Duramax Cold Air Intake

[swatkins]

This is a review of Cool My Duramax air box mod . I have been testing it and wish to report my findings. It's so hot here in Texas now and I figured I might pass on what has been helping me to the people of this forum...

 

First a little history about how my truck runs fully stock.

 

I have been running my stock, late in model year build, 05 3500 with a temp probe in the air box for 7 days now... It is inside the box behind the filter and secured in place.

 

I have seen OAT's from 78 to 102 with very humid air...

 

The biggest delta I have seen is when the truck is sitting still. 78 to 90 OAT the delta is running 50 degrees hotter that OAT. Past 90 the delta is 60 degrees or more.

 

After a stop and up to 25 MPH the delta is usually 40 degrees and stable...

 

30 to 40 mph the delta usually runs 20 degrees.

 

40 to 55 mph delta is 15 degrees.

 

Over 60 MPH the delta is usually 5 to 10 degrees.

 

Engine temps have always been 210 on the stock gauge and the tyranny temp is usually about 175. NO fan operation in the last 4 days and I have been running in Houston freeway traffic at least 1 hour per trip, 130 miles per day. Also no load on the truck and no trailer for the above readings.

 

My fan only comes on when the truck thinks I am going to hitch up the trailer It does not come on in the morning and the truck has been at OAT when I start it, usually around 80 degrees.

 

Christopher from www.Coolmyduramax.com sent me a prototype of his air box mod for testing. I did not pay for the kit and apart from living 30 miles away have no connections with Christopher. In other words I have nothing to gain or lose by stacking this report

 

The mod came with everything needed to install and everything was of good quality and appropriate for it's function. Christopher informed me that the rubber material would not be degraded by heat, oil or diesel fuel. The kit consisted of a large piece of rubber material that was cut and scored into a complex shape. (Must have taken him weeks to figure out the cuts needed.) Also included in the kit was a metal bracket and three screws needed to fasten the mod in place. Other existing bolts are removed and reused to support the rubber and metal pieces. 4 pages of color copied instructions are included.

 

Christopher has posted that the Mod will cost only 60.00 including shipping.

 

This mod required no cutting or modifications to the frame or stock air box. The install took me all of 20 minutes using simple sockets and a screw driver.

 

You begin the install by removing the stock air box and mounting pan. All these parts are reused. Next a 7" metal bracket is installed using existing bolts. Once that bracket is in place you install the lower part of the rubber shield below the air box pan. This part of the shield blocks off the air from the fan area and forms a “tunnel" to the open air below the air box. After the shield was in place I could see the roadway through this tunnel and all engine compartment air was blocked from the tunnel.

I then replaced the lower mounting pan and folded the shield into place around the reinstalled lower air box. After about 3 minutes of inspection and readjustment I replaced the filter and upper air box. Total time 20 minutes.

 

Thoughts on quality of kit and install.

1. All materials were well suited for their intended purpose.

2. The install required no drilling and Christopher made great use of existing holes and bolts.

3. It was very simple to install following the furnished instructions. The instructions were well written and made use of many photos. This was on an included CD.

4. The rubber shield material was well suited to the job. It was easy to bend to install and conformed very well to the sides of the compartment and air box. Almost all air was blocked after I adjusted the material to the correct locations. Tabs are cut into the material that allows it to be fixed in place without fasteners.

 

Results.

 

I have seen a great reduction of my IAT both loaded with a trailer and unloaded. I have noticed no difference in the operation of the truck and have not had time to see about increased MPG.. My truck temps were about 5 degrees reduced according to the stock gauge.

 

My trailer is 12'8" tall and weighs 13,000 lbs. Total weight of the rig was 21,000 lbs. Speed was 75 mph and RPM's around 2200. Outside air temp was 98 to 102 degrees. Truck is totally stock with only Christopher's mod in place.

 

Did it work?

 

Most of the time.

 

Before the mod the IAT was always 5 to 10 degrees over OAT at highway speeds. After the mod IAT was within 2 degrees while at speed.

 

Good improvement as now IAT is near OAT.

 

The best improvement is seen just after a stop while waiting on a red light. This morning before the mod my IAT was over 170 degrees, off the scale of my temp probe, while waiting on a red light. After the mod the IAT would stay in the OAT + 10 to 15 degrees for about 5 minutes, while waiting on a red light. It would start to climb and rose to 137 (OAT 102) after 6 minutes while stopped for a soft drink. Still well below the over 170 recorded an hour earlier.

 

Great improvement in this area!

 

After sitting still for 10 minutes the IAT rose to about 45 degrees over OAT. I think the cause of this is a total lack of cool air in the area of the intake. The fan and stack was putting out over 170 degrees and I think it was just flooding the surrounding area. And the mod does not help in this situation.

 

But as a final test I placed two probes in the air box area. One internal and one on the outside of the shield. After running for 14 minutes the IAT was 129 and the external probe was over 170. Before the mod it would have been almost the same temp...

 

 

So,,, I am going to keep Christopher's mod in place. I find it very simple in design, cost effective and it works very well at reducing my IAT's.

 

Steve