You Do Need 4" Exhaust

[R.ebel]

Fanless is the way to go

Ditched my winter front and tried going fanless

Noticed that after installing my cardboard winter front my egt's seemed to run about 200* higher than normal during WFO events

After several sleepless nights... it dawned on me... the winter front must of been obstructing airflow for the intercooler! Took out the card board winter front that was between the radiator and intercooler, removed the cooling fan and pulled the A/C clutch relay. Then I went to my local test hill and the egt's were back to normal, and the SOP meter indicated a slight increase in HP due to lessoned parasitic drag of the fan, I have no problems with the engine running hot and it warms up like it did with the winter front in place. It is also noticibly quiter in the cab without the fan, should have done this a long time ago





EDIT: Don't know how it happend but the thread title should be "Fanless in Wyoming" not "you do need 4" exhaust"-----a little help from a moderator or admin would be nice!

 

[Cooker]

How did you remove the fan. I am looking for some other "tips" as I was unable to remove it on my first attempt. Maybe I didn't hit the hammer hard enough



-Ryan

 

[R.ebel]

fanless

Cooker, Mine came off after a soaking of penetrating oil and several hard blows with a BFH and long punch. Just remember that its left hand treads. Standing in front of the motor strike the nut on the righthand side.

 

[Cummins Corvette]

I just have to laugh when I see you guys having so much trouble with removing that nut. No offence though. I have always used some vise grips to hold the pulley (not too tight or it could mess up the pulley) and some channel locks to remove the fan. I have never had any problems and have removed the fan from both of my trucks this way a few times. Good luck.

 

[Joseph Donnelly]

Use the Lisle tool or a long breaker bar in 3/8 drive to put extra tension on the belt tensioner. Put the wrench on the fan nut, hit with hammer. Done.



I tried no fan vs. stock fan @600 hp on the Dynojet. Gained 4 hp with no fan. Lessee, the Horton at about $800/4hp = $200/hp. Kinda expensive

 

[illflem]

I have to wonder what's going on also after removing 25+ fans with no problem. Just use a bigger hammer, don't worry about making a mark on the nut.



You can still use a winter front fanless, enough air flows in from under the truck, but a piece of cardboard in front of the coolers raises the intake temp too much.

 

[SlyBones]

illflem,



Does a winter front raise intake temps too much? Or does enough air still get in there, from under the truck? Trying to distinguish between the grill inserts and cardboard in front of the cooler. Is it the same or do inserts allow 'that much more' air than the cardboard.

 

[R.ebel]

Fanless

SlyBones,

My findings were with a winterfront on, there was not enough airflow across the intercooler (actually its an aftercooler) to keep the EGT's under control during the occasional drag race. For everyday easy driving a winterfront works just fine

 

[Hootguy]

Maybe you could try putting the piece of cardboard between the intercooler and radiator,,,,works for me,,,and you can leave the auot trans cooler uncovered...

 

[illflem]

Sly, in my experiments with intake temps I've found winter inserts only raise the intake temp about 10° on a 32° day. With only inserts below 32° the intake temp is still too low. There is still enough airflow under them to keep intake temps in the ideal range of 50-90° until the temps hit 75°. In other words inserts don't do much by themselves and are sort of a waste. I've found the best combo is inserts and fanless to keep the intake and coolant temps in the best range for maximum engine efficiency from Oct - May in the inland NW. If you run cardboard it should have at least a 8" hole in the middle to keep the fan blades from breaking, this will do fine with coolant temps but the intake temp will sometimes go too high as will AT and AC temps. Cardboard and fanless together work too good, I wouldn't recommend the combo except in below 0 conditions. If your EGTs are running high in cold weather with just inserts they must run dangerously high in summer with no inserts.

 

[JohnE]

CAC

The real term is <b>C</b>harged <b>A</B>ir <b>C</b>ooler.



Bill (illflem) gives the better rundown on this topic to date.



The only thing I add is the 8" hole in the cardboard is to give the required 1 ft&sup2; airflow through the CAC. Positioning the hole concentrically with the fan (if you leave it installed) is thought to save stress on the fan blades by avoiding a loading and unloading situation.



I used a pair of water pump pliers to hold the fan pulley while breaking the nut loose with a 1-7/16" wrench. The breaker bar in the idler pulley did not even come close to holding the pulley from turning.



I ordered a set of cold fronts from Eric Buckel, to dress up the truck this winter. Combined with fanless and the ESPAR, things should be toasty this winter.



-John

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