Throttle Body Heater - Why NOT to bypass it!
#11
But seriously, NOBODY ever touch my truck, the keys are in my pocket.
And in response, yes, the TBH is still in there, although it is not connected. I'll have to find out a smart way to remove those tiny screws, unless I first find a complete spare truck.
François
#12
It bears mentioning that heating the throttle body with water doesn't degrade performance significantly. Cold air is denser and richer in oxygen and so things like turbo-intercoolers can significantly improve performance (because intake air temperatures post-turbo can be 150 degrees higher than ambient). Simple "cold air intakes" rarely produce such dramatic improvements, but many people are determined to do their best in this regard. Heating the intake may seem counterproductive with respect to charge density and performance.
This is generally true, but by using water/ethylene-glycol-based engine 'coolant' doesn't necessarily heat the throttle body. The temperature of liquid is limited by it's boiling point at the present pressure and the radiator works to exchange any excess heat with the air. The result is that at some higher temperatures, the throttle-body heater actually becomes a throttle-body cooler. More significantly the 'heater' will not overheat the intake charge.
The intake charge needs some heat. Having very cold intake temperatures becomes counterproductive to performance as fuel will fail to vaporize in carburettors and from fuel injectors it can condense into liquid and combust poorly. That's not to say the throttle-body heater is necessary to provide this, but that "absolute coldest possible" is not a good goal. A water-jacket type throttle-body heater should bring the throttle body up to operating temperature without overheating the intake charge.
In other words, if it's working properly, you gain nothing by bypassing it.
This is generally true, but by using water/ethylene-glycol-based engine 'coolant' doesn't necessarily heat the throttle body. The temperature of liquid is limited by it's boiling point at the present pressure and the radiator works to exchange any excess heat with the air. The result is that at some higher temperatures, the throttle-body heater actually becomes a throttle-body cooler. More significantly the 'heater' will not overheat the intake charge.
The intake charge needs some heat. Having very cold intake temperatures becomes counterproductive to performance as fuel will fail to vaporize in carburettors and from fuel injectors it can condense into liquid and combust poorly. That's not to say the throttle-body heater is necessary to provide this, but that "absolute coldest possible" is not a good goal. A water-jacket type throttle-body heater should bring the throttle body up to operating temperature without overheating the intake charge.
In other words, if it's working properly, you gain nothing by bypassing it.
#13
Just to be clear, as far as I know the only function of the tbh is to prevent ice. I do not believe the tbh is required or useful to heat or cool the intake charge. I just believe it has a neutral (no negative) effect on the intake charge and therefore there is no good reason to bypass it.
#15
Apples and oranges but it was one of the first to do free mods anyone with an LT1 would do to thier motors:
Modifications #8
I did it with my LT4, never had a single problem with "icing" and thats with a ram air short intake and dual 58mm throttlebody in NJ a few blocks from the ocean. Humidity is always high, but winter temps usually in the low 30's upper 20s, maybe teens on a really cold day or on an overnight. its rare to go under 10 and not including windchill, I cant remember a recent below zero day here. also didnt notice any changes positive or negative with the bypass, but alot of dyno graphs out there to try and prove/disprove on the fbody forums over the last decade pretty much show small increases with the reduced temp... but its also suckin alot more air then the lr 4.0 hahahaha so precentage wise 1-3hp maybe at the flywheel, half to the wheel after awd but, why not, its cheap, easy, and youll never have to worry about the slow tb leak gasket problem again.
Modifications #8
I did it with my LT4, never had a single problem with "icing" and thats with a ram air short intake and dual 58mm throttlebody in NJ a few blocks from the ocean. Humidity is always high, but winter temps usually in the low 30's upper 20s, maybe teens on a really cold day or on an overnight. its rare to go under 10 and not including windchill, I cant remember a recent below zero day here. also didnt notice any changes positive or negative with the bypass, but alot of dyno graphs out there to try and prove/disprove on the fbody forums over the last decade pretty much show small increases with the reduced temp... but its also suckin alot more air then the lr 4.0 hahahaha so precentage wise 1-3hp maybe at the flywheel, half to the wheel after awd but, why not, its cheap, easy, and youll never have to worry about the slow tb leak gasket problem again.
Last edited by grandkodiak; 02-27-2013 at 02:31 PM.
#16
That moisture collects on the throttle and then freezes and it just builds up on itself and eventually causes things to freeze in place.
Now when you live in the mountains where it is very dry and the humidity level is always low you will not have this problem, but live by the water, and I dont mean the overflow pond in your apt parking lot, I mean by the ocean, the Great Lakes, etc. you WILL have problems.
Driving across town it wont freeze, driving down the highway it will.
#17
#18
Good point Buzz but i guess what I was thinking and didn't say is "if the the only thing keeping the throttle from sticking is the heater. I think I would replace The throttle body". Something else could be wrong and after awhile it may do it with the heater working.
#19
Forget you and your science. Cold air rules:
Cold Air Intakes Mythbusted - YouTube
On a Rover, that would be like 1 1/2 horsepower. Wow!
Cold Air Intakes Mythbusted - YouTube
On a Rover, that would be like 1 1/2 horsepower. Wow!
#20
Have you driven on long highway trips in high humidity low temp conditions?
Do you guys have freezing fog?
No one is saying it is going to happen each and every time you drive, but it is enough of a concern that it was installed at the factory.
You can do what you want, but to recommend that people by-pass it and never fix it is just wrong in my opinion.