tiochango wrote:


I did that, but I didn't trim enough. I like my solution of just removing the second fan better. That thing was 8 lbs!

I just gutted the driver's door. I left the door bar and cut out the center of the door. It was good for 24 lbs. That means I've pulled 71 lbs out of the car already!!! I am now under weight!

I'm going to gut the other door too, but leave the heater core for now. I really don't want to pull the dash until I have time to rewire the whole car. Got to start thinking about ballast. I need to get it on the scales to see where I want to put the weight. I'm guessing the passenger floorboard.

-bj

71 pounds? That's gotta be good for, oh, I dunno.... .055 seconds or so???

Re-read your post right after I replied and realized you removed the offending fan altogether. A valid fix!

I've still got a few lbs left to get out of my car. When the time comes, I hope to use a cool suit system as ballast on the passenger side. Got a few expenditures to make before that, though.

It is common for the lower radiator (water pump to radiator) to be cut by the fans. Most of the the time the problem is down to a couple issues.

1) wrong hose
2) hose installation alignement

Wrong hose.
This one is easy to do as the early cars use a different hose from the later cars. It is a very subtle difference, but get it wrong and hose get in the path of the fans. I believe the issues comes down to the changes in the radiator mounts in the 85.5 chassis to allow for the turbo cars. Look at any early vs late 944 and you will see changes to the radiator mount area. The small one cause a different position of the radiator and if you use the wrong hose it will rub. Solution is to match the hose to chassis. So late chassis = late hose. Early chassis = early hose.

Hose alignment.
Even when you get the right hose take care when installing to make sure the fan will clear it. That can me introducting some twist in the connections to ensure clearance.


I have had hoses cut by the fan in the past, but once you get the installation right you can run that second fan a never cut the hose ever.

I personally recommoend the second fan for running in warm climates. In Arizona we run in the winter and into May and September. Both May and September races can be run in temps of near or over 100F. On these days my manual fans see extra attention. I have a switch for each one. In the morning it is still relatively cool (80's) and I cna run 1 fan. However by race time I need to run both fans to keep the engine temps in line especially if following closely in traffic. By contrast in the winter I can run both fans off for qualfying runs. Temps run good and I get think I get 0.25 more hp from not having the electrical draw.


So point is figure out the hose issue so you can run both fans.

Thanks, Joe! Good info on the hoses.

I think I'm going to stick with the one fan on the hot side of the radiator. I'm also going to modify the thermostat to increase flow to the radiator. With a single fan, modified thermostat, and some Water Wetter. On my BMW race cars, I can get away with no fans in 110 degree weather with a modified thermostat. I'm hoping for similar results on this 944.



-bj

it may be more of a matter of cooling the car once it is off the track not getting a good flow of air and heat soaked from racing conditions.
Lee

944cer wrote:


Pop the hood and these all aluminum motors cool fairly quickly. Leaving the electric fans running when the motor isn't running doesn't do a whole lot to cool the water in the block anyway.

It's really a matter of try it and see. If I have temp problems I'll add a bigger single fan--probably a Spal 14-16".

-bj