Helping out my LS1 fans

[Hit Man X]

I noticed a VAST difference in cooling capacity with the 34" core over the 28" one. Currently I'm halfassed looking for a 34" core with the motor oil cooler and ATF cooler with a bad core to have it recored. The one I have is without motor oil cooler. A 130-145A alt really needs to be done with e-fans for idle speed charge, hell even the AC blower fan slows down when the fans come on!



SlammaDingdong... can your fans still run at 50% power also? I also have a manual override switch I used incase I needed it. The VSC is no more, so forget about that. lol

I agree, having the fans cycle On & Off with the compressor is annoying. Do keep us posted on what you discover. Would an extra relay turning that from a "+" to "-" work in that situation? Could the PCM ground one of the relays and the Low Pressure Switch be the positive 12V for the other?



TXsilverado... I don't have any cooling problems, but before I add e-fans AGAIN I'd like to limit their quirks once and for all. They don't need to be on when I'm going faster than 45mph unloaded.

[RedHeartbeat]

I bought my 34" rad that has coolers for the oil and trans for $175 from a local company that sells the asian copies of GM sheet metal. It's a quality piece especially for the money. I can't tell it from the original other than it doesn't have a big hole in the middle of it.

[SlammaDingdong]

Originally posted by TXsilverado@Jun 21 2005, 02:56 AM
im still on the 28" radiator. lots of people use the ls1 fans without any problems...is it making a seal around your radiator?

edit. and they are pulling air towards the motor and not pushing air out right? i had to reverse the wiring on my harness whe i got it because they were pushing air instead of pulling. if you put a peice of paper in front of the grille with the fans going it should suck the paper onto the grill, not blow it away.

make sure you do the paper test because mine felt like they were pulling air when i put my hand down in the motor compartment but it was really pushing hot motor air through the radiator.

Thanks for the input man. I love this forum because of the good advice and we don't slam each other.

Just to clarify things, the performance of the original "stock" LS1/Nelson Harness setup was pretty adequate, so I was not having overheating issues or anything like that. If I somehow overstated this, my bad

My intention was to optimize the setup for what I was observing in relation to normal, "base" operating temperature, which for me is about the 185* tick on the temp guage. During high amounts of city street, stop and go driving, w/o the A/C on, the fans at 50% power would lower the temp. Problem was at 50% the fans would never bring it back down to "normal", until hitting a stretch of road where I could roll for quite a while at least at 35-40 MPH or so.

Now, if I was running the A/C, and then the PCM triggered and spun the fans up to 100%, it worked great, even while sitting in traffic. I could have lived with this but didn't want to.

Adding the aux fan and a little rewiring made my setup much more optimal. The A/C is very frosty, the operating temps drop quickly when fans get triggered and I'm happy. I spent about $100 (including the fan) on parts to get this configured. It was best approach, since I was protecting an existing investment (LS1 fans and harness). Just need to upgrade the alt, which should have been in the first place anyhow.

I just wish the PCM supported mutiple fan stages. I've heard some '05s do, but can't confirm that.

[SlammaDingdong]

Originally posted by Hit Man X@Jun 21 2005, 12:34 PM
I noticed a VAST difference in cooling capacity with the 34" core over the 28" one. Currently I'm halfassed looking for a 34" core with the motor oil cooler and ATF cooler with a bad core to have it recored. The one I have is without motor oil cooler. A 130-145A alt really needs to be done with e-fans for idle speed charge, hell even the AC blower fan slows down when the fans come on!



SlammaDingdong... can your fans still run at 50% power also? I also have a manual override switch I used incase I needed it. The VSC is no more, so forget about that. lol

I agree, having the fans cycle On & Off with the compressor is annoying. Do keep us posted on what you discover. Would an extra relay turning that from a "+" to "-" work in that situation? Could the PCM ground one of the relays and the Low Pressure Switch be the positive 12V for the other?



TXsilverado... I don't have any cooling problems, but before I add e-fans AGAIN I'd like to limit their quirks once and for all. They don't need to be on when I'm going faster than 45mph unloaded.

Hey Hit Man!

No, I gave up the functionality of both LS1 fans running 50%. If the bleepin' PCM supported more than one temp trigger stage I would have definitely kept it. I was halfway tempted to use an adjustable temp sensor (not VSC), to provide an intermediate stage for 50% fan function. I may end up doing it, who knows. It would require another relay and diode based on the way I got things wired now. Then you'd have something like this:

A/C on only: LS1 fan2 + aux at 100%
Sensor temp trigger only: both LS1 fans 50%
PCM temp trigger: both LS1 fans 100%
A/C on + Temp trigger (PCM and/or sensor), or Override switch: all fans 100%

Unless using a VSC of some kind w/ these fans, we're really dealing with discrete states and cooling latency. So of course, the more stages the better. The clutch fan, basically an analog device, does not have these inherent issues.

I've got vacation days tomorrow and Friday, so will be looking at the proposed solution using the A/C accumulator switch.

[TXsilverado]

i guess ive never left my truck sitting without the ac. ac is a MUST where i am so its always on. ive got it idling outside right now without a/c in about 98* weather right now to see if mine gets warmer than usual. ill give an update

[TXsilverado]

my trucks mirror reads 102 and the temp guage on my padio reads 101. i let my truck sit in the sun parked in the street without the a/c on and listened to the fans cycle on and off 3x @ 50%. the dummy guage in my dash hovered just above 185(not even to the next mark) guess im just one of the lucky ones???

could my functional cowl hood be helping?? heat is flying outa that hole when the fans kick on

[SlammaDingdong]

Originally posted by TXsilverado@Jun 22 2005, 04:49 PM
my trucks mirror reads 102 and the temp guage on my padio reads 101. i let my truck sit in the sun parked in the street without the a/c on and listened to the fans cycle on and off 3x @ 50%. the dummy guage in my dash hovered just above 185(not even to the next mark) guess im just one of the lucky ones???

could my functional cowl hood be helping?? heat is flying outa that hole when the fans kick on

It was only 92* here today, but w/ like 70% humidity. Nice.

Anyway, that's a good point, the hood cowling probably does help alot. And those beastly 292s have big time cfm capacity, even at 50%. The big FALs are probably what i should have gone with from the start. Oh well, live and learn.

Stay cool

[SlammaDingdong]

Okay, so this thread went on ad-nauseam. I started it, so here's the end result...

These are my LS1 fans, they needed help!



Here's the pusher (FAL #108) i added.



[Nice tranny cooler too huh!]

Finally, just call me Johnny Relay!



That's four extra relays (you can only see three). Two integrated into the Nelson harness, two for an override switch in the cab.

[metalmulisha777]

what size radiators in my truck its a stock 99

[jethro_3]

Measure inside the caps, it's either 28" or 34". Z71 most likely 34".