Bill Ball

I rewired the muffins to run 2 off fan 1 and 2 off fan 2. I wired in a relay as well on fan 2 to control the auxiliary fan. At about 185F ALL the fans came on. No staging of 1 then 2. Probably OK except for AC switch signal. Could that be because the AC compressor is off the car (going back in later today)?

Bill Ball

Hmmm...nope. Forgot about that. So, again, maybe things are working fine.

Bill Ball

I agree. I believe I shorted the leads on that fan at some point. AC signal is not doing anything, but the compressor is off the car at the moment. Don't know for sure if that is a factor. I'll try the other configuration again. At least I know now that fan 1 and 2 come on when the engine reaches temperature. Yesterday we ran around with the lower radiator temperature switch pulled, fans running all the time and the temp barely crept beyond the 75C T-stat point.

Bill Ball

Konstantin drove down to get new tires put on. Car got to 185F or so and all the fans came on and temp went down. Stayed there nicely. After the tires, I drove the car home, a bit more energetically and it went to 210, fans running, on a 68F day. Odd. Opened the hood when we got home and it was hot. The SC was real hot but I didn't push it THAT hard, just first and second and cruising in 3rd. If it does this on 68F, we have to wonder what happens when it gets hot out. Checked the fans - all working and turning in the right direction. I'll puzzle over it in the morning.

Shmurzik

Kevin,

Thank you, this does sound like a good idea. With the smaller fans there is a lack of forced flow in the middle of the radiator right where the supercharger heat load originates. Once again, thank you for the lead

FUSE69

Should work regardless... I have no AC components on my car, so the AC switch serves as a great 'manual override', thermo on/off switch...

Vlocity

Bill:

I didn't want to trust the old factory wiring and switches. I ran a 30 amp relay off of the jump post with a key on switched trigger wire. I then used an aftermarket adjustable termal switch with the sensor placed near the radiator input hose.

With the switch being adjustable I have it dialed in to come on at about 185- 190 degrees. It never runs at cruise, but will cycle in city traffic. Also after a track run I can return to the pits shut the car down and then turn the key back to the on position and the fans will run until the temp drops. I also have the circulating pump set up the same way (except for the thermal switch) and the pump will circulate with the key on.

Regards,

Ken

hacker-pschorr

I would run a colder switch and thermostat. You want to keep the heads as cool as possible to cut down on detonation. If your fans (and thermostat) are not kicking in until 190+ degrees, just imagine how hot your heads are.

Todd modified his engine to run without a thermostat (you cannot simply remove it) and has fans with motors the size of your average alternator. These suckers are so powerful, they are hard to hang onto when turned on. He keeps his engine as close to 160 degrees as he can.

The first addition to my car once I start working on it again is a digital temp gauge for the coolant. I want to know exactly how hot my engine is getting.
I already added an intake air temp gauge / sensor, helps me keep an eye on intercooler performance.

Vlocity

I understand your point.....I have a 175 degree thermostat and once the fans cycle the temp will drop immediately. The adjustment is set so that the fans don't run cruising down the road, beyond that they come on pretty quick and I have always been able to recover to a safe temp without a thermal runaway. Even after 25- 30 minutes of track time I am just at the upper white mark...(whatever that is). Here's a picture of my Mother of All heat exchangers for the intercooler.....you can read more about it in the Twinscrew thread. I was after intake manifold cooling and I have succeeded in getting as close to ambient as I think is possible.

I have a 2950 cfm PermaCool on the radiator side as a puller and the two 1250cfm Spal fans on the Heat Exchanger side as pushers. AC is deleted and is also a big advantage for cooling.

Regards,

Ken

hacker-pschorr

Wow - that is awesome!!!

Vlocity

Just some additional thoughts about taking advantage of as many small items as possible for cooling. You willl note in the picture that I built a small panel to close off the original air intake. I didn't want air flowing freely through those openings when I could drive it through the radiators. I also have wrapped my exhaust manifolds with header wrap (4 years now with no issues), this reduces a lot of the underhood temps. I also insulated the bottom of my intake manifold (in the V) where the intercooler resides and last but not least I trimmed the center section out of the hood to cowl seal at the back of the engine compartment so that air can readily escape there....

All a few little things, but they add up.

Regards,

Ken

Bill Ball

Thanks for the ideas, guys. We will look this over an consider some options today. Just puzzled why it seems to vary from good to not so good in a few hours.

Bill Ball

OK, I'm getting a bit annoyed with this fan wiring. In order to get the muffins to all pull we have to wire one pair backwards (blue wire on fan to brown on harness).

Also, we put the AC compressor back on and started to charge it, and now the AC switch trips all the fans as it is supposed to, although charging the AC was a weird experience.

the flyin' scotsman

When wired backward does that pair spin backward?

Vlocity

Bill,

On the Spal style fans that I used, the baldes were also "reversible".

Can you just flip the fans.....typically the fans produce more CFM when rotated in one direction over the other. So....it would be best to flip the blade instead of just running the fan "backwards".

Hope this helps.

Ken