drive by wire custom revving

Hi guys,i had a few projects over the years but i am now still stumped with this dilemma. I have now a client that wants what his brother has which is remote controlled revving of engine outside his vehicle,I explained to him that he has a E90 bmw which is servo controlled throttle body and his bro has a cable accelerator cable which made it easy for me to use a clutch solenoid motor to pull able and bring up revs. Now i did my research, and i have not found a way to do this via analogue (mechanically),I looked at the throttle actuator and its kinda scary and to i decided to give up on a mechanical way,but i am sure electrically it can be done starting at the accelerator(gas) pedal which is complicated on its own,I mean your foot depresses a potentiometer which in turn sends signals data..voltages to a vehicle computer which in turns sends signals to throttle body to open adjusting...pheww damn. Guys so if there was a way where do i start..do i build a logic circuit that send 2.5v to the throttle body opening it halfway via my remote receiver then protect it with a diode..:D    Is there any suggestions that i can follow.Also i am sorry if this was asked before and i appreciate all the tech help thanks.the only interesting answers are the one that destroys the question.

I did a similar deal to fast-idle a Powerstroke Diesel. I can activate the fast-idle with an aux channel on my RS for enhanced warm-up. I interrupted the pedal assemble signal, and inserted the resistance required to make it idle at 1200 RPM. I used two relays and a toggle switch, plus the aux channel. It also disengages with brake pedal, which is required to shift out of Park. You do not want to open the throttle "half way" in neutral. The engine will red-line. Your deal being a BMW, there's probably a lot more to making it work than the Ford was. Good Luck.

Thanks so much for the information,can you provide a wiring diagram of what you did,maybe just maybe i could send a low voltage to the throttle body directly to just open it a tad when its idling.thanksthe only interesting answers are the one that destroys the question.

A Diesel engine doesn't have a throttle body. I intercepted the signal from the Throttle Pedal Assembly, and inserted a resistance value that the ECM interpreted as 1200 RPM. In the Powerstroke system there is also an "Idle Validation Switch" that is a SPST switch that is open at 0-pedal, and closes as soon as the pedal comes off zero. My system had to close the IVS as well, so the ECM thought there was a foot pushing on the pedal. The throttle motors I'm familiar with are all stepper motors. In both directions. My suggestion is to make the ECM think you advanced the throttle pedal. Not interrupt the signal to the throttle motor. A diagram of my system won't be useful to you because the two systems are probably very different. I've learned that the European car systems (Porsche, Benz, BMW) are usually above my frustration level to try to figure out. I don't work on them, nor have I owned any, so I have little hands-on experience with them. Sorry I can't help more. I showed what I had done, and the suggestion is to try to do the same. Figure out to simulate a "foot" holding the pedal at the speed you desire. EDIT ADD: How about a solenoid that holds the throttle pedal at the desired position? Similar to what you did on the "normal" throttle body. Don't mess with the electrics at all.

thanks,i forgot diesel dont have throttle boddy..lol. the idea of solenoid on the pedal seems viable,it would have to be very small indead and not hinder ones foot or hook anywhere,I am gonna study the bmw e90 foot pedal wiring diagram and see if i cannot do the same you did.If pedal is at rest 0v,i might try a low voltage spike to see if the throttle response,Will take great care in protecting feedback also.Thanks again,will post if i have a breakthrough.the only interesting answers are the one that destroys the question.

Not sure if it will help you but I remember when the 08+ Silverado's started coming out, there was a kit from ROSTRA (the cruise control company) that had us doing pedal pulls through the floor.

Might be an even easier solution if you can find one, and have space for it of course. I believe it went through the firewall and came out under the pedal and simply pulled the pedal towards the floor for a mechanical solution.

Obviously a Silverado has more room in that area than a BMW..

To master and control electricity is perfection. *evil laugh*

You're ringing bells RJ, When I lived in Florida in the early 80's I did loads of cruise controls on 244 Volvos, the ARA unit for that vehicle used the same method, grab at the throttle pedal.