Turbo cooling...disconnect TB lines?

cjthor · Post by **cjthor** » June 19th, 2006, 1:56 am

Ive heard that this is ok to do. Its moreso for cold weather right? I was thinking of just taking the hoses that go there off and just have those hoses go directly to my turbo. The hoses are currently T'd into the TB hoses but id rather have the bulk of the coolant go to the turbo.....I was thinking that or... getting a seperate water pump and getting a small radiator for water and have a cooling system for only the turbo and TB... This way the air intake charge would be very cool. Any thoughts??

XxantwawnxX · Post by **XxantwawnxX** » June 19th, 2006, 6:40 am

Just route it to the TB to the turbo from the turbo to the TB...or to the TB from the TB to the turbo back to the the block. Thats howed i do it..then u could have both.

ryanlindenberg · Post by **ryanlindenberg** » June 19th, 2006, 11:51 am

i'd run it this way

BLOCK -> TB -> TURBO ->BLOCK

the lines on the TB just adjust the IACV to let a different amount of air by. i don't think the coolant temp would increase at all if you passed it through the TB so it would still be cool when it gets to the turbo. if you send the coolant to the turbo first, it will get hot and then it could effect the IACV.

cjthor · Post by **cjthor** » June 19th, 2006, 12:41 pm

Here is another prob. Garrett says they reccomend 3/8 inch coolant lines. The lines on the TB are 5/16 and are shared with the TB. Id hate to not have enough volume of water to cool this thing! I found an aux water pump off a late 80's BMW 7 series. Gonna see if I can mock something up tonite....

jschrauwen · Post by **jschrauwen** » June 19th, 2006, 7:14 pm

ryanlindenberg wrote:i'd run it this way
BLOCK -> TB -> TURBO ->BLOCK
the lines on the TB just adjust the IACV to let a different amount of air by. i don't think the coolant temp would increase at all if you passed it through the TB so it would still be cool when it gets to the turbo. if you send the coolant to the turbo first, it will get hot and then it could effect the IACV.

Agreed, but to a point. The coolant I believe is already at it's warmest point before going to the TB. That's the whole purpose of the ISC valve in the first place. The coolant leaving the block at it's warmest temp then entering the TB from the rear, exiting out the front then entering the union just before the thermostat. Another alternative may be to tap into the radiator's side large hose fitting of the thermostat. There may be enough metal there to easily drill and tap for a fitting to allow a 5/8" line. There will or should be adequate pressure at that point too in comparison to the TB lines. I thought turbo's were oil cooled/lubricated. FWIW.

cjthor · Post by **cjthor** » June 19th, 2006, 7:40 pm

jschrauwen wrote:
ryanlindenberg wrote:i'd run it this way
BLOCK -> TB -> TURBO ->BLOCK
the lines on the TB just adjust the IACV to let a different amount of air by. i don't think the coolant temp would increase at all if you passed it through the TB so it would still be cool when it gets to the turbo. if you send the coolant to the turbo first, it will get hot and then it could effect the IACV.
Agreed, but to a point. The coolant I believe is already at it's warmest point before going to the TB. That's the whole purpose of the ISC valve in the first place. The coolant leaving the block at it's warmest temp then entering the TB from the rear, exiting out the front then entering the union just before the thermostat. Another alternative may be to tap into the radiator's side large hose fitting of the thermostat. There may be enough metal there to easily drill and tap for a fitting to allow a 5/8" line. There will or should be adequate pressure at that point too in comparison to the TB lines. I thought turbo's were oil cooled/lubricated. FWIW.

Garrett's line of ball bearing turbos are also water cooled. I am looking at a small two pass transmission cooler and a small resevoir to have a seperate cooling system. This is probably the way I am going. Getting any water from the TB hoses is definitely going to be hot.

JWMotorsports · Post by **JWMotorsports** » June 19th, 2006, 10:26 pm

Look on the front side of your block below the feeze plugs just to the left of the transmission (cyl #4). There are two plugs there, the one closest to the trans is a oil feed port from a main galley and the one to the left of that is a water feed line with fresh coolant. Use those two ports to feed the turbo. You can return your turbo's used coolant back into the water bypass pipe. If you like we could make you a custom water return block that bolts to the tranny upper mount and completely replaces the OEM steel bypass pipe that runs from the heater core outlet to the water pump inlet. It uses a -10AN SS Braided hose and can be tapped for any fittings you wish. I utilized -6AN fittings w/ -6AN lines on my turbo for water. Used a M10x1.5 to -4AN adapter in the block w/ -4AN hose to feed oil to the turbo and a -10AN hose to return oil to the pan. I also recommend bypassing the throttle body with the stock coolant lines. Remove them from the TB and use a male to male hose barb to connect the lines together. Another good mod is to swap out your thermostat to a 180*F unit and use Red Line Water Wetter. You really don't wanna go much cooler than that or you will not get complete combustion. The other highly recommended thing is to add a inline filter to your turbo's oil feed line, don't forget to inspect it regularly or add a oil pressure gauge between the filter and turbo oil feed inlet so you can see the pressure drop if the filter starts getting clogged. The filter I used is a metal mesh inline oil filter by Earl's.

cjthor · Post by **cjthor** » June 20th, 2006, 1:18 pm

JWMotorsports wrote: I also recommend bypassing the throttle body with the stock coolant lines. Remove them from the TB and use a male to male hose barb to connect the lines together.

This affects the car how? Before I delete the coolant there I would like some pro's and con's

JWMotorsports · Post by **JWMotorsports** » June 20th, 2006, 10:04 pm

By disconnecting them and bypassing the throttle body you are removing heat from the throttle body which will allow cooler intake temperatures. By leaving it connected to the throttle body it will heat the throttle body and the air passing through it into your engine, rasing cylinder temps. The only time it is needed is if your throttle is iced up....if you ask me, your screwed any way if its iced. Another thing you can do to your intake manifold is have the head flange and runners ceramic coated which will minimize heat transfer from the head to the intake manifold which would help keep the intake air as cold as possible going into the intake ports. You can also ceramic coat the head's ports and combustion chambers keeping the heat only where it is supposed to be and maximizing turbine efficiency. All of those mods also help increase the detination threashold allowing you to either run more boost, timing, combination of both or leaning out the air fuel mix. It also raises the volumetric efficency of the engine.

jschrauwen · Post by **jschrauwen** » June 21st, 2006, 6:37 am

cjthor wrote:
JWMotorsports wrote: I also recommend bypassing the throttle body with the stock coolant lines. Remove them from the TB and use a male to male hose barb to connect the lines together.
This affects the car how? Before I delete the coolant there I would like some pro's and con's

I dissagree completely. I don't believe the knowledgeable engineers at Mazda would create anything detrimental to the cars operation. It's not an emissions issue either. It's the only mechanisim available to have a cold engine's idle stepped up until it reaches NORMAL operating temperatures. I really can't see the air passing through the TB at those velocities to get warmed to any substantial point to have any negative affect on performance. If the concern is to have cooler air enter the system prior to detonation than a more realistic CAI or ram air type of intake should be considered. I don't know how many members I've seen opt to replace their factory intake box/tract/system for a cone filter that sits somewhere behind the radiator in an already warm engine bay sucking in even warmer air that has just passed through the radiator rather than using the oem intake that runs to an inlet to the front of the car that is in realistic term a CAI already. The TB will not get any hotter than the operating temps of the coolant. Water Wetter is a good alternative and I've used it myself. You want the engine to naturally do it's high idle routine on cold engine starts. Not only does it get the engine up to operating temps quicker, it also ensures that the engine is getting a richer than average mixture which protects the engine on cold starts and, it also ensures at that higher rpm that oil is getting pumped to critical areas which is oh so necessary when the engine is cold. The smallest of gains achieved does not outweigh the benefits gained IMO. Not really worth it. If one wants to achieve cooler intake air temps, create a good CAI that will always draw in cool air from outside of the engine bay.

JWMotorsports · Post by **JWMotorsports** » June 21st, 2006, 4:42 pm

Ok, the ECU is responsible for responsable for controlling idle and cold start. Thats why it monitors both air temperatures and coolant temperatures. The ECU's data tables have corresponding maps and matrixs that are overlayed to calculate the engine timing, injector pulse width in milliseconds and duty cycle (percentage of orfice lift, or opening over "x" amount of pulse width time). The coolant feed to the throttle body is only there to keep it from icing up...aka freezing closed at extremely low temperatures w/ high humidities (Northern Canadians may see it). That condition is prevented by the antifreeze mix sitting there when the car is off and stone cold (ie.. sitting over night or longer). Ideally the TB should be by passed when the car is running but it is a bit more expensive to manufacture a car that way (I'm an Industrial Design Engineer, I know how these guys work). Think of it this way as well, where is your TB in referance to the hottest point on the intake manifold? It is above it in the mass majority of cases and the hottest point is where it is bolted to the head. Heat rises and most manifolds are aluminum, which rapidly disipates heat. As heat rises to a cooler point it can be disipated faster unless additional heat is added (ie...the TB coolant lines). Then it slows heat disipation and makes the manifold hold more heat. As you introduce coolder air instead of fixing the problem at it's origin (TB coolant connections and head flange mostly) then the colder air going to your intake ports will absorb the heat from the aluminum. The coolant being passed through that TB is a constant 190*F or even higher on stock cooling systems, for the most part. Thats a LOT of heat being introduced, especially at idle or low speeds where air can not circulate well enough. The heat IS going to heat the intake air more than the surrounding air outside the Intake Manifold. Why? Because the air out side is less dense than the internal cooler air which interns of Thermodynamics convects a higher percentage of the heat from the Intake Manifold into the intake air.

You are absolutely right about CAIs...even on turbo cars they help a LOT. Removing the coolant lines from the TB is one of the oldest and cheapest tricks in the book! I've had mine disconnected since at least 2000 and have never had any problems on any of my cars. Tons of people I know do it to both domestics and imports and I've never heard of anyone ever having any problems. Of coarse look at my temprate zone and our lowest static temperature we ever see is maybe around 0*F and frequently 10-15*F for a low static temp in the winter months (static temp being no wind chill factor). Canadians could possibly encounter a rare freeze occurance, but if you do chances are your coolant will be frozen like a rock as well so it would be the least of your worries.

Summary:

TB w/ no coolant:
-will not hurt the car (unless your expecting it to start at -40*F or colder)
-will not add much power with out extinsive tuning but will in both cases give a larger saftey margin from detination occuring due to lower intake air temps and less heat soak. Also raises the convection cooling efficiency of the intake manifold.
-will not effect engine warm up or idle stability as the ECU controls all those events via air temp and coolant temp sensors. Remember, if your engine is cold, so is the coolant and vise versa so it will not help cold start at all. By the time your coolant is warm enough to make a differance the engine has left cold start and has been running closed loop or is right at entering closed loop (depends on ECU's closed loop idle coolent temp requirements).

TB w/ coolant:
-keeps TB heated and will increase the static temp of the intake manifold and intake air passing through it to the combustion chamber
-keeps the TB from freezing closed at REDICULOSE temps while car is not running

jschrauwen · Post by **jschrauwen** » June 21st, 2006, 6:25 pm

JWMotorsports, I must say I agree with a majority of your convincing statements, save one. The ISC controls the cold engine high idle kick-down. The cooolant thermosensors and the air temp sensor in the VAF will only adjust that kickdown (higher or lower) but not engage it. They have other functions as well that deal with idle and fuel mixtures along with O2 info. Take any cold engine that has a fully functional ISC that is connected. Start that engine and watch the idle reach approximately 1200 to 1400 rpm given an outside temp of approximately 60F. Now quickly unlug the 2 wire connector at the bottom of the Tb and repaet same the engine start. Engine idle will be approximately 600 to 700rpm +/-. Now the latter may be an OK configuration given that that MX resides in a temperate region and I'll agree that it would be a viable option in the more Sourthern States. I'm not aware of cjthor's winter temps in Portland. If the weather there is anything like it was for me living on Vancouver Is., than I would not consider it a viable option. Not only would it be subject to icing in the winter, but initial starts would be a real bugger. Been there and have done that. Over 11 years of ownership and putting over 200,000kms on my MX has taught me that. But like I said, if I were a Floridian, I'd do it in a heartbeat.

JWMotorsports · Post by **JWMotorsports** » June 21st, 2006, 7:36 pm

If you unplug the two wire connector then you just unpluged your Idle Air Control Valve and that is why it is idling lower. The IAC is what bumps the idle up, not only for cold starts, but controls the normal idle and holds it there by bypassing air around the throttle plate into the intake manifold plenum in metered amounts and the ECU will add additional amounts of fuel because it can calculate the amount of air being bypassed. It is done usually with a stepper motor or a solinoid valve that pulses on an ECU controlled duty cycle. The ECU runs in open loop on cold start and warm up so it ignores the AFRs until it finishes the after start and warm up tables. The cold start is triggered by the coolant temp being below "x" set real time coolant temp reading and is run for a measured time frame in rpms (maybe a couple hundred and thats it for starting), usually. Next it enters after start for a predefined time frame usually in seconds (just after the engine is turning more than around 500rpms). Then the warm up tables are used until "x" coolant temp is reached. Last they usually bring the ECU to run in closed loop with the base tables and IAC functioning still the same until "x" rpm is reached, then it will stop pulsing the IAC as the engine is spinning fast enough to have a strong normalized vac. pressure and can idle freely without having to bypass the throttle plate (air velocity is high enough to pump the volume needed through the throttle plate gap alone). That is why you can bypass the coolant from the throttle body with no idle problems. You can actually take the IAC off as well but then you have to set your base line idle speed to usually at least 1200rpm to sustain a stable idle (VE is low under those speeds with poor fuel atomization due to the small air gap on a throttle plate alone;ie no IAC). I have been playing with aftermarket performance and studing various methologies and techniques for over 8years. Learned to build engines from a Pro Stock record holder (he ran a 1120HP Naturally Aspirated 454 and held several track records in the 80's). I went to school originally to be a Network Administrator and electronics is something I have a nack in as well. I've been playing with various Engine Management systems for a good while now and had a B6T making 400WHP to the ground with a STOCK bottom end daily driving it for OVER 10,000miles before a rod finally gave out from fatigue (snaped in half just below the wrist pin). The spark plugs had over 3000 miles of abuse on them and the ceramic insulator was still nice and white! I know how EMS systems work, know them very well and can tune very well also. My motor gave out from shear fatigue and I honestly expected to have WAY before it did! I was running the small B6 rods, not even the GTX or GTR rods at that!

P.S.

please don't take my replies offensively as they are not intened to be. There is a LOT of technical data to be input and I'm trying to keep it as short as possible and honestly skip a lot of burried data that most people never need to know unless they are like you or myself and can't let go of issues with out indepth explinations that lead to a "self visual" explination...thats a good thing, most of the time.

cjthor · Post by **cjthor** » June 21st, 2006, 8:14 pm

My car does not really see winter. I park if from roughly November to April.

jschrauwen · Post by **jschrauwen** » June 21st, 2006, 10:00 pm

JWMotorsports wrote: P.S.
please don't take my replies offensively as they are not intened to be. There is a LOT of technical data to be input and I'm trying to keep it as short as possible and honestly skip a lot of burried data that most people never need to know unless they are like you or myself and can't let go of issues with out indepth explinations that lead to a "self visual" explination...thats a good thing, most of the time.

Hey, no worries JW, I enjoy the banter actually. I learn something in the process, and that's a good thing. I believe we are calling the same item by 2 different names. Reason being is that the older original shop manuals ( I have both the large binder type factory one and the over the counter 5 3/4" x 8 1/4" Mazda shop manuals. What I call the ISC is what is called the IAC in newer manuals and the online shop manual. So you're saying that the round cylinder at the bottom of the TB is the IAC, which measures the amount of bypass air based on the setting of the idle air screw ... right? Then why is that same cylinder immersed in coolant? I like your theory though, since if the ecu wants to know what the coolant temp is , all it has to do is get it from one of the 2 coolant thermosensors.