heat shield or no heat shield?

[cumminspower]

How much does it really help to use the heat shield when running bhaf? Does it really help keep intake temps. down any lower than not using one at all?

[dripley]

i dont know. i just put one on 2 months ago with no heat sheild. it is still to cold to tell. it has got to draw warmer air in the summer. but just how hot does it get under the hood when you are driving? i am going to see what happens in the spring and adjust for the summer.

[ISX]

I have a temp sensor on top of the BHAF, zip tied to it and the hotter it gets outside, the bigger the difference between ambient I see. It seems to max out at 20F difference. When ambient is 32F or less, I see no difference, pulling a trailer might get it 5F over. So I don't think a heat shield does anything.

[white01]

idling it is gunna be hot under the hood anyway...driving down the highway at 70m.p.h. the wind ..you would think...is gunna push the heat out....a?

[ISX]

idling it is gunna be hot under the hood anyway...driving down the highway at 70m.p.h. the wind ..you would think...is gunna push the heat out....a?

100% correct. It skyrockets at idle. Maybe if I had the engine fan on it, it wouldn't be as bad but mine shoots way up there.

[Mopar1973Man]

Yeah but if the intercooler is doing its job the IAT temp should follow a +40 offset normally. So what the turbo inhales for air will be cooled back down by the intercooler. So even on a 100*F day I've never seen over 140*F on the IAT while cruising. This is with the A/C going as well. What counts is what the IAT sensor sees not what the turbo is inhaling... But flipping the page again the 24V does do much better with a hot IAT temps for MPG's though... Much better than cold... http://forum.mopar1973man.com/threads/3231-MPG-fooler-Design-phase

[cumminspower]

I was just curious how it would perform here in the south. I want to put mine in but was still thinking it over. Here in Alabama, during the middle of summer, it usually gets up close to 100 F most days with high humidity. I don't spend much of my time driving at highway speeds. Lots of stop & go in traffic. Wasn't sure how correct the studies are, but I've seen some posts where they say the stock air box will keep the intake temps down more than the bhaf in certain cases.....the one problem i have with the stock air box is sometimes it doesn't seem to make a good seal & i see some dirt & residue making its way in around the filter edges & into the turbo.....

[Mopar1973Man]

Sitting and idling in traffic with high IAT temps will not effect the performance because it not rolling anyways... MPG is 0 just sitting at a traffic light. Stop and GO traffic is harsh no matter what the IAT temps are. The other factor is no matter what you want to plumb for cold air intake you got to remember the entire manifold of the 24V has a coolant passage under it not to mention having a coolant pass within 3 inches of the IAT temp sensor now. EDIT: The freeze plug I've been told is intake manifold.

[ISX]

IAT temps do not make any difference at all. I get the same mileage at any IAT/air filter temp from 0-100F, I never can see a difference. Does seem to have more power with it being cold, but I am talking 10F cold, over that, all seems the same.

[JOHNFAK]

IAT temps do not make any difference at all. I get the same mileage at any IAT/air filter temp from 0-100F, I never can see a difference. Does seem to have more power with it being cold, but I am talking 10F cold, over that, all seems the same.

Eh ? But that's the basis of the mpg fooler right ? Or you mean actual temps make little diff but the ECM param does ?

[ISX]

Eh ? But that's the basis of the mpg fooler right ? Or you mean actual temps make little diff but the ECM param does ?

Yes the fooler uses IAT temps but that is just to get the computer to stop doing whatever it does in winter. My truck is set, everything is the same in winter as summer, the computer controls nothing, eveny timing is set. The actual IAT temps matter very little as far as I can tell. I got 25MPG going 45mph which ran the engine so cold that the engine coolant never got over 175F in the 35 mile jaunts I made while testing at 10F ambient(heater was on full blast and that was all the heat the engine was making). I get the same mileage on a 100F day. So it shows IAT does nothing. My theory is that the IAT will warm up once it gets into the intake horn and try to get to the operating temp of the engine, then in the summer the air is already warm so doesn't take on as much heat. Therefore, they both probably end up close to the same temps by the time the air hits the combustion chamber. Mike says the air already raises 50F over ambient in the winter anyways and that is at the sensor, so by the time it gets to the combustion chamber it might be 100F.

If you took the intake manifold completely off and ran 0F air straight into the valve intake port, then I think there might be a noticeable difference. But the way it is OEM, I think the air gets preheated enough that you won't notice a difference between summer and winter because the air gets to the same point.

I'm not absolutely sure about this but I drive extremely consistent and my MPG numbers for winter and summer on the 55mph test runs are basically identical.

[dripley]

lots of good dicusion here. I have no heat sheild on mine. there still has to be air moving in thru the original intake hole for the stock intake. even idling at a stop the fan(for those of us who still have one:lmao2:)has got to move enogh air to keep the under hood temp from getting to high for the intercooler to overcome. are any of you running a heat sheild on yours? i think i will stick with out one and see what happens this summer. i live in the south too with 100* weather and plenty of humidity and will just see what happens. no differance in performance = no heat shield. i dont have any extra sensors to measure the data with, but if i cant feel it my arse or at the gas pump, I think i am good to go.

[cumminspower]

Yes the fooler uses IAT temps but that is just to get the computer to stop doing whatever it does in winter. My truck is set, everything is the same in winter as summer, the computer controls nothing, eveny timing is set. The actual IAT temps matter very little as far as I can tell. I got 25MPG going 45mph which ran the engine so cold that the engine coolant never got over 175F in the 35 mile jaunts I made while testing at 10F ambient(heater was on full blast and that was all the heat the engine was making). I get the same mileage on a 100F day. So it shows IAT does nothing. My theory is that the IAT will warm up once it gets into the intake horn and try to get to the operating temp of the engine, then in the summer the air is already warm so doesn't take on as much heat. Therefore, they both probably end up close to the same temps by the time the air hits the combustion chamber. Mike says the air already raises 50F over ambient in the winter anyways and that is at the sensor, so by the time it gets to the combustion chamber it might be 100F.

If you took the intake manifold completely off and ran 0F air straight into the valve intake port, then I think there might be a noticeable difference. But the way it is OEM, I think the air gets preheated enough that you won't notice a difference between summer and winter because the air gets to the same point.

I'm not absolutely sure about this but I drive extremely consistent and my MPG numbers for winter and summer on the 55mph test runs are basically identical.

wow...i'm starting to wonder if something is wrong with mine....we have farily warm temperatures around here & the best I can do on gas milelage is around 14mpg....i'm pretty light on the gas too....

[dripley]

i am averaging 18 here in tenn and nc. like i said i have only had my bhaf for 2 months. not enough time to see any differance. i will admit the breather looks to be a very good product compared to the k&n i have been running.

[ISX]

wow...i'm starting to wonder if something is wrong with mine....we have farily warm temperatures around here & the best I can do on gas milelage is around 14mpg....i'm pretty light on the gas too....

There is a lot of commotion about how 4wd effects things and such, but I believe that to all be BS. There are guys getting 25mpg with 4wd's. Another thing is mods and injectors and yadda yadda the list of excuses goes on and on. But I get 17 pulling this so there is NO reason any unloaded truck should get less than 17 at any point in time. I can't get below 20 unloaded no matter what I do. The other thing is that I pull that trailer at 70mph down to where we ride dirt bikes which gets into a lot of long hills maybe 5-7% grade which I keep it at 70 going up all of them, but I let off on the downhill, which I believe regains what I lose going up the hill, making it average out to just driving on flat ground. I'd like to prove this getting a flat ground GPH reading, then average out the uphill and downhill readings to see if they end up being the flat ground reading. Also, 14mpg is what Caj gets pulling huge boats..

[Mopar1973Man]

Over all my MPG logs I've kpet since 20K miles to current. My lowest MPG hauling loaded was 14.10 MPG Best was 25.3 MPG (One Hit wonder) But still can hold a floating around 19-21 MPG hand calc'd. But with a heavy foot see a average of 16-18 MPG as well...

[cumminspower]

I take that back....I reset that overhead console thing today & it said that it was getting about 17mpg....i guess it's not bad but not great either.....if it's actually giving an accurate reading.....

--- Update to the previous post...

There is a lot of commotion about how 4wd effects things and such, but I believe that to all be BS. There are guys getting 25mpg with 4wd's. Another thing is mods and injectors and yadda yadda the list of excuses goes on and on. But I get 17 pulling this so there is NO reason any unloaded truck should get less than 17 at any point in time. I can't get below 20 unloaded no matter what I do.

The other thing is that I pull that trailer at 70mph down to where we ride dirt bikes which gets into a lot of long hills maybe 5-7% grade which I keep it at 70 going up all of them, but I let off on the downhill, which I believe regains what I lose going up the hill, making it average out to just driving on flat ground. I'd like to prove this getting a flat ground GPH reading, then average out the uphill and downhill readings to see if they end up being the flat ground reading.

Also, 14mpg is what Caj gets pulling huge boats..

sometime in 02' i think they got rid of the CAD....Mine doesn't have CAD & my front drive shaft turns all the time....I've heard some say that they've seen an improvement in gas mileage after taking their front drive shaft out.....would be interesting to know if it's true & how much of a difference it makes.....

[Mopar1973Man]

I take that back....I reset that overhead console thing today & it said that it was getting about 17mpg....i guess it's not bad but not great either.....if it's actually giving an accurate reading.....

--- Update to the previous post...

sometime in 02' i think they got rid of the CAD....Mine doesn't have CAD & my front drive shaft turns all the time....I've heard some say that they've seen an improvement in gas mileage after taking their front drive shaft out.....would be interesting to know if it's true & how much of a difference it makes.....

Actually if your going for fuel saving I wouls say covert the hubs over to manual hubs and quit rotating the ring and pinion in the heavy gear oil. Pulling the driveshaft isn't going to save much... Because the axle are still twisting the gears around in the front pumpkin in that thick gear oil...

[txmasterplumber]

I've had my BHAF on for probably 4 yrs now, without a heat sheald. I just picked up my SG II today from Autozone, and said I got an average of 21.0 on my trip home. I'll have to read up on the manual tonight..... man, this thing is SWEET