth as possible.
Old Mar 27, 2011 | 12:22 PM
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Old Mar 27, 2011 | 03:22 PM
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Is this an automatic?

From the looks of the run I would say something off on the dyno.

What did the shop say?
Old Mar 27, 2011 | 04:13 PM
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Nah, it's a 5.

The shop didn't say anything other than "Your HP curve looks smooth". I gives a s*** about HP.
Old Mar 28, 2011 | 10:36 AM
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I torque curve like that would be felt by the driver and probably heard from those listening. Point to the spot on the graph and say WTF? What is that? Make them explain.
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