S/C vs A/C vs HOT WEATHER

[WormGod]

SOOOOOO.... I took a little vacation this past week and let the VX be the mode of transport since there was some good dirt and sand trekking involved. Along the way, there was much highway use involved, and with this cursed Mid Atlantic heat and humidity, the A/C was a pumpin'. Cruising along just fine at anywhere between 65-70mph, with the occasional floor mash to pass andone not wanting to get out of my way, I looked down to notice at one point that my temp gauge was quite close to redline. I backed off the accel to about 60mph, turned off the A/C, and dropped the windows (HAAAIIIILP! ITS HOT AND NASTY!!) Within a minute, the temp went back to normal. For pewpew and giggles, I turned the A/C back on and watched it climb back up. Long story short, the A/C was no longer used for the trip, and my flesh was sad for that.

Well, back home this weekend and changed out the thermostat. All appeared to go better, but it still rose rapidly once I was up to highway speed with the A/C on. I tyried it on backroads and even within the city, and it still rose with A/C on. She runs completely normal with it off however. I am SURE that the S/C sucking in hotter than normal air (temps and humidity make it extremely uncomfortable for me to even breathe) is not helping much, but that is unnavoidable.

I am not much of an A/C guy, especially since I RARELY use it, but this summer had been a record intense here. I now come to you folks who may have some suggestions on the S/C operation in hot weather with use of the A/C. Any suggestions welcome.

[newthings]

Hi Wormgod,
Do a search on Aluminum Radiator and my name (Newthings).
Mine is still resting in the garage. Average Oregon temp is about 60.
Ron Davis never put the VX model in the database, but my name and build number should ID it.
Roy

[johnnyapollo]

I'm experiencing the same issue - the SC really jacks up the heat sensor. Get's me worried, especially with the recent 100+ temps locally.

-- John

[Knigh7s]

I'm getting the same symptoms. 'sept I'm not running a S/C.

1.) Only when I mash the pedal to pass on the freeway (AC full blast)
2.) When I'm sitting at a stop light or drive through to long my temp will rise but when I get moving to around 45-60 mph, temp drops right back down. (AC full blast)

I'm thinking If I add a secondary aux fan, that should be enough to pull some ambient air through my rad. But I don't know if that would help considering the ambient air is 100+ degrees

For you S/C guys/gals, I don't know if this has really been discussed, has anyone considered or has installed a water injection system? maybe even a methanol/water system? Since there is really no room for even a small intercooler. It might help to keep the temps down during the summer seasons...

[etlsport]

a secondary fan helps when you are sitting, lowered my temps 5-10 degrees.. but it doesnt do squat at normal driving speeds

[Knigh7s]

a secondary fan helps when you are sitting, lowered my temps 5-10 degrees.. but it doesnt do squat at normal driving speeds

I saw that in your gallery couple days ago. I'm really planning on doing that... What size/brand is that fan? Was it an easy install?

[Ldub]

SOOOOOO.... I took a little vacation this past week and let the VX be the mode of transport since there was some good dirt and sand trekking involved. Along the way, there was much highway use involved, and with this cursed Mid Atlantic heat and humidity, the A/C was a pumpin'. Cruising along just fine at anywhere between 65-70mph, with the occasional floor mash to pass andone not wanting to get out of my way, I looked down to notice at one point that my temp gauge was quite close to redline. I backed off the accel to about 60mph, turned off the A/C, and dropped the windows (HAAAIIIILP! ITS HOT AND NASTY!!) Within a minute, the temp went back to normal. For pewpew and giggles, I turned the A/C back on and watched it climb back up. Long story short, the A/C was no longer used for the trip, and my flesh was sad for that.

Well, back home this weekend and changed out the thermostat. All appeared to go better, but it still rose rapidly once I was up to highway speed with the A/C on. I tyried it on backroads and even within the city, and it still rose with A/C on. She runs completely normal with it off however. I am SURE that the S/C sucking in hotter than normal air (temps and humidity make it extremely uncomfortable for me to even breathe) is not helping much, but that is unnavoidable.

I am not much of an A/C guy, especially since I RARELY use it, but this summer had been a record intense here. I now come to you folks who may have some suggestions on the S/C operation in hot weather with use of the A/C. Any suggestions welcome.

This might be a dumb question...but are you sure your electric (secondary) fan is working, coming on when the AC is on ?
I've had no temps over about 212-214 with the AC on in Moab.

[WormGod]

This might be a dumb question...but are you sure your electric (secondary) fan is working, coming on when the AC is on ?
I've had no temps over about 212-214 with the AC on in Moab.

Ya, I can hear the fan when it kicks on. Even saw it kick in one day when it was just sitting in a parking lot running while I was standing around talking to some friends.

I saw a thread some time ago on the NASIOC forums and there was talk about a synthetic coolant that some people use that race their cars. It's highly recommended for engines that get pretty hot so I am trying to dig it up and look into it. I will see what I can come up with if it ever comes into my sights for researching into.

And ya, another fan has always been on my list, even before I did the S/C. I just have yet to get around to that, but I am sure any little thing will help.

[Jolly Roger VX'er]

I've had no temps over about 212-214 with the AC on in Moab.

My VX's temperature gauge has only exceeded the half-way mark once, and that was in Vermont going up Mt. Equinox (5 miles steep ascent while in the 90's). Its been in the 90's a few times here and still the temp stays "normal" with the AC on and running with SC. Have you tried a radiator flush? Maybe that would help? I've never flushed mine...only changed to Texaco Dexcool AF.

[circmand]

Has anyone tried an under mount scoop? I cant think of the correct name of it but a lot of sports cars that run hot by their nature have an attachment behind and under the bumper which directs air from under the vehicle up into the engine compartment

[newthings]

Alpine S/C people suggest the quick way to get more cooling is to get the trans cooler function out ot the radiator and into an external trans cooler. Where to mount it has always been the problem.
Roy

[Chopper]

Newthings is there...open that rad up. Flush it for sure(should do that every 24 mths. anyway) or look into a new rad. Check those hoses, too soft? It's certainly not unknown for GM radiator to sludge up...they need distilled water and clean antifreeze. Good luck

[WormGod]

My radiator is only about a year old and the latest flush was when I actually put the S/C in, with all new fluids just earlier this year.

I think my future plans include another rad fan and a some better air porting.

I am NOT touching a single thing that involves medium to heavy work because I think my tranny is on it's way out anyways. It's been showing the sure signs of a dog that knows that it's last days are coming. That happens, then she sits in the garage until I decide to drop another money bomb and go full throttle with an overhaul. Or.... I sell her.

[tom4bren]

Sorry to hear about the potential tranny SNAFU. Any chance that it could be heat related? Since your engine is running hot, it follows that the tranny is too.

[tom4bren]

I did some research on upgraded cooling systems and came up with some good info but I need input from some of you that are experiencing the problem. Most of the info I got from Dave at Evans Cooling (888) 990-2665 www.evanscooling.com. I also found www.calsonic.com that seems to carry some nice radiator/fan combos but the guy is out till next week (248) 848-4876.

1) For those of you that have installed the S/C, did it include a new pulley for the water pump? If the pump is turning too fast with a water based anti-freeze, you will get cavitation at the pump which will actually reduce the flow. Evans sells a product called NPG-R that can be used in a stock set up that will not cavitate (their product NPG+ requires upgraded radiator, pump & thermostat). Dave indicated that if you run NPG-R, you can remove the thermostat & eliminate that as a potential cause for the overheating.

2) Some vehicles constantly circulate anti-freeze through the heater core (even with heater off). This actually limits coolant flow through the radiator. Need to determine if that is the case with the VX & if a cut off valve can be installed for summer use.

3) The VX has a 2 stage thermostat set for operating at 192 degrees and also has a bypass circuit. The bypass circuit shunts coolant back to the engine without going through the radiator. If you are overheating, the bypass circuit may be stuck open. Need to determine where this bypass is and if we can plug it off. This should be your first plan of attack.

4) Radiator - The VX comes stock with a single row of 1 inch cooling tubes. Standard configuration for upgrade radiators are 2 rows of half inch (no improvement (0%)) or 3 rows at three eighths inch (small improvement(12.5%)). Dave indicated that if you don't increase the total diameter by more than 25% then you will not get ANY benefit. He would like to see 2 rows of 1 inch cooling tubes for the S/C application.

5) If we meet with screaming success in getting your temps back down to a comfortable level, we may actually create an opposite problem. If the temp gets too low, the computer will sense an out of spec reading from the temp sensor and send it into a "limp home mode". It probably won't send any error codes but the VX will probably run bad or no power or even worse gas mileage (and I'm guessing it would be even worse with a S/C).

I hope some of this info is helpful. If I come up with anything else, I'll let you know.