Revving Engine from under the Hood [Archive] - Drive Accord Honda Forums

: Revving Engine from under the Hood


CaMole
11-26-2009, 08:05 PM
I know that older cars that don't have DBW(Drive-By-Wire) can do this pretty easily. Since we have DBW are we able to do this? I read up on a TSX forum that it is possible even with DBW. Has anyone tried it? I wanna be able to hear my engine up close without the help of a partner.

GTFan712
11-26-2009, 08:06 PM
I know that older cars that don't have DBW(Drive-By-Wire) can do this pretty easily. Since we have DBW are we able to do this? I read up on a TSX forum that it is possible even with DBW. Has anyone tried it? I wanna be able to hear my engine up close without the help of a partner.

I was wondering this as well.

-GT

zexen
11-26-2009, 10:50 PM
I don't think it will be possible because it's electronically controlled, but with the fact that the butterfly valve for the intake manifold needs to be turned somehow, I have no idea what kind of motor would be used to open it accordingly.

fastball
11-27-2009, 03:50 AM
I'd like to meet the person in the TSX forum who said this could be possible, because it isn't. You can't open the valve on the intake manifold, and all fuel delivery is completely computer operated.

In theory, the only way it could be done is if you found the input of the pedal position potentiometer on the ECM, and taped in with an external potentiometer in your hand, and turned the knob.

On DBW engines, changing engine speed is EXACTLY like changing volume on your stereo receiver.

The gas pedal is the volume knob, or in electronics a potentiometer. A pot is a variable resistor that increases or decreases the flow of electricity through it. As you press down on the gas pedal, instead of opening up a throttle body with a cable you are turning the volume knob and increasing the voltage to the ECM (in a stereo that would be the main microprocessor). The ECM sees the voltage change and adjusts fuel injection and sends out the proper voltage to the motor on the butterfly valve in the intake manifold to turn open wider.

MSchu
11-27-2009, 04:57 AM
What I am waiting for is a Manual TB conversion...:D

BPearl2010
11-27-2009, 05:56 AM
I'd like to meet the person in the TSX forum who said this could be possible, because it isn't. You can't open the valve on the intake manifold, and all fuel delivery is completely computer operated.

In theory, the only way it could be done is if you found the input of the pedal position potentiometer on the ECM, and taped in with an external potentiometer in your hand, and turned the knob.

On DBW engines, changing engine speed is EXACTLY like changing volume on your stereo receiver.

The gas pedal is the volume knob, or in electronics a potentiometer. A pot is a variable resistor that increases or decreases the flow of electricity through it. As you press down on the gas pedal, instead of opening up a throttle body with a cable you are turning the volume knob and increasing the voltage to the ECM (in a stereo that would be the main microprocessor). The ECM sees the voltage change and adjusts fuel injection and sends out the proper voltage to the motor on the butterfly valve in the intake manifold to turn open wider.

+1, couldn't say it in any other way..

Edaccord08
11-27-2009, 06:38 AM
I could be wrong but I believe honda has a manual throttle control for DBW throttles so tech can make checks under hood. Its very simple just unplug harness and attach the new one.
I think I saw it in one of Honda TSB's .

zexen
11-27-2009, 09:09 AM
Ed, Honda may have one for the tech's to do it for diagnosis purposes, but there's no reason for any of us to have one to listen to our engine from the engine bay... or spend the money on one for that purpose haha.

Edaccord08
11-27-2009, 09:13 AM
Ed, Honda may have one for the tech's to do it for diagnosis purposes, but there's no reason for any of us to have one to listen to our engine from the engine bay... or spend the money on one for that purpose haha.

well thats going to happen no matter the vehicle as almost all are DBW and use servor to control throttle.
If I was doing a lot of work and thought it be worth while I just make one up, all you need is old pedal pot and piece of wire harness from junkyard .

That's technology for you at its best .

fastball
11-27-2009, 10:01 AM
I could be wrong but I believe honda has a manual throttle control for DBW throttles so tech can make checks under hood. Its very simple just unplug harness and attach the new one.
I think I saw it in one of Honda TSB's .

Yeah, that sounds logical.

Edaccord08
11-27-2009, 10:11 AM
Yeah, that sounds logical.

I have looked over wiring diagrams and this is not simple thing. In fact there are 2 throttle sensors (A,B) and 2 APP pedal sensors in there . I think one set is used for cruise control but not 100& sure.
For sure though DBW is heavy integrated into VSA , idle speed, cruise control . So I don't really see any easy way around it (cable control) as I am pretty sure even if you don't care about cruise, VSA, it still throw codes.
I think best you could do is permanent disable of VSA .

thekash
11-27-2009, 11:40 AM
I have looked over wiring diagrams and this is not simple thing. In fact there are 2 throttle sensors (A,B) and 2 APP pedal sensors in there . I think one set is used for cruise control but not 100& sure.
For sure though DBW is heavy integrated into VSA , idle speed, cruise control . So I don't really see any easy was around it (cable control) as I am pretty sure even if you don't care about cruise, VSA, it still throw codes.
I think best you could do is permanent disable of VSA .

you guys are nuts! that's what gf's are for! put her in the driver seat and tell to rev whenever you need it to :-0 cost, lifetime of naggin...

mrstak
11-27-2009, 12:46 PM
you guys are nuts! that's what gf's are for! put her in the driver seat and tell to rev whenever you need it to :-0 cost, lifetime of naggin...

+1
Ain't that the truth...:lmao:

ApGap
11-27-2009, 01:03 PM
you guys are nuts! that's what gf's are for! put her in the driver seat and tell to rev whenever you need it to :-0 cost, lifetime of naggin...

0$ cost??????????...........not if my wife found out.

CaMole
11-27-2009, 04:15 PM
Seems like it aint worth the time or money to do this. Lets all move on...

Upset w/ Honda
11-28-2009, 01:26 PM
you guys are nuts! that's what gf's are for! put her in the driver seat and tell to rev whenever you need it to :-0 cost, lifetime of naggin...

make sure she isn't mad/pissed at you before working on your car.... she might shift it into D or into gear........:D

elp_jc
11-28-2009, 03:48 PM
As you press down on the gas pedal, instead of opening up a throttle body with a cable you are turning the volume knob and increasing the voltage to the ECM (in a stereo that would be the main microprocessor). The ECM sees the voltage change and adjusts fuel injection and sends out the proper voltage to the motor on the butterfly valve in the intake manifold to turn open wider.
Not exactly, but close. The gas pedal increases the voltage on the servo motor that controls the butterfly only; just like if the butterfly had a mechanical linkage to the gas pedal. When the butterfly opens, it allows more air, which is what controls engine speed. The MAF (mass airflow sensor) relays that info to the ECU to match the amount of air with the appropriate fuel based on maps, and the proper air/fuel ratio is kept in check by the O2 sensor. In other words, the DBW only replaces a cable with a precise servo motor, that's all. Hope this helps.

In contrast, diesel engines regulate engine speed with fuel, rather than air. However, very high-tech gas engines are also eliminating the throttle body by controlling engine speed thru valve lift. I only know of BMW using this technology, called 'valvetronic'.

Oh, and no, there's no way for an owner to rev an engine with DBW that I know of. But may I ask what the heck you want to do that for? Inquiring minds want to know :D.

Domtenn15
11-28-2009, 06:29 PM
Drive by wire technology wont allow you to do that.
Sorry

nehonda
11-29-2009, 03:37 PM
Tie a string arround the gas pedal, loop it under the floor mat and run it out the window to the engine compartment. What could be easier :D