my car is has made a funny noise when starting though, 2 out of 4 times.

will check again today :/

 

Notes on screw in the hole vs. bypass, I tried both.

screw in the hole was noted to cause detonation in hot weather. I saw the same thing her in Orlando. I pulled out the screw, all was well. I put the screw back in, problem returned next hot day. I pulled it out, problem went away.

I went with the bypass route, the coolant now flows, but not through the TB. No detonation. Engine happier than with hot throttle.

Assumption, the hot coolant came from somewhere, and is supposed to go somewhere. In the process of flowing, it cools something important and blocking the line makes that important thing associated with detonation hotter than it should be. This may only happen in hot climates, but it did happen to me, and I could trace it to the screw.

I also did a track event with the screw in and did not feel I was making the power I had at the previous event. Straightaway speeds were down 5 mph. It did not dawn on me to pull the screw there.

 

i did this diy today and i finished in about 20 minutes i removed whole airbox. to get bottom radiator hose. pretty easy with some needle nose to get the clamp to slide along with the hose... not to much leakage in the TB .. noticed a big change in the temp while i was driving usually the temp jumps a little espically down here in Bryan Texas . this weeks avg temp is 102.. the response to the throttle is a little bit quicker..... good diy ....

 

Just did this last night, had to take out my MS CAI and throttle body to get to the bottom hose, i guess I got a big hand....
Did not cut the top hose, just reroute it so I can put it back to stock if needed in the future.
Put two 5/16" rubber caps on the throttle body.

So far from what I can noticed after 45min drive to work:
Although the, throttle body is still very hot (due to engine bay heat?), but it did take longer for engine to warm up, and the temperature is lower than usual after warm up.
Smoother acceleration. (not sure about this, might be my illusion....)


Anyway, will keep monitor it in the next few days and see how it goes

Cheers,

 

This mod has worked flawlessly since I did it in the summer of 2005.

Granted where I live never gets as hot as it does in Texas and while the winter is bitch'n cold my car isn't exactly winter driven either.

 

This is a very interesting thread. I was going to do this DIY till I actually though about what the purpose for having coolant flow thru the throttle body.

I am in the military and am pretty experienced with gas turbine engines in larger boats. Since these boats are at sea level, or ground level per se, my two cents worth may explain the thought process of why the Japanese have incorporated a throttle body that is "heated" or "cooled" by coolant.

One of the operating parameters for a gas turbine engine in a large boat that I have been familiar with is when visible humidity (i.e. low clouds, fog, etc.) is present, an "Anti Icing" mechanism is engaged. What this does mechanically is take air that is derived after the combustion section of the gas turbine and divert it to a nose cone. This nose cone then introduces very hot gases (upwards of close to 1000*F) to the intake side of the turbine. This prevents an icing condition at the nose cone, or intake, of the gas turbine. Air is coming in so fast, that it can freeze the humidity to the nose cone. One big chunk of that ice with destroy the gas turbine engine in a split second. Another operating parameter is regardless of visible humidity, this "Anti Icing" mechanism shall be used if the ambient air temp is at, or below, a certain temperature. With the gas turbines that I have worked with in the past, temperatures that were approximately 54*F with visible moisture and 46*F and below regardless is when the "Anti Icing" mechanism was used.

Now pertaining to the RX8. Here is more of my two cents worth. On a cold engine, the coolant flowing thru the throttle body in no way, shape, or form makes the engine warm up faster. So with all this being said, the coolant flowing thru the throttle body does either two things.

One: Prevents an "icing" condition on cold days with or without excess moisture.

Two: Actually cools the throttle body because without it, the ambient running temperature of the engine under load caused a mechanical failure of sorts within the throttle body and the only logical way to cool it was to use the coolant. Personally, I think that the icing one makes more sense out of the two.

Another way to prove that it prevents an "icing" condition is to see what the actual CFM of the engine is. At 9000 rpms, does this introduce so much CFM that it is causing an icing issue?

*Note: Why guess? Does anyone know anyone at Mazda in Japan? Ask them. I am pretty sure that they just dont throw something on a pretty advanced engine without a perfectly good reason.

 

Ok so i did this mod and took some temp readings of the housing itslef just to see what it was at...

This is not to prove it is an awesome mod or to say not to do it...

It was so cheap and easy i did it and took these pics.

After doing the mod i drove for about 25 min. Normal freeway to store and back home. No traffic, no racing... Normal.

These were taken when i got home and snapped 4 min after engine shut off.
The coolant line with the flow still flowing not the screw mod was at 164 deg f.
The housing was at 103 deg f.

So yes the TB warms up anyways from the engine bay, but it is not as hot as before from the coolant in it. I live the Bay Area Ca. So it will never freeze where i am. Was a 75 deg day when i did this.

 

question: Does coolant flow into the bottom of the TB and out the top or vise versa into the top and out the bottom? kthx

 

free bump
Good question.
I would guess from the top

 

Easiest way to tell is by looking at where the hoses connect to the radiator.
Since the upper hose at the thermostat goes to the top of the radiator, that would be the "exit" side of the thermostat since coolant flows down the radiator.

 

Aren't we talking about throttle body tho? not Thermostat? I guess that still applies though ... *left to the garage to look at the hoses*

 

Sorry bud... thats what I get for skimming through your post
The top hose comes from the rear of the engine and the bottom one goes to the thermostat housing.
So the flow should be from top to bottom through the TB.

 

Ok ... cool thanks ... I couldn't figure it out without taking the UIM off

 

I recently did this along with a few other things (VFAD removal, spark plug and ignition coil replacement). Because more people seemed to agree that a 5/16" barbed connector fit better I bought one that size. I put it in the hose and double clamped both ends, very tightly I might add.

After finishing everything else I was doing I took the 8 for a test drive. I took it around the block and upon returning I noticed smoke/steam coming from the headlight area. After poppin' the hood I notice a nice steady stream of pretty green coolant sprouting from my the bypass.

Unfortunately I had routed the tubes under the throttle body, which meant I had to remove it again... I ended up borrowing my girlfriend's car and driving up to Autozone for some new coolant and a 3/8" connector. Because so much coolant had leaked I went ahead and flushed the system and replaced it all (a little too much but oh well...it should be okay). I undid the previous bypass and did it again with the 3/8" to the side of the throttle body so I could access it again without removing the throttle body.

I believe that many people said to go with the 5/16" because you could get the two ends of the hose to touch. However, it was a little too small and allowed for space between the connector and the hose. The 3/8" has to really be wedged in the hose, and makes it impossible to connect the two ends, but it provides a tight fit that won't leak. It also has a larger diameter center so it is less restricting on coolant flow.

Sorry this was long...but I thought ya'll might want to be aware of this before anyone else attempts it. Good luck! This mod definitely lowers throttle body temp!

 

Mod edit: Non-contributing

 

I did this today, but I used the long hose and placed it on the back port that the second one came from....It was a hell of place to get since the clamp was turned in a way i almost couldn't get it. This mod cost me nothing but time and a few busted knuckles.

One less hose. 1/1000th of a pound lol
Its one hose to clutter the engine bay though

 

Mod edit: Non contributing

 

can't I block the coolant feed on the top of the throttle body with a wooden dowl and a screw clamp ?, all that would do is stop the flow of coolant right?. I don't think that loop through the throttle body is critical to any cooling of the motor or?. Blocking the flow off seems a little easer than removing the throttle body.. Any feed back on this approach?. Thx guys.

 

LOL go for it
Rensis doesn't already suffer already form poor static flow points.

How could that possible make it worse?

It's already a highly critized mod .. if you're even going to go more ghetto then why even bother?
Just leave it alone.

 

Leave him alone wcs. He has wood and wants to use it.

 

nice contribution guys

 

We all have wood and want to use it right. I was actually being serious really. It's not getto at all, you can't see it. The point was ., will it harm any thing if I stop the flow to the throttle body. I'm new here but I think I get the crowd here. Yournot really serious are you guys?. It was a question and didn't think it garnered sacrcasim. If it's a dumb question then my bad. Perhaps this isn't a good sight for asking questions. I wont ask any more then. I will find another sight where I can get real answers. I was trying to get away from removing the throttle body that's all and your smart *** kids answer didn't help. I'm still not sure if I can stop the flow???. I will try another forum and ask. If i'm told there is already a forum( You guys) then I will tell them that getting information is difficult unless you belong to their click and I apparently do not. If I can't get a straight up aswer then I won't ask any more. Thanks for the welcome to rx8 club. sounds like this should be called rx8 click not club. My first impression is a bad one I will pass along to others. Thanks for the grown up smart *** answer(.

 

I personally wouldn't block it. If you are going to bypass it, then just bypass it. No need to make the implementation more complex, nor do you want to negatively affect the flow pattern of the current system.

To be honest removing the TB isn't difficult at all ... it is just four bolts.

 

Hello i'm new here and wanted to ask a question and I want to say I would really like to know if I can stop the flow to the throttle body by mearly inserting a wooden dowel into the feed like into the throttle body and hook it back up?. Just trying to avoid the throttle body removal that's all. I tried this question and was made fun , so I hope I am on the rigt sight for this as my last attempt at asking was met with juvenile childish remarks ment to belittle so that the people hurling smart *** remarks could some how look good??(.

I have had my 8 for 4 years. It's a series one 4 speed atomatic with 78,000 miles. I change my oil every 2500 mles. Just installed new coil pacs /new plugs/new plug wires. I thought a person could ask a question and not be judged, but my last experience here was really bad as a first impression, I don't get it, unless I just happen to run up on te children of this group who usurp the only status the can get by ridiculing others?, who knows. So my question still is .can I block off the coolant flow to the throttle body or not?. Just a question guys just a question.

 

@Paimon.soror: Thank you for your answer. I will revisit the throttle body today. I have built a mock up for my intake ad it works so well at freeway speeds, then I saw the throttle body (this) forum and decided to ask the question. It seems you are the only adult in the house. What happend's to the kids here when you leave?.

Im new here but with the reception I got with my question, I really think its best to go some where else where the people are really enthusiasts and ADULT about things. You must admit , it wasn't a good ffirst impression or a very nice welcome to the site. I hate clicks because they are nothing more than idiots trying to garner political capital and show off how cleaver the are for there friends here,, very nasty welcome I think. But I do thank you for your honest input. I am going to search for another site I think . Too bad , this site has a lot of good people on it but it only takes a few *** holes like the answers above to chase away people.

Again thank you for your answer sir. This forum has proven the point "we are not as dumb alone as we are together". lol UGG!.