SUHleen
forum member
I tried searching on Google and on here for about 2 hours and could not find what the specs are on the stock radiator fan. Trying to decrease under hood temps.
So this rad may be my issue?
I have an Afco radiator, so that is why I am surprised my under hood temps are what they are. I do need a cowl hood, which will help vent air out, but I feel like I could take advantage of a better fan setup. I just do not remember what kind of t-stat was put in when I had everything done 4 years ago. I guess I can change it out since it does not cost very much and it would be good piece of mind. Even 20 minutes of running idle and the engine coolant tank will burn my finger just barely touching it seems like. Afco makes great products so I do not think the radiator needs swapped.
And thats even with ambient temps being about 85 and no AC
A larger capacity radiator just keeps the engine colder longer and is more efficient at cooling down when hot. The T-stat is an easy thing to check and swap first.
Contrary to popular belief a cowl(induction) hood does not vent air out the back, it actually pulls air into the engine bay from the back of the cowl at the windshield as its a high pressure area. Not the same thing as a vented hood or hood scoop. You need to promote flow through the engine bay this will get more air through the core and transfer more heat, but the key is giving it a place to go.
A higher flowing fan will just simply run full time to try to correct the issue you have. When driving at 30-40mph+ the fan should not even come on.
http://www.svtperformance.com/forums/showthread.php?873526-Lower-engine-and-IAT2-temps-with-free-mod&highlight=
I read the above from beginning to end last June. He proved that on our cars the hood does vent out the rear while stopped and on the road moving. He made a video and attached strings to the back of the hood so you could see them blowing outward from the hood. So I did this to my car and it actually made a big difference. I never had any cooling problems as my car cools immediately when the fan comes on and has never ran hot. The biggest difference was stop and go traffic when your IAT's want to creep up. And it made at least a 20 degree difference from a Hot start. Before I would go out to eat lunch. Shut the car off. A half hour later come back and the IAT's were thru the roof. Not now as the hood vents heat out while it sits. I did also put one washer on either side to help the venting.
So the cowl wouldn't even work if I opened up the grill area? So air would flow in through the grill and make a straight path out of the back?
So are you recommending I don't change the fan out? I figured if I throw in a better tstat and better fan that should help out until I get a better hood put on. If I did a better fan, it would be wired to the factory harness so it would kick on whenever the stock fan would just move more air and move it quicker
Got a nice thermal temp gun for christmas so finally got around do doing some testing of the open hood scoop mod I did years back.
To see info on this mod and how I and others have done it look here:
http://www.s197forum.com/forum/showthread.php?t=22443&highlight=scoop
(on mine I left the stock honeycomb in place and opened up the back of it)
I will do another run this summer on a hot day as well and add it to the thread later on.
Intial conditions for todays "wintertime" test. 45 degrees outside. Let the car warm up to 190 degrees before testing (where my high speed fan kicks on). I then drove for 15 minutes on the same route before each test which involved a mix of city and highway driving. Then I came back home immediately opened the hood and took the temps with engine still running.
Run 1 - Hood scoop taped shut.
Turbo compressor cover
Intake pipe
Thottlebody
Intake manifold
Fuel rail
Run 2 - Hood scoop open.
Turbo compressor cover
Intake pipe
Thottlebody
Intake manifod
Fuel rail
So results for "wintertime" 45 degree day test are:
-----------------------------Closed Scoop-------Open Scoop---------Difference-----
Turbo compressor cover------ 141.5 -------------- 115.5 ------------- -26.0
Intake pipe------------------- 98.0 --------------- 78.5 ------------- -19.5
Throttlebody----------------- 85.0 --------------- 68.5 -------------- -16.5
Intake manifold--------------- 101.5 -------------- 87.0 ------------- -14.5
Fuel rail---------------------- 114.0 -------------- 106.0 ------------- -8.0
So big difference! And overall average underhood temps were 13 degrees cooler with the scoop open. Not bad for a free mod.
Just remembered I did this awhile back here is some numerical data vice touching things with your hand etc.
I tested hood scoop open vice taped closed.