3rd gen single fan enough for the LS1?
3rd gen single fan enough for the LS1?
So my LS1 91 Firebird is now running. It currently has a 3rd gen radiator with the single fan. The fan is hooked up to pcm and works, but I'm wondering if the single fan is enough to cool the engine properly since the 4th gen has dual fans. Your help is greatly appreciated. Thanks.
Supreme Member
iTrader: (2)
Joined: Dec 2006
Posts: 5,538
Likes: 0
From: Hou. TX
Car: 86 TA, 91 B4C
Engine: 5.3, 4.8
Transmission: 4L80 4000, T56
Axle/Gears: 4.30 M12, 23.42 10 bolt
Re: 3rd gen single fan enough for the LS1?
I have the stocker on my 89 with a front mount pusher, works great, my 86 TA with the stocker and no pusher gets hot when i beat on it or just cruising, but it is a T56 in the 89 and a TH400 in the 86, but i think the 86 still needs a pusher.
Stock third gen duals would work great i think.
Stock third gen duals would work great i think.
TGO Supporter
iTrader: (2)
Joined: Jul 1999
Posts: 13,579
Likes: 9
From: Readsboro, VT
Car: 85 IROC-Z / 88 GTA
Engine: 403 LSx (Pending) / 355 Tuned Port
Transmission: T56 Magnum (Pending) / T5
Axle/Gears: 3.42 / ?
Re: 3rd gen single fan enough for the LS1?
Stick with the fan you have and watch your temps. If you start to see them creeping up, then it might be time for more fan. On the thirdgens, as far as I'm aware, the 2nd fan only comes on when the A/C is on, so unless you rewired it to run both fans all the time, the single fan is likely to do more than the dual fan setup in most cases.
Member
iTrader: (9)
Joined: Aug 2007
Posts: 338
Likes: 2
From: Lafayette, IN
Car: '85 IrocZ
Engine: LS1
Transmission: 4L60E
Axle/Gears: 3.73
Re: 3rd gen single fan enough for the LS1?
I was actually going to make a quick thread about this, just wondering if when using our single large fan setup, how does it connect to the pcm? I've got the wiring diagrams and will be looking at them more closely in a bit, but do i need to run a newer style relay for the fan?
Re: 3rd gen single fan enough for the LS1?
Use the fan 1 or low speed fan when wiring it in. Some diagrams label it differently, but its the same thing. If theres even a passing chance you may want to upgrade to dual fans later, go ahead and run the fan 2/hi fan PCM wire to where you're mounting your relays
Trending Topics
Supreme Member
Joined: Mar 2004
Posts: 2,519
Likes: 4
From: In the Garage
Car: Camaro
Engine: 6.2L
Transmission: T56
Re: 3rd gen single fan enough for the LS1?
I ran both hi/low to one relay on my last LS1. Not saying its by the book but it worked aces for a few years
Supreme Member
iTrader: (4)
Joined: Mar 2009
Posts: 3,079
Likes: 4
From: Pepperell, MA
Car: 1987 Trans Am
Engine: LQ9/L92
Transmission: 4L60E
Re: 3rd gen single fan enough for the LS1?
my setup's not done yet, but I'm giving the single a shot and seeing how it does. I did wire up my harness and got my pcm programmed for 2 just in case its not enough though.
COTM Editor




Joined: Oct 2008
Posts: 1,365
Likes: 216
From: PA
Car: 91/89/85/82 Z28s, 88 TA, 88/88 SC
Engine: SBC and LS variations
Re: 3rd gen single fan enough for the LS1?
On my LS376/480 setup when it was NA i was using just the standard 3rd gen single fan and it worked fine without any issue
This year when i have added the TVS2300 and put a big heat exchanger for the TVS in front of the existing rad, the single fan couldn't keep up even in cool temps... i changed to a Be Cool high eff dual fan and it works great in that application, keeping both water temp and intercooler temps in line
This year when i have added the TVS2300 and put a big heat exchanger for the TVS in front of the existing rad, the single fan couldn't keep up even in cool temps... i changed to a Be Cool high eff dual fan and it works great in that application, keeping both water temp and intercooler temps in line
Joined: Sep 1999
Posts: 1,405
Likes: 8
From: Grand Rapids, MI
Car: 1985 IROC-Z
Engine: Magnacharged LS1
Transmission: T56
Axle/Gears: Ford 9" 4:11's
Re: 3rd gen single fan enough for the LS1?
I run the stock single fan as well. I also run A/C and a magnacharger heat exchanger up there too....never overheats. I do have a big griffin rad though.
Former Sponsor
Joined: Jun 2001
Posts: 98
Likes: 0
From: Indiana
Car: 91 Firebird
Engine: LSX
Transmission: T400
Axle/Gears: 3.50
Re: 3rd gen single fan enough for the LS1?
Stock Single puller for me. Gets a bit hot after hot lapping a few quarter mile passes, but then again, it makes pretty good power (782 RWHP)
Supreme Member



Joined: Nov 2001
Posts: 2,266
Likes: 37
From: Canada,Ont
Car: 1987 TransAm Ttop
Engine: 2005 LQ4
Transmission: Ls1 T56
Axle/Gears: 3:54
Re: 3rd gen single fan enough for the LS1?
Single fan will work fine,and you can have it tuned in the pcm to turn on sooner if you like.I have dual fans on mine and no a/c.Second fan is my fail safe incase the motor ever started getting too hot..comes on at 210* and I also have a it wired to my a/c switch to turn it on manually if I need to.Havent yet but on the really hot days it has kept the motor at 180* in heavy traffic and never budged.
Thread
Thread Starter
Forum
Replies
Last Post
eightsixseven
Tech / General Engine
2
Dec 16, 2024 01:50 PM






