Is there such a thing as to cold of incoming air?
03-04-2007, 06:46 PM
#31
Registered User
My airbox mod works great for cold temps. During the warm season the 3" blue tubing (RV dump hose) goes from the backside of the airbox to a hole in the firewall that sucks air from the base of the windshield.
During the winter I remove the tube from the firewall, fold the insulation back over the hole and place the tube end near the turbo. Takes maybe ten seconds.
This nets an average IAT increase at the airhorn of about 50°. It's very obvious that the engine likes above freezing air just by the sound at idle.
During the winter I remove the tube from the firewall, fold the insulation back over the hole and place the tube end near the turbo. Takes maybe ten seconds.
This nets an average IAT increase at the airhorn of about 50°. It's very obvious that the engine likes above freezing air just by the sound at idle.
03-04-2007, 09:33 PM
#32
1st Generation Admin
Well I guess my heap's messed-up then as I get better performance in cooler weather. I've been running 100% outdoor air for over a year now.
The typical BHAF fed directly from behind the passengers headlight.
Perhaps it just doesn't get cold enough in central NC (teens might be a normal extreme).
The typical BHAF fed directly from behind the passengers headlight.
Perhaps it just doesn't get cold enough in central NC (teens might be a normal extreme).
03-05-2007, 04:06 PM
#33
Chapter President
Nice filter box bc847..
It seems to me that keeping the water temp up is the most important part. If you can keep the engine operating at its efficiency temperature and also manage the air temp incoming everything should be good. I would say then that covering the rad is only 1/2 the equation for winter operation, you should also cover the CAC to achieve optimum air temp..
Hmm, my SAII definitely lets in the fresh stuff....I might have to re-think the winterfronts on my rig..
It seems to me that keeping the water temp up is the most important part. If you can keep the engine operating at its efficiency temperature and also manage the air temp incoming everything should be good. I would say then that covering the rad is only 1/2 the equation for winter operation, you should also cover the CAC to achieve optimum air temp..
Hmm, my SAII definitely lets in the fresh stuff....I might have to re-think the winterfronts on my rig..
03-05-2007, 04:44 PM
#34
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When a gas of any form gets cold, what happens? It will eventually turn to liquid. Pure oxygen will do this around -327*. At least that's its boiling point. The air we breath doesn't have to be as cold, though. I know this when my wife yells at me for not using a coaster with my glass of iced tea. So in lower temps the air will be harder to burn.
03-05-2007, 07:24 PM
#35
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BC847 Is it possible that the air your getting is allready warmed up before it gets to your intake? So the reason it works so good for you in cool weather is that it's actually operating at it's optimum temp?
03-05-2007, 08:34 PM
#36
1st Generation Admin
So much so that the electrical connections are actually within the filter housing. . . .
When a gas of any form gets cold, what happens? It will eventually turn to liquid. Pure oxygen will do this around -327*. At least that's its boiling point. The air we breath doesn't have to be as cold, though. I know this when my wife yells at me for not using a coaster with my glass of iced tea. So in lower temps the air will be harder to burn.
Enter the heater-grids. Here again, Dodge put them there so as to help ensure reduced cold operation emissions by providing additional heat to the final charge-air. Once the engine comes up to normal operating temps, they shut down (as per that sensor on the intake cover).
While a great deal of the heat for combustion is provided by the final charge-air, a notable percentage is provided by the iron of the engine itself. Maintaining the recommended minimum operating temperature will help ensure nominal performance.
We may look at the after-cooler as a means of upping final power output (via a denser charge with additional fuel), Dodge put it there as a means of emissions reduction. Using the same means of operation, Dodge's goal was to reduce smoke and such (oxides of nitrogen, etc) by keeping peak combustion temps down through reduced charge-air temps and excess air (I think).
03-05-2007, 08:50 PM
#37
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Man I wish there was a air temp sensor after the intercooler. I guess one can be installed. I know they make dynos that put a constant load on a engin and then modifications could be made under load and see real time what changes are good/better.
03-05-2007, 09:27 PM
#38
1st Generation Admin
I've got a four input digital thermometer I use for HVAC&R work. If I can find four probes that are long enough, perhaps I can sneak one in pre-turbo, one pre-after-cooler, one at the after-coolers output, and the fourth down-stream of the W/M injectors in the head's intake manifold .
Hmmmmm, . . . . .
Hope this isn't hijacking folks.
Hmmmmm, . . . . .
Hope this isn't hijacking folks.
03-05-2007, 10:52 PM
#40
Registered User
You guys should install some temp probes like we did - it's easy enough.
Type K thermocouple probes work well - up to near instantaneous response and more resolution than you'd possibly need. We've used both thread-in probes and open (no thermowell) air probes for maximum responsiveness.
Type K thermocouple probes work well - up to near instantaneous response and more resolution than you'd possibly need. We've used both thread-in probes and open (no thermowell) air probes for maximum responsiveness.
03-06-2007, 06:17 AM
#41
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You guys should install some temp probes like we did - it's easy enough.
Type K thermocouple probes work well - up to near instantaneous response and more resolution than you'd possibly need. We've used both thread-in probes and open (no thermowell) air probes for maximum responsiveness.
Type K thermocouple probes work well - up to near instantaneous response and more resolution than you'd possibly need. We've used both thread-in probes and open (no thermowell) air probes for maximum responsiveness.
03-06-2007, 08:21 AM
#42
Registered User
The differential is measured between the outside ambient air temperature at the driver's side of the charge-air cooler, and in the center of the intake manifold air horn just above the grid heaters. There is another pyro mounted just ahead of the intercooler in the pre-CAC ducting, but I don't have enough data to report from that sampling point yet:
The pyro probe is just behind the boost gauge.
The intake and exhaust have been heavily modified for maximum flow within the stock sheetmetal envelope (i.e. no stack through the bed, hood scoops, etc.). The exhaust is comprised of an Aeroturbine welded to the downpipe, followed by the cat-shell, which has a 65 degree downturn welded on the end.
Soot exits at the rear of the cab, underneath the H2O/meth injection pump.
As for the intake, this picture sums it up best:
Normal driving yields about a 5-10 degree F differential (in any temperature), while WOT (stock fueling) results in as much as 25*F differential before running out of road or RPM. On the dyno, delta differential is much faster than the street, since there's no airflow to speak of to delay the onset of heat soak. Of course, these values correspond to 32 psi max boost, so later this spring we'll have the data for boost in the 45 psi range.
p.s. Tyler, ULSD has 1% less energy content than LSD, which is essentially un-measurable on a commercial dyno.
The pyro probe is just behind the boost gauge.
The intake and exhaust have been heavily modified for maximum flow within the stock sheetmetal envelope (i.e. no stack through the bed, hood scoops, etc.). The exhaust is comprised of an Aeroturbine welded to the downpipe, followed by the cat-shell, which has a 65 degree downturn welded on the end.
Soot exits at the rear of the cab, underneath the H2O/meth injection pump.
As for the intake, this picture sums it up best:
Normal driving yields about a 5-10 degree F differential (in any temperature), while WOT (stock fueling) results in as much as 25*F differential before running out of road or RPM. On the dyno, delta differential is much faster than the street, since there's no airflow to speak of to delay the onset of heat soak. Of course, these values correspond to 32 psi max boost, so later this spring we'll have the data for boost in the 45 psi range.
p.s. Tyler, ULSD has 1% less energy content than LSD, which is essentially un-measurable on a commercial dyno.
03-09-2007, 06:32 AM
#43
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Didn't miss that post XLR8R. Great information. If our intercooler is cooling the air back down withing 5-10deg of outside air temp under normal driveing we sure don't need some special cool air intake then. Maybe more air intake with less restriction.
03-09-2007, 09:03 AM
#44
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My response to the efficiency of the stock charge-air cooler is: "
We can raise the boost pressure for more power and make the engine run more efficiently in cool temps to boot!" 
We can raise the boost pressure for more power and make the engine run more efficiently in cool temps to boot!"
03-10-2007, 08:20 PM
#45
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I wonder if there isn't something to all this as well. I noticed on my wifes' Jetta the intake air for the air filter comes from inside the engine compartment rather than from the fender like most trucks do. Maybe the Germans know something that we don't? I keep thinking that maybe I should make a mount for a different filter closer to the turbo and manifold.
Somebody do that and tell us if it works. I've got too many projects right now to mess with it.
Somebody do that and tell us if it works. I've got too many projects right now to mess with it.