ken800

I decided to do some testing with my JL ram air to measure the intake air temp sensor... I have a 20 minute long log file so I won't post it... I'll just post the summary.

Started the engine, let it run until temp was up to about 2/3 normal operating temp. At this point, intake temps started to rise. So, I took off for work. At 15-25MPH through my neighborhood, the intake temp stayed within 1 degree of ambient. At full operating temp I slowed at a light (didnt' stop, down to 20MPH) briefly and temps jumped 7 degrees quickly. Back up to freeway speed and temps stayed at ambient for next 10 miles or so. I hit a patch of traffic and dipped into the 10-30mph ranges and temps climbed about 8 degrees very quickly. Single digit MPH and the temps jumped to 16-20 degrees over ambient and were still climbing. I rolled at a constant 30MPH for about a 1/2 mile and temps maintained 13-14 degrees over ambient. Maintained 40 mph for another 1/2 mile or so and maintained 12-14 degrees over ambient. Back down to 10 mph and back up to 16 degrees over ambient. The cooling fans now kicked in and hot fan wash complicated things. I sped up again and the fan went off right before I parked. I let it run in park with the fan off and peaked at 33 degrees over ambient. The fan kicked in and the fan wash made temps jump very quickly. I let the engine run for a couple of minutes and reached 142 degrees intake temp. Ambient was 83-84 degrees the whole way which meant I was at 59 degrees over ambient sitting there.

Summary:

While engine is cold, low MPH will keep intake close or at ambient. Once the engine bay is completely heat soaked, it takes at least 30MPH to keep intake temps down within 10-15 degrees of ambient. In stop and go traffic, it's going to be just plain ugly. I'll test again this afternoon when the truck has been sitting in the sun and I'm running around at lunch. I suspect the heat and difference between intake and ambient will be quite large....

Assuming the adage that a 10 degree change in intake temp is worth 1%, it stands to reason that in stop and go traffic, until you get up to speed, those little quickie throttle jumps are missing (on my truck at 380HP) around 1.5-3% HP which equates to 5.7 to 11.4 HP. I am assuming a 10-15% ambient vs. intake temp which is somewhat conservative because I hit a 39 degree spread sitting there this morning for just a couple of minutes. Keep in mind this test was at 83-84 degrees ambient with the sun on a low horizon. At noon, that number may climb very high. I suspect that if given enough stop and go time that the engine bay will approach the operating temp of the engine... we'll soon find out eh?

This doesn't mean JL's box is bad. Quite the contrary. Without the ram air setup, I don't think intake temps would come down nearly as quickly or ever even reach ambient. The fact that ambient can be reached with a hot motor is good, but the ultimate question is how much HP off of launch and through the early part of first gear am I losing due to heat soak and hot air being ingested?

An even bigger question that always begs: Is more warm air better than less cold air? And what will the stock airbox look like?

I'll keep you guys posted as I'll be doing the same thing with a stock airbox and K&N panel filter in a week or two.

Ken

Richo

To make things easy for a quick test, try putting duct tape over the ram air inlet and see the temp changes...This would be equivelent to just a cone type filter under the hood.

__________________
NHTOC # 21
2003 10th Annv Torch Red Convertible Cobra

Predator/Runnin With The Devil
Billetflow 2.76, idler and 4 Pulley Kit
LFP Ported Blower
LFP Heat Exchanger
K&N FIPK
LFP Brisk Plugs
Bassani Catback/Catted X-Pipe
LFP/Kirban Shifter
MGW Shifter Handle
470HP 481.5tq new KB numbers soon

2002GreyHD150

Ken great info... I too would love to see the same info comapred on the stock air box.

how were you measuring the ACT?

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--My momma always said, opinions are just like Butt-holes everyone's entitled to one, but not always entitled to show it.

ken800

Not sure what you meant by ACT... so...

I was measuring intake temp using an autotap plugged into the diagnostic port. It gets that information from the intake temperature sensor.

I was measuring ambient using the thermometer on the A/C control. It is always within 1 degree of various thermometers I have compared it to. (while moving, of course).

I'll try the duct tape idea tomorrow.

Thanks, Richo.

Ken

2002GreyHD150

Sorry Ken the sensor that reads the air iintake is the "Air Charge Temperature Sensor" or ACT.... sorry

The autotap is a Ford diagnositc tool?

Wow I would love to have something like that to see temps, MAF voltages, TPS ranges... very cool

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--My momma always said, opinions are just like Butt-holes everyone's entitled to one, but not always entitled to show it.

Crockett59

I had a Snap-on micro scan that told me all the Temps, TPS voltgae and %, and MAF info. I sent it back but I may buy it again.;Y

I think that I'm going to MAKE a custom airbox myself here at the shop and do some testing with it. It will probally be a few weeks before I do any thing But I will keep everyone posted. It will pull air from the stock location and from a Ram air setup (With blow off valve) but not from inside the engine compartment.;)

ken800

Ack! My autotap crapped out. Going back on an RMA for a replacement. My testing stops for about a week. Dayum.

This is a product made by B&B electronics and can be found at www.autotap.com. It plugs into the diagnostic port that along the bottom edge of the moulding underneat the steering wheel.

It's an OK tool, but update speeds kind of bite. You get 20ish updates per second which is then divided by the number of parameters you want to measure.

Its fun to play with for sure, but you'll need a notebook computer or a good quality pocket PC to use it. I think they support Palm OS, too.

Ken

ken800

ok, it was the computer and not the autotap. Another notebook setup and I'm back in biz.

updated data: 91 degrees outside... hotter part of the day. I let the truck warm up to full temp. Intake reached 153 degrees which was a spread of 62 degrees. I took off and tried to maintain 30mph. I hit 40 a couple of times, but kept it mostly between 30-35... The best I got was into a fairly strong headwind (obviously netting over 35mph) was 111 degrees. That is 20 degrees over ambient.

Stopping just at a stop sign jumps the intake temp up 10 degrees in that short a period of time... At a stoplight, I hit 132 degrees after sitting there for no more than 20 seconds or so. It climbs QUICK as soon as I slow down. The temp moves downward less quickly once moving.

Tonight I'll test on the way home and see how long it takes to get to ambient at freeway speeds.

The net of all this is that I am more and more convinced that a sealed enclosure that pulls air from OUTSIDE is going to net more horsepower -- period.

I'll try again tomorrow with the duct closed up and see if the cooling is due to the ram air or due to air coming in from the front of the vehicle...

ken800

last update on the JL airbox for now... On the way home it took 2 or 3 miles at 55-60mph to get the intake air temp within 10 degrees of ambient. As soon as I slowed down, it jumped right back up again.

I don't know how the stock airbox will perform, but I sure would love to see ambient air at all times...

Richo

Ken, I believe that Sal (PSP) did quite a bit of this testing and determined that a sealed ram air will cause the engine to lean out to the point that the PCM can not compensate for the changes in the A/F. To much air, not enough fuel...

__________________
NHTOC # 21
2003 10th Annv Torch Red Convertible Cobra

Predator/Runnin With The Devil
Billetflow 2.76, idler and 4 Pulley Kit
LFP Ported Blower
LFP Heat Exchanger
K&N FIPK
LFP Brisk Plugs
Bassani Catback/Catted X-Pipe
LFP/Kirban Shifter
MGW Shifter Handle
470HP 481.5tq new KB numbers soon

N2TRUX

Ok buddy, hurry up with more data. It seems what you are about to tell us, is the stock box mod might not be the thing to do. Maybe I should have just done the K&N by itself.

Let me know if you need a modded box, or a stock box to play with. I have both...

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ctkarella

Real good info - can't wait to see the stock numbers. Thanks for all the great work. CTK

ken800

Thanks guys...

Ken, I may take you up on that... I was thinking of taking the scoop off of the JL ram air setup and just using the tube to pull more air into an opened up modded airbox since the lean issue concerns me...

If I end up doing that, I might as well remove the entire JL setup and just fab my own. That way I can sell the whole JL box if I end up proving the stock setup is best...

I'm trying to decide whether or not to dyno with the JL box on and then dyno with the stock airbox with a K&N and extra air feed tube from outside...

My 7lb pulley is now "in hand" and I'd like to put it on, but then I'd need to dyno pull for proper chip tuning first, etc...

Gathering data is a pain in the arse. (but well worth it)

Also- Ken, do you have a notebook computer? If you do, we can autotap your truck with whatever you have done just to see some comparisons... I'll loan you the autotap and show you how to set it up and all you have to do is turn on the log file and drive around...

Ken

ken800

upate:

First, I plugged the ram air tightly with a towel so no air could get in... I went out of my neighborhood at full operating temp. 10-15mph for about 6 blocks. 40mph for about 3 miles to the interstate. 60mph for about 3 miles. Turned around and did the same course coming home without the towel stuffed in the ram air. Temp outbound was 91 degrees, coming home it dropped by 1 degree to 90. Here is what I got:

lowest leaving the neighborhood about 111. Going 40mph toward freeway, lowest I got was 106 degrees. I stopped and let it climb to 127 degrees and then did a 1/4 mile or so at 40mph and it only dropped to 118 degrees in that short run. I then jumped on the freeway and did 60mph for about 3 miles. In a minute and a half, it reached 109 and had a low of 108 degrees. That's 17 degrees over ambient with the towel in place. I stopped and pulled the towel and started the opposite direction on the freeway. I was at 122 when I took off. In 19 seconds I was at 109 degrees. (it took 1.5 mins with the ram air blocked). I reached a low of 94 degrees coming back down the freeway. That's 14 degrees cooler on the freeway with the ram air unplugged... The 40 mph trip back down the back road for about three miles saw a low of 102. Returning in the neighborhood I saw a low of 108.

So, it appears that the ram air setup on JL's box does keep intake temps cooler. It brings down temps pretty quick at speed though the ram air is not as effective at low speeds as expected...

It also seems to depend on how long the engine compartment was sitting and being heated as to how fast and how close to ambient the box can get. If I run the truck all over town and then let it sit, intake temps climb very quickly and take longer to come down. If I just wait until the engine comes up to full operating temp and then take off, intake temps rise slower and peak lower. The interesting part of this test is I did the blocked ram air on the way OUT which means the engine compartment was less heated than the return trip. The return trip showed lower intake temps and faster cool downs with the ram air functioning.

This test was done around 6:30PM and the hot sun wasn't superheating the concrete I was driving on.

Next up is the stock airbox. First, I need to find a K&N panel filter to run in it. After the pure stock airbox, I'll cut a hole and run a hose and test again just to be sure, but the hose will be run to the outside of the engine compartment.

stay tuned...

N2TRUX

Ken,
If you don't want to wait till Monday for the K&N, call me on Sunday. You can use mine. Right now it's in the moddded stock box, but we can switch it to my un-cut stock box. I still have a clean stock filter too if you want to play with that.

To answer your other question, yes, I do have a laptop. I need to get a new battery for itthough. It never has held a decent charge. Now it won't last but a few minutes...