[NB] Overheating issue with AC
 

Alright so I purchased my first Miata almost 2 weeks ago in Washington state and drove it back home to Texas. I'll have the list of mods in a bit but it's supercharged and supposedly putting down 250 hp to the wheels according to the previous owner. Anyway, I had no issues cruising 70-80mph most of the way. I didn't have to use the air conditioning until I hit Arizona and that's when the temperature gauge on the stock cluster started rising past 12o'clock and close to the 'H'. For the rest of the trip I had to leave the AC off or bring my speed down in order to use the AC. I've driven it around town here in Texas where it's currently 90 degrees during the day and if I'm putzing around town doing 30-45mph I can have the AC on full blast as long as I keep my rpm's down below 4k and it won't overheat.

My goal for this Miata is to make it my track car so it will definitely be pushed at the track and I will definitely need tip top cooling for it. AC is a must in the Texas heat for traveling to and from the track.

2000 Miata LS, 5spd, 112k miles
Flying Miata Coolant Reroute Mod
Oil Filter Relocation Kit
Eaton Supercharger (forgot which model)
10psi pulley
131mm crank pulley
Hydra Nemesis 2.5 EMS
550cc Injectors
Intercooler with heat shield up top
Undercarriage metal guard

Yesterday I drove about 15 miles along 30-50mph roads, AC cranked on full blast and I kept my revs below 3500 and the temperature needle didn't move past the 11:30 position. After that 15 miles I stopped and then continued again along the same roads but played around a bit keeping the revs up in the 3000-4500 range trying to simulate the highway driving (cruising at 80 left the rpms around 4200) and that's when the car started to overheat which is when I pulled over, popped the hood and the coolant was bubbling in the overflow reservoir.

I'm pretty sure the thermostat is fairly new due to one being included in the Flyin' Miata coolant reroute kit the previous owner put on but I could always test it again I suppose. Friends have been suggesting it's either (1) bad AC causing excess heat (2) water pump possibly not pumping as much as it should (3) car is running lean causing excess heat (4) being that the thermostat is a couple of inches away from the head now due to the reroute mod it might actually not be heating up the same time as the head causing heat issues. I know that both fans run when they kick on so they must have been wired in parallel. It's possible that the intercooler may be blocking airflow to the radiator.

Just wanted to let you know as well that cruising at 80 on the highway without AC the car was perfectly fine. Turning on the AC is when the temperature started climbing. I'm kind of stumped at the moment and not sure which direction to head in for debugging this issue. Has anyone encountered a similar issue? I thought about going to the Koyo 37mm radiator (can't do the 55mm since I have the large Eibach swaybars) but my friend told me that solution would only delay the car from overheating. Is this true?

Pics for reference...
After we rerouted the long coolant hose under the strut brace (didn't fix it)
http://i389.photobucket.com/albums/o...ute/photo2.jpg

Time for a radiator....... Might take a look at the PRC unit all the V8 guys are using.

think you mean m-tune reroute, fm don't make one, they sell the m-tune kit.

i had the same set up with out a reroute but with a pwr and i had a problem not getting hot enough in weather under 80*

get a pwr and duct your radiator better.

edit: i just looked at this photo http://i389.photobucket.com/albums/o...aEngine013.jpg you have what i'm guessing is a water hose going from your dummy throttle to some were if that's water going into you dummy body then cap it, your just reheating the air after the intercooler cools it. not sure where your getting water from and where it's going to after words but i'm betting it's not needed.

That's just so the IAC uses metered air but it can probably be replaced by a small filter at the IAC instead since he is running the MAP-based Hydra.

Next step is RAD for sure. What percent mixture coolant/water are you running? Perhaps try some redline water wetter? Also how well is it shrouded, pics?

I just so happen to have a PWR rad from my NB that I pulled out.

Frank

Make sure you coolant/water ratio is not too high. You could probably run a 70% Water 30% Coolant Mix. Also make sure the T-Stat in the reroute has a 1/8 holes drilled in it.

Hope this helps,
Marc

Nah, Flyin' Miata actually makes a kit... http://www.flyinmiata.com/index.php?...umber=09-60000 I took that spring out of the old hose when I rerouted it under the strut tower brace. Edit: Wow, I just looked at the M-Tune kit and they're almost identical. BUT the metal piece of the back of the engine denotes "Flyin' Miata" on it. :)

That's actually an air-line, we shortened that as well to get rid of the kink on the right side of the enginebay. :) Like saboteur said, which is actually what my friend told me, is I can cap that line at the air filter side and run a catch can on the dummy throttle side.

Currently in there is a new stock radiator that the previous owner installed. I'm running a 70/30 distilled-water/coolant mixture after I flushed whatever the previous owner had. It also seems like he got a set of aftermarket fans that are bolted to a this sheet of metal that sits a good 1-2 inches away from the radiator. Doesn't seem to be affecting idle temperatures though.

I haven't heard of the PWR radiator. Is it a bolt on replacement or custom? What kind of fans are attached to it?

I'll get closer photos of the front intercooler, AC condensor, and the radiator tonight when I get home from work. :)

That sure looks like the M-tuned coolant reroute to me.

Jeff knows what he's talking about on cooling, he's been tracking a supercharged NB for about 3-years. You need to duct the radiator so air cannot go around it, you need a real radiator in general for when you start tracking it, and run 10% anti-freeze (good to around 10*f freeze protection).

Oh, I think I misread what jeff said, me mentioned FM doesn't make one but they sell the m-tuned kit. I guess FM just stamps "Flyin' Miata" on the part connected to the motor of the m-tuned kit. :hsugh:

How do people go about ducting the radiator?

Take a roll of 2-4mm plastic and seal the mouth of the bumper to the radiator so no air can go around it. Its that simple and absolutely required for tracking a car. I have a "coolradiator.com $150 pos) and I can run all day long at 100*f ambient temps and the gauge never goes above 180*f on engine water temp, and the fans never turn on.

Hey, RavynX, welcome to the forum and to Miata ownership. :cool:

I'm guessing that the supercharger is an MP62, and the kit was packaged by a company called BR Performance out of South Carolina. They don't exist anymore.

I think the 'undercarriage metal guard' is a knockoff of this.

Please go to "Edit Your Details" and insert your city. Texas is a big place. Plus, that'll make it easier to send you to the right performance shop.

For now, all you need to upgrade is the radiator. The stock rad is insufficient for forced induction on the track. I use a PWR (great radiator from Australia) but there are others just as good. Personally, I use pure distilled water and a sip of Water Wetter by Redline.

One more thing: you should find out what size your pulleys are (in millimeters). That info will come in handy later. Looks like Flyin' Miata helped out with the build, maybe they have the specs on file.

Here's my shit:

I had the same overheating with A/C on a trip across I90 on a 33 Celcius, humid day.

Stock Rad, BRP 62, no reroute, no intercooler, no funky fairings to direct the air into the rad.

I was able to eliminate the overheating by removing the front license plate (required in Ontario, Canada) which was installed in the mouth.

Spent the day at the track in Shannonville, On yesterday, it was hot. No overheating problems.

YMMV.

Most everything they sell is sourced.

That was there when I bought the car. That hose was actually kinked on the right side of the enginebay but we shortened it and rerouted it. I plan on capping the right side off and putting an oil catch can connected to the left port. As for the air being trapped, we had the front jacked fairly high on jack stands so that we could properly burp the system. I think we let it burp for a good 20 minutes; does it need longer?

Thanks for the welcome! I updated my profile info from the '06 s2k to the Miata. I still have the s2k, but I'm tracking the Miata. :) I'm from San Antonio so I'll be frequenting H2R a bit. I can't wait to make it out to TWS, MSR-H, and MSR-C.

Since I have that thick Eibach swaybar I can probably only do the Koyo 37mm radiator. How is the fitment with the PWR radiator? Can you keep your AC unit with that one? Would you happen to know if the current FM fan shroud setup is worth keeping or is it a hindrance with aftermarket radiators? Not sure if I'd have to replace the fans I have now if I went Koyo or PWR.

According to his excel sheet of mods/repairs that previous owner gave me...
110 mm s/c pulley
131 mm crank pulley

Should I keep the stock thermostat with the M-Tuned reroute, drill holes in it, or go for the 160 degree thermostat?

I'm running the 1.125" RB front bar and a 53mm Koyo. i doubt that the eibach bar will cause any interference with a 53mm rad.

Keep the 180* thermostat. Lowering the t-stat temp will not increase the thermal capacity of the cooling system.

What type of fans are you running with your 53mm radiator? You're Colin from TrackJunkies, right?


Sounds good, thanks.

I sure am. and i'm running the stock fans with some fuel line to seal the fan shoud to the rad better.

It isn't how long you burp it, but where you burp it. Air will not go down to come out. If you have a higher spot at the back of the head than any part of the hose coming forward you will have air in it.

And follow Hustler's advice on sealing the bumper inlet to the radiator with no leaks, after all, he is a moderator. If you don't do it he will ban you. :giggle:
Actually, I think I mentioned it also.

I've got the stock A/C condenser and the Track Dog Racing intercooler in front of my PWR radiator. It had to be moved and tilted back a little, so there was some cutting done.
Well, something's wrong there; maybe Flyin' Miata has the correct specs. Nobody would put a pulley ratio of 1.2 on an MP62 supercharger.

For example, I'm running a 120mm supercharger pulley and a 60mm crank pulley. That gets me 225 max rwhp.

This also calls into question the previous owner's claim of 250 rwhp. :doh:

Yeah, a definite d'oh. :crx:

Here's the guy's tech sheet of everything he's done... http://spreadsheets.google.com/ccc?k...wYTRrLVE&hl=en

I will say though that it does feel faster than my lightly modded s2k, but you only need about 155 whp or so on the Miata to be about as quick as the s2k if you're just using power-to-weight ratios.

If you have a tuning question, much like you alluded to on the other forum, you should ask it here and not listen to those bench-racing ******s on the other board. BTW, Stanford is cool in my book.

You should especially ignore the guys who run around in $30k cars and brag that they outran you on their home track...yet can't seem to find their datalogs to compare for when they were gang-fucked in the wet.

I will definitely have tuning questions for you all on this board as forced induction is a completely new field to me. I have the Hydra Nemesis software setup on my laptop but I need usb-to-serial drivers first to get it connected. But that's for another post. ;)

Yeah, Stanford is a cool guy. I autocross with him at the SASCA and SPOKES events here in town. His red s2k is a beast!

Doesn't it now have the sequential box and the ford IRS?

Something to that extent. Everything from the transmission back is non-honda, haha.

for people who don't know:
s2k
Full Race gt35r parts (450whp or so)
Motec 8c
Getrag sequential box
ford IRS
Moton w/ external tanks
ccw10's w/275f 315r Hoosiers
fast
fast
fast

and he's pretty good at tuning:
http://www.innovatemotorsports.com/resources/Stan2.php

Here's a quick vid of my Miata when I arrived in Provo, UT to stay for the night...
http://www.youtube.com/watch?v=K5uTcHh3qWI

Here's Stan's S in front of me at one of our autocrosses (it was dusty that day)...
http://www.youtube.com/watch?v=P92QeqLa0m8

Wow, so the previous owner sent allllll of his documentation of what has been done to the car. Receipts, installation guides, everything. Very nice!

BRPerformance Track Dog Racing MP62 Supercharger (installation guides mention R1 (205whp) and R4 (250whp) packages). The invoice does not specify a package.
Invoice states: TDR MP62 supercharger kit with 6-rib pulley, 95mm crank pulley, 70mm throttle body. Below that it mentions Gates 6-rib supercharger belt for 105mm crank pulley. :dunno: All purchased 5 years ago (2005).

Hydra EMS & injectors installed 2 years later (2007)
Dyno Tuned shortly after

Timing belt, Water pump & gasket & o-ring, fuel filter, & clutch slave all replaced at 63k miles in 2007

110mm crank pulley installed beginning of 2007 but documents state "did not work, gas mileage went down to 21mpg" Not sure if he kept or not.

Supercharger rebuilt in 2008 at 70k miles

Those are the main points in the documents aside from all of the suspension upgrades and the TDR Intercooler. I'll be checking the thermostat later this week or sometime on Saturday. I have engine/tranny/&diff fluid coming in soon to replace.

Oh! and I finally got it registered in Texas. Woot!

See if it has the TDR style radiator ducting. If it does, go ahead and buy a PWR radiator unless you're a cheap gay (like me). A PWR with the TDR plastic ducting/blocking plate crap is proven to work in 100* heat at the track. If you have questions about specifics, PM johnwag who works at TDR. He is my boyfriend.

Are there any other solutions for the intercooler? I was at our local autocross meeting tonight and brought the Miata over. Everyone was telling me the TDR radiators don't let much airflow through it which is most likely causing the issue. They said even if I shrouded it, it wouldn't do much. One had put a fan on one side (off of the car) and couldn't feel much on the other side of the intercooler. :facepalm: I haven't gotten a chance to look up into the bumper area to see if there is any type of special TDR ducting. The intercooler, ac condenser, and radiator sit basically right next to one another since the intercooler piping enters and exists from the top rather than the sides.

Let me share a little advice with you about the Austin crew...they're wrong most of the time. Most of those dudes on the trackjunkies forum are checkbooking it and love to run their mouth about how much you don't know and how they hold a lap record on some track in some bullshit capacity...I can't believe how many people I know in Austin who have a lap record they're willing to share, its pretty lol. Barry Wolf is one of the few I know with a clue. I've met a few cool guys like the guys who run TXMC of course, but there are a couple who can eat my shit on toast. I've met very few who know how to make a car work on the track...most just take it to JC and throw their hands up in the air and cry.

There is a short list of people in Texas with reliable FI Miatas, I'm one of them, Gary who owns TDR is another and with a big radiator, blocking plates/ducting, and his FMIC set-up he sees "good" intake air temps verified with a gauge in his 300whp car and the car runs wonderfully in the heat. The kit you have is tested on the track, and has proven reliable over the past 5-years with very few problems on hundreds of cars.

I've only run in Austin once but it was very entertaining to see the suspended disbelief when I ran my turbo car without overheating, like they'd seen a ghost.

You can do better ducting than what Gary sells at home, though his will get the job done. We have threads here about ducting with lots of pictures or you can look at my car next time you're in Dallas. We've told you what to do, we know what works, we've done it before...so do whatever you want.

This wasn't the Austin crew. These were the San Antonio autocross guys; I know autox and track are different so let's not get into that, they've been to the track. One currently has a turbo'd NA miata and ran into similar issues. Other friend has had super and turbocharged CRX and were sharing their experiences with me. I didn't mean to step on anyone's toes I'm just trying to get different points of view on the subject so I'm not stuck on one path hoping it'll work. This whole area of expertise is brand new to me so I'm taking in what I can.

I'm currently reading other build threads to see how people have been ducting their intercooler/radiator setup.

Heh, interesting. I was able to view the Hydra Nemesis EMS software while driving the car tonight. AFR ranged from 14.2 - 15.2 cruising on the highway.

Ambient Temp: 20* C (68* F)
Speed: 63 mph
Tach: 3100 rpm
------------------------------------------------------
Fan Speed: 0
A/C: Off
Coolant: 88* C

Fan Speed: 1
A/C: Off
Coolant: 88-90* C

Fan Speed: 1
A/C: On
Coolant: 89-92* C
===========================


Ambient Temp: 20* C (68* F)
Speed: 75 mph
Tach: 4000 rpm
------------------------------------------------------
Fan Speed: 0
A/C: Off
Coolant: 89-90* C

Fan Speed: 1
A/C: Off
Coolant: 90-92* C

Fan Speed: 1
A/C: On
Coolant: 92-93* C
===========================

Arriving back at the apartment, idling in front of the garage with A/C off and Fan Speed at 0 temperatures climbed from 88* C to 95-104* C

Tuning Screen Shots... http://s389.photobucket.com/albums/o...0Miata/tuning/

http://i389.photobucket.com/albums/o...3at12232AM.png

Those tables are fine. I know a lot of the spokes guys...I don't know any that can run their car in July at HHR without overheating. They also don't understand the need for ducting. If you're referring to that teal/mint green miata...nice guy, sincerely cool dude, great driver...that car was a little "disjointed" last time I saw it.

On to the cooling discussion:
See this car, it makes well over 350whp...easily. This is pic is from when "we" ran it in the Mojave desert in 101* heat. See that little air foil divider thingy 1" below the top of the bumper-mouth? That's all the air that goes to the radiator, which is ducted, and it runs cool.
http://i45.tinypic.com/sg0g8i.jpg
The TDR FMIC set-up works, I've seen the data first hand, you're auto-x buddies have not, and this set-up is proven to work over and over for the last 5-years in Texas heat by drivers who are no slouch.

This is pretty simple, you can dick around and try other stuff and spend more money or you can put a radiator in it, duct it, drive the car...or you can waste your time and fail. There are a handful of people here who've tracked turbo Miatas in the summer successfully, we know what to do.

BTW, I think Savington has a badass radiator for sale.

Care to share some more details (or a link to same) on the arrangement of ducts behind that little air foil divider thingy? Would I be right to think it diverts the outlet of the IC to exit below the car?

It dumps to the sides and there is a chamber built for the radiator. I don't have any more pics but you can search for them from the old magazine article now on the "modified mag" website when Matt wrote-up the build with SCC. edit: http://www.modified.com/projectcars/...ack/index.html


You can also get it on Forza now:
http://farm5.static.flickr.com/4034/...a912e782a5.jpg

That's full of Win right there! haha.

I've never worked with sheet metal before so this ducting stuff will be quite an undertaking for me. Wish I had a bigger garage. ;)

Find a roll of plastic and look at what everyone here made. You can do it with a straight edge, box cutter, and zip ties. I tried rivets on mine, but I go off-track at least once per day so I now use zip ties. Brain has great pics on his I believe...this is really easy to do and it works. I've run this car at 290whp for 2-hours in 100* heat as MSR-C and I'll run it at 98* at Hallett next weekend. I've never seen the water temp gauge (omori so it reads correctly) go above 180* even with triple digit temperatures tucked behind other cars for laps at a time.

Next time we are at the same event, identify youself! I'm sure I've seen you a number of times.

Great driver? No. Disjointed? Yes, my 26k mile Exedy Stage 1 clutch finally gave up at H2R on my first launch(line lock assisted).

There are many different ways to set up the IC/radiator/condenser stack. I spent more time thinking about it than it took to install the entire turbo, fuel and exhaust system.

The mindless test that made the decision for me was holding the intercooler up to a box fan and that very little airflow was coming through the core. I was shocked and it was very apparent that the radiator/condenser were going to be short on airflow.

The path I chose was to separate the IC and radiator as much as possible. I have a "small deflector" that guides air into the IC opening and the majority of the radiator airflow is coming from underneath via a plastic lip below the radiator like the 'vettes had. The separation greatly reduces heat soak when you are stopped.

Sealing and ducting is must. High pressure on the front side is good but it is about the pressure differential. Properly placed hood vents make a huge difference.

In RavynX's case, I don't think you can force enough air through the stack to make everything work considering how much heat the IC is dumping. The discharge temps from that blower are disturbing at 200°-300°.

Either way, it's a really nice car!

Stanford sucks! Do you know he ran his old four door street tired automatic BMW and won SSM a few times? Then to make us not feel so bad he took a bone stock S2k and smoked SSM again. Hopefully RavynX will be the one to give him some comp since he can actually drive.

lol and Stanford dominating.

I agree with you on everything but flow through the stacked TDR FMIC. The numbers are there in testing and driving on the track to indicate that IAC temps are dropping to nearly ambient at speed on the street and track. My buddy has before and after IC temp probes to monitor each, it works.

The moral of the story is that this dude needs to duct and buy a real radiator.

I miss hanging out with the "Skopes" crew.

Ι am running into the same problem too.
I have a coolant reroute and a bigger radiator. When I hit the a/c button the temp starts climbing and settles at 233F

http://img218.imageshack.us/img218/5968/img4994.jpg

Is your radiator ducted/chambered like everyone else here?

I'm going to start banning anyone who posts in here and ignores "ducting". DO NOT PISS ME OFF!!!

Yes it is, but no stock under tray.

Well, maybe you know what to do now.

Hustler you have no idea what your talking about! The guy obviously needs the Hyper Status Internal Flowbusting Indoplasmic Reticulum.....Geez, you call yourself a moderator?

My friend informed me of the Mishimoto radiator. I haven't found much info here or miata.net on it but it does have a lifetime warranty on it. Anyone worked with it before or should I just stick with Koyo? Edit: Nevermind, found some comparison photos and it looks like Koyo has a better build quality.

I'm about to drain the coolant & check the thermostat. I can pull the bumper off if I have enough time today.

I say either buy the dirt cheap one or pony up the cash for the Trackspeed radiator, a Ron Davis, CRR, or maybe even some big ass "stock car" radiator.

Got caught up in a few things but finally got the thermostat out. Temperature between 185-200 F (analog thermometer for the oven is all I had at the time, need a digital one) and the thermostat opened halfway. Up in the 200-215 range the thermostat was open completely with the spring fully compressed.

Mishimoto 52mm has been very good to me. Koyo has been made in Malasamnesia and not Japan for several years anyway.

If you are going to put it on the track in a hot climate don't go small. Do it right and only do it once.

Cool, thanks for the info. I ordered the Koyo 53mm last night due to its history here. If that one fails on me at some point I will try out the Mishimoto. Hopefully it gets here by next weekend. :)

I've got a TDR with the original M1 MP62 4-rib (so roughly an R1 now), and I haven't had a lot of issues on the track with heat... but I also don't have any way of tracking temps with EMB....

I have found though, in stop-in-go and such like, with 30+ degree days the AC adding additional heat to the system is enough to get the gauge to move.

Another local car has the similar setup, but with MSPnP + the PWR rad, and temps at the track were mint.

Right now, I'm probably going to grab one of the PWRs (fitment issues with the TDR + Koyo on m1's...) and be done with it.....

Dave,

Hi Chris...never met you but I've seen you at the SASCA auto-x events. Looking forward to seeing your car at the next event. That's if I get my car back from BEGi before the next event.

Huh, interesting. I can understand the system heating up in stop-n-go traffic but does yours heat up while just cruising on the highway like mine has?

Ah, cool. Yeah, if you see me in grid just come up and introduce yourself. :) Do you autox as well or just go out to watch?

Yes I do auto-x #37 CSP, still a :noob: and switching to SSM when I get my car back. I'll be Stanford's fresh meat :giggle:

Cover your anus with Jeff and Troy around. They touched my bad place.

:giggle:

All Photos... http://s389.photobucket.com/albums/o...undercarriage/



http://i389.photobucket.com/albums/o...x5Under001.jpg

Intercooler. Horns in front of it.
http://i389.photobucket.com/albums/o...x5Under005.jpg

http://i389.photobucket.com/albums/o...x5Under007.jpg

http://i389.photobucket.com/albums/o...x5Under011.jpg

http://i389.photobucket.com/albums/o...x5Under023.jpg

Found where the exhaust rattle is coming from. Didn't happen until I scraped on 2 speed bumps though. Odd.
http://i389.photobucket.com/albums/o...x5Under034.jpg