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Old 04-08-2009, 03:00 PM   #10 (permalink)
semtex
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Quote:
Originally Posted by RCZ View Post
Semtex needs to dyno the WHOLE thing.... I am not interested in losing low end torque.

I'll paypal you $5 to help with Dyno fees!
Sheesh, why is this all on me???

In all seriousness though, I think this is a bit of a red herring. We're going to lose some low end torque with these headers, because any time you reduce back pressure, you will lose some low end torque. And it doesn't matter if it's headers or HFCs or test pipes or a cat-back exhaust. All of those components reduce back pressure, hence all of those components reduce low-end torque to a degree. Here's the thing. Low end torque is typically anything from 0-2500 rpm. As far as I'm concerned, what happens in that range is virtually inconsequential. I just got home from the grocery store and was deliberately watching my tach. When I upshift from gear to gear, my tach needle doesn't even drop below 3000 rpm. When I launch, I'm past 2500 rpm in less than a second. So unless you deplete low-end torque so badly that you're in danger of stalling at each launch, it's just not relevant. What does matter as far as driveability goes is mid-range torque, typically 2500-6000rpm. And that's why I was alarmed when RelentlessRY said he saw a loss in the mid-range. But the bet right now is that it was because of the factory y-pipe. So I'll be interested to see the torque curve on Wstar's dyno. I, for one, couldn't care less if I lose a little more low-end torque over and above what I've already lost with the HFCs and cat-back exhaust, especially not if I'm gaining hp and torque in the ever-important mid-range. This is also one instance where I'm glad the car has a heavy flywheel, because the mass of the factory flywheel more than offsets any loss in low-end torque, IMO. Plus, I used to drive an S2000. You want to talk about crappy low-end torque? Try driving one of those. Let me put it this way. I had a lightweight JWT flywheel in my 350, and it still had more low-end torque than my S2000 did. I do appreciate the S2000 for one thing tho. That thing really taught me how to manage my available low-end torque well. So much so that I haven't stalled my car even once in over 5 years!
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Last edited by semtex; 04-08-2009 at 03:02 PM.
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