bbk throttle body

[cumberlander]

just wondering if the bbk throttle body is worth buying.

 

[MAKG]

No. Your stock throttle body is very much sufficient for the airflows the engine demands.

 

[b_aldredeg]

mm i got one and my truck runs much better than it did before

 

[SoLongStang9499]

With respect I'm going to have to disagree with MAKG. Anything that is providing more effeciency ( smoother edges, larger bore etc ) will yield overal more engine effeciency, aka power. 9 times out of 10 its mild to none, and the cost usually isnt worth it, but you be the judge.

 

[Bird]

MAKG is 100% right on this - unless you do a lot of internal mods to increase the airflow needs, the stock TB is more than enough for the 4.0.

That being said, the larger TB will increase throttle response up to the airflow limit of the engine because for the same throttle positions as the stocker TB, it will allow more airflow due to the larger bore. The top end horsepower doesn't change as the WOT airflow requirements of the stock engine is still the same.

For those that think they can go to an even larger TB and get even more throttle response - it won't necessarily work. Going too big on the throttle body size can throw a code of the MAF airflow not matching the tps readings and will hurt performance inless you have a custom tune done to 'rematch' the parameters.

Bird

 

[Hahnsb2]

I've noticed by putting the 58mm TB on my 2.9 the throttle response went DOWN because the larger size you let more air in a the same throttle opening. I do like the difference, there isn't any more power but it feels like it moved the power curve down if that makes sense. Whether it's worth it to by a $200+ TB is up to you, not worth it to me.

 

[Bird]

Hahsb2 - when I say it 'increases' throttle response, it does not mean that it moves the response 'up' in the throttle range - it means that the response increases for the same throttle opening as before - ie: you feel more response for the same amount of pedal. Please note the use of the word 'same' in the following "because for the same throttle positions as the stocker TB, it will allow more airflow due to the larger bore".


Bird

 

[Twizzler09]

That increased airflow through the Throttle Body won't do you any good if the motor can't use it.

In this case, a stock 4.0, a larger Throttle Body will do no good because the motor has no need of increased airflow. Dumping more air into it via a larger Throttle Body is akin to giving a fat kid candy. Hes already got enough of that shit in him, he doesn't need anymore.

 

[mav37075]

On newer vehicles the computer controls the spark and fuel curve of the engine by using numerous sensors to monitor them. Improved airflow will result in more fuel being added to the mix or the timing being retarded. In the right environment (altitude, temperature, and barametric pressure) and a cool air charge you will see gains with more air being introduced to an engine. I have a k&n fipk kit on my 04 and made 7 H.P. at the wheels. They claim more but the conditions are a lot different where i am located. The throttle body will actually improve power in (most situations) due to lowering the IAT by allowing more air to flow. The PCM sees this and introduces more fuel and raises the timing.

 

[MAKG]

Just how is a BBK or K&N "cold air intake" going to get a cooler air charge than the stock location? It's just below the passenger headlight. That's the coolest part of the vehicle, aside from inside the evaporator core.

 

[mjonesjr]

On newer vehicles the computer controls the spark and fuel curve of the engine by using numerous sensors to monitor them. Improved airflow will result in more fuel being added to the mix or the timing being retarded. In the right environment (altitude, temperature, and barametric pressure) and a cool air charge you will see gains with more air being introduced to an engine. I have a k&n fipk kit on my 04 and made 7 H.P. at the wheels. They claim more but the conditions are a lot different where i am located. The throttle body will actually improve power in (most situations) due to lowering the IAT by allowing more air to flow. The PCM sees this and introduces more fuel and raises the timing.

Ha ha ha ha ha ha. You are humerous.

The PCM programming is limited to what is factory set. The only way to advance the timing or change the fuel curve is to get a programmer (ie: XCalibrator 2, etc.). The PCM will NOT change the fuel map by itself; it takes an outside source.

How do you know you made 7HP at the wheels with the K&N? Did you actually do dyno runs?

No K&N intake will draw in cooler air than the stock intake system does. K&N intakes draw in air from UNDER THE HOOD where as the stock setup draws in air from behind and under the headlight. Now you really ask yourself, is the air under the hood really cooler than the air that is being forced into the stock intake? Doubtful.


It takes a lot of modification to get a BBK throttle body to be worth it. It doesn't matter how much air you take in if you can push it out through the exhaust; without headers and a custom exhaust, a larger throttle body or MAF will do you no good.

 

[mhughes165]

personally....i think its turd polishing, unless u already have everything else mentioned here done to the truck, its a waste of money, and personally id rather just get a junkyard 5.0 tb and adapt it to work instead of wasting money on the BBK unit.

now, if u have the work done(programmer, full exhaust, headers, bigger injectors, ported heads), then i say by all means do so, itll help u take advantage of the other mods that are already done.....if not

 

[mav37075]

So your telling me that a pcm cannot change a timing curve on it's own? Wrong answer. Then what is the purpose of a cam phaser? Why do vehicles have o2 sensors. A pcm will change the timing curve, whether it be due to inlet air temp. changes or even lower octane fuel. I did not say that the k&n gave me a cooler air charge, i said it gave my truck 7h.p. and yes it was on a dynojet in our shop. A programmer is not the only way to change a timing curve or the fuel being introduced through an injector. A pcm will control the pulse width of the injector letting more fuel through it.

 

[MAKG]

The ONLY sensor that tells the PCM what the timing curve should be (rather than what it is) is a knock sensor. Some models have them, some models don't. The adaptivity is limited to retarding the entire timing curve for a fixed time.

The shape of the timing curve is not adapted. One might imagine a very sophisticated control system that attempted that, but it borders on the impossible to do it correctly. Adaptivity has to converge under fixed conditions or it's just a POS, and this is VERY much harder to pull off automatically than you seem to assume.

But for vehicles without knock sensors, there is NO FEEDBACK to know whether the timing curve is correct or not. Cam phasers tell you what the timing curve is. Not what you want it to be. So you can be sure that the PCM sticks to the programmed timing curve.

The oxygen sensor(s) doesn't detect detonation; it's only used for fuel trim. You do know the difference between fuel and spark curves, right? Your post above suggests very strongly that you don't.

 

[mav37075]

A knock sensor is not the only thing that tells the pcm what the timing should be. A knock sensor will pull timing out of the engine, The pcm also reads the IAT sensor and when it is cooler air, Let's say 57 degrees the pcm will advance timing. If the IAT sensor is seeing 85 degrees it will pull timiming out of it. To anyone who is reading this check out some tuning forums or even type in Iat sensor retarding timing. We use a resistor on LS1 and LS7 engines that is put in pigtail of the IAT sensor to trick the PCM that it is reading around 40 degrees of inlet air temp. This keeps the timing optimized and makes better power. I'm not trying to argue.