Running hot

[theman1990]

My 87 GN is hot... I have done "all the cooling mods" and still running hot. I'm wondering if it's the high/low speed relay situation?

I have a moderately built engine, 375hp at the wheels, large front mount IC. I run about 210 degrees here in Tampa, FL w/ the A/C on. I've put in the 160* thermostat, fresh coolant and flushed the whole system, bled out all the air, has a big Champion aluminum radiator and the GN performance dual fans. The fans helped quite a bit b/c it was running in the 230-240 range!!! I know the temp sender is accurate b/c I can watch the temp rise at start then drop to 160 when stat opens before it rises again.

I have the Fast XFI 2.0 and fan comes on at 160. What I notice is that it doesn't "feel" like what I'd expect for 3100+ CFM. My mustang has a smaller Black Magic fan that feels like a hurricane when it engages. Makes me wonder if the FAST is only engaging the "low speed" relay rr is this just where these cars live temp wise in hot climates?

 

[mblum]

It shouldn't run that hot with that radiator and big dual fans.
What condition is the water pump in? Is it possible that its old and maybe the fins are deteriorated and not flowing coolant well?

I run this setup with a 180 degree thermostat and I have seen 190 once while setting in traffic when it was 98 degrees outside. AStock Appearing Aluminum Radiator with Dual Fans

My fans move a ton of air and I can easily hear them from the drivers seat with the windows down. The whole setup is hot wired from the battery and the OEM low speed fan relay circuit is what turns on the SPAL fans. Mine do not have a high/low function but both fans run at the same time. There is a slight 3-4 second delay from when the first fan turns on until the second fan turns on, I assume this is to avoid a current draw spike.

Are both your fans running when commanded to?

 

[theman1990]

Yah both are running

 

[theman1990]

It shouldn't run that hot with that radiator and big dual fans.
What condition is the water pump in? Is it possible that its old and maybe the fins are deteriorated and not flowing coolant well?

I run this setup with a 180 degree thermostat and I have seen 190 once while setting in traffic when it was 98 degrees outside. AStock Appearing Aluminum Radiator with Dual Fans

My fans move a ton of air and I can easily hear them from the drivers seat with the windows down. The whole setup is hot wired from the battery and the OEM low speed fan relay circuit is what turns on the SPAL fans. Mine do not have a high/low function but both fans run at the same time. There is a slight 3-4 second delay from when the first fan turns on until the second fan turns on, I assume this is to avoid a current draw spike.

Are both your fans running when commanded to?

That's the same rad/fan setup I have. If I turn the AC off it'll drop quite a bit. I'm thinking maybe the big front mount intercooler as well as the AC condenser are heat soaking the radiator. The water pump only has like 10,000 miles on it.

 

[mblum]

I run a PTE SLIC and my AC is not charged so I'm not running it, but my AC system is intact.

Maybe someone with a setup that more closly matches yours can chime in.

 

[jlat]

It shouldn't run that hot with that radiator and big dual fans.
What condition is the water pump in? Is it possible that its old and maybe the fins are deteriorated and not flowing coolant well?

I run this setup with a 180 degree thermostat and I have seen 190 once while setting in traffic when it was 98 degrees outside. AStock Appearing Aluminum Radiator with Dual Fans

My fans move a ton of air and I can easily hear them from the drivers seat with the windows down. The whole setup is hot wired from the battery and the OEM low speed fan relay circuit is what turns on the SPAL fans. Mine do not have a high/low function but both fans run at the same time. There is a slight 3-4 second delay from when the first fan turns on until the second fan turns on, I assume this is to avoid a current draw spike.

Are both your fans running when commanded to?

hello: I've never heard of that chip your runnin. Would U know the temps the chip is set for the fans to come on
IBBY]

 

[theman1990]

hello: I've never heard of that chip your runnin. Would U know the temps the chip is set for the fans to come on
IBBY]

Not a chip... Stand alone ECU. XFI 2.0 ECU w/ Internal Data Logging

Fan is set to come on at 160

 

[jlat]

hello: so what's an axis chip I see in your cars wright up.
thanks
IBBY

 

[mblum]

hello: so what's an axis chip I see in your cars wright up.
thanks
IBBY

The axis chip is one that Eric offers. It involves an axis MAF translator thats different than the original thats been on the market for a long time. Check out Turbo Tweaks website for accurate info.

 

[TType85]

I am running a similar dual spal fan setup along with a CAS V2 Front Mount, AC and a 160 stat and have not seen over 190 even on a hot day (southern California). I wired the fans so there is no low speed. With both fans on there is enough air pulling though that it will hold a paper towel to the grill.

How are your fans wired?

 

[jlat]

The axis chip is one that Eric offers. It involves an axis MAF translator thats different than the original thats been on the market for a long time. Check out Turbo Tweaks website for accurate info.

hello: I have his 5.6 chip and translater. LT1 maf. Axis Looks about what I can do. I did snot see any control of the fans with the Axis, is it there.
IBBY

 

[mblum]

hello: I have his 5.6 chip and translater. LT1 maf. Axis Looks about what I can do. I did snot see any control of the fans with the Axis, is it there.
IBBY

The axis chip is like Eric's 5.7, 5.7, and 6.1 chips where the fan control parameters are set in the chip when Eric burns them, they are not user adjustable that im aware of.

 

[626gn]

hello: I have his 5.6 chip and translater. LT1 maf. Axis Looks about what I can do. I did snot see any control of the fans with the Axis, is it there.
IBBY

The axis chip is like Eric's 5.7, 5.7, and 6.1 chips where the fan control parameters are set in the chip when Eric burns them, they are not user adjustable that im aware of.

Correct, no user adjustable fan controls on the Axis unit itself with a TT or Axis chip, but if you ask Eric to burn an Extender chip specifically for use with the Axis, then you would have control of turning the fans on at 175* or 165*, along with all the other features that chip provides.

 

[XracerX]

Makes me wonder if the FAST is only engaging the "low speed" relay

The Spal fan harness (if I'm correct, like the Caspers Spal and Intrepid dual fan harness) should only use the low speed fan relay to engage both fans on high speed. The second fan being delayed to turn on by a few seconds. Both should be on high speed. The is no low speed fan.

 

[Pronto]

I have that set up on my radiator and when xfi commands it to turn on, one starts and a second or 2 the other turns on. They are full speed. Very strong pull.

 

[1KWIKSIX]

Install a flowkooler water pump & add a bottle of RMI-25 to your 50/50 glycol-water coolant and your overheating troubles should be behind you

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RMI-25 - Engine Coolant System

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[BEATAV8]

Park it in the driveway let it warm up to 210
When it gets there put a box fan in front of it to boost the air flow and see if cools down.
If it does, you just need more fan. Get a black magic fan for it. As you know they are bad ass. You’d need good 10ga wiring both power & ground and a heavy duty relay I wouldn’t use the stock harness to run it.

 

[XracerX]

Something for you to check...... Ya never know
See if your radiator is boxed in. Stock box in kit is made of rubber and theres 3 pieces. If those are missing then air is traveling around the bottom and sides of the radiator. This pic shows the 2 side pieces only.

If missing you have 2 choices for replacement.

Stock style rubber box in kit = GN Radiator Air Box Kit (NEW), GBodyParts.com
or
New aluminum style = https://www.gnsperformance.com/bodyframe-g-body
GNS Radiator Box in Kit #20100GNS

 

[Pronto]

Maybe the impeller on the waterpump came lose.

 

[theman1990]

The Spal fan harness (if I'm correct, like the Caspers Spal and Intrepid dual fan harness) should only use the low speed fan relay to engage both fans on high speed. The second fan being delayed to turn on by a few seconds. Both should be on high speed. The is no low speed fan.

Yeah now that I think about how it's wired it makes sense...