Dave. In the winter when the ambient temps are below 50* just remove the mechanical fan. The aux fan will be sufficient if you drive hard in that cold of conditions. Tell me what you feel. I did that for a couple months in the winter before doing the e-fan conversion. I think you'll like it.

The main drag of the fan clutch is at low rpms. Once the pulleys are spinning that fast (3000 rpms+) there is very little drag. This is why I doubt the gains will be very much on a dyno.

 

I remember you doing this. I'll try it out this fall and report back.

 

how do i check if i have an E-fan or a mechanical fan?
i have a 2003.5 sedan..

i "think" i have a mechanical fan.. when i changed my belts, i had to go "around" the fan...

 

I did the fan converson on my sedan and I actually ran a slower time at the track ( just barely and probably totally unrelated to the fan mod ).

 

If you have two fans stuck to the radiator = no. If you have a big arsed fan stuck to a pulley attached to the engine = yes.

 

about the power issue.

i'm going to say it will be the same thing as switching to any lightened driveline parts: no hp increase.

Now, the car could "accelerate" quicker, but taking weight off doesn't affect the dyno. Going from a stock flywheel to a 14lb flywheel does zero on a dyno and it's much more rotating weight off the driveline than this fan.

 

It should give you power even at the dyno. If the wheels accelerate quicker with the same axle ratio, it's more power to the wheels...there is no way around it. The only thing that doesn't show up is final drive changes becuase the car is acutally making the same power per rpm while the ratios just change ( kinda of like doing a run in 3rd gear and then in 4th gear..the outputs rarely change much )...but this is not the case when talking about lightening drivetrain parts since you ARE making more power to the wheels ( or rather, loosing less power to the wheels ).

Either way, I tried it already and it didn't help me out at all.

 

on an AT, 3rd vs 4th gear pulls result in significantly different numbers on the dyno.

 

On my car it didn't...both posted near identical numbers which is why I always ran 3rd instead of 4th because it was quicker. On not one of all of my N/A cars did gear changes post different numbers....Turbo cars are different though because the longer the gear the more time the turbo has to spool up.

Plus, you say "on an AT" as if it were any different from a 6MT when talking about gear ratio changes.

 

ATs pull in 3rd gear on dyno... the ratio is totally different than MT... Every single AT G I've ever seen dyno (and its been many) dyno much lower in 4th... I have dyno's that show it on my car - and you can ask any dyno shop (that has dyno'd these cars) they will tell you the same thing... ask Hydrazine, he's a member out here.

 

For whatever reason it's loosing power, it's not directly related to the gear ratio. Probably more to the dyno calibration or to the engine heat soaking since the run is longer.

 

It shouldn't be "significant" if the operator knows what they're doing. The numbers should be within 2% or less. Like GT-ER stated, it could be a engine temp issue. Longer gears make the engine labor on the dyno pass too long. Many of our dyno shops in KC typically dyno lower torque cars like Honda's in 3rd instead of 4th to reduce some of the load on the motor.

 

I disagree. Things like running lighter wheels will most definitely show up as added power on a dyno. Things like lightened pullies show any measureable difference because they don't do squat to improve power on the VQ. Believe me, it's not because reduced rotating weight can't be seen on a dyno.

 

I guess Tony at Motordyne and Shawn Church (who has been dyno tuning cars since you were in school) dont know what they are doing?

Dave - have you even dyno'd your car?

 

thats one (of several) reason to use a chassis dyno (like Dynapack).