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Discussion Starter · #1 ·
My driving style is suited for torque, and the area I live in is hilly, so torque is what I'm after. I don't mean in the low rpms, bu once the turbo is up and spinning as it should.

I have done some digging and can't find a thread that deals with how to wring torque outta the engine. I do however remember seeing Weasel 555's numbers. The hp/torque numbers are similar and so forth. I'm looking to get a nice flat hp curve and big torque numbers.

My to-do list includes these goodies:

Up-pipe of some flavor
Down pipe and catless to a probable Carbon/Ti exhaust
Maybe, just maybe some Samco IC hoses, kinda 50/50 on that one

I'm aiming foe efficient and predictable, so when the ECU is cracked(I hear Cobb is at the cusp), I'll jump on that too.

So, whats the recipie for unlocking torque?
 

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Like you, I'm much more interested in tuning for real world performance, since that's where my car is used 99.9% of the time.

I don't know the science behind the proper tuning for more torque, but I can tell you that I've had a significant increase in torque with the installation of my OE hybrid turbo. As I was driving to work this moring, as a matter of fact, I did a WOT 4th gear pull and was quite impressed. MUCH better than stock. I'm running stock fuel and ECU. So far the ECU has tuned itself nicely to the new compressor. It's increased the powerband about 1000 rpm and it's much more lively.

I'm still running stock boost. The ECU is in full control. I think a EBC would be good if you like to take it to the redline all the time, but I usually like to shift at 6000 - 6500. I find that keeps it in the meat better. Even though boost is kept at 12 - 14.5 psi the increased flow rate of the new comressor makes a noticable difference. Plus it doesn't (not supposed to anyway) heat the charge air as much which also helps.

I'm also running full stock exhaust.
 

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Torque = VE

The simple thing to remember is torque is directly related to MEP ( mean effective pressure) in the cylinder, and this it tied very closely to VE (Volumetric Efficiency).

As a general rule max torque occures at the engines max VE point.

Sooooo -

To get good torque concentrate on good breathing/exhaust mods.

On the exhaust side run the smallest header dia you can find and you will have much better low-mid range torque.

A too small header gives up very little top end power but makes a very drivable engine. A too large header makes small improvements in max power at an rpm you seldom visit in exchange for a huge drop in the fun factor at low and moderate rpm.

Larry
 

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Thank you Larry,

That was an excellent explanation.
 

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Discussion Starter · #6 ·
I'm not too concerened with low rpm torque numbers, its a 2.0 liter and yer not gonna get very much out of it anyways. I'm looking for big torque numbers when the turbo is doing its thing.

So what I gather is:

Free up the exhaust, but keep a modicum of back-pressure(header).

Figure out how to get air to the engine better.

Pulleys might give it a kick low down too.

Thanks for the help y'all.
 

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Some FYI on engine torque:
The engine torque increases with engine speed until the engine is drawing in the maximum amount of fuel mixture. Torque is the greatest at that point, and it diminishes with any rpm increase after the point.

Found this from last year's auto shop class...
 

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Thinking Man's Engine
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brembo said:
My driving style is suited for torque, and the area I live in is hilly, so torque is what I'm after. I don't mean in the low rpms, bu once the turbo is up and spinning as it should.

I have done some digging and can't find a thread that deals with how to wring torque outta the engine. I do however remember seeing Weasel 555's numbers. The hp/torque numbers are similar and so forth. I'm looking to get a nice flat hp curve and big torque numbers.

I think you meant flat torque curve and linear hp curve.

Some of Weasel555's mods include the VF23 turbo, Samco turbo inlet pipe....lightened pulley....he didn't do too much. He has some sort of computer (can't remember which one) which has tuned to get the flatest torque curve possible.
 
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