Cooling system upgrade
Thread Starter
Teching In
Joined: Apr 2012
Posts: 44
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From: Berlin
Cooling system upgrade Hey my fellow americans. My Cooling system and radiator on my Z28 finally is showing signs of tiredness with a small crack in the plastic sides and in it that sprays coolant when it gets hot. Was wondering what its step above a stock one? Im surprised the stock one made it this far with 40 GPM with high water pressure on the original radiator. Im still driving but having to fill the system with about 1 gallon every time before I go to work.
The car had been getting noticeably hotter when cruising 150kmh and cools down at 220kmh. I guess because more air flow at higher speeds. Checked the fans and they work normal.
3rd thing is water is leaking out the little hole in the bottom of the water pump. I hear that is when water pump is ready to be replaced. Should I stick with a gear driven pump or electric one? I read that Electric flow 55GPM and stock flows to the amount of RPM. 3000rpm = 30gpm.
Thanks,
Adam Luckovich
The car had been getting noticeably hotter when cruising 150kmh and cools down at 220kmh. I guess because more air flow at higher speeds. Checked the fans and they work normal.
3rd thing is water is leaking out the little hole in the bottom of the water pump. I hear that is when water pump is ready to be replaced. Should I stick with a gear driven pump or electric one? I read that Electric flow 55GPM and stock flows to the amount of RPM. 3000rpm = 30gpm.
Thanks,
Adam Luckovich
What do you plan on doing with the car?
I'd just get a replacement radiator, the only upgrade really is BeCool (aka $$$$)
There are pros and cons of each style as far as the water pump goes.
I'd just get a replacement radiator, the only upgrade really is BeCool (aka $$$$)
There are pros and cons of each style as far as the water pump goes.
Been running a becool for 8+ years now with no complaints. Coolant temp never got above 190 degrees at Sebring. As far as waterpumps the stock one outflows electrics by a mile at anything over idle.
Thread Starter
Teching In
Joined: Apr 2012
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From: Berlin
Thanks for the quick replies. I really like the stock pump because reading on other forums and how if the electric ones fail the motor fails. I hear griffin rads are good and not too pricey. Anyone running them? But for the right now the car is just a daily driver. Nothing crazy. Just want some reassurance and have something on the car before hand incase I do mod the car for more performance.
Another thing to consider is the RK sport air dam that's another couple inches lower than the stock one. I only run it at the track since it scrapes quite a bit on my lowered car, but if your stock height it should be fine. It will probably help with aero too.
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Coolant temps went from 250 running at 50% throttle short shifting at 4500-5k to 190 running 100% on the track with another 60rwhp.
Not to mention you don't have to worry about it springing a leak in another 5 years.
TECH Fanatic
Joined: Feb 2006
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^^^ Yea I can definitely see someone upgrading to this if their car sees a good amount of track time. Like you said, don't have to worry about springing leaks. Dad just spent a little under $500 for a radiator for his GTO.
But hey, if you've got money to burn, why not?
It's my educated opinion the GM installs cooling systems that are barely adequate for their application. Having the oil and transmission cooler in the radiator's tanks HEATS the oil and trans fluid when the situation is hot and the cooling system is at it's limitations. And the stock LT1 oil "cooler" really isn't a true cooler.
In my experience, most GM cooling systems, once approaching their maximum cooling limitations due to outside temperature and traffic, can't effectively perform.
In other words, the hotter they get, the harder it is for the system to cool itself down again.
A larger capacity radiator is the answer here. Better fans, water pump, etc. all help in small percentages. The big leap in better cooling is ditching the stock radiator for a true high capacity unit with metal end tanks.
OEM style radiators are crap. Once while running hot, the plastic hose end sheared off and without it, the hose popped off and dumped. I'll NEVER trust the plastic end tanks on radiators again.
In my experience, most GM cooling systems, once approaching their maximum cooling limitations due to outside temperature and traffic, can't effectively perform.
In other words, the hotter they get, the harder it is for the system to cool itself down again.
A larger capacity radiator is the answer here. Better fans, water pump, etc. all help in small percentages. The big leap in better cooling is ditching the stock radiator for a true high capacity unit with metal end tanks.
OEM style radiators are crap. Once while running hot, the plastic hose end sheared off and without it, the hose popped off and dumped. I'll NEVER trust the plastic end tanks on radiators again.
Last edited by Paul Bell; Jun 19, 2013 at 08:14 PM.
10 Second Club
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Most cooling issues that i've seen involve broken or missing air dams.
Thread Starter
Teching In
Joined: Apr 2012
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From: Berlin
Looks like a cool thing for airflow to radiator.
Thread Starter
Teching In
Joined: Apr 2012
Posts: 44
Likes: 0
From: Berlin
My car when I first got it ran around 180 and with the crack runs ~210-20 
You can get carried away with core thickness since it can reduce airflow.
Far as electrics they are free flow rated whereas the data we have on the stocker is in the circulating system fighting the restrictions like radiator and thermostat etc.
On my car in 40degree weather the car ran hotter on the highway than in the city with the electric waterpump. Was only like 3-4 degrees but shows that with 4.10s at a 70-75mph cruise is already beginning to lose control. They are adequate for most use, but not a cooling upgrade.
Far as electrics they are free flow rated whereas the data we have on the stocker is in the circulating system fighting the restrictions like radiator and thermostat etc.
On my car in 40degree weather the car ran hotter on the highway than in the city with the electric waterpump. Was only like 3-4 degrees but shows that with 4.10s at a 70-75mph cruise is already beginning to lose control. They are adequate for most use, but not a cooling upgrade.
On The Tree
Joined: Oct 2004
Posts: 145
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From: Everett
Hey my fellow americans. My Cooling system and radiator on my Z28 finally is showing signs of tiredness with a small crack in the plastic sides and in it that sprays coolant when it gets hot. Was wondering what its step above a stock one? Im surprised the stock one made it this far with 40 GPM with high water pressure on the original radiator. Im still driving but having to fill the system with about 1 gallon every time before I go to work.
The car had been getting noticeably hotter when cruising 150kmh and cools down at 220kmh. I guess because more air flow at higher speeds. Checked the fans and they work normal.
What you do want to worry about is making the free ram air flow go through the radiator. Make sure all the little bits of plastic, seals, etc, that seal the airpath to the condenser and between the condenser and radiator are intact. You want every molecule of air that goes under the nose to have to go through the radiator. The extended airdam Speed mentioned above will help as well.
3rd thing is water is leaking out the little hole in the bottom of the water pump. I hear that is when water pump is ready to be replaced. Should I stick with a gear driven pump or electric one? I read that Electric flow 55GPM and stock flows to the amount of RPM. 3000rpm = 30gpm.
Neither of those things puts more than a small fraction of the load on the cooling system as doing what the OP does, much less lapping a roadcourse as Speed was talking about.
Bare minimum parts and capacity is how GM does cooling.
Ive got a be-cool that came with the car otherwise i cudnt justify the price.it runs real cool tho with stock wp and 160tstat, never seen it above 185 and that includes autobahn style driving @ 145 for 3+ hrs in the summer
