SmogSUX

iTrader: (12)

Finally a nice warm day (87F) to see if my car STILL runs hot...well it does.

Here's the low down:

Was 87F today, took the 7 out to a BBQ. Cruising there in the morning when it was cool out my temps were at 190F which was normal. It was 180F in the winter though for the operating temps. On the way home though it got up to 87F outside and crusing at 60-80mph on the highway (no boost) my coolant temps were at a steady 200F, oil 200F. I'd really like to track my car, but if it's getting that warm just sitting on the highway I doubt I would make it through the course without overheating.


My car:
1988 TII, Rick's Rotary rebuild with 3mm apex seals
Replaced the water pump, Super Koyo radiator, thermostat, running 70/30 coolant/water with water wetter, has the Shine Type 3 front end that allows more airflow.
BNR stage 3 turbo, 3" catless exhaust, bar and plate fmic, Underdrive pulley, no emissions, Microtech LT8s standalone, meth/water injection, N/a hood

Last summer I had all the coolant stuff replaced, and was using an oem thermostat from Mazda yet in hot days (95F+) my car would reach up to 215 cruising on the highway...

This season I am trying out a thermostat with holes drilled in it, but that doesn't seem to be working either...



Notes:

When just idling the Black Magic e-fan can bring the car back down to 185F after a minute.

Just getting off the highway and pulling into my garage I noticed my hotside on the turbo WAS red hot even though I was just cruising.

I DO HAVE MY PLASTIC UNDERTRAY ON


Could this be a timing issue or something?? My buddy tuned the car last year and he said he left it somewhat rich just to be safe.

Amur_

70% coolant? Wrong wrong wrong. The coolant does 2 jobs: lubricate the pump and prevent the whole mixture from freezing. It's the water that actually moves the heat. First thing I'd do is drain the system and replace it with 60%-70% coolant. Then see if your problem persists.

SmogSUX

iTrader: (12)

Oooppps my bad 70/30 water//coolant hahaha I did it so I'd have more heat dissipation with the water.

EDIT: One thing I was thinking of was that the bar and plate intercooler is just blocking too much air? Anyone have a bar and plate with no heating issues? I pulled the a/c condenser so I figure I have decent airflow...also the red hot turbo from cruising-can that be due to bad timing?

SmogSUX

iTrader: (12)

Bump...

specialop

Go back to a thermostat with no holes drilled. The thermostat the allows the cooling system to build pressure which raises the boiling point. No holes=1.3bars, holes=a lot less. 1 bar=atmospheric pressure. Atmospheric pressure is around 14.2 pounds. I can not remember what the ratio is, but an example is 1 lb of pressure=3 degrees boiling point increase. A solution to dissipate heat may be to get a vented hood.

jackhild59

iTrader: (7)

Ok, do you have the airpump off or on the car?

If it is off, what have you done for belts? Double alternator belt or yoohoo belt?

If the airpump is off and you haven't upgraded your belts, then your waterpump pulley is probably slipping. This slipping can get worse if you are running a belt driven fan. When the temp (ambiant and the radiator temp) rises, the fan clutch stiffens to pull more air. If you have only one belt on the waterpump/fan pulley it will slip and cause this overheating. The hotter your car gets, the less air the fan can pull.

Also...the underdrive pulley. Why? Underdrive pulleys are for racing applications where the engine is turning high rpms. The underdrive pulley prevents impeller cavitation at those high rpms by slowing down the waterpump. At the highway speeds you are travelling, this hurting you by moving fewer #'s of coolant through your radiator-and the temps get higher.

How thick is the intercooler and does it cover most of the inlet?

Good Luck!

SmogSUX

iTrader: (12)

My coolant isn't boiling though so I don't see why the pressure deal matters...Water boils at 212F, but I'm running 25% coolant so I'm sure it's a bit higher than that. The car ran hot last summer with the oem thermostat, it runs hot now with the drilled one..idk

I was going to get a vented hood, but couldn't afford one at the time...I shouldn't have to rely on one though to get acceptable temps when I'm not even putting a load on the car. I'm running the N/A hood due to the stock TII hood's design actually hurts airflow when you're running a front mount..that should be good enough.

I drilled the thermostat due to my car still running insanely hot (215F cruising) last summer...the underdrive pulley is really minor and it's a 6 rib belt. I used to run a dual belt setup, but it was ugly, so I picked up the 6 rib. I was using the highway as an example. My car does run warmer than it should in town too. It's just hard to really get an exact temp in town due to acceleration and such.

The intercooler is about 2.5" thick. It's identical to the Greddy fmic for the FC. The only difference is that it's bar and plate rather than the Greddy tube and fin design. It does cover the whole grill of my front bumper, as with most people who run a front mount.

The car has no emissions or anything like that. Just motor and turbo..

Thermostat:


Pictures of the belt:


The motor before the belt install:


The front end opening:

jackhild59

iTrader: (7)

Ok, so the belt is likely not slipping.

Left in my mind is
Underdrive pulley-reduced coolant flow

2.5" intercooler- reduced airflow


Just a suggestion: Try removing the intercooler. Put a piece of pipe in it's place. Drive the car without boosting on the highway. This should tell you if the airflow is the problem.

Good Luck!

specialop

Do you have another picture of the electric fan?

SmogSUX

iTrader: (12)

It's the black magic fan...2800 cfm. Should be plenty.


(Ignore my dirty engine bay >.>)

EDIT: Also I don't think the pulley is the cause, since last summer when I hit 215F cruising I had the stock pulleys running a dual belt setup.

SupSai7

iTrader: (8)

Few suggestions:
1)get a turbo and downpipe blanket and or thermal coating
2)switch to the stock clutch fan and shroud(it works great)

Also are you measuring your h20 temps before or after the t-stat?
Another thing i'm sure you know, that the stock t-stat doesn't open until 198*F +/- a few degrees, so there is nothing wrong with 200*F water temp.

jackhild59

iTrader: (7)

Ok, then lets zero base this thing.

What exactly has changed in your setup since you were happy with your temps last summer ?

Post a list.

KhanArtisT

iTrader: (2)

I don't think there is anything wrong at all with the cooling system. 200*F is fine from all the water temp threads I've seen. As stated earlier the t-stat doesn't fully open until ~195*. When you run the car hard I would assume the thermostat would stay open longer. If you want to help it you could fabricate an upper radiator panel to cover the gap b/w the radiator and the front bumper to trap the air in.

clokker

iTrader: (2)

Assuming that you know the thermostat is fully open at 184°, I think your problem lies with the intercooler and fan.

Not sure what you can do about the intercooler but you should make up a fan shroud that covers the entire radiator matrix. Since it looks like you've got the room, space the shroud 2-3" from the core, this will help alleviate the fan hub's dead spot.
Pulling air through the entire core instead of the 70% or so you're currently using should help a lot.

SmogSUX

iTrader: (12)

I'm in the works of making a cover for the bumper to the radiator right now...still looking into a fan shroud idea, but I know plenty of track cars don't even have fans on them since a proper setup really shouldn't need a fan if you're always moving. It's kinda why I'm wondering about my higher temps just cruising..

I kinda changed A LOT from when I had acceptable temps.
All at once I upgraded the turbo to bnr stage 3, cat delete, emissions delete, fmic, standalone, etc...everything happened at once.


Does anyone know of a company that sells t-stats that open sooner?

My sensor is reading the temps off of the upper coolant neck.

Ideally I'd kinda like to put the a/c back on this damn car. I'd go back to my dual belt setup and just run a/c for the highway. I don't mind sweating my ***** off when I'm running the car on the track, but the 1 hour drive there and the 1 hour drive back with no a/c kinda kills me.

EDIT: Also, should my turbo's hotside be redhot just from cruising? No boost, just constant speed at 70 mph, drive 1/8 mile down the road and parked in my garage...I know the turbo will get that hot when you get on it, but just from cruising??

SmogSUX

iTrader: (12)

Ttt

SupSai7

iTrader: (8)

Get a good tune and report back, IMO and experience that is not normal. Yes you will run lean when just cruising(no boost) and egt's will rise, but not that much in an 1/8 mile to make the turbine glow red. You've probably just anwsered your own post.

SmogSUX

iTrader: (12)

No, I had been on the highway for about 40 miles then decceled down 1/8 mile or so to my house and checked the turbo and it was red hot. Not redhot just from an 1/8 mile.

SmogSUX

iTrader: (12)

TTT again..

Turblown

iTrader: (12)

Sounds like your ignition timing is very retarded. Turbo shouldn't be glowing from cruising.

Most of the cars with FMIC's I've seen run those temperatures without a vented hood. You need to add ducting between the undertray and the radiator. There is like a 2" gap between the two and a lot of the airflow just goes right under. Cooling panel is a good idea too.

ITSWILL

iTrader: (12)

Could the turbo glowing red hot like that, be causing the coolant to heat up like that?

I noticed tonight, my turbo was glowing bright red/orange. I set the timing the factory spec?

Its an s4 engine with a t5 turbo, rtek 1.7, 720s and 550s, FMIC, duct is still there. Koyo rad. sealed between rad and rad support. Street port ( do I need to change timing for this ?).

I just assumed since the turbo was so F'ing hot it was heating the coolant. Also mine glows, just cruising with no positive boost, or boosting it.

It really sounds like a similar problem. I hope we can figure this out.

ITSWILL

iTrader: (12)

the vacuum line that goes directly to the compressor, had come off of mine.

I didn't see any where for it to go so I just blocked it off, no more glowing turbo, no more overheating.

If I were you I would look for vacuum hoses that have popped off, specifically the one that goes to the compressor housing,

J-Rat

iTrader: (2)

Problem 1, you drilled your thermostat.

Problem 2, it looks like you could drive a bus through all the paths AROUND the radiator. Seal those bad boys up, air will take the path of least resistance!

rx7_FREAKKK

iTrader: (1)

Im looking at your car... And that is No S4- S5 everything from what i can see

Zell

iTrader: (2)

Dude i dont think your cooling system is the issue, and you have taken similar steps like me when i was having the same issue, just from crusing my exhaust housing was redhot which indicates you either running really rich or lean, i have a power FC in mine however this may not be the same but in the setup it had 115C set to turn on the fans even though mine are manually turn on via swtich we changed the setting down to 85C and the car never went over 84C on the dyno, your probably asking why would that make a difference when the fans arent controlled by the ecu well apparently the correction map changes therefore your timing and fuel does aswell which maybe causing your rich mixture. As soon as i loaded up my car on the old setting it started to overheat but on idling it would be fine so year have someone look at the settings on the computer it could just be that.

I made a customer undertray, fitted efans to the oil coolers and none of it help untill this setting was changed then the oil woulnt get hot enough, the heating was the only concern i had when we put it on the dyno, untill the engine decided to swallow parts of the compressor wheel.

Panspeed do a themostat that opens at 68C, my friend is in Jap now and is picking me up one of these metal cooler necks with a aux port on it for a temp sensor, they dont list the themo on there website but i can try and find out what brand they offered my friend as i turned it down.
http://www.panspeed.jp/fc3s.html