Date: Wed, 24 Aug 2005 18:58:52 +0100 From: Colin Stamp <col.dustbinnospamp.plus.com> Subject: Re: "Throttle body" on 9-5 -- why!?
Oh dear. I don't really know where to begin... On 23 Aug 2005 16:02:08 -0700, "Mike Deskevich" <mikedeskevichnospaml.com> wrote: >i think the main reason is emissions. this way the ECU reads from the >gas pedal what you want to do, compares that with what the car is doing >and then opens or closes the throttle in a way to reduce emissions. if >you open the throttle faster than the injectors can keep up, then >you'll have lean issues resulting in more NOx and if you close the >throttle quicker than you can shut the injectors down, you'll have a >rich condition resulting in more HCs Nope. That's not how it happens at-all. Some damping is, and always has been, a good idea. Nothing to do with the speed of injectors. They open and close in microseconds. It's all about gas-flow. >(this can easily be taken care of >with a damper on the throttle closing, my old toyota has this and it's >fool proof). This has nothing to do with electronic throttle control. When you go to electronic control, you might as well put the damping into the software. Take off the electronic control and you'd still need the same amount of damping. >personally, i hate throttle-by-wire. No. You hate some cars which have throttle-by-wire. Unless you've tried the same car both with and without it, you can't tell if it's the throttle-by-wire you hate. >when i drive a >throttle-by-wire car, i can notice quite a lag between the time i press >the go pedal and the time the car starts going. If that's really the case, then it's because the throttle has had to be heavily damped for some reason. Maybe to meet some new emissions standard or whatever, but nothing to do with the electronic controls. >it makes pulling out >into traffice a pain. i guess you'd probably get used to it, but i >don't drive throttle-by-wire enough to know. there are simpler ways to >handle things like torque limiting,anti-skit control, rev limiting, >etc. it all falls under messing with the timing. but i guess they'd >rather put some cheap servos on there and chare $500 when they go bad. "Messing with the timing" is a very badly flawed way of controlling engine torque, as is cutting sparks or cutting fuel. They all have serious problems with smoothness, efficiency, emissions and engine strain. The best way of reducing torque is to use the same control the driver uses - the throttle. > > >i just wish you had a choice when you bought a car. i'd order >mechanical controls on everything from the throttle to the windows to >the door locks. i like stuff that i can fix myself. You do have a choice. Just buy a car that was built in the '70s. Cheers, Colin.