1975 Vega GT

[Rickracer]

I use a temp switch (actually a pair of them), to trip the low and high relays on my truck. But you could run low off a temp switch and high off a manual toggle, or just run high only. With that little surface area, I would probably wire a relay for low, one for high, and trip both with a single low temp switch. Summit racing sells the switches, on @185°/off @170° (for low), and on @200°/off @185° (for high).
I built my own control system, but Summit sells a kit for dual fans: http://www.summitracing.com/parts/SUM-890014/?rtype=10 ...



...or the temp switches alone/separately: http://www.summitracing.com/parts/SUM-890017/



There are quite a few other kits out there, but most are a fair bit more money, and my relatively cheap setup works just great,

[73astregt]

bowtie as rick said forget the pusher fans and get something behind the rad to pull the air thru, pusher fans are ok for an auxiliary for some help in heavy traffic but they dont work as a primary setup. i went thru all this when i built my astre, all it had was pushers at first and all it wanted to do was overheat after a few blocks in town ,id have to shut it down and cool off then continue. what i ended up going with was a 15 1/4 flexalite mechanical fan with the pushers as a backup, i dont think i have even turned on the pushers in the last year except for the hottest of days in traffic and my rad is a copper 3 core that only measures 13x 25! i only have the silly little metal upper shroud piece on the car with nothing the rest of the way round too. another thing i did that helped a lot was to put on the front chin spoiler wich helps drive some air up into the rad and creates a vacume behind it to let the hot air escape under the car. to make a shroud you can do it in fiberglass with a wood frame similar to how the subwoofer enclosures are done there is a thread here somewhere where a member made one this way and we copied his design to make a shroud for the bosses sons cougar with a 351 in it worked great! i think i have a pic of it ill try to find it. edit, heres a couple pics of the fiberglass shroud we built for the cougarwith a electric puller fan,

[BadBowtie]

Thanks for all the input guys, just chilling out researching after my 43 hour four day work period! I'm looking for how people mounted their rads / header panel when they pushed the rad forward.

7879730014_medium.jpg

This is V8astregt's picture from his online album, and I have the same fan in my basement set up to be used on this rad... BUT i need to somehow move the rad 4" forward to clear everything. I'm wondering if my hoses will work etc/if i can even go that far forward. I'm not sure if i will have the time tomorrow, but i will look at the possibilities. Also if you move the rad that far forward, how are you supposed to fill it with fluids? Remove the header panel every time?

I will be sending V8astregt a pm

Thanks again for all the help, id be wasting my money on new pushers and still not be cool enough

[73astregt]

take another look at joshes pic you can see the remote fill rad cap just by the edge of the air filter on top of the thermostat housing. i believe josh has pics in hisproject journal of how he modified his rad cradle to move the rad forward.

[BadBowtie]

Found the post v8astregt made on installing the rad http://forums.h-body.org/viewtopic.php?f=20&t=1289 probably what i will have to do. Unfortunately im realizing that I might have to get the rad modified again (for the third time) so the upper rad hose clears the fan shroud

and the speedphreake's install http://forums.h-body.org/viewtopic.php?t=22634

[BadBowtie]

bowtie as rick said forget the pusher fans and get something behind the rad to pull the air thru, pusher fans are ok for an auxiliary for some help in heavy traffic but they dont work as a primary setup. i went thru all this when i built my astre, all it had was pushers at first and all it wanted to do was overheat after a few blocks in town ,id have to shut it down and cool off then continue. what i ended up going with was a 15 1/4 flexalite mechanical fan with the pushers as a backup, i dont think i have even turned on the pushers in the last year except for the hottest of days in traffic and my rad is a copper 3 core that only measures 13x 25! i only have the silly little metal upper shroud piece on the car with nothing the rest of the way round too. another thing i did that helped a lot was to put on the front chin spoiler wich helps drive some air up into the rad and creates a vacume behind it to let the hot air escape under the car. to make a shroud you can do it in fiberglass with a wood frame similar to how the subwoofer enclosures are done there is a thread here somewhere where a member made one this way and we copied his design to make a shroud for the bosses sons cougar with a 351 in it worked great! i think i have a pic of it ill try to find it. edit, heres a couple pics of the fiberglass shroud we built for the cougarwith a electric puller fan,

Im starting to consider the possibility of a mechanical fan, my choices are move the rad 1-2 inches or relocate the rad 4-5 inches under the header panel to get the taurus fan in there right... Do you have any pictures or what type of fan you are running (is it plastic or metal) and how close your setup is? Id constantly be worried about the fan hitting the rad! (also id make an enclosure for it)

[spencerforhire]

Lots of great cooling ideas in this thread; and as a few members pointed out it takes a combination of different things to cool a big motor in as small space. Airflow has to be "managed" from the time it enters the grill until it exits the engine compartment. Even if you do EVERYTHING- add a chin spoiler, seal the gaps around the front of the rad support so all air that enters the grill(and the lower valance) has to go through the rad, switch to an aluminum rad, use puller(s) or a mechanical fan AND a pusher, then you still have to figure out how to get all that hot air OUT. A cowl induction scoop can help, and so can drilling some 2" or 3" holes through the firewall into the cowl area but there can be an issue with fumes getting into the passenger compartment through the heater ducts and kick panel vents. I like the solution that local forum member "mbreen" found- punch some louvers in the hood; it works(he says the car runs cooler) and it looks great too!
Here's the thread about his louver project-
viewtopic.php?f=1&t=30877&p=169741#p169741
And a pic I took on Sunday at a local show-

[Rickracer]

Here's a few ideas I used on my S10, and a great wiring diagram for a Taurus fan controller setup.....











In addition to adding the "wings", I divorced the radiator cap as well, so it sticks out from under the core support. I hate the way a lot of guys just hack up the top of the core support for access to the cap, it just makes them look butchered IMHO.

Taurus Fan Controller Diagram:

This is a fully automatic control system, with an optional manual override to turn the fan on high. It does turn off the low side when the high side comes on, and it can be altered to include a low speed temp control switch or manual override as well, simply by replacing the ground on terminal 86 of the bottom relay with your own low speed temp switch, controller, or manual override switch.




These are the temp switches I have now, (using them with my Intrepid fan setup), and are what I recommend :
SUM-890017 for the 185° on/170° off switch, and SUM-890018 for the 200° on/185° off switch.

BTW, I do build these fan controllers for people if they ask, $90 + shipping.

[BadBowtie]

Thanks again guys, i might have some time to work on the car today so i will figure something out soon!

[BadBowtie]

Its been a while, but i finally got a start on the rad support modification.
I was toying with the idea of just getting enough room for a mechanical fan but if I'm going to drive this car daily i want to be able to have confidence in its cooling wherever i go. Therefore I'm going to relocate the rad 4" forward onto the other side of the rad support and run the taurus fan setup.

Thanks Rickracer for the schematic, it will definitely save me some time to get the wiring started, I plan to have the low speed come on via sensor (current is on 200 off 185, but I'm going to try and find an on 180 off 160) and then have the high speed connected via mini toggle in the car (I'm into electronic wiring).

I am a little concerned about getting the airflow to the rad because it will be so far forward, but the taurus fan sits flush on the face of the core and should provide good suction. I will try and get the fan close-ish to the engine so that the rad is as far back as possible and maybe an air dam will be made in the long run.

Cant wait to get this sucker back on the road

[spencerforhire]

Here's the fan switch I've installed in a dozen or more customers' cars-
http://www.summitracing.com/parts/PRF-30111/
There are lots of different temperature ones available and even adjustable units($$$) if you want to experiment; every motor/chassis/climate/traffic combination is unique.
If you have enough holes in your head( ) and intake you could use 2 separate sensors for the high and low speed fans, but I still suggest a bypass toggle switch on at least the higher temp one just for peace of mind. Speaking of different holes, the coolant temp often measures 15-20 degree higher in the cylinder head between 2 exhaust ports than it does in the intake manifold next to the water neck. This could actually make your high temp sensor come on before your low temp one!
Some cheap electric fan controllers have a probe or sensor that attaches to the rad; these I do not like. The way I look at it is that it's too late to try to control the temperature of the engine once the thermostat is open and the coolant is in the rad.

[BadBowtie]

Here's the fan switch I've installed in a dozen or more customers' cars-
http://www.summitracing.com/parts/PRF-30111/
There are lots of different temperature ones available and even adjustable units($$$) if you want to experiment; every motor/chassis/climate/traffic combination is unique.
If you have enough holes in your head( ) and intake you could use 2 separate sensors for the high and low speed fans, but I still suggest a bypass toggle switch on at least the higher temp one just for peace of mind. Speaking of different holes, the coolant temp often measures 15-20 degree higher in the cylinder head between 2 exhaust ports than it does in the intake manifold next to the water neck. This could actually make your high temp sensor come on before your low temp one!
Some cheap electric fan controllers have a probe or sensor that attaches to the rad; these I do not like. The way I look at it is that it's too late to try to control the temperature of the engine once the thermostat is open and the coolant is in the rad.

I'm pretty comfortable with the on 185 off 170 to turn on the low side and a bypass and/or secondary sensor that's on the car now for turning the high side on at 200. And if i run two sensors I will make sure to have them in similar areas so that I don't have any problems.

However I am noticing a lot of over expensive stuff out there that doesn't work, summit wanted 81$ for a two relay fan kit, just bought all the parts i need (with better relays) minus the 30$ sender for 27$ thing get a lot cheaper when you're willing to DIY However I'm about to splurge on this because the rad will be mounted on the other side of the rad support.

csi-914c_w.jpg

[BadBowtie]

Well after a busy week I can say the vega is finally road worthy! Drove her all afternoon without any problems. I mounted the rad 6" forward along with the two speed taurus fan. Had a small problem yesterday with my clutch not working but it was my pedal assembly not properly mounted (missing the upper bolt that keeps the firewall from being pulled downward on the later pedal assemblies).

Car ran great, FAST and surprisingly well behaved. I dove into this project blind by buying a vega and test driving it a few times then beefing up the whole car /dropping a 4speed and V8 so i had no idea what to expect! I am very pleased with the "feel" of the car, it is unique and very distinct/already an eye catcher. I did however experience a bit of wheel hop after easing into the gas from a roll, but it seemed to be related to the roads surface (bad roads = wheel hop) and how much throttle i applied (more throttle = less hop).

What can i say, no feeling better than easing into the gas, feeling the car squat and smoking the tires from a roll without dumping the clutch!

PICS to come tomorrow of my new rad setup.

Thanks for everything guys
James

[ironwillsv8vega]

Envy and happy for you all at the same time......

[BadBowtie]

Envy and happy for you all at the same time......

It all comes in due time! In fact my pain isnt over yet, the front brakes locked up on me again after a 15 minute drive... i think i've found the problem to be my master cylinder pushrod and will be taking it apart shortly. And i've got water in the car (recent rain has pointed out some good flaws... haha