Dodge Ram CTD Grille Block Question

[Saltsman]

I have several questions about blocking the grille on my 06 Dodge Ram 3500 Diesel Automatic. I've been using foam pipe insulation to play with the config for now (1/2" fits perfectly between the ribs of the grill BTW). Hope others might have some of the answers from their experience. For the record, I'm in Texas where I'm somewhat concerned about summer heat and as a newbie, not as confident with my ideas, so I'm being conservative for now. The truck is not my daily driver, but it does do some 500 mile+ long hauls each year and the once-weekly around town Home Depot/Lowes/ranch run.

Anyway, on the questions.

1) There is a scoop inside the passenger side of the grille that appears to feed the cold air intake in the wheel well. I've trimmed the block to leave this area completely unblocked for now. What's the best for this? My thinking is the diesel needs the cooler air more than it needs the aero mod for that space?

2) I've wedged pipe insulation in the inch or so gap between the hood and the lower flaring. I had to step up to 1.25" for that really large gap in the front near hood release. I'm assuming this is all well and good. That is a really odd gap around the entire front end. So odd I started wondering if there was some reason for it I couldn't see.

3) The cross hair thing Dodge does in the grill styling divides the opening into quadrants. I've fully blocked the top two (minus the scoop referred to above). Any experience blocking the lower areas as well. Is that too aggressive?

4) There is a 3" to 4" tall and 24" wide opening where the tow hooks are located. I've read the discussion on adding back a factory part that blocks this gap for gas engines. Because this opening exposes the very bottom of the heat exchangers, I'm not sure it it would be best to leave this open and close up more of the lower two quadrants on the grille, or close this up and leave the grill open more. My thinking is while the grill area is higher up on the front profile, it would be exposing the center of the exchangers rather than the bottom and that would be most effective for cooling. For now, both are open. With the radiator, AC, transmission, and intercooler, there are a lot of things to cool in there.

5) Finally, any ideas on a variable block? Most of the time, the truck is hauling lighter loads, but from time-to-time, it is working at loads closer to the maximum capacity in the Texas summer. I was thinking a permanent block of the upper two quadrants with coroplast installed behind the grille, but a removable block for the lower two quadrants for hauling in the summer or adding back in the winter, or with working lighter loads in the summer, etc. For now, that might just be pipe insulation that gets pulled out or added back as needed, but it would never look as good a stealthy coroplast install behind the grill. Ideas?

Thanks for the advice. Feeling a bit timid with the block but wanting to get as close to maximum as possible without damaging anything like the automatic transmission.

[ksa8907]

you want to block it as much as possible while maintaining cool air for the intake and an opening for the transmission cooler. beyond that as long as your cooling fans stay off the majority of the time and have enough of an opening to pull plenty of air when they come on, you'll be ok.

it is worth mentioning that you can add a water injection system that, on diesels, will help you keep cooler ECT temps as well as add a bit of power.

[aerohead]

No easy answer.
The big dogs have access to isobaric profiles at he nose and know exactly where the highest stagnation pressure occurs,which would be where you'd want to harvest all your air from.
Secondly,with so many separate heat exchangers involved,technically,each circuit would be treated individually.I believe that the GM' OLDS AEROTECH of 1987 had eleven discreet and separate 'cooling system' ram ducts and outlets.
*Since Diesels are air-starved,keeping the combustion air inlet wide open is a good call.
*I would attempt to do the same for all other 'systems' except the AC condenser and radiator itself.
*Walter Korff of Lockheed Aircraft Corp. advocated airtight ducts to the heat- exchangers which were at least as 'deep' as the heat-exchanger was 'tall',and just as ' wide'.It's a lot of sheet metal work.NASCAR does it religiously,however they have only the radiator to deal with.
*'Active' systems will have a thermistor located to read the mean average temp inside the system,and the logic portion will vary the signal to a stepper motor which articulates an internal damper to vary the airflow accordingly.Renault used such a system on their Vesta-II of 1987 to help achieve 138 mpg at a steady 62 mph,and 103 mpg at 75.

[skyking]

you have the huge benefit of an electric clutched fan on your rig.
Can you easily tell when it comes on?
If so, that will help you to determine when having a block in there will help you and when it may harm you.
I'd go pretty aggressive during periods that I know the fan NEVER comes on.
My fan has the thermo "clutch", and stirs a whole lot of air even when cold. I took it off and run it all winter without a fan at all. I only get hot if I leave it in gear, in moderate temps, stuck in traffic.
I now have a pair of electrics that are not automated just yet.

[Diesel_Dave]

Originally Posted by Saltsman

I have several questions about blocking the grille on my 06 Dodge Ram 3500 Diesel Automatic. I've been using foam pipe insulation to play with the config for now (1/2" fits perfectly between the ribs of the grill BTW). Hope others might have some of the answers from their experience. For the record, I'm in Texas where I'm somewhat concerned about summer heat and as a newbie, not as confident with my ideas, so I'm being conservative for now. The truck is not my daily driver, but it does do some 500 mile+ long hauls each year and the once-weekly around town Home Depot/Lowes/ranch run.

Anyway, on the questions.

1) There is a scoop inside the passenger side of the grille that appears to feed the cold air intake in the wheel well. I've trimmed the block to leave this area completely unblocked for now. What's the best for this? My thinking is the diesel needs the cooler air more than it needs the aero mod for that space?

2) I've wedged pipe insulation in the inch or so gap between the hood and the lower flaring. I had to step up to 1.25" for that really large gap in the front near hood release. I'm assuming this is all well and good. That is a really odd gap around the entire front end. So odd I started wondering if there was some reason for it I couldn't see.

3) The cross hair thing Dodge does in the grill styling divides the opening into quadrants. I've fully blocked the top two (minus the scoop referred to above). Any experience blocking the lower areas as well. Is that too aggressive?

4) There is a 3" to 4" tall and 24" wide opening where the tow hooks are located. I've read the discussion on adding back a factory part that blocks this gap for gas engines. Because this opening exposes the very bottom of the heat exchangers, I'm not sure it it would be best to leave this open and close up more of the lower two quadrants on the grille, or close this up and leave the grill open more. My thinking is while the grill area is higher up on the front profile, it would be exposing the center of the exchangers rather than the bottom and that would be most effective for cooling. For now, both are open. With the radiator, AC, transmission, and intercooler, there are a lot of things to cool in there.

5) Finally, any ideas on a variable block? Most of the time, the truck is hauling lighter loads, but from time-to-time, it is working at loads closer to the maximum capacity in the Texas summer. I was thinking a permanent block of the upper two quadrants with coroplast installed behind the grille, but a removable block for the lower two quadrants for hauling in the summer or adding back in the winter, or with working lighter loads in the summer, etc. For now, that might just be pipe insulation that gets pulled out or added back as needed, but it would never look as good a stealthy coroplast install behind the grill. Ideas?

Thanks for the advice. Feeling a bit timid with the block but wanting to get as close to maximum as possible without damaging anything like the automatic transmission.

Sounds like you've done your homework, but here's 2 threads you should check out if you haven't already:

http://ecomodder.com/forum/showthrea...wer-19810.html

http://ecomodder.com/forum/showthrea...ctd-22770.html

If you don't have a fog lamp in the fog lamp hole, that mod can help your intake temps. Another thing to remember is that the amount of cooloing the intercooler requires is directly dependent upon the amount of boost you're producing (because the heat has come from the turbo compressing the air), so when you're operating at light loads, you don't need much intercooling becuase you're not running hardly any boost. Note that full boost on a CTD is somewhere around 30 psi (stock).

If you're concerned about transmission temps, I might suggest getting a transmission temperature probe. I have a manual, so I don't really have to worry about it.

As far as telling whether you've overly-blocked the grille with respect to coolant temps, check out this post:
http://ecomodder.com/forum/347009-post34.html

[Saltsman]

Thanks everybody! Fast feedback.

Diesel Dave... I had read the first and third of your posts three or four times previously. My rig has fog lights so number 2 isn't an option anyway, but still a clever idea.

Your grille block was my inspiration. I think i'm going to make lower grille block like yours (or buy that part) and seal up the lower area. The cooling fins catch a lot of bugs and grass and stuff down there anyway when I'm doing ranch driving. I don't have a way to test this other than to do it.

I'll start by fully blocking the upper quadrants on the upper grille, save the CAI scoop. My permanent block will cover the area shown in the picture below with my temporary foam strips. Given how many heat exchangers I need to cool with 110+ degree summer heat and the importance of the transmission cooler to my savings account, I think I'll leave the lower quadrant open in the summer. That is roughly the center of the grille area so that should help if the fan does come on.

I'm going to tinker around with a quickly removable block for the lower quadrants. I'm confident I can cover them in the winter, but would need to pull them off when it heats up in April - September. U-bolts permanently attached with wing-nuts or something so I can quickly pull them during those 90 degree winter days and put them back on when it get back to the 30's.

As for the pipe insulation between the lights, hood and the bumper flaring... any reason that idea shouldn't be used to help close the gap between the cab and the bed? The 1.5" insulation fits in there nice and snug. I don't think it would rub the paint down and it has plenty of flex for the bed to move around as needed. It's not the most dirty area on the truck, but for a $1.25, why not?

[slowmover]

As in those other threads I simply purchased a pre-made [4] piece block that bolts into the grille quadrant. I'd imagine that in the hottest weather I can still leave the upper two pieces installed for solo (non-towing) miles.

I distinguish between a true "wnter front" (the MOPAR piece) and the grille block as the former is strictly cold weather (Jan/Feb, here), and the latter is use-able through most of the rest of the year (I'm expecting that June - September that it will be but two pieces in operation as A/C use becomes non-optional. I also, FWIW, block off the heater core circuit via valving during this stretch of time).

I use an ULTRAGAUGE OBD-II reader to monitor temps. A few spikes above coolant thermostat opening don't mean too much, IMO, but steady temps above that point to the need to admit more air, directly.

I don't believe that in our climate/terrain that blocking off the non-grille openings is a good idea (as maiming the ability of the truck to do work is counterproductive . . it would take very little to damage this expensive motor in re overheating). Same for aftermarket tuners. No matter the brand or the specific programming, the need to monitor exhaust gas temperature becomes a requirement to avoid melted aluminum when using one of those toys.

On a thread on CF one poster indicates that the air intake system opening to the fenderwell originally had a seal. I'll add one. The turbulence before this location should shake out most of the dust/bugs (the reason I don't use what has been called the HOME DEPOT CAI).

I don't know the daily time of my departures on workdays (on-call) so I don't always use the block heater outside of "winter". On days off, then, yes, about two hours of time. It's easily worth 30-40F of heat rise.

The grille block definitely makes a difference on my "commute"; temps come up faster and don't stall in their rise while on the highway in this 7-mile drive. On days when I am off of work and doing errands the grille block makes for steadier, higher temps when the ambient air temps are cool and would otherwise make for lower coolant temperatures.

All in all I think pre-heating fluids in a CTD is more likely to be of value over a mainly "closed" set of grille openings in the South Central and Southwestern US. The four piece grille block on mine is more about slowing down the air hitting the heat exchangers. This, I think, makes it useable over a longer calendar period.

[Diesel_Dave]

Originally Posted by slowmover

I also, FWIW, block off the heater core circuit via valving during this stretch of time).

What's supposed to be the benefit of this?

[Saltsman]

Originally Posted by Diesel_Dave

What's supposed to be the benefit of this?

I was looking for increased FE by improving the aero (less drag/turbulence) and to boost warm up times for optimal fuel burn. Warmer cab temps in the winter would be a nice side effect but not my main goal. I've gone about as far as I can go with this rig and driving habits. At highway speeds this thing displaces a lot or air.

[Edit: Just realized you were asking slowmover about the heater core circuit. Enjoy my response while slowmover responds :-)]

[slowmover]

Originally Posted by Diesel_Dave

What's supposed to be the benefit of this?

As this was on the subject of CTD heat exchangers, there are, externally:

1] Coolant
2] CAC (charge air cooler)
3) PSF
4] HVAC condenser
5] And, for those trucks so equipped: ATF

Internally, the "heater core" and A/C (blast it, can't think of name).

Up to seven, IOW.

I shut off the heater core circuit (would be better to bypass-flow the thing with several valves & bypass hoses) as this keeps the A/C a minimum of 5F cooler in hottest weather measured at the center A/C vent outlet.

About every month or so I open it for a while to keep things "fresh" in the heater core circuit. The drawback to this is that one has only coldest air temp available (i.e, not a drawback in this USGS-designated "humid desert" where it almost never rains but is 90% humid daily; and never cools off at night, in main, even though temps don't stray above 95F. The worst, IOW, of both of those climate types. Why few people live south of San Antonio).

I never turn off the A/C from about April first through mid-October. Fastest cooldown via RECIRC, and then fan speed lightens the amp/volt draw of the HVAC blower. Shutting off the heater core circuit brings this time in temp transition down considerably.

We don't have winter. But we have a summer that kills (large group outcome life expectancy). Many companies with outdoor jobs will not hire those not already acclimated (already working thusly).

Consider it the reverse of the worst of winter. A/C is mandatory, so how to limit drain on engine accessories. Etc. I don't see the FLEXLITE electric fan replacement of the mechanical fan as workable.

The thinking is:

Radiator fan run time :: How to reduce?

In depth on A/C usage

.