jacobcartmill

iTrader: (6)

i have the greddy vspec fmic and i've been having a problem with keeping my coolant temps down on the highway... just cruising around town on a hot day, the coolant temps are around 200*F. when cruising on the interestate between 70-75mph, they go to around 215*F which worries me, so i slow down to 65-70 and they drop to 210-211 or so.

i was always told that when using the stock FC coolant temp sensor (the one on the back of the waterpump housing) it will just read about 10 degrees high on the haltech, so just take 10* off of whatever it says and you're good to go, but is this true? if so, how high does it read?

Claudio RX-7

iTrader: (1)

Not necesarily, that is the most ideal location for it, im not sure the factory Mazda sensor is supposed to read that high, but i would ask, do you have your thermostat installed and if so is it in working condition? also, if you have a coolant reservoir, ive noticed better cooling when you have both a good thermostat and a reservoir.

Might your engine also be in need of a radiatior/system flush/clean up?

jacobcartmill

iTrader: (6)

nah not really in need of a flush/clean for the coolant system, engine has about 600 miles on it so everything is pretty much fresh

Mike_REW

iTrader: (2)

I ran into the SAME problem with my 10th AE when I had it.

It was fully built up, same Greddy FMIC, stock radiator with stock clutch fan. Belly pan installed.

I was seeing temps as high as 110C on the freeway on the way to the dyno.

What we wound up doing, and I know this is going to not sound like fun, is to cut the front bumper to allow for more air to pass through the intercooler, and then into the radiator. Once we cut it, the temps were back down to normal, in the 82-90C range.

It is not a haltech issue, for sure.

Edit: I also had a brand new Mazda t-stat, and fresh coolant system with new radiator caps.

J-Rat

iTrader: (2)

Got a pic of the hole you cut?

jacobcartmill

iTrader: (6)

we made a nicer underbelly tray to direct air at the radiator and it actually did something....


it was about 80* out tonight and the coolant temps were about 190-195 cruising on the highway. i'll post up tomorrow and see where they are when its 90* out again tomorrow.

edit: also, yeah i wanna see this hole yall cut

RETed

Yep, the specs (i.e. resistance charts) are off by about 10 to 15 degrees.
If you're not comfortable with this, just install the Haltech unit.

The FMIC usually induces cooling problems.


-Ted

20B10AE

iTrader: (14)

Ted, can I assume that this applies to all the Mazda temp sensors? i.e. I have a Cosmo (same as FD, I THINK) temp sensor in the 20B. Would it make sense that my Haltech, which is seeing 100-103 C (212 - 217 F) at cruise at NIGHT, may actually only be closer to 96 or 97 C (205 - 207 F)?

I have a temp gauge that is getting its signal from the front rotor housing where the AC system would be, so I know there would be a bit of a difference anyway, but when the Haltech is showing the higher temps, it looks like it is closer to 99 C (210 F).

I'm just trying to confirm the information, since I'm having issues keeping heat down lately. I'm probably going to have to pull the motor again to put the ONE heat shield I left off the car back ON. :sigh:. Last time I pulled the engine, I left the sort of oval shaped shield that goes all the way around the stock manifold so I could get to the bolts easier. I never thought that leaving ONE shield off would cause the temps to go up so much! I did that on my 13B-T and never notied much of a difference.

Ah well...

reese

RETed

Yeah, all the Mazda temp sensors spec the same.
I know at least the FC, FD, Cosmo (both 13B-RE and 20B) water temp sensors are all the same resistance characteristics.

You should already know the 20B is a pain to keep cool.


-Ted

20B10AE

iTrader: (14)

Ugh...tell me about it! I'm about to ditch my Fluidyne and go with something else. I just need to figure out WHAT. There isn't a whole lot of room in there.

I wonder if those double pass universals would be any better than the Fluidyne?

C. Ludwig

iTrader: (27)

Yes. The single pass Fluidyne is nothing more than a stock replacement IMO. Double pass is more efficient. I've had three made for FCs and all have thicker cores than the Fluidyne. More efficient and cheaper...what's not to like? Alternatively you can also have an extra row or two added when going custom if cooling is a big problem. We have a turbo FB running around with a FMIC and no undertray that cools without issue running a very large custom two-row double pass. Alternatively we have an FC with a very similar engine/turbo package with a Fluidyne and it runs on the hot side when it's 90*+.

jacobcartmill

iTrader: (6)

coolant temps are staying right around 195 degrees when its 85-90 degrees outside cruising on the interstate. driving around town they get to about 205*F. this is also on the stock mazda coolant temp sensor so if they reading 10-15* high, thats right around 180*F which definitely works for me.

i am running a greddy vspec FMIC kit, t04b turbo 115 a/r turbine with no heat shielding, and a koyo radiator btw. i'm planning on heat-wrapping my downpipe and getting a blanket thing for my turbine housing, and also doing a little more work on my underbelly tray. i'll report back next week.

Bukwild

jacob I have the same problem. I worked on some ducting last week and got the temp to drop down to 89-90c which is 194. I am going to try and rig up a second fc oil cooler and see if that gets me down to 185 again. Also I am running the stock rad & clutch fan with the greddy FMIC.

jacobcartmill

iTrader: (6)

oh i forgot to mention im using a black magic efan (supposedly not as good as stock with the big shroud)

jacobcartmill

iTrader: (6)

ok now that its getting a little bit cooler outside (at night atleast) i watched my coolant temp on the 2 hour drive back to school last night. stayed right around 88*C so about 189-190*F the temperature outside was about 72*F

also the air intake temp was hanging out around 81-82*F which is very acceptable.