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Discussion Starter · #1 ·
I am working on a system to cool my throttle body and intake runners by using a ram air scoop to duct air up into the engine compartment and a shield to run it along the intake runners. Any ideas on this in terms of how much of a temperature drop would need to be achieved in order to gain any benefit? I already ran a little over 300 miles like this with a primitive set-up just aimed at the throttle body. I am going to go ahead and fab up a shield to fit over the top of the intake runners (about a 2 inch air space) to help conduct the air along the top of the runners as well as a scoop. Currently running with just a 3 inch Diameter tube with the scoop. According to my calculations the 3 inch tube ducts roughly 200 cubic feet of air at the throttle body at 70 MPH.

I think that with the addition of a scoop, the shield to conduct the air along the intake runners, a throttle body coolant bypass (just for the summer) and a method of getting the air out of the engine bay that maybe this might help a little.

Also thinking about insulating my air filter box and intake that runs from the air filter box to the throttle body. I popped the hood one day and felt them and they were nearly too hot to hold my hand against them.

Thoughts?
 

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Discussion Starter · #3 ·
did you already bypass the coolant to your throttle body?

When I hold the accelerator to the floor up a long grade and pull over, the intake is cold to the touch. Used to get so hot you couldn't touch it.

Hey Escondidotundra,

I am going to do the coolant bypass but would like to see some pictures first - do you have any pics or can you send me some? Obviously I need to do this when the engine is cool and relieve the pressure but is there is anything else?

Thanks a million.
 

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HighwayLiazrd, on my 06 Ram I made a custum intake tube to run from the factory air box over to the throttle body (4" aluminized tubing with a pair of flexable hoses to connect it) and then wrapped the whole thing in header wrap (the idea was to keep the incoming air charge that was already cool cool). I noticed a slight increase in MPG, not sure if it was the intake of the wrap but on a 800 mile trip I got 1.5 MPG better than I ever did. I have the recurring thought that the cooler you can keep the air charge and the straighter (less restrictive into the throttle body) the more effective you will burn the fuel. I have even cooled my fuel (my old Mustang had an improvised cooler (an old coffee can) with about 20 feet of fuel line coiled inside that I would fill with ice, it made hella power at the strip and got pretty decent MPG.

Hope this helps, good luck.
 

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Here is a write up I did on another forum. It has pics that I posted and others have posted of their truck. I would think the 2004 would be exactly the same. It's simply plug and play.

Like I've said in other posts/threads. My baseline before all the exhaust I've built is like 20hp to the wheels more than stock. The throttle body bypass is probably a major contributor to these gains. Unfortunately I didn't dyno the truck bone stock.
 

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Discussion Starter · #6 ·
Here is a write up I did on another forum. It has pics that I posted and others have posted of their truck. I would think the 2004 would be exactly the same. It's simply plug and play.

Like I've said in other posts/threads. My baseline before all the exhaust I've built is like 20hp to the wheels more than stock. The throttle body bypass is probably a major contributor to these gains. Unfortunately I didn't dyno the truck bone stock.
Just did my bypass - took about ten minutes. Going out for a drive and will check the temperatures by hand (poor man's thermometer). I am taking the short hose that I took off with me along with a nut driver and will stop by the auto parts store to get some quality worm drive hose clamps just in case I need to put it back the way it was and to make winter/summer conversions easier and quicker.

I will post my findings tonight and will test this over the next couple of tanks of fuel.

Thanks

EDIT Just ran 40 miles down and back to pick up my son and the Throttle Body and intake runners do not seem to be any cooler. Way too early to tell if it is helping in the MPG department.

I read the link you posted about the mod on another forum and on there someone (perhaps you?) mentioned that this should not be done if the PCV connects into the Throttle Body - where else could it connect to? Mine does connect into the Throttle Body. :sad3d:
 

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the pcv has no effect, it's the egr you need to be concerned about. The car I know has egr going thru the throttle body is a 5.0 Mustang. You have to pull the upper and lower manifold and cut out pieces of beer can to plug the egr from entering the intake.

With the Tundra there is no EGR in the intake. If there is no diff in temp, are you sure you bypassed the coolant from entering the throttle body?
 

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Discussion Starter · #8 ·
the pcv has no effect, it's the egr you need to be concerned about. The car I know has egr going thru the throttle body is a 5.0 Mustang. You have to pull the upper and lower manifold and cut out pieces of beer can to plug the egr from entering the intake.

With the Tundra there is no EGR in the intake. If there is no diff in temp, are you sure you bypassed the coolant from entering the throttle body?

Hey Escondidotundra!

Thanks for the clarification on the PCV and EGR - I did not catch that when I read through it.

Yeah, definitely pulled the correct hoses from my Throttle Body. Both of them are on the driver's side and both had fluid come out of them. I just held a shop rag under them as I removed them. Pretty tight in there but only took about ten minutes.

Going to reinstall my skid plate today and mark it for the opening where I will mount the new scoop. I will call my fabricator and see about a time frame for the new scoop and shield to direct the air along the intake runners which will give me some time to mull over how to get all that air out of there. Thinking about jamming 1400+ cubic feet/minute of air in there to direct at the Throttle Body and intake runners while running at 75 MPH.

That is a sh!t ton of air and now that I think about it I should fabricate an insulated barrier around the air box and an insulated tube to go around the intake tube from the air box to the Throttle Body and run some of that air through there too.

I wish I had a Scan Gauge - don't they measure IAT?
 

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Hey Escondidotundra!

Thanks for the clarification on the PCV and EGR - I did not catch that when I read through it.

Yeah, definitely pulled the correct hoses from my Throttle Body. Both of them are on the driver's side and both had fluid come out of them. I just held a shop rag under them as I removed them. Pretty tight in there but only took about ten minutes.

Going to reinstall my skid plate today and mark it for the opening where I will mount the new scoop. I will call my fabricator and see about a time frame for the new scoop and shield to direct the air along the intake runners which will give me some time to mull over how to get all that air out of there. Thinking about jamming 1400+ cubic feet/minute of air in there to direct at the Throttle Body and intake runners while running at 75 MPH.

That is a sh!t ton of air and now that I think about it I should fabricate an insulated barrier around the air box and an insulated tube to go around the intake tube from the air box to the Throttle Body and run some of that air through there too.

I wish I had a Scan Gauge - don't they measure IAT?
Any good code reader will be able to measure IAT. I can't possibly see the still warm manifold being heat soak, but maybe that's what it is. Try this: find a pretty steep grade and floor it up the grade. Immediately pull over when up the grade, shut off the engine, and run out and check the temp of the manifold. It should be cool to the touch.
 

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Discussion Starter · #11 ·
Any good code reader will be able to measure IAT. I can't possibly see the still warm manifold being heat soak, but maybe that's what it is. Try this: find a pretty steep grade and floor it up the grade. Immediately pull over when up the grade, shut off the engine, and run out and check the temp of the manifold. It should be cool to the touch.
Hey Escondidotundra!

Maybe on my next trip down to see my girlfriend's family I will be able to pull a few hills and see.

Got a few other ideas but need to do some research and get some money together first.
 

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Just a word of caution on this mod; the coolant passage was done for a reason and not for Toyota to waste money. The coolant passages in the throttle body are designed to keep a constant temperature in the throttle body. In the winter it keeps the assembly from freezing up as happened in the early days on GM's where the throttle would freeze open causing stuck throttles ( and the outside temperature did not have to be below freezing for this to happen, just cool temps, moist air, and highway driving). In higher temperatures the coolant actually cools the throttle body from higher transferred engine heat. This also keeps the throttle motor from getting too hot. This more costant temperature is taken into account with the MAF calculation as one less variable change downstream.

With your air cooled mod, as long as you are moving you will keep the intake cool, however if you sit for any length of time on a hot day you may find the throttle temperature climbs much higher than it would with the coolant passage connected. Of course it will all depend on climate as to how you are affected.

By all means go ahead and experiment, but just keep in mind both ends of the temperature spectrum and the potential effects.

HV
 

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Discussion Starter · #13 ·
Just a word of caution on this mod; the coolant passage was done for a reason and not for Toyota to waste money. The coolant passages in the throttle body are designed to keep a constant temperature in the throttle body. In the winter it keeps the assembly from freezing up as happened in the early days on GM's where the throttle would freeze open causing stuck throttles ( and the outside temperature did not have to be below freezing for this to happen, just cool temps, moist air, and highway driving). In higher temperatures the coolant actually cools the throttle body from higher transferred engine heat. This also keeps the throttle motor from getting too hot. This more costant temperature is taken into account with the MAF calculation as one less variable change downstream.

With your air cooled mod, as long as you are moving you will keep the intake cool, however if you sit for any length of time on a hot day you may find the throttle temperature climbs much higher than it would with the coolant passage connected. Of course it will all depend on climate as to how you are affected.

By all means go ahead and experiment, but just keep in mind both ends of the temperature spectrum and the potential effects.

HV
Hey Hi Volt,

Thanks for chiming in - I was getting ready to shoot you a PM on this and another topic. I only intend to run this during the warm months but I had not considered the possibility of overheating the intake while sitting stationary. This concerns me. I wonder if it would be possible to rig up some kind of thermostat that would open at a given temperature and allow the coolant to flow during the heat and close up when not needed. That would be a cool (pun intended) set-up. It would also eliminate the need to change this over in the spring and the fall.

Thanks again for your thoughts and I hope all is great with you and yours.

Toby
 

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Discussion Starter · #14 ·
Here is the latest. A little more city than highway. 160 miles with truck very over loaded (rear squatting) hauling yard debris to the dump. Air Conditioning running the entire time. Using same pump as last fill-up.

  • 367.7 miles
  • 20.508 gallons
  • 17.9 MPG

Not too bad. Now I just need to see if this is sustained. I am a little concerned about heat transfer from the engine to the Throttle Body and more specifically to the Throttle Body motor.
 

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Discussion Starter · #16 ·
Yes the scan guage does measure IAT
Hey Big Al1 good to see you are still around. Are you still running the True Flow?

Thanks for the response on the IAT question. Good enough excuse to get one - someday.
 

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Yes I am still running it and believe that of all the filters I have tried in my time its still seems to filter better than the rest, I check my intake regularly and the tube and throttle body stays very clean. Only problem is now that they have gone out of business now I am having trouble tracking down some recharging kits for the filter.
 

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Here's what I did to bypass the throttle body cooling lines. Very easily reversible once the months start getting colder. Total cost was about $6. Would've been less if I reused the oem clamps.



parts list:
3/8" to 3/8" vacuum line connector (qty:1)
3/8" vacuum rubber end caps (qty:2)
1/4"-3/4" ss hose clamps (qty:4)

Auto part Fuel line Carburetor Engine Automotive engine part
 

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Discussion Starter · #19 ·
Here's what I did to bypass the throttle body cooling lines. Very easily reversible once the months start getting colder. Total cost was about $6. Would've been less if I reused the oem clamps.



parts list:
3/8" to 3/8" vacuum line connector (qty:1)
3/8" vacuum rubber end caps (qty:2)
1/4"-3/4" ss hose clamps (qty:4)

View attachment 31522
Hey Tundradrenalin,

How's that electric fan set-up working out for you? I think the coolant lines are different on the 2004 vs 2005 and 2006. I will get a picture of my set up as soon as I can.

Yes I am still running it and believe that of all the filters I have tried in my time its still seems to filter better than the rest, I check my intake regularly and the tube and throttle body stays very clean. Only problem is now that they have gone out of business now I am having trouble tracking down some recharging kits for the filter.
Yeah, I am a little worried about the recharge kits myself and am wondering if any other manufacturers are compatible with the True Flow. I would not get rid of mine for the world and it does filter better than anything else I have tested.
 

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Your manifold is going to heatsoak when the throttle is closed, and the truck is stationary. There is very little airflow past the throttle body. Directing ambient air over the IM and runners will of course only work when your moving, at that point you will have some airflow through the manifold and it will start to cool down anyway. If you want the iat's a little lower, why not try some water, or water/ methanol injection?
 
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