[kircher]

Hi all.

For a while now I've been wondering about throttle response with fuel injection. In my experience cars/bikes with well tuned carburettors have had throttle response that absolutely shat on the fuel injected cars I have driven. Am I just driving the wrong fuel injected cars? Some of the fuel injected cars I've driven also had electric throttles which made it even worse. The fuel injected cars I've driven are as follows, from best to worst:

V6 Magna
1996 Subaru Liberty (daily driver)
2007 - 2008 Toyota Corolla (electric throttle)
2008 Toyota Yaris (electric throttle)
2005 Peugeot 307 (electric throttle)

And the carburetted vehicles (in no particular order):

4.9 XC fairmont (my Ford)
Datsun 180B
202 Kingswoods
1998 Harley Davidson

Now as I understand it when you put your foot down in a carbed vehicle, the accel pump squirts fuel into the airstream as the throttle plates move, providing response only limited by the distance of the carb to the intake valve and the speed of sound (the pressure wave as the throttle position changes), with other variables such as the cam also playing a role here. With a fuel injected engine, when the throttle position is changed, the computer has to respond and adjust the fuel squirt accordingly, thus creating a delay.

Of the vehicles I've driven/ridden, the Harley was by far the most responsive (it has a CV carb), and the other cars had basically equally good throttle response. Of the fuel injected cars I've driven, only the Magna has response that was close to the carbed ones, then followed by the Liberty. The worst was definitely the Peugeot. It was so bad that I stalled it on take off a lot because the throttle simply didn't respond quick enough to me pulling the clutch out. When making a high RPM gear shift, it would continue to rev even after I had taken my foot off the accelerator and put my foot on the clutch. The Yaris was the same, although not as sloppy on take off. The Corolla was an auto, but was still not responsive.

Now I can understand a Mercedes Benz with a 380kw 630Nm V8 having an electric throttle to make take-offs and accelerator adjustments smooth and not jerky to suit the personality of a high powered luxury car and it's need to waft along and not behave like a 1960s big block Muscle Car. Why should a gutless Yaris or 2 litre Peugeot be made even worse with a throttle with a half second delay to any change in position?

Now my main question is; can fuel injected vehicles be made to have excellent almost instantaneous throttle response? If so, I guess I've been driving bad fuel injected cars. Still, I don't see why anyone would want their car to do anything other than what their hand and feet dictate. Any other inputs to this topic are greatly appreciated. I want to know as much about this subject as possible

Sorry about the long post

Kircher