Throttle body coolant bypass mod
03-29-2004, 08:28 PM
#1
Throttle body coolant bypass mod
The TB mod is to bypassing the hot coolant lines running through the bottom of the throttle body. By design, the coolant lines are there to prevent the throttle plate from freezing under cold temperature. Because of this, the throttle body receives the same coolant temp running through the engine, which also heats up the intake temp. Therefore, this mod is usually done along with the Hondata heat gasket to further reduces intake temp.
Pros: The TB mod is cheap and easy to install. It costs approx. $1.50 for a fitting and 20 mins of labor after removing the intake tube.
It's very effective. The throttle body is no longer hot after driving even in hot weather. It will be warm due to under hood heat but no longer heated by hot coolant.
It's easily reversible back to stock.
Cons: It's not recommended if you live in very cold/freezing area, as the throttle plate may become sticky.
Warning: If you decided to do this mod, you assume all risks including gains relating to this mod.
Step1:
Wait for the engine to cool down. Remove intake tube from TB (No instructions provided).
Step2:
Get yourself some crimpers. I had to custom made mine with needle nose vise grips and some vacuum hose. This is to avoid damage to the coolant hoses.
Step3:
Go pick up a 5/16" fitting from any auto parts store. Mine is plastic but you can get brass if available.
Step4:
Identify and crimp two coolant hoses. Place some paper towel beneath the TB to catch any spills. Look at the bottom of the TB. It's very easy to tell which two lines are the coolant lines.
Step5:
Remove hose clamps and coolant hoses from the TB. Insert fitting onto coolant hoses and reinstall clamps.
Step6: Optional
I also installed two 5/16" plugs onto the TB to have a cleaner installation. You can also see the placement of the hoses and fitting.
Step7:
Reinstall intake tube. Start the engine and check for leaks. Replenish coolant if necessary. Done!
Pros: The TB mod is cheap and easy to install. It costs approx. $1.50 for a fitting and 20 mins of labor after removing the intake tube.
It's very effective. The throttle body is no longer hot after driving even in hot weather. It will be warm due to under hood heat but no longer heated by hot coolant.
It's easily reversible back to stock.
Cons: It's not recommended if you live in very cold/freezing area, as the throttle plate may become sticky.
Warning: If you decided to do this mod, you assume all risks including gains relating to this mod.
Step1:
Wait for the engine to cool down. Remove intake tube from TB (No instructions provided).
Step2:
Get yourself some crimpers. I had to custom made mine with needle nose vise grips and some vacuum hose. This is to avoid damage to the coolant hoses.
Step3:
Go pick up a 5/16" fitting from any auto parts store. Mine is plastic but you can get brass if available.
Step4:
Identify and crimp two coolant hoses. Place some paper towel beneath the TB to catch any spills. Look at the bottom of the TB. It's very easy to tell which two lines are the coolant lines.
Step5:
Remove hose clamps and coolant hoses from the TB. Insert fitting onto coolant hoses and reinstall clamps.
Step6: Optional
I also installed two 5/16" plugs onto the TB to have a cleaner installation. You can also see the placement of the hoses and fitting.
Step7:
Reinstall intake tube. Start the engine and check for leaks. Replenish coolant if necessary. Done!
03-30-2004, 07:35 AM
#4
GEEZER
Nice job...any before / after Dyno Results???
03-30-2004, 07:47 AM
#5
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How much HP are we talking about if any before I do this.
03-30-2004, 09:31 AM
#6
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It would be nice if we can figure away out on how to use whats there to chill the TB durring the summer months....
Just a thought
Opps had another thought...two thoughts in the same space wow!
Or in line on\off valve, on in the winter, off in the summer.
I also read in the mazda6 fourm, they do this to their TB too.
I think they call the mazda6 a TSX Killer.
Is it true??
Just a thought
Opps had another thought...two thoughts in the same space wow!
Or in line on\off valve, on in the winter, off in the summer.
I also read in the mazda6 fourm, they do this to their TB too.
I think they call the mazda6 a TSX Killer.
Is it true??
03-30-2004, 02:02 PM
#7
Kickstand
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It also appears you can just take the bottom line and connected directly up to the other place where the top tube connects to the coolant line. I dont expect much gain off this...maybe 1HP...but if its free then thats good enough for me.
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03-30-2004, 03:21 PM
#10
TinkySD, I haven't done IAT datalog on the TSX after the TB mod. Since the IAT sensor is sitting before the TB, I doubt it will pick up the temp difference. But the TB surface temp test is very noticeable. Since the TB is attached to the intake manifold, eliminating the heat source from the coolant lines also helps reducing the heat on the intake manifold by a certain degree.
03-30-2004, 03:43 PM
#11
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q1. Where does the tb colant go after it enters the tb (ie. how does it drain out and does this mod effect that?)?
q2. What about just putting an inline valve for the winter?
q2. What about just putting an inline valve for the winter?
03-31-2004, 08:32 AM
#12
You want me to break it?
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Please forgive my complete and total ignorance on the subject but for clarification:
1) The coolant lines are ONLY for heating the throttle body, not in anyway responsible for cooling/regulating temp otherwise
2) If it sticks =WOT? that could be bad in a school zone about 3 PM
3) Do you think that this will effect the longevitiy/reliability of the part? I mean, it was designed to work with the coolant, right?
1) The coolant lines are ONLY for heating the throttle body, not in anyway responsible for cooling/regulating temp otherwise
2) If it sticks =WOT? that could be bad in a school zone about 3 PM
3) Do you think that this will effect the longevitiy/reliability of the part? I mean, it was designed to work with the coolant, right?
03-31-2004, 12:13 PM
#13
Originally posted by Gpump
Please forgive my complete and total ignorance on the subject but for clarification:
1) The coolant lines are ONLY for heating the throttle body, not in anyway responsible for cooling/regulating temp otherwise
2) If it sticks =WOT? that could be bad in a school zone about 3 PM
3) Do you think that this will effect the longevitiy/reliability of the part? I mean, it was designed to work with the coolant, right?
Please forgive my complete and total ignorance on the subject but for clarification:
1) The coolant lines are ONLY for heating the throttle body, not in anyway responsible for cooling/regulating temp otherwise
2) If it sticks =WOT? that could be bad in a school zone about 3 PM
3) Do you think that this will effect the longevitiy/reliability of the part? I mean, it was designed to work with the coolant, right?
2. Anytime when the throttle plate sticks, you have no control of the engine rpm. That's why the mod is not recommended for people who live in extremely cold area. Also, since freezing temp is 32 degrees F, as long as the under hood temp is above 32 F, it shouldn't be a problem.
3. No
However, I can see the problem if the following situation exists. Therefore, if you have any doubt, DON'T DO IT!
The TB is mod. Live in extremely cold area. Start the engine and drive without any warm up time.
BTW, if you live in such cold area. Lowering intake temp is not even an issue.
04-02-2004, 06:28 PM
#15
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JTso: hey man... I found that there is 3 lines
one on the very bottom of the TB and and another very close that hose. THE THIRD ONE is very easy to see and it right infront of you like on the left side of the TB ( NOT SHOW on the pic below)
DO i just connect these 2 in the pic? I just wanna make sure I don't want to fuck up
one on the very bottom of the TB and and another very close that hose. THE THIRD ONE is very easy to see and it right infront of you like on the left side of the TB ( NOT SHOW on the pic below)
DO i just connect these 2 in the pic? I just wanna make sure I don't want to fuck up
04-05-2004, 08:47 AM
#19
it looks like a good mod!! but still too cold to try here
i am wondering the coolant in the TB, did you drain them out and flesh with water or left it there? yes, collant is pretty making tb pretty hot...
i am wondering the coolant in the TB, did you drain them out and flesh with water or left it there? yes, collant is pretty making tb pretty hot...
06-02-2004, 11:52 PM
#21
any excuse to drive
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Does anyone know of a place to purchase a 5/16" brass barb elbow fitting online? I checked four different auto stores & Home Depot none had a fitting in 5/16". WTF!? I'm sure I've spent more in gas finding the parts than the parts themselves 
Thanks
Thanks
06-04-2004, 12:18 AM
#22
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never mind, I made my own with two brass 5/16" barb to 3/8" male into a 3/8" female elbow.
Had to learn the lingo just to find the darn parts.
The amount of heat that transfers into the throttle body is amazing.
Thanks jtso for this thread
Had to learn the lingo just to find the darn parts.
The amount of heat that transfers into the throttle body is amazing.
Thanks jtso for this thread
06-06-2004, 10:51 PM
#26
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Originally Posted by JTso
Another option if you can't find the plastic fitting is to use the brass ones. 1/8" npt right angle adapter and two 1/8" npt fittings.
Lowe's has a straight 5/16" brass with barbs in the plumbing dept.
This worked just fine. I loosened
the lower hose and twisted it a bit to get the best alignment, no problem with
a staight fitting. This assembled fitting is good too, use some teflon tape.
Lowe's has a straight 5/16" brass with barbs in the plumbing dept.
This worked just fine. I loosened
the lower hose and twisted it a bit to get the best alignment, no problem with
a staight fitting. This assembled fitting is good too, use some teflon tape.
06-21-2004, 01:32 AM
#28
Bye TSX, hello domestic?
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I made mine like the brass one above, 3 parts from Home Depot in the plumbing section. I'm going to zip tie it down since its heavy and I'm worried it'll move around when driving. I'm dreading winter when I have to hook it all back together again.
06-21-2004, 02:07 AM
#29
That's why I used the plastic fitting but the brass ones should work fine too. I wouldn't worry too much about winter unless it gets extremely cold where you live. I have the same setup on my Civic for the last 4 - 5 years without removing it during winter. It should only take a few minutes to restore back to stock if necessary.
Btw, I probably can pick up some plastic ones for whoever that wants one. Just pay for the cost of the part + shipping. But shipping is going to cost more than the part.
Btw, I probably can pick up some plastic ones for whoever that wants one. Just pay for the cost of the part + shipping. But shipping is going to cost more than the part.
06-21-2004, 03:42 PM
#30
Bye TSX, hello domestic?
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Originally Posted by JTso
Btw, I probably can pick up some plastic ones for whoever that wants one. Just pay for the cost of the part + shipping. But shipping is going to cost more than the part.
Wow that bypass gets really hot being brass, but the TB is totally cool to the touch.
Here's mine:
07-15-2004, 09:28 PM
#31
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Originally Posted by xizor
Just curious.
07-15-2004, 11:30 PM
#32
Bye TSX, hello domestic?
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hmm... jtso is the pro on this. but I think a L shaped one is better... the 2 hoses that connect are more or less perpendicular to each other, the L shape matches the throttle body. I saw the same 1 piece connectors too, and the 3 piece is more expensive. jtso can find some nice 1 peice black plastic ones, a better choice IMO, the metal color stands out too much.
05-28-2005, 06:04 AM
#33
2nd Gear
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Hello there!
Sorry for being a little offtopic but do you think it's possible to do the throttle body coolant bypass mod on the Integra Type-R (1998)? Or is it already done by the manufacturers?
Sorry for being a little offtopic but do you think it's possible to do the throttle body coolant bypass mod on the Integra Type-R (1998)? Or is it already done by the manufacturers?
05-28-2005, 10:15 AM
#34
The 98 Type-R has the same TB coolant hose setup as the TSX. Also, it has the additional IAC valve on the side of the intake manifold just like a Civic. I've bypassed both areas on my Civic. However, some have reported problems with idle after bypassing the IAC valve but I have not experienced such problem. When in doubt, just do the TB only.
05-28-2005, 10:40 AM
#35
TB freeze test
Btw, I just did a freeze test on the TB last night. I put the TB in a plastic bag and stuck it in the freezer for about 12 hours under -3.8 F temp just to see what happens. This morning I took it out and manually move the throttle plate and it moves freely and returns to normal position without any problems. The throttle cam return spring is so strong and the plate movement is driven by a motor. I don't think it would have any problems bypassing the coolant hoses even during winter time. However, like any other mods, you do it at your own risk.
05-29-2005, 04:54 PM
#36
2nd Gear
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Thx for the quick response jtso! I think I'm gonna stay with TB mod then.
I read on this forum that you have installed a Hondata heatshield too. For my ITR I'd like to purchase and install a heatshield too but I'm not sure which one I should choose. Beside the Hondata heatshield there is the Outlaw Engineering ThermoBlok spacer kit which includes spacers not just for the IM but for the TB and the IAC as well. Do you have any experience with this stuff? Is it any better than the Hondata gasket?
I read on this forum that you have installed a Hondata heatshield too. For my ITR I'd like to purchase and install a heatshield too but I'm not sure which one I should choose. Beside the Hondata heatshield there is the Outlaw Engineering ThermoBlok spacer kit which includes spacers not just for the IM but for the TB and the IAC as well. Do you have any experience with this stuff? Is it any better than the Hondata gasket?
05-29-2005, 06:17 PM
#37
Since I don't have personal experience with gaskets other than Hondata, I can't really comment on how well they work. However, I've heard some of those gaskets have alignment and sealing problems, but not sure which brand. I'd just stick with the one that has proven records.
If you are bypassing the TB and IAC hoses, then you shouldn't need those additional gasket.
If you are bypassing the TB and IAC hoses, then you shouldn't need those additional gasket.
05-29-2005, 09:16 PM
#38
Drives With Hands
Originally Posted by JTso
Btw, I just did a freeze test on the TB last night. I put the TB in a plastic bag and stuck it in the freezer for about 12 hours under -3.8 F temp just to see what happens. This morning I took it out and manually move the throttle plate and it moves freely and returns to normal position without any problems. The throttle cam return spring is so strong and the plate movement is driven by a motor. I don't think it would have any problems bypassing the coolant hoses even during winter time. However, like any other mods, you do it at your own risk.
06-30-2005, 04:04 AM
#39
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Thanks for the info, did the install tonight.
I couldn't find a 5/16th barbed brass connector anywhere in town, so I decided to use a 3/8th. Home Depot and Osh didn't have exactly what I wanted. The 3/8ths works, just needed a little grunt work to get the hose ends on each side.
Capped the ends like you did, turned out A-OK!
I couldn't find a 5/16th barbed brass connector anywhere in town, so I decided to use a 3/8th. Home Depot and Osh didn't have exactly what I wanted. The 3/8ths works, just needed a little grunt work to get the hose ends on each side.
Capped the ends like you did, turned out A-OK!
06-30-2005, 05:26 AM
#40
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Originally Posted by JTso
So, do you guys notice how much cooler the TB is after the mod?
Only thing is, the winter makes me a little nervous to run without the lines. I wonder if a little moisture (like normal humidity in the air) would contribute to any freezing? My guess is if you let the car warm up, the engine bay temp would take care of that though.