Overheating - City Driving - HELP!

[Treachery]

I've posted this in several Mustang forums.. Please read on and help.

A Vortech SQ-Trim supercharger was installed in my '93 GT about a year ago. I've been very happy with the results except for the fact the car overheats in city driving. I had the 7 year old head gaskets replaced shortly after the Vortech was installed. So the gaskets are not the issue... I hope. I also don't believe that the temperature guage is the issue either. The overheating is obvious just by lifting the hood... HOT!

On the freeway, the temperture where it should be- between 1/4 and the 1/2 way point (or even cooler). When i come off the freeway and start city driving... up goes the temperature. Then back on the freeway, the temperature cools down.

I began with the FMS aluminum radiator and a slimline Flexalite fan. I then bought a Ramcharger dual-fan but the thing does NOT fit. I don't know how people with supercharged Mustangs can make the Ramcharger fit when clearance is slim. Ok.. I then buy a Fluidyne radiator... one of the best. The Ramcharger fan still did not fit even after "modifying" it. There goes $140!!! So back goes the Flexalite which is about the only type of fan that will fit.

Even with the new Fluidyne radiator and the Flexalite fan, the damn car STILL overheats in city driving!!! You can feel the heat from the engine when lifting the hood.

10% coolant- 90% water+ Redline WaterWetter ; 20% coolant - 80% water+ Redline WaterWetter; Mr Gasket 180 degree thermostat; it doesn't matter! The engine overheats! WHY! WHY!

I was thinking of the Vortech Aftercooler but i'm sure that other Vortech supercharged Mustangs are running cool without it.

What else do i need to do to get Vortech'ed Mustang to run cool in city driving??? What's the secret? I'm sick and tired of this cooling issue and i want resolution once and for all!

Suggestions!! Please!

 

[65ShelbyClone]

Well, stop spending money on your cooling system for a second and get a good temperature guage. If you're only going off the stocker, then its anyone's guess just how hot its getting. Mine would reach a point where 15* would make it jump 1/4 of the full needle's sweep based on what my Autometer was telling me. You're hardly running any coolant; have you actually boiled it over yet? I doubt you can tell the difference between 190* and 220* by merely opening the hood...

If its actually overheating at low speed, then its your fan. Everyone swears by the Lincoln Mark VIII fans. My fanclutch is trash and even with my mild engine and giant radiator, it starts warming up if I let it sit and idle.

Also, an aftercooler isnt going to make the engine run cooler. All it does is cool the compressed intake air charge to reduce detonation and make more power.

 

[ILLKreations]

Get a coolant flush, check your water pump, change to a 160 thermo, get a accurate guage, AND do not use any stop leak , ever! Good luck!

 

[autoXr1]

One other thing, which wasn't discussed was your air/fuel ratio. If it is running on the lean side (12.5-13.5:1) versus (11-12:1), it may run significantly hotter. Street engines running boost should run a "conservative" 11:1, or so. Race engines can be tuned a little more lean to gain power for the 1/4 mi.

It looks like you've taken care of the coolant issue. I'd double check the thermostat for accuracy and, in addition, I'd have a tuner check the air/fuel ratio.

The GTs tend to run a bit hotter than the LXs mainly because of the front bumper cover is continuous up to the hood and fresh air flow to the radiator is compromised. It's up to you, but I have seen people open up the front by using a hole saw and creating 3 or 4 large bore holes to allow more air flow...or simply change the front bumper cover to something that allows more air flow. It can be a challenge with a street engine that sees a lot of slow or stop-n-go traffic because the air has to sucked into the engine compartment vs. being blown in when cruising at speed.

Another mod which some roadracers employ is using baffles between the front bumper cover and the radiator. Remember air will ALWAYS go path of least resistance, so if it can go around the radiator instead of through it, it will. Air will typically go under or around either side of the radiator. Using some polished sheet aluminum, you can cut and install baffles to plug the holes on either side of the radiator. Under the car, you can shape a piece that directs the air upward into the radiator.

My .02

 

[65ShelbyClone]

The GTs tend to run a bit hotter than the LXs mainly because of the front bumper cover is continuous up to the hood and fresh air flow to the radiator is compromised. It's up to you, but I have seen people open up the front by using a hole saw and creating 3 or 4 large bore holes to allow more air flow...

Bleh, an easier and better looking route is to install a Cobra grille insert.

Another good idea is improving on the stock airdam. Check this out: http://www.brazeauracing.com/mustang/airdam.htm. This wont help low speed cooling, though. That is where the fan isnt keeping up with the engine.

Has the engine actually boiled over?

 

[gt90stang]

I've been working on a simular problem. When the ambient temp gets over 85*F the engine gets warmer than the theromostat temp with AC on, hasn't gotten hot enough to know how much yet. I did some temperature readings using a thermocouple in front of my radiator. I found that totally blocking the space above the radiator and under the hood reduced the temperature by 10*F. Then I tried blocking the spaces on the sides and bottom of the radiator and blocking a 2.5" strip of unused radiator core (outside the shroud) and this lowered the temperature by another 10*F. I my case my Lincoln Mark VIII fan was pressurizing the engine compartment and blowing air around the radiator (recursion) increasing the heat load. I used closed cell foam from a piece of pipe insulation to block the areas.

Good Luck, Don

 

[PRO50SC]

I've posted this in several Mustang forums.. Please read on and help.

A Vortech SQ-Trim supercharger was installed in my '93 GT about a year ago. I've been very happy with the results except for the fact the car overheats in city driving. I had the 7 year old head gaskets replaced shortly after the Vortech was installed. So the gaskets are not the issue... I hope. I also don't believe that the temperature guage is the issue either. The overheating is obvious just by lifting the hood... HOT!

On the freeway, the temperture where it should be- between 1/4 and the 1/2 way point (or even cooler). When i come off the freeway and start city driving... up goes the temperature. Then back on the freeway, the temperature cools down.

I began with the FMS aluminum radiator and a slimline Flexalite fan. I then bought a Ramcharger dual-fan but the thing does NOT fit. I don't know how people with supercharged Mustangs can make the Ramcharger fit when clearance is slim. Ok.. I then buy a Fluidyne radiator... one of the best. The Ramcharger fan still did not fit even after "modifying" it. There goes $140!!! So back goes the Flexalite which is about the only type of fan that will fit.

Even with the new Fluidyne radiator and the Flexalite fan, the damn car STILL overheats in city driving!!! You can feel the heat from the engine when lifting the hood.

10% coolant- 90% water+ Redline WaterWetter ; 20% coolant - 80% water+ Redline WaterWetter; Mr Gasket 180 degree thermostat; it doesn't matter! The engine overheats! WHY! WHY!

I was thinking of the Vortech Aftercooler but i'm sure that other Vortech supercharged Mustangs are running cool without it.

What else do i need to do to get Vortech'ed Mustang to run cool in city driving??? What's the secret? I'm sick and tired of this cooling issue and i want resolution once and for all!

Suggestions!! Please!

What's up with that coolant to water ratio. Looks a little low. Have you tried a 50/50 mix? Do you have to add coolant b/c the water is evaporating? Water boils at a much lower temp than antifreeze. What is the boiling point of the water wetter? Don't know much about that water wetter

 

[65ShelbyClone]

What's up with that coolant to water ratio. Looks a little low. Have you tried a 50/50 mix? Do you have to add coolant b/c the water is evaporating? Water boils at a much lower temp than antifreeze.

Water is a much better coolant than eythlene glycol, so much so that racers frequently use just water and Water Wetter. All ethylene glycol does is keep your engine from boiling over, freezing, and corroding.

 

[Michael Yount]

Most racers use just water because most sanctioning bodies prohibit antifreeze in the system - they don't want (very slippery) glycol all over the racing surface if there's an incident. Water transfers more heat than glycol does - so it's also the better cooler - provided the system is working up to snuff. Remember - in addition to lowering freezing points, glycol also raises the boiling point of the coolant mix - which can help stave off an overheating issue.

Treachery - you're simply not moving enough air across the radiator at low speeds. It's a fan issue plain and simple. Check this out - I use this controller on a different type of fan - but this controller with the MkVIII fan will solve the problem. As for space issues, well, you'll have to work that out -- because you've got to find a way to move more air at lower speeds. http://www.dccontrol.com/kitsr1.htm

 

[Silentst2000]

Water is a much better coolant than eythlene glycol, so much so that racers frequently use just water and Water Wetter. All ethylene glycol does is keep your engine from boiling over, freezing, and corroding.

Grassroots Motorsports magazine will say otherwise. Infact they called it overkill for most applications.

 

[Michael Yount]

Calling it (the use of just water) overkill for most applications is a completely different judgment than talking about the physics of the liquids. It's fact - water will transfer more heat per volume at the same temp. differential than glycols, antifreezes or mixtures of antifreeze and water. However - it's usually a moot point as most of us need the rest of the benefits that antifreeze offers - higher boiling points, lower freezing points, corrosion inhibitors and water pump lubrication.

 

[Silentst2000]

Well Grassroots argued the Leidenfrost effect and how water begins to fail as a coolant in hotspots. Glycol won't corrode your block and radiator and has a lower surface tension.

"When traditional coolant hits these hot metal areas, the water boils violently. This violent boiling is not at all conductive to transferring heat out of engine."

 

[miamifiveoh]

I agree with Michael Yount. This seems to be a "simple" case of lack of airflow at low speeds. I don't know how your setup is for clearance, but the a dual fan setup is usually easier to fit on our cars than a Mark VIII fan. The fan motors on the dual fans protrude in areas where there is usually clearance. The fan motor on the Mark VIII fan protrudes right where there is the LEAST clearance, in front of the water pump.

You can also try a 3.8 V6 Taurus fan. They have the same motor as the Mark VIII fan with a different blade & shroud setup. You can usually mount it around the bottom or top of the radiator and have some left/right movement, too.

I run this on my N/A combo with a big, fat FMS aluminum radiator. With a thinner radiator, I'm sure I wouldn't have a problem with even the Mark VIII unit.

Oh, and use that controller from www.dccontrol.com

Good luck,

 

[Michael Yount]

If you look at the data in Evan's website, they clearly show the higher specific heat of water compared to both their products -- NPG and NPG+. The issue is keeping the water from vaporizing - which pressurizing the system does quite effectively in most automotive applications. (http://www.evanscooling.com/html/npgPls2.htm)

It's kind of a moot point we've gotten into anyway. For street applications, if the components are in good working order, a normal cooling system with a mix of water and traditional antifreeze will keep the car from overheating and from freezing. And most sanctioning bodies will only allow you to run water anyhow. It will be interesting to see if Evans has moderate success marketing their propylene glycol-based products (although they've added ethylene glycol back in for the + product). I suspect the benefits were so marginal that folks weren't willing to change out pumps and other components to use the pure (and quite viscous) propylene glycol in NPG. I've wondered why the oem's haven't starting using this 'better mousetrap'. I suspect the problem is that while fuel efficiency might be improved by running hotter, NOx emissions would probably increase as well. There's likely a razor's edge being walked between potential efficiency increases at the cost of higher controlled emissions. And for older vehicles like ours, who's gonna install Evans' newer npg+ to slightly reduce the size of the radiator that might be needed? Especially when traditional antifreezes can control operating temperatures with properly operating cooling system components.