Ruff

What gives maximum torque, a regulated throttle input or WOT? IMO a regulated input seems to give me more response. But that may be psychological. Can anyone enlighten? Cheers..

john banks

Depending on many factors if the car is not setup right it could make more torque on less than WOT if it is too rich on WOT for example. Yes you will get more response on part throttle because there is still a response to be had. The driver at WOT has already had the response and is waiting for the gearchange

Mycroft

This is a great question...

Fuelling holds the key to this, if you have a 'standard' factory set-up then the fuelling will be fairly basic on WOT, and the cylinders will get an overly rich mixture for a short time...
If you have an after-market ECU/Fuelling module then they problem will not be so exaggerated.
What you experience is a 2-fold depletion in the power with the factory set-up,
First, an over-rich mixture will not generate as much power per explosion as the stoich. so there is not so much power in the acceleration compared to if the fuel is metered with a sensitive foot.
Second, the least realised effect is that efficient Torque generation is a product of heat, so WOT with its concommitent rich mixture is a 'cooler' reaction, the heat is not generated as it would with the stoich. or steady foot, this lessens the Torque also.

So in summary with factory set-ups WOT can actually deplete your accelerative power by a little and at the same time reduce the torque generation.

WOT is only any good with a quality aftermarket fuelling system that has a seriously fine tuned map.

Regards
Mycroft.

[Edited by Mycroft - 4/20/2003 11:57:47 AM]

Ruff

Thanks John and Mycroft. I am indeed using a factory ECU and do feel the difference with a feathered foot. But it does make squeezing that very last lbf of torque that much harder.

RT

My opinion is that the "feathered foot" approach makes the charge air squeeze thru a partially open throttle butterfly. If the MAP is 1bar on a 100% opened throttle, it surely is much cooler than 1bar on a 60% opened throttle. In the latter case, the turbocharger would have had to overcome the restriction of the throttle by working even harder.

Now, how much this contributes/subtracts from the fueling mix in terms of torque output, is hard to quantify I guess. Comments?

nom

Not necessarily, as there's no reason that the throttle butterfly needs to be 100% open to allow the air flow for 1 bar - it may reach one bar at 50% opening & any more than that the turbo can't 'keep up with'.
Also, if you're set to 1 bar peak, then that's the limit of your air flow - the wastegate will dump any further exhaust to keep the air flow (inlet) the same, irrespective of throttle opening.