cooling re-route for Cold Sides

[MS2KSE]

I've been reading all the posts about everything and now can't remember where I read something about someone offering a "simple" :confused: cooling re-route for FFS Cold Siders ?

[99mx5]

It was Gearhead's Garage that was making the Q-Max cooling reroute and was going to make a version for the FFS coldside.

[Tink]

Yeah, and their web site still says a release by Feb of 2008!

[pat conlon]

FYI, Emillo at 949 Racing is also working on a reroute kit. No ETA yet.
You may want to send him a e-mail. Pat

[Race Grandpa I]

I would appreciate someone explaining what the cooling re-route is and what equipment it requires.

I thought the Coldside's cooling mechanism is from the
5th injector, which in my simple mind could not be re-routed.

:stuart:

[99mx5]

This cooling reroute is for the engine cooling system. The coolant goes from the radiator to the front of the engine and exits at the front of the engine. The premise is that the rear of the engine does not get sufficient cooling as the front of the engine. The reroute changes the flow of the coolant from exiting the front to the rear so that the coolant flows from bottom to top and from front to back.

The miata engine is shared across mazda car models. Originally the engine was designed in a transverse orientation in front wheel drive cars, such as the 323/Protege and others where the coolant flows from front to back. When the engine was used in the miata, mazda engineers changed the coolant to exit the front of the engine. The reroute changes the flow according to the original design. In daily driving, the factory system works just fine, but when using FI and racing, cooling can be a problem.

Hope this helps.

[Race Grandpa I]

Thanks. Any guess to how much it reduces the heat. And is this really needed when one has a KOYO or PWR radiator.

I certainly do not need it here in the NW.


:scooter:


This cooling reroute is for the engine cooling system. The coolant goes from the radiator to the front of the engine and exits at the front of the engine. The premise is that the rear of the engine does not get sufficient cooling as the front of the engine. The reroute changes the flow of the coolant from exiting the front to the rear so that the coolant flows from bottom to top and from front to back.

The miata engine is shared across mazda car models. Originally the engine was designed in a transverse orientation in front wheel drive cars, such as the 323/Protege and others where the coolant flows from front to back. When the engine was used in the miata, mazda engineers changed the coolant to exit the front of the engine. The reroute changes the flow according to the original design. In daily driving, the factory system works just fine, but when using FI and racing, cooling can be a problem.

Hope this helps.

[bogey]

The idea of the reroute is to even out the engine temps front to back. The back of the engine only gets the small amount of flow that is run through the heater core.

A bigger radiator will not even out the cooliing, it just increases the thermal capacity due to higher volume of coolant, and higher surface area of the radiator. The "cooler" coolant will still only flow as much as the thermostat permits.

[Race Grandpa I]

Thanks. I should have read MX-5's reply closer.


Another question. Can the need for a coolant reroute be gauged by the water temp or oil temp? Or are the water temp and oil temp senders in a location that do not detect the problem?

Thanks,

SC Student

:stuart:


The idea of the reroute is to even out the engine temps front to back. The back of the engine only gets the small amount of flow that is run through the heater core.

A bigger radiator will not even out the cooliing, it just increases the thermal capacity due to higher volume of coolant, and higher surface area of the radiator. The "cooler" coolant will still only flow as much as the thermostat permits.

[bogey]

The stock temp gauge on a Miata is not linear enough to show a problem. The "normal position" of the needle covers a wide temperature range. I have an oil temp gauge that I watch, and it will move up and down depending on load (slowly), while the water temp gauge stays still. When the stock temp gauge starts heading past halfway, the engine is already too hot.

There are two thermal sensors on the car, one on the thermostat housing and one on the back of he engine. (One for the gauge and one for the ECU.) I'm not sure, but I believe the thermostat one goes to the gauge. This sender is not located at the hottest spot, so it is not a good indicator of the engine temp, just the coolant temp.

I would not worry too much about it, as thousands of forced induction cars run fine with stock cooling configuration. However, if you are on the track, you need every advantage you can get to minimize the stress on the engine.

[Tom @ Fast Forward]

Without doing some research, I'm not sure I can speak for the pre-99 models but the 99+ has 1 temperature sensor that I can find and it is in the water at the rear of the engine. It is what the computer reads and also what runs the gauge. The gauge, however, has an electronic clamp (zener diode?) that limits it from moving higher anywhere in the range from about 190 to about 230. Like Bogey said, when you see it start to move it is probably too late. However, if you get a scan gauge or equivalent and monitor it, you will know the real temperature of the water at the rear of the engine and, yes, a larger radiator will help to keep it cooler as all of the water passes through the radiator.

There is some controversey about the need for the cooling re-route. From day one, the Miata was designed for the track. The boys at Mazda went out of their way to make sure we had plenty of fun. That is why there are so many SPEC racers out there beating up old Miatas. Personally, I can hardly believe that they would make such a blatent error as to cool the front two cylinders and let the rear two fend, more or less, for themselves.

Not completely sure about the earlier Miatas but almost sure the sensor is at the rear and it runs the ECU, idiot light and gauge. Maybe some pre-99 owners would post a picture of their front water temperature sensor in/at the thermostat and get me the wire colors?

[bogey]

Tom, I think you are right.

On my 96, there is a "coolant temperature sensor/top of engine" on a blue/white that goes to the ECU and the 2L connection of the instrument panel which is connected to the temp gauge. I think this wire at the rear engine connection.

There is another "temperature sensor/front of engine" on the thermostat housing that controls the cooling fan.

[Tom @ Fast Forward]

Hm, the fans are controlled by the ECU. I would think they would want them coming on from the hotest water as well?

Can't say one way or the other but the 99+ has one sensor to the best of my knowledge and it's at the rear.

[lds2002black]

Our 90 SM had a separate switch for the fans on the front housing. I haven't looked at my '02 so don't know.

[tann3r]

I'm not sure how important a re-route would be even on a track car. I've run my 99 in the Texas summers and have never had a problem. High 90*s and 30% humidity and the highest coolant temp i recorded was 208*F. That was at Texas World Speedway, a pretty high speed track, I bounce of the limiter in 5th at the end of the front straight. Maybe a lower speed track may pose a problem, since you're not getting as much air through the radiator.

My only changes to the cooling system are a 53mm Koyo and a 180* thermostat. Still have the stock undertrey and shrouded stock fans (sealed w/ fuel lines thanks whoever posted that tip Ari/Tom?).

[Race Grandpa I]

Thanks. I alos got an oil temp gauge because of this problem. I went on Mnet to see what they think the maximum oil temp can be before they pull it off the track. There did not seem to be a concensus. What do you think the maximum oil temp is before one gets in the danger zone?

A Spec Miata shop told me that these cars do not have an oil temp gauge.

should before theyThe stock temp gauge on a Miata is not linear enough to show a problem. The "normal position" of the needle covers a wide temperature range. I have an oil temp gauge that I watch, and it will move up and down depending on load (slowly), while the water temp gauge stays still. When the stock temp gauge starts heading past halfway, the engine is already too hot.

There are two thermal sensors on the car, one on the thermostat housing and one on the back of he engine. (One for the gauge and one for the ECU.) I'm not sure, but I believe the thermostat one goes to the gauge. This sender is not located at the hottest spot, so it is not a good indicator of the engine temp, just the coolant temp.

I would not worry too much about it, as thousands of forced induction cars run fine with stock cooling configuration. However, if you are on the track, you need every advantage you can get to minimize the stress on the engine.

[bogey]

I think max oil temp is a function of the oil you are using. A good synthetic can get a lot hotter (350-400) than a dino oil (230-260?) without breaking down. However, I prefer to keep my synthetic oil temps below 230 degrees. I run about 210-220 if I push it hard for a extended period.

[Tom @ Fast Forward]

Oil coolers are your friend if you are going to track the car. Remember, the engine is not just water cooled. It is oil cooled (60%?) and the remainder is water cooled with a little air cooling. When you see those big engines with lots more oil in the sump, that is to add more cooling by turning the oil over slower, not because they have that much more lubrication.

[Race Grandpa I]

210 to 220 :sweatdrop:

Due to various ugly circumstances I have not been on the track for more than 5 laps over the last 2 years. So I do not know what to expect on the track.

However, last summer I was pushing the car somewhat on the county roads for a very limited amount of time and the oil temp got up to 205 from a normal 180. This was on a day where the temp was somewhere between 80 and 90 degrees. I use 100% synthetic oil. I also had a new KOYO 36m rad at the time. (Which I later sold along with lots of other things to pay for the 2nd engine.)

Getting up to 205 off the track could indicate that being on the track for 20 minutes that the oil temp could easily get up to 250. :eek:


At the present time I am weighing getting a used small KOYO rad or go the less expensive route of using distilled water, water wetter and high pressure rad cap.


I am real low on $$$ and need to figure out what to do before summer. The only thing good about the situation is that our summers are real cool and getting over 90 degrees is real rare. But last summer I was schduled to go to Portland for a class last summer when the temp got up to 100. (Never made it, but paid for it. :mad:)




If as Tom says the oil cooler is responsible for 60% of the cooling, I would be better off with an oil cooler and go the less costly way on the water cooling options.


Any thoughts?????????????????????????????

:stuart:


PS: Tom I will be on the Dyno the last week of January. Need to accumulate some $$$ to pay for this the 3rd time on the Dyno since I got the new engine.



I think max oil temp is a function of the oil you are using. A good synthetic can get a lot hotter (350-400) than a dino oil (230-260?) without breaking down. However, I prefer to keep my synthetic oil temps below 230 degrees. I run about 210-220 if I push it hard for a extended period.

[bogey]

I think you are worrying WAAAAAAYYYYY too much. Not sure you can even drive more than a few miles and maintain that low of a temp.

Normal oil temps should be higher than boiling water. No load temps of 180-190 are normal, but under load, oil temps should increase to at least 210-220. "Normal" operating temps for most oils is about 225.

On the track, it would not be unusual to see 230-240, even 260 in the pan. These higher temps for extended periods call for a synthetic to keep viscosity breakdown to a minimum.

Oil at the compression rings is exposed to temps in excess of 320 degrees. Coolant can hit 240+ degrees. You can't keep the oil temps lower than everything else.

It sounds like your cooling capacity for the car is more than sufficient. Add an oil cooler if you oil starts exceeding 240 on the track.

[FormerDatsun510Man]

Like the others said... oil cooler. However, I doubt you will even need that. I ran my Hotside which had a nice big FMIC blocking most of radiator at many track days and never had a problem. I didn't put an oil cooler on it for years. I just made sure I ran synthetic oil. With the Coldside you have the advantage of nothing blocking the radiator, so I would be really surprised if you have any issue with this on the track. The oil cooler I did wasn't cheap though... it ended up around $350 and I put it together myself using big steel braided lines, a sandwich plate with a thermostat in it for 180 deg, ANR fittings, etc. I still have it on my car even though it is NA now. I figure it wouldn't hurt since I am cheap now and use regular Castrol GTX dino oil and still like to go to track days even though it lacks top end for sure now LOL.

Bill

[Race Grandpa I]

Thanks for all of the info.

Do any of you use water wetter and distilled water?

Redline says that it's Water Wetter can reduce the temps by 30%.

That sounds way to high.

[bogey]

I always use distilled water in radiators. You should not use tap water as it has minerals that can gum up the works.

Usually a mix of 30-40% coolant with distilled water on my "summer cars". Water wetter is a good product, but many have said a drop is dish soap does the same thing.

[Steve in VC]

Thanks for all of the info.

Do any of you use water wetter and distilled water?

Redline says that it's Water Wetter can reduce the temps by 30%.

That sounds way to high.
I don't know about 30%, but the idea of water wetter is twofold, better contact
(wetting), and higher percentage of water, water has higher specific heat than anti-freeze.

Use the highest percentage of water possible, consistent with the need for antifreeze and corrosion prevention.

[maggie]

When I was shopping radators I inquired about water wetter. I don't remember if it was TDR or Goodwin that told me they tested cooling with and without it and found about 3 degree difference in temp. The reccomendation was the PWR radiatior for optimum cooling and as much water (distilled) as I could get away with in my region. Since it never freezes here I went with 70/30. I am really happy with the PWR and the install was about an hour. That included trimming the fan shroud and gently prying an A/C line back and enlarging one hole on the steel fan shroud. Note: :no: Do not reuse the factory hose clamps. Screwtype for a leakproof install.

[Gord96BRG]

Greetings, gents, and Happy New Year! I haven't checked in here for almost a month... it's nice to stop in here again. :cheers2:

I installed an oil temperature gauge in my FFS Coldside Miata last fall - I used the Moss Motors oil filter sandwich mount to locate the oil temperature sender at the oil filter. I don't know how oil temps taken at the pan compare to oil temps taken at the filter, but...

Oil temp at moderate cruising speed (~60 mph) - 205F
Oil temp at fast cruising speed, some boost (~80 - 90 mph) - 245 - 250F!
Oil temp after repeated acceleration runs in boost (while tuning and datalogging) - 260F !! :surrender:

Am I desperately worried? No. Am I somewhat considering adding an oil cooler? Yes.

I have always run synthetic oil, and in fact running an oil temp of 260F is not a big deal for a good synthetic (I use the German Castrol Syntec 0W30 - it's made by magical elves in the Black Forest, according to the gurus on the BobIsTheOilGuy forums! ;) ). I was more surprised to see 245 - 250 at fast cruising speeds, as my coolant temperatures never budged above 92C (sorry for the mixed units!). I don't know if perhaps the front end of the Italia kit results in less airflow through the engine compartment at faster speeds...

[Mark]

When I did my SC install, I installed an oil cooler and the same filter sandwich at the same time so that I could also use an oil temperature sensor. The filter is relocated inside the passenger side wheel well. Does it work? Heck yeah it does. I've NEVER seen my oil temp go over 205, including while running autocrosses at or above 85. In fact, the oil cooler works too good. One of my biggest joys is taking the Miata out for a spirited drive around this time of year when we get that odd 40 degree day. Top down with the heater blasting. Well I can't get any heat out of her now. On a fall 70 degree evening, I can't get the oil temp above 170!

So if anyone is looking at adding an oil cooler, I'd seriously look at getting the thermostat too. It wont let oil flow into the cooler until it hits 180 degrees. I myself am looking at adding that this spring when we thaw out a bit...

[BlownMX5]

So if anyone is looking at adding an oil cooler, I'd seriously look at getting the thermostat too. It wont let oil flow into the cooler until it hits 180 degrees. I myself am looking at adding that this spring when we thaw out a bit...

Couldn't you just cover the heat exchanger with something when you have trouble getting it up to temp?

[Mark]

That's an option. But I myself would rather have something in place that I don't have to worry about. We can frequently have 30-40 degree temperature swings during a day which would require always making sure I have it covered or uncovered.... Call me lazy :)

[lds2002black]

This is information from my FSS 2002 Coldside from a track day at Carolina Motorsports Park run in May 2008. At the beginning of the track session the oil temp was 170º. At the 5:00 minute mark into the session the oil temp was 266º with a water temp of 200.9º. At the 20:00 minute mark into the session the oil temp was 279º with a water temp of 204.8º. I run a 37mm Koyo radiator that has been sealed to the front of the car. The factory water-oil cooler (under the oil filter plate) is used. The oil temp was taken at the base of the Thompson oil filter relocation plate. Oil pressure (also measured at the Thompson plate) at the 20 minute mark was 66.0 psi @ 6190rpm. I typically see 225-230º oil temps and 192-195º water temp in normal spirited hiway driving. I do run synthetic oil in the engine.

As a point of reference the 1989 5.0 Mustang track car we have runs in the 240º oil temp range but has an oil cooler installed in front of the radiator (this radiator is also sealed to the nose of the car).