Throttle plate mod

[nickledimed]

Originally Posted by ccrtw88

I have heard some rumors that doing this mod would cause the front 2 cylinders to run lean. Is there any truth to this??

I dont see how or why it would make them run lean. Again common sense here would say "no" seen as how all the cylinders use the same intake, program, sensers and everything else used to make the engine run properly.
actualy doing this mode is good for your engine. it doesnt have to work as hard to do the same amount of work it did before the mod. Remember, All car manufactures do stuff like this to make more revenue, safty, laws and what not. The things to look for are the grimlins that are on the vehicle just to create revenue, not just for the auto manufacturer either, theres the oil companys and the parts makers to consider also.

[Cloud Strife]

I was just thinking on the way home from my g/f's about this mod. If you remove the restrictor plate, wouldn't you have to reprogram the computer for the extra airflow you are now getting? Or will the computer adjust itself pretty quick.

[old_master]

It may take a couple of days to re-learn. To speed the process up, hook up an OBDII scanner and reset it. It will learn immediately.

[nickledimed]

It took my truck about 10 seconds to relearn, after I did this mod. the thing is I warmed my truck up and did the mod while the engine was hot.

[Eslhockey92g]

Originally Posted by nickledimed

It took my truck about 10 seconds to relearn, after I did this mod. the thing is I warmed my truck up and did the mod while the engine was hot.

How do you know that ur comp relearned this mod?
Did i like run bad than run good or was there like a CEL that came up than went away? you know what i mean

[old_master]

Originally Posted by Eslhockey92g

How do you know that ur comp relearned this mod?
Did i like run bad than run good or was there like a CEL that came up than went away? you know what i mean

The OBDII keeps in memory, fuel mixtures that it has used under different driving conditions. This memory is called long term fuel trim. This data builds a history file that the computer can draw on until the codes are erased, or "re-set". At that point, the history starts building again. In the case of a sensor failure, the long term fuel trim history file is searched for a fuel mixture that was used under a particular driving condition and applies it. Any time a change from the norm is noticed, as in the case of a tune up or the throttle body modification, the computer will keep looking at the history and adjust fuel trim as necessary to achieve the proper fuel ratio. The larger the history, the longer it will take to "learn" the new condition. If the OBDII codes are re-set at the time of the throttle body modification, it has no history file and therefore will "learn" immediately.

[2000blazerls]

Well I did the TB plate mod a few weeks ago and it was a nice improvement. I was not aware of the MAF sensor deal. I did it tonight (actually took about 10 minutes) and will try it out tomorrow. Thanks for the info.

[nickledimed]

Your very welcome, What happened after I did the plate mod: I started the truck up while it was still warm, it ran rough for about 10 seconds and then started purring like a kitten. The idle rpms are like 600 at idle instead of 500 but that doesnt bother me. If you want im sure there is some way to turn the rpms back down to 500. There were no codes thrown.

[tom3]

Not sure I understand how this mod would affect cruising RPM. With tranny in OD and the converter locked up the motor should run the same speed at the same MPH I'd think. GM has been restricting air intakes for years for different reasons, one is to quiet the engine at full throttle, as if anyone wanted that in the first place. I'd guess this deal is a way to make a smoother throttle response at low rpms or something.

[nickledimed]

Originally Posted by tom3

Not sure I understand how this mod would affect cruising RPM. With tranny in OD and the converter locked up the motor should run the same speed at the same MPH I'd think. GM has been restricting air intakes for years for different reasons, one is to quiet the engine at full throttle, as if anyone wanted that in the first place. I'd guess this deal is a way to make a smoother throttle response at low rpms or something.

Before the mod, even with the throttle wide open I would say at least 1/4 of the throttle body is blocked. If you remove that peice that is attached to the bottom of the plate you have increased the air intake at least 1/4. Now we all know that the better an engine breaths the better it runs. In turn the better an engine utilises the air/gas mixture the more work it can perform using less energy.

[herkyhawki]

Originally Posted by nickledimed

Before the mod, even with the throttle wide open I would say at least 1/4 of the throttle body is blocked.

Please take another look, take some pictures, take some measurements, do the math (hint 1/4 =25%), take some asprin, sleep it off, and then tell us all if it really blocks off 1/4 of the throttle body area. Please, I'll be waiting.

[old_master]

Originally Posted by tom3

Not sure I understand how this mod would affect cruising RPM. With tranny in OD and the converter locked up the motor should run the same speed at the same MPH I'd think. GM has been restricting air intakes for years for different reasons, one is to quiet the engine at full throttle, as if anyone wanted that in the first place. I'd guess this deal is a way to make a smoother throttle response at low rpms or something.

You're on the right track here.

This modification can not and does not affect engine RPM at any given speed. Whatever engine RPM at any given speed was before the modification, will be the same after the modification. If you want engine RPM to change, a gear ratio must be changed.

What this modification does accomplish, (besides void the warranty) is reduce air turbulence, and air velocity, while at the same time increasing air flow. Any time a restriction is introduced, the velocity will increase and flow will decrease. The shape of the "baffle" on the throttle plate causes a "venturi" effect, just as the throat of a carburetor narrows down inside. In this case air turbulence is desired. The fuel is introduced at the point where the air is moving the fastest to atomize the fuel. With fuel injected vehicles, the fuel is atomized by the injector spraying the pressurized fuel. Therefore removing the “baffle” will increase air flow allowing a smaller throttle opening, (less pressure on accelerator pedal). Both before and after the modification however, the OBDII system will maintain the desired fuel ratio so any difference in fuel mileage would be negligible. Removing the “baffle” may increase induction noise slightly. Low end performance / throttle response should improve, and may even prove to be too sensitive for the likes of some drivers. Hope this helps.

[old_master]

Originally Posted by nickledimed

Your very welcome, What happened after I did the plate mod: I started the truck up while it was still warm, it ran rough for about 10 seconds and then started purring like a kitten. The idle rpms are like 600 at idle instead of 500 but that doesnt bother me. If you want im sure there is some way to turn the rpms back down to 500. There were no codes thrown.

"If you want im sure there is some way to turn the rpms back down to 500."

Not true. The ECM is programmed to control idle RPM at a certain speed. It will adjust ignition timing and fuel mixture to achieve that speed. If it leans the fuel mixture or retards the ignition timing too far, engine performance will suffer greatly.

The ECM noticed a change and it is trying to compensate for it. That's why it's idling at 600 RPM. The longer the period of time since the ECM was reset, the longer it will take to "learn" the change, give it time. Once the ECM "learns" the change, idle RPM will return to where it was before the modification.

[Eslhockey92g]

Originally Posted by old_master

"If you want im sure there is some way to turn the rpms back down to 500."

Not true. The ECM is programmed to control idle RPM at a certain speed. It will adjust ignition timing and fuel mixture to achieve that speed. If it leans the fuel mixture or retards the ignition timing too far, engine performance will suffer greatly.

The ECM noticed a change and it is trying to compensate for it. That's why it's idling at 600 RPM. The longer the period of time since the ECM was reset, the longer it will take to "learn" the change, give it time. Once the ECM "learns" the change, idle RPM will return to where it was before the modification.

I know physicaly i won't have a problem doing this to my 97 blazer, But will i run in to computer problems you guys are doing it to an OBDII system, Does any one know if i have the same OBD? or will i have to do other types of computer flashing or what now?

[old_master]

1996 and newer all use OBDII