Miata Turbo Forum - Boost cars, acquire cats.

Miata Turbo Forum - Boost cars, acquire cats. (https://www.miataturbo.net/)
-   Engine Performance (https://www.miataturbo.net/engine-performance-56/)
-   -   Need Help With Cooling System (https://www.miataturbo.net/engine-performance-56/need-help-cooling-system-93872/)

cruisin 07-12-2017 11:49 PM

Got some pics to see the set up.

I did use a mocal sandwich plate with thermostat for oil cooler. But i had 3/8 lines going to a 8'' x 8'' cooler. I think it was more to do with the stock oil pump not being able to flow enough for such a bigger area to keep pressure up. I found that when i added the turbo oil pressure went down around 5 psi at every point. Coolant temps were same with oil cooler anyways.

Looking at the pics; engine under tray is all there un modified, everything in bumper is there but i did cut a rectangular hole in that shroud on bottom for IC to sit in its exact size for IC to drop in. There is room below BOV for a 10-11'' diameter fan just oem fan cant fit there, so looking for a fan.

As i drive coolant temp seems to stay at 95 celsius so around 200-205 F, this normal for a turbo car i think oem is 92 celsius but maybe im wrong. At idle is just where it gets hot, the hotter ambient temp the faster it goes from 95 to 102 and above. There was one day where ambient was 30 celsius and i got stuck in some stop and go traffic for 20 mins, car came like 80% to overheating according to dash gauge. Im thinking with second fan it will still get hot just take a bit longer.

So looking to add fan, undecided about thermostat, looking into reroute, im stuck with the mishimoto for now since i got it all modified to work with my IC piping. https://cimg0.ibsrv.net/gimg/www.mia...af662abb4e.jpg
https://cimg2.ibsrv.net/gimg/www.mia...0a26a86408.jpg
https://cimg3.ibsrv.net/gimg/www.mia...ad0a518f58.jpg
https://cimg4.ibsrv.net/gimg/www.mia...91114b0910.jpg
https://cimg5.ibsrv.net/gimg/www.mia...c1b173ef55.jpg

Bronson M 07-13-2017 05:37 AM

Yup 3/8" lines and possibly the type of cooler is the reason for your oil pressure loss. You need 5/8" (-10) lines and a stacked plate type cooler.

If your overheating is only when stopped and fine when moving then it's a fan problem, plain and simple. Your ducting around the intercooler piping looks good so that's not the issue.

yossi126 07-13-2017 05:51 AM

And that grill isn't helping your airflow either. It's not the cause of your overheating, but every little thing helps.

sixshooter 07-13-2017 06:55 AM

My car came with that grill. Ditch it because it hurts air flow more than you know.

I went from the stock radiator to the thicker mishimoto and it did make a significant difference on cooling especially doing track days here in Florida. I was using two stock fans. Once I added boost a better radiator and oil cooler were needed for the track, but probably wouldn't be necessary for the street. It shouldn't be so tough to get it cool in Canada.

TheBandit 07-13-2017 09:24 AM

If you decide to go the way of a reroute, we've got you covered. :bigtu:

Steve Dallas 07-13-2017 10:35 AM

Very clean build.

If it were my car, I would ditch the grill, add a fan, do the re-route, and add a proper oil cooler setup. A 180F thermostat won't hurt anything, so you can do it while you are in there, if it makes you feel better. I believe the Stant Superstat is the favored one.

On the oil cooler topic, when you are pushing the limits of cooling, you need to cool everything you can cool. Bear the heat load everywhere you can. Oil is typically 20 to 50F hotter than coolant, so yours is pretty hot. Here is the Oil Cooler Bible:

https://www.miataturbo.net/race-prep...er-tech-80234/

Agreed that you need at least 5/8 or 10AN lines to maintain oil pressure. Known good oil coolers are Long (TrueCool), Koyo, Mocal, and Setrab. Make sure whatever oil cooler you choose accepts the appropriate size hose without the use of adapters.

cruisin 07-13-2017 10:56 AM

Ok will look into all of that.Thanks for all the comments!

Couple more questions;

Am i ok to tap a second fan into the first one so they kick on together, at what point will it put too much load on that circuit?

Will lowering my fan on temp help? Currently set to 215 so 102 celsius, maybe setting to 212 or 100 celsius could help delay the heating a bit.

hornetball 07-13-2017 11:11 AM

Definitely lower your fan-on temp. It is not a coincidence that your fan-on temp matches where your water temp seems to settle while stopped.

This makes a huge difference on our old cars (based upon direct, personal experience) . . .

More Information for FOUR SEASONS 35240

Steve Dallas 07-13-2017 11:31 AM

I think I would start at 205F / 96C for my fan turn-on temp; that is the factory temp.

Use the original wiring for your 2nd fan, and set the ECU to turn it on with the 1st fan. Barring that, jump the relay inputs on the 2 fan relays, so the 2nd fan turns on any time the 1st is triggered. Two fans on 1 circuit will be too much current draw for that circuit. Each fan needs its own relay.

For < $30, the fan motor hornetball is recommending is a definite no-brainer.

.

yossi126 07-13-2017 12:11 PM

Woah! 102c is your fan-on temp? Now I see why you overheat. Stock ecu turns the fan on at 96c (Or 205f).
For turbo cars usually sooner is recommended. You can set it at 94-95c.
The point of overheating is 98c. Very difficult for the cooling system to cool down from there.

sixshooter 07-13-2017 01:00 PM

If the bov was located differently you could use a stock fan.

Art 07-13-2017 07:36 PM

.

cruisin 07-13-2017 11:36 PM

Ok thanks for the feedback.

Hornetball, i am looking into what you suggested just forget to mention it.
Yeah BOV can be relocated just need modify the pipe. I can fit a slim 10-11" fan under so ill do that instead of trying to get another stock fan on.

Fan is not used while moving, so thats why i gotta play with the fan on temp a bit. Dont want fan to turn on while moving. Since i cant get it to be cooler than 95 celsius while moving i will set fan on to 97ish for some head room. Not ideal but will help. Basemap had the temp set to 215 F.

This car never had a second fan, did not come with AC. Can you spoon feed a bit more, where are the relays and hows it get wired.

Art 07-14-2017 12:56 AM

.

olderguy 07-14-2017 06:56 AM

And definitely remove that grill. You are recirculating the air under the hood through the radiator and getting very little flow from the outside when standing still..

sshamrockk 07-14-2017 07:35 AM

Can anyone recommend which spal fan is best? Need to be slim as I plan on using a koyo 37mm Radiator and I don't think stock fans will fit with my Intercooler piping.

Steve Dallas 07-14-2017 08:53 AM


Originally Posted by cruisin (Post 1427576)
Ok thanks for the feedback.

Hornetball, i am looking into what you suggested just forget to mention it.
Yeah BOV can be relocated just need modify the pipe. I can fit a slim 10-11" fan under so ill do that instead of trying to get another stock fan on.

Fan is not used while moving, so thats why i gotta play with the fan on temp a bit. Dont want fan to turn on while moving. Since i cant get it to be cooler than 95 celsius while moving i will set fan on to 97ish for some head room. Not ideal but will help. Basemap had the temp set to 215 F.

This car never had a second fan, did not come with AC. Can you spoon feed a bit more, where are the relays and hows it get wired.

You are over-thinking the fan turn-on temp. The running fan does not become an obstruction until somewhere around 60mph. It is much better to have it on than not, when moving at speeds below that. Set it back to 96C.

[ReallyBasicRelayPrimer] A relay is a remote switch, that allows you to control a high current circuit, with an isolated low current circuit. The switching side of the relay is activated by a constant 12VDC signal and a switched ground signal. In the case of the fan circuit, the "ground" signal is sent by the ECU, when it determines the fan should be on. These 2 signals "flip the switch" to activate the high current circuit, which powers the fan. Obviously, you do not want high current coursing through your ECU, so a relay is used to isolate the ECU from the 20 to 60 Amps required to run the fan. [/ReallyBasicRelayPrimer]

If the NA relays are in the same location as the NB relays, they are near the cowl on the passenger's side. There are 2 of them in cars that ship with A/C. One is obviously already in use for the 1st fan. Hopefully, the 2nd one is there, and you can just use it for the 2nd fan. If not, the signal wires may be in the bundle, and you may still be able to use them to easily wire in a new high current relay. (Find the wiring diagram for your car to determine wire colors and verify with a multimeter.) If you need a new relay setup, SPAL makes a wiring kit that greatly simplifies things. With that kit, you would need to tap the signal wires for the 2nd fan, which allows you to control the fans independently with the ECU. Or, tap into the ones for the 1st fan, which will turn the 2 fans on in parallel. Another option is Spal's thermostatic wiring kit, which will turn the 2nd fan on, at a fixed coolant temp, using its included sensor.


Originally Posted by sshamrockk (Post 1427606)
Can anyone recommend which spal fan is best? Need to be slim as I plan on using a koyo 37mm Radiator and I don't think stock fans will fit with my Intercooler piping.

There is no "best" fan. There is the one that is appropriate for your application. Go to Spal's web site, click into the area for the fan diameter you need, and click on the specs link for each fan you think might be suitable. Find one with the dimensions that will fit, with a current draw that is appropriate for your circuit, and that pulls enough CFM for your application.

tyhackman15 07-14-2017 08:53 AM


Originally Posted by cruisin (Post 1427576)
Ok thanks for the feedback.

Hornetball, i am looking into what you suggested just forget to mention it.
Yeah BOV can be relocated just need modify the pipe. I can fit a slim 10-11" fan under so ill do that instead of trying to get another stock fan on.

Fan is not used while moving, so thats why i gotta play with the fan on temp a bit. Dont want fan to turn on while moving. Since i cant get it to be cooler than 95 celsius while moving i will set fan on to 97ish for some head room. Not ideal but will help. Basemap had the temp set to 215 F.

This car never had a second fan, did not come with AC. Can you spoon feed a bit more, where are the relays and hows it get wired.

I don't see an issue with the fan running while the car is moving. I'm pretty sure FM or someone had data showing a fan can help even at relatively high speeds.

Steve Dallas 07-14-2017 09:01 AM


Originally Posted by tyhackman15 (Post 1427611)
I don't see an issue with the fan running while the car is moving. I'm pretty sure FM or someone had data showing a fan can help even at relatively high speeds.

I'll see if I can find it again, but I authored a thread on the Rx8Club forum about this, wherein I tested the effectiveness of the so-called "Fans on Low" mod for those cars in 95F ambient temps. That mod turns both fans on low speed, using a remote switch. The results proved having the fans on low aided in cooling at least up to 50mph. There was no penalty up to at least 60mph. Above that, things were murky, but having the fans on did not seem to be a problem at normal driving speeds.

sshamrockk 07-14-2017 01:52 PM

I know there isn't a "best" fan, I'm just looking for a recommendation for a 12" spal fan, stock wiring with ac..


All times are GMT -4. The time now is 05:47 AM.


© 2024 MH Sub I, LLC dba Internet Brands