What really is "Throttle boost"?

[sniper226]

I hear conflicting stories on what throttle boost so I am looking to hear it from the horses mouth.

So far I heard:

1) It advances the drive by wire throttlebody. It just fools the computer into thinking that you have pushed the pedal farther than you actually have. make the car feel more responsive.

AND

2) Basically it opens the throttle body sooner, and because the oxygen sensor loop / tuning keeps the a/f ratio the same, with it getting more air it puts fuel in faster to maintain 14.7:1 a/f ratio, basically mroe power faster. This increase in air flow combined with the compuer keeping it at 14.7:1 (adding fuel) increases throttle responce between 2,000 and 4,000 almost like getting a new rear end installed.

#1 sounds like I can achieve basically the same thing with my right foot and consequently, I would not want a quirky accelerator that artificially throttles up more than my foot tells it to.

However #2 sounds interesting if this is in fact what it does. Basically I am trying to eliminate the the low rpm response lag and it sounds like #1 won't do that if I already have my foot all the way into it.

Thanks for the support & response!

[mikel]

It increases throttle response by allowing for more throttle blade opening vs. how much pedal is applied.

Where in the world did #2 come from??

[Gekko]

It increases throttle response by allowing for more throttle blade opening vs. how much pedal is applied.

Where in the world did #2 come from??

Maybe it came from here:
http://www.challengertalk.com/forums/f1 ... post794693

[sniper226]

It was from the Challenger forum. I guess I really don't see a benefit then in throttle boost and why people would really want it. It's kind of like a having a hair trigger on a gun where it's more or less on and off but hard to find something in between.

[airportdave]

It was from the Challenger forum. I guess I really don't see a benefit then in throttle boost and why people would really want it. It's kind of like a having a hair trigger on a gun where it's more or less on and off but hard to find something in between.

Actually, it's not "hair trigger" at all on my 2010 Jeep Grand Cherokee, and it's been a huge benefit for me. The throttle boost is adjustable from 0-20%. I've bumped mine up to five, and it has made my GC eminently more responsive off the line, but not "hair trigger" by any stretch.

I supposed if you went the full 20, it would be too jumpy, but the best boost setting probably varies greatly by vehicle and personal preference.

[sniper226]

Actually, it's not "hair trigger" at all on my 2010 Jeep Grand Cherokee, and it's been a huge benefit for me. The throttle boost is adjustable from 0-20%. I've bumped mine up to five, and it has made my GC eminently more responsive off the line, but not "hair trigger" by any stretch.

I supposed if you went the full 20, it would be too jumpy, but the best boost setting probably varies greatly by vehicle and personal preference.

Yea I suppose the hair trigger analogy is a bit of an over exaggeration. I still don't get why you want to do it when you can easily hit the gas pedal more when you want more throttle. It's like everyone wants to be surprised when pressing the gas pedal so they can say, wow, that's fast! lol

[Charger250]

It increases throttle response by allowing for more throttle blade opening vs. how much pedal is applied.

Where in the world did #2 come from??

If you think about it logically it makes sense. How can opening the throttly more earlier help? Why do they even have a throttle body to begin with? Why dont they just leave it open? The throttle bodys job is to stop / reduce the flow of air makeing it lean, then the computer with the oxygen sensor reduces fuel to keep the a/f ratio at 14.7:1 If you reduce the air flow entering the car, you aren't going to lean the a/f ratio because the computer and oxygen sensor operating in closed loup will reduce fuel comming out of the injectors (within limits) Same thing happens when you allow more air, the engine will get more air, and the oxygen sensor will inform the comptuer and it will tell the injectors to add fuel to maintain that 14.7:1 a/f ratio in closed loop.

IF opening the throttle body more earlier actually helps, what its doing is allowing more air to be sucked into the combustion chamer. When you have more air, you need more fuel to maintain that 14.7:1 a/f ratio, and in closed loop the oxygen sensor will keep the computer updated and the computer will be increasing fuel to compensate. IF all this didnt happen, and opening it early lets more air flow, then it would simply lean out introducing the posibility of detonation / spark knock and reducing hp.

With the stock tune the throttle body opens slower and that slows the flow of air into the combustion chamber, and because the computer and oxgen sensor maintains the perfect tune of 14.7:1 a/f ratio the throttle body is in sense controlling how quick you get power. Keeping it closed longer reduces how fast power comes on, and reduces power, and increases mpg.

When you open it sooner allowing the piston to draw air in with less resistance and it gets all it is trying to pull, then it will pull more air faster, requiring more fuel and the computer will then apply more fuel constantly striving for 14.7:1 a/f ratio.

If opening the throttle body sooner / faster didnt allow for more air (thus requiring more fuel to maintain 14.7:1 a/f ratio) then it would'nt provide a us a quicker "throttle responce" or more power faster. Its necessary to reduce a bottle neck in air flow to actually accomplish gians.

Personally I have found somewhere in the 2000-4000 rpm range at part throttle where closed loop is working, it has a faster responce.

[Charger250]

It was from the Challenger forum. I guess I really don't see a benefit then in throttle boost and why people would really want it. It's kind of like a having a hair trigger on a gun where it's more or less on and off but hard to find something in between.

We arent talking about a 1,000 hp engine, its a 372 hp rated in a 4200 pound car. Adding ~10hp to the rear wheels with the DiabloSport 93 tune doesnt make it have hair trigger, any more than opening the throttle body early. It simply optimizes it for performance.

Ever seen a carborator work? When you push on the throttle it opens the air intake at the rate your foot pushes. With the drive by wire modern fuel injection the computer controlls the throttle body. This is done to optimize it, BUT the government steps in and regulates mpg, and emmissions, and people want 70 mpg 400hp v8's, so they do tricks to get that 25-27 mpg highway we love.

Opening it sooner is more like what we had with the wired throttle body fuel injections a few years ago, your foot determins when and how open the throttle body is, the comptuer only knows what you did, and reacts by adding fuel.

Its not a hair trigger with a small 5.7L making about 400hp, it simply increases it a bit. In fact when I first drove it I couldnt see any difference 0 change. Later I found a zipper responce between 2000-4000 rpm. Not a huge difference, just more like you would expect a modern high tech VVT EFI 400hp HEMI to produce.

[sniper226]

It increases throttle response by allowing for more throttle blade opening vs. how much pedal is applied.

Where in the world did #2 come from??

If you think about it logically it makes sense. How can opening the throttly more earlier help? Why do they even have a throttle body to begin with? Why dont they just leave it open? The throttle bodys job is to stop / reduce the flow of air makeing it lean, then the computer with the oxygen sensor reduces fuel to keep the a/f ratio at 14.7:1 If you reduce the air flow entering the car, you aren't going to lean the a/f ratio because the computer and oxygen sensor operating in closed loup will reduce fuel comming out of the injectors (within limits) Same thing happens when you allow more air, the engine will get more air, and the oxygen sensor will inform the comptuer and it will tell the injectors to add fuel to maintain that 14.7:1 a/f ratio in closed loop.

IF opening the throttle body more earlier actually helps, what its doing is allowing more air to be sucked into the combustion chamer. When you have more air, you need more fuel to maintain that 14.7:1 a/f ratio, and in closed loop the oxygen sensor will keep the computer updated and the computer will be increasing fuel to compensate. IF all this didnt happen, and opening it early lets more air flow, then it would simply lean out introducing the posibility of detonation / spark knock and reducing hp.

With the stock tune the throttle body opens slower and that slows the flow of air into the combustion chamber, and because the computer and oxgen sensor maintains the perfect tune of 14.7:1 a/f ratio the throttle body is in sense controlling how quick you get power. Keeping it closed longer reduces how fast power comes on, and reduces power, and increases mpg.

When you open it sooner allowing the piston to draw air in with less resistance and it gets all it is trying to pull, then it will pull more air faster, requiring more fuel and the computer will then apply more fuel constantly striving for 14.7:1 a/f ratio.

If opening the throttle body sooner / faster didnt allow for more air (thus requiring more fuel to maintain 14.7:1 a/f ratio) then it would'nt provide a us a quicker "throttle responce" or more power faster. Its necessary to reduce a bottle neck in air flow to actually accomplish gians.

Personally I have found somewhere in the 2000-4000 rpm range at part throttle where closed loop is working, it has a faster responce.

Isn't what you just wrote option #2 where the Diablo folks wrote where the heck did you get that from?

[mikel]

Im still confused.

its so simple, you shouldn't even be able to write a paragraph about it.

It increases the throttle opening relative to pedal input.

[sniper226]

Im still confused.

its so simple, you shouldn't even be able to write a paragraph about it.

It increases the throttle opening relative to pedal input.

Lol, thank you. That's what I thought. Some people are making it out to be much more than it is.

[SRT8Tech]

Actually Chrysler has a TSB on some of the 392 Challengers to increase the throttle "boost". Its not called throttle boost from chrysler but throttle sesitivity. Some of the early build 392's have a lag and a PCM flash is needed to increase the throttle sensitivity for a more power "feel".

[mikel]

Interesting. Wish we could just fix it for them

[blackdeuce]

I installed the throttle boost yesterday. I randomly selected a 15% boost. All I can tell you is that it made my car a lot more "spunky". I like it. It's quicker at low rpms, but it doesn't seem like the same thing as stomping on the gas. Whatever.

[CanadianHemi]

So the boost makes it feel more responsive. For instance in my Ram it will give me the same feeling my truck gets when I start it up on a cool morning and the throttle feels sensitive and responsive to my input?