, Don't call me radio unit 91.

Would it be worth it to replace all of the Hoses? I was looking at the Samco 6 Piece Kit. Is there really a major increase in cooling by throwing those on as well?

 

If you can "somehow" get the Mazsport fan mod then that would be the best choice.

I'd then recommend the RE-medy water pump and thermostat.

Don't bother with the radiator, especially the Koyos.

 

what's the use of the cooling fan if he already has an accessport?
anyway that device can be built for like 50-60$ at home

 

what exactly does the aftermarket water pump do to help with cooling? does it just circulate faster or something?

 

RX8 RE-medy Hi Flow Water Pump

Its my understanding that it works better, pushes out more coolant, and keeps the coolant pressure up even at high rpms. If coolant pressure drops to low, you'll get a bubble in your coolant system which will impead/stop flow. Am I correct?

 

from what I understand, at high RPMs, (7000 to 9000), the pump begins to cavitate. Rather than actually pumping the coolant, it churns it around inside the pump itself. This is due to the poor impeller design on the OE pump. You can see the difference in the pics on the Remedy thread.

 

WAit wait wait....what is everyone talking about?

You're worried about long ROAD TRIPS? on the HIGHWAY? At normalish RPMs?

You don't need any modifications to the car unless MAYBE if you're planning on being in a lot of stop and go traffic in EXTRMELY hot weather. Like traffic jam in texas in august at high noon kind of conditions. Or if you're running on constantly high RPM's like in a racing scenario, but you said you're worried about highway driving.

I'm so confused....this is a MODERN CAR, people...in stock form it's well-equipped for driving on the highway, even with a LOT of high-RPM sprints or "fun" thrown in the mix as well.

Also - if you have the accessport already, that does the same thing as the "cooling fan mod". The Koyo radiator has been shown by a number of people to offer no cooling benefit over the OEM radiator. New/different/aftermarket radiator hoses....will not change anything except look nicer. Again all of these things only pertain to high-termperature scenarios, which driving on the highway should not include.

Just....wow.

 

^ +1

If you want to keep it more within this thermostat range you can use the AP maps to turn the fans on earlier, or bump the speed up earlier. The fans come on when the A/C is running anyway. If you have the AP maps, dual oil coolers, and you are just doing daily driving there is absolutely no need for any cooling modifications. None. When do the factory Rx-8 fans come on at something like 98 C or about 210 F. They could come on earlier, but even then that's not that bad. A lot of subaru's have their factory fans come on at 203 for low speed and 210 for high speed, just to put things in perspective.

Let's review some rotary facts here. The factory Renesis thermostat cracks open at 82 C, right around 180 F. The thermostat does not fully open until 95 C or 203 F. You can run the car all day long at 200 F and absolutely nothing will go wrong with it. It's been like that since the 12A in the Rx-2. The basic temperature range of a rotary has not changed at all in almost 40 years, although cooling system capacities and fan control systems have. First Mazda went from a sort of on/off engine fan clutch (fan was engine driven, not electric) on the earlier 12A's to a fan clutch which would gradually increase the speed of the fans as the temperature increased.

Then on the 13B's they had this progressive fan clutch plus an auxiliary electric cooling fan that come on at various temperatures depending on the model, but usually around 95 C or 203 F, right when the thermostat opened fully. On the FD Mazda went to a 3 speed, dual electric cooling fan system with an aftercool function. The fans were controlled by four relays. Two relays were switched by the ECU at 103C or about 218 F [sic], that would run the fans at low speed. The electric fans were also triggered by the A/C, which would turn on one relay to bump up the fan speeds or switch them on if they hadn't been turned on by the ECU yet. Finally, the FD had an external thermal switch that triggered another relay to enable max fan speed at 108 C (226 F). The engine ran very hot and it's amazing how long they did last (70-90k mile coolant seal failre was not uncommon). The aftercool function only came on if the engine had been running at 108C/226F for a couple minutes before the engine shut off.

Depending on various factors, many people drove stock Rx-7's around at 220 F all day every day for years and now we have people freaking out that their water temps are 195 degrees or something, where the thermostat hasn't even fully opened yet. Clearly the FD has big cooling issues, and I'm not trying to say that we should run our cars that hot on a continous basis. But it puts things into perspective a little.

I can bust out all the service manual pages to back this stuff up later when I get home from work.

 

That............will............be............the. ........day......... when I learn........... HOW TO FLY

 

Hey guys I live in southern california and our summer heat can get up to 120 degrees. I usually have to drive in a 30 minute or more traffic jam to get to work. I'm lucky to see 15 minutes of highway speeds. Where would i start?

 

See the above posts....don't worry about it.

This is the problem with car people, as much as they/I hate to admit it; people don't think before they yell MODIFY!

 

Don't forget that you have to remove the alternator adjustment bracket to remove the thermostat housing and the water pump.

 

I did. Repeat. 120 degress for 30 + minutes. Car completely Stoke. Concerned if this MODERN CAR was design for this heat. Thats all.

 

Call me paranoid, but I've had lots of issues with my car (I was the second owner) all of which did not include the engine.

That being said, I want to keep my engine nice and cool at all times.

Now when I said I'd be doing lots of Highway driving, I'm talking over 9 hour drives. I know I have a drive to Florida in the spring (17 hours).

BUT i also drive to work and school and do sit in a decent amount of stop and go traffic.

I'm just trying to keep my engine running for as long as it can, with my driving habits in mind.

 

elyscium---have you ever driven an rx8 in traffic jams when the ambient temps are 100F?
With a temp gauge or someway to monitor coolant temps.
I dont think you have? Or you wouldnt be saying that.
Yep 200F all day long NP--BUT,trouble, is this car will get to 230F easy-- plus a lot of people do not run heavy enough oil(added problems). Look at the cooler placement on this car---HARDLY NO AIR FLOW.
The FD has a much better flow through its cooler.
OD

 

Dude Pettit makes a secondary cooler install that fits in the bellypan--that way your intake will not be in the way--check their site.
OD

 

I'm failing to find it on their site. The only thing they have on their site cooling related is TT Thermal barriers for rx7's and a hose kit for rx8's.

 

you have to call Cam---he makes them on demand. It is what he runs in his own car.
Several people have them.
Its a really neat set up. Cheaper than a new radiator.
Go in the Pettit thread (Owners) and do a search in that thread for a picture)
olddragger

 

That's because of the factory fan programming, hence the advice about reflashing the ECU to turn the fans on at a lower temperature.


Renesis cooling fan control system


13B-REW cooling fan control system

On the Rx-7 the common practice is to switch the fans on at low speed around 87 C or so (189 F) in the ECU and then bump them up to high speed at 95 C (203 F). You'd be surprised how hot engines run from the factory and how long they last anyway. Here's a table from a DA1 1987 model speed density 5.0 Mustang computer:



That's as hot as the FD! Clearly engines can run a lot longer than you think at very high temps. If you drop the fan control trigger speeds down it'll be fine, there's no need to go overboard.

 

Now thats a good piece of data arghx7, good work.

I nabbed Re-Emedy Water Pump and T-Stat. I'll log my average temperatures before the Re-Emedy install and after. We'll see the differences. I am using FL-22 coolant in my system and MM Maps flashed.

 

nice data and its good to share --now tell us something we dont know.
rb's flash has been turning the fan at 180F for a few years now(long before cobb)
fans would help more if the rear part of the radiator wasnt mostly blocked--but fans will never take the place of proper airflow.
Are you saying it is ok to run this car at 230F
OD

 

Heat on the highway is not really a problem for most, so I'm not totally sure what you are worried about here - not where you live, anyway.

If you have an OE undertray, this will do nothing for you at all.

These do absolutely nothing, especially at highway speeds. Worse than nothing, actually.

You have the AccessPORT - it already controls your fans significantly better than the MazSport external controller.

This works well (might be overkill if you are just worrying about highway performance) and would be the 3rd most important step.

The FIRST most important step is to seal your radiator (either your OE unit or the BHR if you go with it) to the tray and panels inside the engine compartment.
The OE foam barely works and is usually gone by the time the car gets to 60k miles.
For quick/ghetto/easy, you can just use that "Great Stuff" expanding foam.
A prettier option is to use high-density foam and rivet it to the plastic bits around the rad.

Do NOT do this. They are ****.

Precisely.

Definitely not.
It is helpful (especially in track situations), but it is going to be beyond the level of involvement of the other options and provide the least improvement.
I have one in my car (and its far away from the other rad with its own fan, not pancaked on top of the OE rad like OD's, effectively making it a radiator pre-heater) and it is a supplement, not a primary improvement.


Correct. Mazda doesn't even think your motor is warmed up until it hits 205°!
You are good all the way to 230°F, at which point the PCM will start to take countermeasures.
The only issue is that 260°F is the end of life for the Renesis, so its a fairly small window. Coolant mixture turns out to be the most important ingredient in controlling that window.

Please review the current discussions on oil to understand why this statement is irrelevant.

Terrible design for a multitude of reasons (and no, not just because Moon did it).


The RB flash came out 3 months before the AP. Not exactly "long". lol

Actually, the factory air path is pretty decent.
The exit "port" area is larger than the face of the radiator, so flow is not impeded by that.
Its only the partial change of direction that is "bad" and its not bad.

 

Sweet jesus jeff, colossal input!

Now you mentioned that coolant mixture is quite important. Is the Mazda FL22 coolant proper or is there a better fluid?

 

Stick with that, but use the lightest mixture possible for your climate.

 

You got it Jeff. Thanks again. I'll have some logs for you after my install this weekend. BTW the car feels much stronger just with 4.0.1, I can't wait to get my next map done so I can get into the performance tunes.

Anyway, back on topic.

Now the FL22 comes premixed, correct? If it is to potent, what should it be diluted with? Distilled water right?