Hey All
As we all know the FD suffers from barely adequate cooling in stock form at stock power levels. Do some mild power upgrades and the cooling systems are now no longer going to take it. It maybe fine on the highway or moving, but stop and go traffic or track days can really test it. It seems there are a few upgrades like duel/larger oil coolers, larger SMIC or V-mount and the electric water pump like Davies Craig. Would you say bang for the buck the electric water pump kits (Sakebomb, Turblown,or DIY) are the most effective upgrade to keeping these cars cool? In my research so far it seems to point that direction, but wanted your opinions.

Thanks
Mike H

 

A better/more efficient radiator, dual oil coolers, and ducting will be your best improvements. If the physical system of heat exchangers is weak then a programmable waterpump won't be nearly as effective as it could be.

I believe that the biggest flaw of the stock waterpump is cavitation at high rpms. The EWP solves this nicely but it isn't a necessity.

An EWP is probability the last step I'd take in cooling mods. Coincidentally, it's also a step I'm in the process of taking right now.


I wanted to get rid of the useless WP housing, but keep the factory alternator location. Parts needed to be milled as a result 🤣

 

No doubt what modifications are wise to do depend on what you want to do with the car. I think common wisdom around here is that DP and aftermarket radiator are no-brainers and offer great bang of the buck on pretty much any car.

if you’re going to track the car dual oil coolers are probably a good idea as well (as mentioned here before, even Mazda thought dual oil coolers were a good idea for the “R1” model).

 

I agree with the radiator and duel oil coolers. I'm in the final stages of going single turbo.. I've done most of the cooling mods, just down to deciding if V-mount or ewp is the best way to go. Currently have the M2 medium and was thinking ewp but wanted further in site.

 

VMIC (with proper ducting) is going to be a far better modification. I would really only bother with an EWP if your particular circumstance REQUIRES it, or if you're so far down the rabbit hole that it just makes sense...

 

For street use, a good v-mount (radiator and IC) is the way to go. Even better with proper ducting.
I haven't found the need for bigger oil coolers on the street. The stock dual oil cooler setup is sufficient. There's a thread somewhere on here with oil temps with a single stock oil cooler. It is probably ok with a good synthetic oil but not much head room if you are doing a lot of spirited driving.

 

*Lower the stock temp threshold (from 108 C.) for the radiator fans, either thru the S5 FC thermoswitch (95 C.) or the ECU.
*WI can be a pretty effective cooling mod (along with carbon control and knock suppression).

 

i've noticed a few things over the years. the first was that the dual oil cooler setup worked great on the street, if the car was moving oil temps were right where you'd want them (180f), they would go higher, but if you were stuck in traffic or something, and that actually probably good, the contaminates can "burn" off out of the oil.

the other thing is that the temp the fan turns on is high, i have an FC with an FD ecu in it, and the fan doesn't run very much at all. in fact now that it has been cold, the fan hasn't run in the last 2 drives.

so in summary, for a street car the basic system is fine, lowering the fan on temp, and running the dual oil coolers is all that you really need.

the INTERCOOLER can use better ducting, and then its kind of small...

 

A good cheap bang for buck mod is to replace the stock motors/fanblades in the oem FD shroud and replace them with the S2 RX8 motors and fanblades. You can find these assemblies for sub $100 off ebay/junkyards. The S2 was plug and play for me aside from just making new connectors due to me just chopping the wires instead of unpinning the old and repinning them into the newer motors.

 

I have dual 19 row oil coolers, VMIC with no ducting, and a vented hood (FEED replica from Shine). I had ducting on an old VMIC setup but didn't notice much difference (if any) in temps. With this newer setup, I made a duct for the radiator and I actually noticed the temps go up a bit, but they were more stable and didn't fluctuate as much. With this setup, my temps are perfect in the summer, and too cold in the winter. Then again, I am in Colorado, but it stays fairly warm most days in C Springs even in the winter. It was in the 50s today actually. Anyway, I did add a fan to each oil cooler for when I do autox days because I'll be sitting for a while at times, and it's triggered by a temp switch in the oil cooler lines, going into the thermostat from the second cooler IIRC. I swapped to the RX-8 radiator fan motors and blades, mostly to pull less amps. I haven't paid attention to if they do any better cooling, but I believe I saw someone on one of the facebook groups do a test with good results.

I swear by VMIC and dual oil coolers. WI wouldn't hurt either, I love that too, but for different reasons.

 

One cool thing with an EWP is you can run it with the engine off

 

The best thing you can for cooling, especially in a modified car is to get a proper Vmount setup. These cars lack the frontal area to fit a large enough capacity radiator and intercooler in the stock location. Stock mount intercoolers don't work well as they sit directly in the path of the hot radiator discharge. The best kit on the market by far in our experience is Greddy. Second important is to add another oil cooler if you have a single cooler or upgrade your duals to something like the Sakebomb kit if pushing any significant power.

 

Thanks for all the replys guys. Just a little background on my project. It is a R1 but I did upgrade to the SakeBomb duel oil coolers, M2 medium intercooler, single turbo, mid-pipe with silencer, Haltech elite 1000, installed a w/m system using the Holley injector & SakeBomb tank, larger fuel system, excessive lim, bunch of other stuff down the rabbit hole. Anyway. It's still on break in, about 500 miles so far, but it seems to run on the warm side..around 191 f. Fans are controlled by the Haltech to come on 180, but highway driving it stays around that 190 mark. I know that's not overly hot just seems like it should be more around the 180-185 mark. Am I just overthinking this? I know the Greddy Vmounts are great but they are not cheap. Was hoping to control the temps better with the SakeBomb electric pump kit. But maybe I don't even need to worry about it. Any further opinions are welcome.

 

You may be over thinking this one - coolant temps in the 190's are fine. Especially if they are consistently in that range regardless of conditions (i.e. ambient temps, A/C on or off, loading on the engine, etc.)

 

^^
190F coolant temps in an FD are the factory cooling system compoments doing what they are supposed to be doing.

According to Factory Service Manual thermostst cracking temp is 177-182F and not fully open till 203F.

Fans come on low speed (1st stage) at 221F, medium speed at 224F and highspeed as commanded by ELD or AC.

Having a higher capacity/efficiency radiator will help cooling system run a bit cooler at low thermal loads (thermoatat just cracking open), but you really need some combination of lower temp thermostat, lower temp fan switch or lower temp ECU fan on set point to appreciably lower operating temps under load.

 

What radiator do you have?

Forcing the fans on at 180 as you are should be able to hold the temps to the thermostat cracking temp under light loads with a very large/efficient aftermarket radiator (like Koyo N-flow) in my experience.

And I assume you are getting the 190F operating temps off Haltech as well and not something inaccurate like an Autometer gauge?

 

Ah, on highway.
I think you are fighting the remaining stock cooling components (thermostat).

Okay, fans being on at 180 could be blocking enough highspeed airflow through the radiator at freeway speeds that the fans cannot overcome the thermal load and so the stock thermostat is actually able to regulate the engine temps as it was designed to.

Put in the lower temp thermostat.

If you want to experiment to see if Im on the right track - use the Haltech to turn the fan ON temps UP to 195 so fans wont kick on freeway cruising and see if temps go back down to thermostat opening (182 ish).

 

Radiator is a Fluidyne. Is there any recommendations on a good lower temp thermostat? Temps are from the Haltech and not the guages. Unfortunately my tune is locked as I was not comfortable doing it so I had to have a tuner do my map. I'm not able to adjust those temp settings without some phone calls but I may try that as well. Thanks for the in site so far, appreciated.

 

my greddy vmount with stock fans with 93 front bumper i get 185-190
fan on temp is set at 190f
thats reading on new haltech sensor in stock location
I used the greddy ducting and a crap ton of foam. temp seems pretty steady with ac on or off in fl. have had setup for a couple months now

 

I had a fancy 165F thermostat in my FC for many years and finally swapped it out for normal 180F one.

Combined with big (old school) injectors, early opening ports, and polished intake tract the car just needed too much fuel to run with the 165F t-stat. It was smoother and could run leaner running in the 180F t-stat.

So, I dont know if you want to go that route.

Maybe just check how it keeps temps under control once you are able to flog it.