HP gains by passing TB coolant line?

[jibbby]

I am reading that many Lexus hotrodders by-pass and or delete the coolant line that runs hot coolant thru the throttle body. This procedure is recommended if you live in a warm climate...Small HP gains can be made by reducing intake air temp.

The hot coolant is run thru the throttle body to keep it from not freezing up in colder climates.. What do you guys think, bypass or keep it intact?

 

[UZZ30-Québec]

0.0002 % of 1 HP ?

i think the most of the gain will come from your butt dyno, wich might not be very accurate.

 

[UZZ30-Québec]

If you want better intake temp

get a cold air intake system
Build some phenolic intake spacer/gasket to not transfer the engine's temp to the intake, bypass your TB line.

Now you will probably have some small gains. phenolic gaskets will provide better gains since heat transfers is what kills your intake charge.

 

[jibbby]

I am reading on the CL forum, many are doing this proceedure and are seeing some results...Of course those that live in hot weather climates are deleting the coolant line...No reported ill effects either...Apparently hot coolant running thru the throttle body was designed by Lexus engineers mainly for when the Lexus's are to be driven in the colder climate areas so the TB won't freeze up and get stuck... So if you live in warm weather this hot coolant flow is probably doing more harm then good..No?

 

[UZZ30-Québec]

sure it is, but do the math

500CFM (est.) passing trough this hole, deleting the coolant line won't reduce your intake charge temp of 10 degrees.

actually, you could use this line to cool down your TB. use 2 lines, a small pump and a small PC radiator plus fan could be a nice little cooling system for your TB and absorb some heat from the intake.

 

[Loroh]

I found my plenum (that bit where the lexus or toyota badge is) would get dam hot. Say after 30 min of driving.

So I pulled of the TB to clean it and while I was there I by-passed the coolant line.

Now, drive around as long as I want and the plenum is cold to touch.
ok.. ok.. not cold but a lot cooler
I'd say around ambent temp, witch is dam good as the plenum is in the middle-top of the motor.

As for HP gains im not sure, there might be a little.

I think the main people thinking about this should be the turbo guy's.
No point having it if you've got a turbo. or should I say no point having an intercooler if the TB heats the air back up (depending on how good your intercooler is)

 

[jibbby]

sure it is, but do the math

500CFM (est.) passing trough this hole, deleting the coolant line won't reduce your intake charge temp of 10 degrees.

actually, you could use this line to cool down your TB. use 2 lines, a small pump and a small PC radiator plus fan could be a nice little cooling system for your TB and absorb some heat from the intake.

That may be a good idea if you could introduce cold water/coolant instead of hot water/Coolant that is flowing thru the throttle body...Never thought of that, but does the TB really heat up if the coolant line is deleted and no water flows? Do you think the TB still gets hot with transferred engine block heat anyway?...Combine that with a true cold air box intake then you should get a true very cold air intake all the way into the motor. That will give you some gains..Right now I have a pod filter and half a***d heat shield with bigger air flow coming in from under the headlight area....Don't think my current setup is doing much for my intake as I am still pulling in way too much engine bay heat....

This is a link to how to by-pass the coolant line to the TB..

http://lexusmodz.netfirms.com/GS DIY/coolant bypass/

My linking skills stink, but that is the web address anyway that shows pictures and a full tutorial on the whole subject...



I am thinking of reworking my entire intake. I want t to go in a different direction then the legendary BFI intake design....I am thinking of pulling the intake air flow from a pre-drilled large hole that will be created just above the tire wheel well...Pull the air in from directly above the front tire...There is kinda vacume affect when pulling the air in from that specific location...The only problem is the tires kicks up alot of dirt and water so I would need to find a diversion or special screen or filter to make it all work..Any ideas?

 

[Smitherz]

Toyota Tacoma trucks take the air from this location. They have a hole right above the front of the tire and they run a snorkle type piece of plastic through this hole and back about 1.5 ft. Of course the snorkle runs along the top inside of the passenger fender. When I took mine off there was a small amount of rocks in the very beginning of the intake before reaching the airfilter. This is from a truck that was driven offroad much more than normal. There were little recesses molded into the plastic to catch anything like that I believe. You won't have any problems from rocks as long as you don't point the intake right at the tire.

 

[jibbby]

Thanks Smithers....You got any pictures of your intake and how it is setup?

 

[Smitherz]

The 1uz isn't in my truck yet =] My intake on my 3RZ is just straight pipe in. I grabbed a plasma cutter and cut a hole in the front wall of the compartment and cut the plastic grill insert out to get air to it. It's gets as much air as possible this way.



I'm bypassing my TB line as well on my engine. No use for that sort of heat here in sunny CA.

 

[jibbby]

You live in Ca...Cool...So Cal?

So your intake air comes from the front corner of the wheel well...How is it when it rains or you drive thru a major puddle of water? How do you keep the water out of the filter and intake?

I would think if you hit a major puddle, the water would then be sucked up into the intake iespecially if you were hammering on the throttle, no?

PS. Thanks for the pic...Your engine bay heat shield looks like it works like a charm...

 

[stevechumo]

Toyota Tacoma trucks take the air from this location. They have a hole right above the front of the tire and they run a snorkle type piece of plastic through this hole and back about 1.5 ft. Of course the snorkle runs along the top inside of the passenger fender. When I took mine off there was a small amount of rocks in the very beginning of the intake before reaching the airfilter. This is from a truck that was driven offroad much more than normal. There were little recesses molded into the plastic to catch anything like that I believe. You won't have any problems from rocks as long as you don't point the intake right at the tire.

It's just a coincidence that I just thought of making a true cold air intake for my Tacoma. Similarly like your design, I'll cut a hole through the metal wall behind the headlight and extend the air filter underneath the headlight and right in front of the front right tire. This way, I'll have a real cold air, especially in the winter, coming straight to the throttle body.

To prevent the water to get into the engine, I'll use an AEM by-pass valve that totally eliminates any water from being sucked up. This design was first made by AEM on 4 cylinder Hondas. I used it before and it gained very noticeable power. AEM showed it gained about 7 hp on the dyno chart by itself and I totally believe it. You can imagine it's for a V8 or a V6. The gain will be even better. In summer, I didn't use the AEM by-pass valve at all and I even had more power gain because the pipe now is a 1 piece air director.

With headers, exhaust, cold air intake, cams, ignition box, hot plugs and wires, and tuning, I'm very positive the 1UZFE can make at least another 50 whp easily. Cost isn't cheap but it's still cheaper than a turbo system.

 

[jibbby]

Steve, Where can I view and purchase a AEM by-pass valve? Does that come factory on a certain model vehicle?

 

[stevechumo]

John,
This AEM isn't factory made. It's made by a reputable aftermarket hi-performance parts by AEM. Here's the link to its website: http://www.aempower.com/Faqs.aspx?CategoryID=20. The website says this bypass valve can only be positioned behind the air filter pod and before the fuel & NOS lines for the NOS system. The FAQ section will tell more about this product. On Ebay, it's here: http://cgi.ebay.com/ebaymotors/AEM-...ryZ38634QQssPageNameZWDVWQQrdZ1QQcmdZViewItem.
If you're interested, you may use the 3" valve. I wish there's a 3.5" valve but there isn't.

 

[Smitherz]

Hey guys, I live in San Luis Obispo on the coast right between LA and SF. My truck is lifted and I took splashing into consideration when putting my intake together. As long as I don't fully submerge it I don't have to worry about sucking in any water. I have air being pushed in from the front but the water really has to come up over the bumper. I rammed a couple mudholes/ puddles at a friend motocross track enough to submerge it and get stuck real quick. I pulled it out with a backhoe, let it drip dry and drove home later. I run an oversized foam filter which is always oiled which deflects any water splashed at it fairly well. The foam is so thick anyways that water will not go through it if it was squirted at it. The large surface area of the filter element allows for air to be pulled in around any water that might be in there. It dry's out while driving and everything is fine. Foam filters can't be beat. That's why they are in all dirtbikes and lawn mowers. They are subject to the worse conditions and the worst maintenance schedules. K&N and paper filters are a death sentence off-road and after you wash them (K&N or cotten element fileters)they are worthless anywhere.

I sealed up the old holes in my fender wells good so that no water comes in from the side. I removed any rubber curtains that are designed to keep water out of the engine compartment. Of course you see the headers and I removed all of the stock heat shields and such. There is a lot of airflow in the engine compartment now. Because of these mods I don't even have to use the electric fan I have wired up unless I'm driving offroad a slower speeds at full throttle. I took off the regular fan clutch and fan to pep up the revvs a little. The engine stays very cool since the stock radiator is more than adequate for the 3RZ.

Another good thing about this is that when I slam into puddles or sand it all falls out of the engine compartment. I always go over my truck before and after I drive offroad and spray it off inside and out to prevent corrosion and buildup. It is more high maintenance, yes, but I really take care of my stuff even though I drive my truck really hard. If something break, big deal, I fix it. I like keeping everything in good operating order.

I would steer clear of the AEM component. Read some reviews of it around the web. It's just a device that allows air to enter it in when the filter is completely choked with water as if you drove through a huge puddle. People say they are a weak link and come loose sometimes. I think the people here are smart enough to steer around puddles. Seems like a waste of time and not a long term solution. I would much rather make a diverter inside the airbox to deflect any h2o into a vented reservoir. I'm contemplating making my new one out of aluminum when I get my engine in. I like to go overboard though.

The toyota air box I had taken off was engineered to catch rocks in the bottom of the airbox if any could get through the long snorkle. You would have to seriously shovel rocks and dirt in there to accumulate enough dirt for it to reach the level where it would actually touch the filter element. When you change the air filter it's really obvious if there is any dirt in the box anyway so a person can vaccuum it out if needed. It's not a smooth tube going into a flat airbox at all... it goes up and down and there are lots of places for dirt to get trapped in the plastic box recesses. No water or rocks ever made it into the filter element with the stock box after lots of off-roading. If I fun across mine in my shed I'll pull it out and take a picture of it.

 

[Smitherz]

Ok I didn't want to post all of that trash talk about the AEM valve without looking into it. They did a nice little test of one on a nice NSX just to test the theory of the product over at SCC (Sport Compact Car). I doubt that anyone that works for the publication has installed one of their car though =]
http://www.sportcompactcarweb.com/tech/0104scc_aem_air_bypass_valve/index.html

Then we have what an example of what happens when someone puts on in their car and assumes that it will last forever: http://hondaswap.com/general-tech-maintenance/aem-bypass-valve-no-good-58291/

If you are worried that on a rainy day that your vaccum nozzle, ram air intake equipped ride might accidently be forced into a deep puddle for a long amount of time at full throttle... then this product is for you, hehe. :reporter:

 

[jibbby]

Ok I see how they work now.. It sounds like that little by-pass deal would turn to rubble in just a short time especially if it were to be mounted at the cut hole in the front wheel well...Unless it placed and mounted up higher where an after market cold air box would be, hhhhmmmm??....I am trying to think of the absolute best intake design for an SC...

Steve, do you have an idea on how you would set up a true cold air intake design with this bypass installed for our SC's?

What's funny is that the AEM bypass valve looks just like the back sides of 2 cone speakers that were glued together, then a skirt put over it all...

Thanks for the input guys...Very helpful...

 

[stevechumo]

Ok I didn't want to post all of that trash talk about the AEM valve without looking into it. ....

Smith,
That's a good finding on the AEM valve. However, with my personal experience, I had been using that AEM valve for years, installed it on my car, my friends' cars and we never had any problems. The key is the AEM valve has to be installed per AEM's instruction, which is in the upper stream of the pipe. Several guys didn't know this so that's why it didn't work or last. The soft foam of the AEM valve isn't supposed to touch anything, or directly in contact with a lot of water over and over again, rocks, or even in direct heat from the exhaust...etc. It's just the same for many other compartments in the engine bay. It has to be correctly located.

I'm not standing for any of AEM products (because I don't care who they are), but I have a saying: there's no one product that works the same if it's not used the same.

John,
The AEM cold air with that bypass valve is what I would do if I don't have the turbo system for my SC. That bypass valve doesn't have to be used all the time. It should only be used in the winter where there's rain. Without that valve, I guarantee more power will be gained absolutely along with a little more loudness. I will make this cold air system on my Tacoma when I get some times.

I actually wouldn't take risk to have the air filter exposed to any water. Here's my experience on the air filter of my SC. Last year, I covered the aftermarket air filter with a supermarket nylon bag so that I could wash the engine. I forgot to remove that bag prior to starting the engine. After about 10 seconds while the engine was running, I found the air filter was squeezed to its smallest form. This air filter has the metal wire frame as you see on any aftermarket air filter. What I mean is the engine sucks in a lot of air, thus any water on the filter can be easily sucked in.

 

[Smitherz]

Yeah the key to any custom work is to install if correctly and keep an eye on it. The people that just throw it on and forget about it are the ones that always have the wierd stories and crazy opinions. It's all about experimenting to find what suits your ride the best! It's such a cheap addon that you really can't lose. :smoker: