Throttle Body Coolant Bypass - Do I revert it to stock for the winter?

[timxpx]

Just wondering if anyone has done this mod in colder climates and how it affects daily driving.

A friend of mine did it for me when he installed my CAI this summer.

I use my car to commute for about 27 miles each way, daily. I live in New Jersey and today it snowed for the first time this winter...

The biggest noticeable difference with the TBB is that now that it's been colder, my car takes a *lot* longer to warm up, especially after sitting overnight. What I've been doing on the mid-30-degree mornings is starting my car and running back in the house for about 10 minutes.

Even if I'm rushing in the morning, I'll sit in the car for at least 2 minutes to let the idle RPMs drop from ~2k to about 1.5k (with the thermostat still on cold) and just drive it without revving over 2.5k until it reaches normal temperature on the gauge and my shifter stops feeling chunky from the cold. Usually, this takes about less than mile of driving through my town at ~25/30mph and the first mile or so of highway that I hit at ~50-60mph.

Rinse, repeat the same cycle when I leave my office at the end of the day.

So with that I have a couple of questions:

-I don't mind the routine now, but is the cold weather going to hurt my TB since there's no coolant running through it now, and subsequently, should I revert to stock?

-I've also been debating getting a remote starter. Compustar makes a pretty good 2-way setup that has good range. Consequently, I can start my car from the shower at home or from any window in my office and have a warm car waiting for me. I think the half-mile range system with the clutch bypass and the chipped key bypass will run about $450. -- Is this a good idea since I can keep the TBB without reverting it each time the seasons change?

Thanks guys, I'm looking forward to your responses

 

[sniperruff]

IIRC the proper way to warm up an engine is to let it sit for a minute, then drive around 2k rpm until it warms up. letting it idle just wastes gas.

 

[boomerang]

Hook it back up.

It could get pretty exciting if your throttle body ices up and the throttle sticks part way open. Coolant is circulated through there for more than warm up.

Now, if you lived in Florida, well I'd say let it be. But NJ, get on it.

 

[TerryMathews]

Think of it like this, and tell me if it sounds like a good idea to leave it uncorrected:

-The TB is cold to the touch while the car is sitting

-Air in motion causes a cooling effect (wind chill)

-While you're driving, air comes into the throttle body at the velocity the car is travelling

Conclusion: What do you think the wind chill is on 70 MPH wind?

 

[timxpx]

Originally posted by: boomerang

It could get pretty exciting if your throttle body ices up and the throttle sticks part way open. Coolant is circulated through there for more than warm up.

how should a driver react if that happens before someone gets a chance to put it back?

Originally posted by: TerryMathews

Conclusion: What do you think the wind chill is on 70 MPH wind?

i drove about 40 miles through freezing rain last night. the air temp according to my dash was 27 degrees at the coldest and never went above 30, and i'm guessing the wind chill was a whole heck of a lot colder than that. :Q

 

[iamwiz82]

Originally posted by: timxpx

Originally posted by: boomerang

It could get pretty exciting if your throttle body ices up and the throttle sticks part way open. Coolant is circulated through there for more than warm up.

how should a driver react if that happens before someone gets a chance to put it back?

Originally posted by: TerryMathews

Conclusion: What do you think the wind chill is on 70 MPH wind?

i drove about 40 miles through freezing rain last night. the air temp according to my dash was 27 degrees at the coldest and never went above 30, and i'm guessing the wind chill was a whole heck of a lot colder than that. :Q

Put it back? If it gets stuck you won't be able to put it back without stopping the car first, as the engine will rev like crazy. If it happens you turn off the car but leave the keys in the ignition so you don't lock the wheel.

 

[mooseracing]

Originally posted by: TerryMathews
Think of it like this, and tell me if it sounds like a good idea to leave it uncorrected:

-The TB is cold to the touch while the car is sitting

-Air in motion causes a cooling effect (wind chill)

-While you're driving, air comes into the throttle body at the velocity the car is travelling

Conclusion: What do you think the wind chill is on 70 MPH wind?

Doesn't need to be 70 even, I have had icing up on carb's at 40 mph.

Most icing for me has occrued around the high 30's to 40F and high humidity. It occurs lower than that all the time also.

 

[LTC8K6]

This bypass is done because some people think a hot throttle body heats up the intake air enough to decrease their horsepower...

Good grief, Charlie Brown!

 

[jagec]

Originally posted by: TerryMathews
Think of it like this, and tell me if it sounds like a good idea to leave it uncorrected:

-The TB is cold to the touch while the car is sitting

-Air in motion causes a cooling effect (wind chill)

-While you're driving, air comes into the throttle body at the velocity the car is travelling

Conclusion: What do you think the wind chill is on 70 MPH wind?

The "wind chill" effect is due to evaporative and convective cooling. The wind chill figures reported on the news are actually there to give you an idea of heat flux, not temperature. If it's 32 degrees, 0 degrees with wind chill, that just means that at a constant body temperature, the combined evaporation from your skin and convective flow will cause you to lose heat into the 32 degree air as if it were 0 degree still air. Since cars don't sweat, there is no evaporative effect, and while the "wind chill" effect can certainly speed the loss of heat from the engine via convection, it cannot cool the throttle body below ambient temperature.
If that's cold enough to cause icing, it could be problematic.

Originally posted by: timxpx

Originally posted by: boomerang

It could get pretty exciting if your throttle body ices up and the throttle sticks part way open. Coolant is circulated through there for more than warm up.

how should a driver react if that happens before someone gets a chance to put it back?

Originally posted by: TerryMathews

Conclusion: What do you think the wind chill is on 70 MPH wind?

i drove about 40 miles through freezing rain last night. the air temp according to my dash was 27 degrees at the coldest and never went above 30, and i'm guessing the wind chill was a whole heck of a lot colder than that. :Q

Stomp the clutch to the floor, switch the engine to "off" WITHOUT going to the "lock" position, steer to the side of the road and stop. Turn on your hazards, open your hood, and reconnect the throttle body coolant loop. Thaw out the throttle body with your hands or something, work the throttle a few times with your hand until it closes, then restart the car (in neutral or Park), and let it warm up and the coolant circulate around the throttle body. Continue on your way.

 

[timxpx]

Originally posted by: jagec

Stomp the clutch to the floor, switch the engine to "off" WITHOUT going to the "lock" position, steer to the side of the road and stop. Turn on your hazards, open your hood, and reconnect the throttle body coolant loop. Thaw out the throttle body with your hands or something, work the throttle a few times with your hand until it closes, then restart the car (in neutral or Park), and let it warm up and the coolant circulate around the throttle body. Continue on your way.

thanks jagec! hopefully i'll never have to do this, but it's good to know. when some of the more knowledgeable car guys in my office are around this week i'll ask one of them to help me reverse it during lunch. i don't feel too comfortable trying it myself.

it's going to be 21 degrees tonight here! yikes!

 

[LTC8K6]

It's the venturi effect that will get you into trouble with icing, isn't it?

The pressure drop on the backside of a constriction is what causes the problem.

This is why the throttle body is heated in the first place, isn't it?

 

[TerryMathews]

Originally posted by: LTC8K6
It's the venturi effect that will get you into trouble with icing, isn't it?

The pressure drop on the backside of a constriction is what causes the problem.

This is why the throttle body is heated in the first place, isn't it?

So I had the right idea but quoted the wrong principal.

And the OP said something about the thermostat saying 27oF or something like that when he was driving. You have no idea where the car is sampling that from. It could be anywhere in the engine compartment or even near the transmission and away from the wind.

TB Bypass isn't a good idea. In the winner, you're working on earning your very own Darwin award. I hope you don't take an innocent family with you when the TB sticks open.

 

[timxpx]

Originally posted by: TerryMathews

Originally posted by: LTC8K6
It's the venturi effect that will get you into trouble with icing, isn't it?

The pressure drop on the backside of a constriction is what causes the problem.

This is why the throttle body is heated in the first place, isn't it?

So I had the right idea but quoted the wrong principal.

And the OP said something about the thermostat saying 27oF or something like that when he was driving. You have no idea where the car is sampling that from. It could be anywhere in the engine compartment or even near the transmission and away from the wind.

TB Bypass isn't a good idea. In the winner, you're working on earning your very own Darwin award. I hope you don't take an innocent family with you when the TB sticks open.

I'm glad that you optimistically read my post that said I was going to reverse it, with some help from a co-worker. Don't have too much faith in humanity, do you?

 

[Vetterin]

I tried the TB bypass on my Corvette about 10 years ago. Drove it that way for a few years (although very little in the winters) and never noticed any difference in performance but did notice some problems with the cold weather warm ups. Hooked it back up and that's the way it's going to stay. IMO it's a very overrated (if not useless) mod.

 

[jdoggg12]

Wind chill doesn't affect inanimate objects. It may speed up a process, but it will not cause water to freeze at 35degrees when traveling at 70mph.

Per wiki
Wind chill is the apparent temperature felt on exposed skin due to the combination of air temperature and wind speed.

 

[TerryMathews]

Originally posted by: timxpx

Originally posted by: TerryMathews

Originally posted by: LTC8K6
It's the venturi effect that will get you into trouble with icing, isn't it?

The pressure drop on the backside of a constriction is what causes the problem.

This is why the throttle body is heated in the first place, isn't it?

So I had the right idea but quoted the wrong principal.

And the OP said something about the thermostat saying 27oF or something like that when he was driving. You have no idea where the car is sampling that from. It could be anywhere in the engine compartment or even near the transmission and away from the wind.

TB Bypass isn't a good idea. In the winner, you're working on earning your very own Darwin award. I hope you don't take an innocent family with you when the TB sticks open.

I'm glad that you optimistically read my post that said I was going to reverse it, with some help from a co-worker. Don't have too much faith in humanity, do you?

Here's a better question for you: Do you think it was worth the hassle? Somehow, I think if you looked at your before and after MPG, I think you'd say no.

 

[LTC8K6]

"Wind chill doesn't affect inanimate objects."

The venturi effect is not wind chill, though.

In any event, the TB bypass is a waste of time, imo, and may cause trouble, imo.

It's not my car though, so I'll shut up now.

 

[timxpx]

Originally posted by: TerryMathews

Here's a better question for you: Do you think it was worth the hassle? Somehow, I think if you looked at your before and after MPG, I think you'd say no.

actually, the TBB was done during my CAI installation in july ... after that, my gas mileage during the rest of the summer went up from 28-29 mpg to 30-31 mpg on 93 octane from exxon (same station/pump if i can help it).

iirc, it wasn't a hassle to do the TBB at the time because we had to replace the stock hoses with the ones in the CAI kit, and my friend had a box full of those nipple caps as well.

so... i'm not quite sure what you're getting at?

my gas mileage did fall a bit since it got colder (27 mpg)... but i think that's because of the winter gas mix?

---

thanks everyone else for your input -- i'm dropping my car off at my mechanic tonight to get new brake pads installed, and i'll leave a note for him to put the coolant hoses back. i am not very in touch with my DIY side, so i'm glad he can do it for me, instead of me and a guy from work leaking coolant all over our parking deck.

 

[timxpx]

Originally posted by: LTC8K6
"Wind chill doesn't affect inanimate objects."

The venturi effect is not wind chill, though.

In any event, the TB bypass is a waste of time, imo, and may cause trouble, imo.

It's not my car though, so I'll shut up now.

waste of time? maybe, since its just going back to stock anyway. learning experience? sure! people on message boards for my car posted small/nominal gains on the dyno from it with a CAI, but really, the numbers were nothing to write home about. i don't run my car in the 1/4 mile, and i missed the september-october non-points autocross weekends- no need for something that is debatable on whether it hurts / helps performance and that could cause problems when it gets c-c-c-old.

also, i thought the point of the forums (especially this one where i asked an open question) was that even if though it's not your car, you don't have to shut up?

 

[TerryMathews]

Originally posted by: timxpx
actually, the TBB was done during my CAI installation in july ... after that, my gas mileage during the rest of the summer went up from 28-29 mpg to 30-31 mpg on 93 octane from exxon (same station/pump if i can help it).

2-3 MPG could be the CAI kit, or it could just be luck.

Is a Civic really recommended for 93 octane? You want to run the lowest octane you can without knocking/pinging for the greatest power/MPG.

 

[timxpx]

Originally posted by: TerryMathews

Originally posted by: timxpx
actually, the TBB was done during my CAI installation in july ... after that, my gas mileage during the rest of the summer went up from 28-29 mpg to 30-31 mpg on 93 octane from exxon (same station/pump if i can help it).

2-3 MPG could be the CAI kit, or it could just be luck.

Is a Civic really recommended for 93 octane? You want to run the lowest octane you can without knocking/pinging for the greatest power/MPG.

i'm going to go ahead and guess the CAI has been helping my gas mileage (assuming i don't spend most of the tank redlining it). if not, well then, it's been a lucky 11,000 miles since july... i should play the lottery!

re: 93 octane

my owners manual says to put at least 91 in. that, and my engine's compression ratio is 11:1.

i usually use exxon because of routine / location. they have 87 < 89 < 93, hence the 93.

 

[jagec]

Originally posted by: TerryMathews

Originally posted by: timxpx
actually, the TBB was done during my CAI installation in july ... after that, my gas mileage during the rest of the summer went up from 28-29 mpg to 30-31 mpg on 93 octane from exxon (same station/pump if i can help it).

2-3 MPG could be the CAI kit, or it could just be luck.

Is a Civic really recommended for 93 octane? You want to run the lowest octane you can without knocking/pinging for the greatest power/MPG.

It's an Si. Quite a different beast than you run-of-the-mill Civic.

 

[TerryMathews]

Originally posted by: timxpx

Originally posted by: TerryMathews

Originally posted by: timxpx
actually, the TBB was done during my CAI installation in july ... after that, my gas mileage during the rest of the summer went up from 28-29 mpg to 30-31 mpg on 93 octane from exxon (same station/pump if i can help it).

2-3 MPG could be the CAI kit, or it could just be luck.

Is a Civic really recommended for 93 octane? You want to run the lowest octane you can without knocking/pinging for the greatest power/MPG.

i'm going to go ahead and guess the CAI has been helping my gas mileage (assuming i don't spend most of the tank redlining it). if not, well then, it's been a lucky 11,000 miles since july... i should play the lottery!

re: 93 octane

my owners manual says to put at least 91 in. that, and my engine's compression ratio is 11:1.

i usually use exxon because of routine / location. they have 87 < 89 < 93, hence the 93.

I wasn't giving you a hard time, I was seriously asking. A lot of people assume that higher octane == better and put it in cars that don't need it.

 

[timxpx]

Originally posted by: TerryMathews

I wasn't giving you a hard time, I was seriously asking. A lot of people assume that higher octane == better and put it in cars that don't need it.

excuse the sarcasm then.

if it really didn't need the higher octane, i would definitely be using regular ($$$).

but yeah, as jagerc said, the si is a different animal. the engine is a k20z3 if you ever get curious.

i believe the engine in non-si models for 2006+ is r18a1 -- i assume those take regular gas.

i posted in the VVT article topic that one of the things i like most about my si is that it's your regular commuter car up until 5800 rpm, and after that, it gives me more than enough pep than what i would need in a daily driver.

 

[Demo24]

not even sure why you would bother disconnecting that.

also 11k miles and already replacing the brake pads? damn!