Fox T-Bird/Cougar Forums

Technical => Engine Tech => Topic started by: 20thanniver-ls on December 05, 2008, 05:56:41 PM

Title: smog pump, a/c, clutch fan....
Post by: 20thanniver-ls on December 05, 2008, 05:56:41 PM
If you remove the smog pump, and the a/c compressor would it make the car faster?, i know it would be less strain on the engine having 2 less pulleys, and a little bit of weight loss, but would it really make much a difference? And how hard would it be to find a belt after doing so? One more thing, if you remove the clutch fan and add an electric fan would the same prinl take effect(less strain on the motor)? :confused:
Title: smog pump, a/c, clutch fan....
Post by: Haystack on December 05, 2008, 06:10:58 PM
yes but not much. Smog pump is 1 hp on a dyno. The Ac is basically just a pulley when its not engaged, so I would guess 1 hp or less. The fan I could see some drag being on it. An electric fan requires a 3g fan, fan controller.
Title: smog pump, a/c, clutch fan....
Post by: 20thanniver-ls on December 05, 2008, 06:27:10 PM
couldnt you rig a fan to a toggle? or would it burn the motor out too quickly?
Title: smog pump, a/c, clutch fan....
Post by: 20thanniver-ls on December 05, 2008, 06:39:17 PM
And really it sounds like too much work for such a small gain - just a thought
Title: smog pump, a/c, clutch fan....
Post by: rancheronut on December 05, 2008, 10:30:18 PM
Quote from: Haystack;246341
yes but not much. Smog pump is 1 hp on a dyno. The Ac is basically just a pulley when its not engaged, so I would guess 1 hp or less. The fan I could see some drag being on it. An electric fan requires a 3g fan, fan controller.



plus weight is horsepower too. if you weight those parts, that how much less your car is.
(so in the1/4 mile race or street that will make your car faster because it don't have to push as much weight to get going).
 extra plus there less weight on the front wheel for weight transfer and your weight bias from front to rear is better, for handling.
Title: smog pump, a/c, clutch fan....
Post by: dadstoys2 on December 06, 2008, 02:51:42 AM
Generally 100lbs = 1/10th of a sec on the 1/4mile
So the weight plus the tiny gain from less drag might get -0.005 quicker time.
But the time and money spent will proably out weigh the benifit.
I bypassed mysmog and a/c by ussing a smaller belt and left the parts on so come inspection time I can reconnect the smog.
My bearings are going bad in my smog so I needed to.
~Rich
Title: smog pump, a/c, clutch fan....
Post by: 20thanniver-ls on December 06, 2008, 01:38:45 PM
Where(or really how...) would you find a belt for it?
Title: smog pump, a/c, clutch fan....
Post by: softtouch on December 06, 2008, 01:48:43 PM
Quote from: 20thanniver-ls;246451
Where(or really how...) would you find a belt for it?

Wrap a string around it and measure the string.

Switching to an electric fan is not zero load on the engine. More electrical load on the alternator makes it harder to turn.
Title: smog pump, a/c, clutch fan....
Post by: 20thanniver-ls on December 06, 2008, 02:04:16 PM
well i know its not zero load but it seems like it (clutch fan) would cause more resistance to the pulley system and drag the engine down more than a higher electrical load on the alternator would. Im not really saying im going to do any of this (yet) im just going through ideas in my head and throwing them out there to see what you guys think - most of you are quite a bit more knowledgeable with these cars than i am:bowdown:
Title: smog pump, a/c, clutch fan....
Post by: Haystack on December 06, 2008, 06:10:48 PM
do a search. It has been covered many times. I just barely posted up a belt routing diagram, including how to bypass things if you just look around.
Title: smog pump, a/c, clutch fan....
Post by: dadstoys2 on December 07, 2008, 01:16:39 AM
Quote from: 20thanniver-ls;246456
well i know its not zero load but it seems like it (clutch fan) would cause more resistance to the pulley system and drag the engine down more than a higher electrical load on the alternator would. Im not really saying im going to do any of this (yet) im just going through ideas in my head and throwing them out there to see what you guys think - most of you are quite a bit more knowledgeable with these cars than i am:bowdown:

A clutch fan is actually better on drag than a normal fan.
On the fan idea.... the tiny bit that you might gain(maybe 1hp at peak rpm) would not be worth the time. Now eliminating the a/c and smog might get you a couple(most of it being the loss when the a/c is on).
Also the elimination by using a short belt is actually quite easy and generally cheap. I think on yours it was a 76 or a 79 inch belt.
Mine was 85.5 6rib belt but mine is a 92.
I myself would not even take off the smog because when you have to get it inspected you might have problems. I kept my old belt in the trunk for inspection time and come spring I will get one to get my a/c back.
~Rich
Title: smog pump, a/c, clutch fan....
Post by: Sick88Tbird on December 07, 2008, 11:51:41 AM
When I did the E-fan in my old 'Bird, I did an underdrive crank pulley at the same time...picked the pulley at a J-yard for next to nothing....just those two things gained me 3 more mpg and I dropped 2 tenths at the track...probably would have been more if I wasn't going into a steady 25mph headwind with 35+ mph gusts.

But yes, you'd need to do a 3G alt swap which isn't a big deal...if you do a j-yard E-fan set up, you'll be using a lot more amperage with a stock type fan from another vehicle...I have a flex-a-lite fan set up that pushes 3300 cfm(way more than enough) and only pulls 18 amps peak...most stock type fans (taurus or mark VIII) pull a heck of a lot more amerpage...less amperage draw=less strain on the alternator=less parasitic loss.  And just about anything is better than the junk clutch fan.

Good luck,
Don