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Old 02-08-2003, 03:19 AM   #1
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Default Intake Heat Shield

Well I've just about beat this one to death but I couldn't help doing some final touches to the insulated cold air box for my new 4" inlet x 7" *&B cone air filter.

Initially without the box, the temperature at the cone was 135 degrees F, basically underhood temperatures. :(
So I bent up some Reflecto plastic bubble insulation (it has 250 deg F limit) and wrapped it around the cone on two sides. It boxed it in nicely so the only openings were into the fender for cool air ingestion.
The temperature dropped to 85 deg F with a noticeable gain in pull.

This last week I have been refiining the 'Silver bubble'....it'* amazing what you can do with this stuff and a roll of aluminum tape. It'* like molding fiberglass. I've been using it in my Firebird for many years and it stands up well for around 3 yrs. After that it'* easy to clone using the old one as a template.

So I molded it for better sealing to the fender and the underside of the hood.

The temperature has now dropped to 60 deg F.
All readings are relative to an outside temperature of 50 deg F.

Wow. Now that'* a drop of 75 deg F from just running with an open cone under the hood.
Very significant.
It'* a well know fact that for every 10 deg F drop in inlet air temperature the engine will gain 1% more power. So a 270 hp motor will put out 7.5% more hp.
Worth a grand total of 20 Hp.
Holy ****.....and I can feel it.
I'm going out tomorrow for some new time trials.
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Old 02-08-2003, 03:36 AM   #2
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Ok, bubble boy. I'm gonna bust your bubble now.

Did you measure the temperature under the hood near the cone while you were DRIVING? The entire engine bay will run cooler while moving, ESPECIALLY right behind the headlights where the filter is located.

Gotta compare apples to apples here. You're not going to see that amount of temperature differential in real world conditions.

I'll give you credit though, you never give up
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Old 02-08-2003, 03:54 AM   #3
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Yes I was comparing apples to apples ...Dr. Watson.

During all testing, I stop and immediately pop open the hood to check. I take very accurate temperatures of all surrounding areas of the engine bay. I use a Rayteck infrared heat gun. I have been monitoring these temperatures year round for the last 3 years. I know that the temperature of the metal filter cone takes 2 minutes to cool down 20 deg F. So when I check temps after seconds, I know they are as accurate as running under hood temps.

The temperature of the cone must be the air temperature that the engine is ingesting because it equalizes.

It'* a true 75 deg F drop in temperature.
And I can FEEL the difference.
I will prove it ...at least to myself...if you don't believe it....with some time trials tomorrow.

I'm dissappointed that you, as a fellow Bonne enthusiast, don't appriciate the sharing of my NO COST knowledge.

I hope we can meet this summer at the gathering in Vancouver to share some Attitude !
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Old 02-08-2003, 04:02 AM   #4
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Quote:
Originally Posted by 2000SilverBullet
Yes I was comparing apples to apples ...Dr. Watson.

During all testing, I stop and immediately pop open the hood to check. I take very accurate temperatures of all surrounding areas of the engine bay. I use a Rayteck infrared heat gun. I have been monitoring these temperatures year round for the last 3 years. I know that the temperature of the metal filter cone takes 2 minutes to cool down 20 deg F. So when I check temps after seconds, I know they are as accurate as running under hood temps.

The temperature of the cone must be the air temperature that the engine is ingesting because it equalizes.

It'* a true 75 deg F drop in temperature.
And I can FEEL the difference.
I will prove it ...at least to myself...if you don't believe it....with some time trials tomorrow.

I'm dissappointed that you, as a fellow Bonne enthusiast, don't appriciate the sharing of my NO COST knowledge.

I hope we can meet this summer at the gathering in Vancouver to share some Attitude !
Don't misunderstand me.....I'm not flaming you. Just speaking from the perspective of many performance shops for many years......you won't see 20hp from a heat shield. Period. You probably won't see 5hp. The surrounding surfaces in the area are what you're reading. The ambient air as it travels through this area is not as hot as the surfaces while in motion. I have the same gun you do. If you blow air across the top of your toaster, the air doesn't automatically become the same temperature as the heating coils in the appliance. Your heat gun is picking up the hottest temperature it can find along it'* detection axis.....a very thin, precise line projected from the IR pickup. The last surface it hits will be a hot surface. Hotter than the ambient air.

Now, if you take a measurement through that toaster air with a cold wall in the background, it will measure the air temp fairly accurately. The problem you have is a nightmare. There are warm and hot air currents swirling around in there. As soon as you open the hood, everything changes. Any heat that passes in front of the gun is detected. You have to know what'* actually going INTO the intake while driving. This is why manufacturers put the IAT in there.

What you're trying to do isn't easy. I AM giving you credit here. You've gone farther to prove this than anyone here in the last year. What you need to do is suspend a thermocouple INSIDE the cone, and take readings while in motion. That air coming in isn't picking up 50 between your headlight and the cone, or not at least if your cone is properly won't see 5hp. The surrounding surfaces in the area are what you're reading. The ambient air as it travels through this area is not as hot as the surfaces while in motion. I have the same gun you do. If you blow air across the top of your toaster, the air doesn't automatically become the same temperature as the heating coils in the appliance. Your heat gun is picking up the hottest temperature it can find along it'* detection axis.....a very thin, precise line projected from the IR pickup. The last surface it hits will be a hot surface. Hotter than the ambient air.

Now, if you take a measurement through that toaster air with a cold wall in the background, it will measure the air temp fairly accurately. The problem you have is a nightmare. There are warm and hot air currents swirling around in there. As soon as you open the hood, everything changes. Any heat that passes in front of the gun is detected. You have to know what'* actually going INTO the intake while driving. This is why manufacturers put the IAT in there.

What you're trying to do isn't easy. I AM giving you credit here. You've gone farther to prove this than anyone here in the last year. What you need to do is suspend a thermocouple INSIDE the cone, and take readings while in motion. That air coming in isn't picking up 50 between your headlight and the cone, or not at least if your cone is properly positioned as close to the rear of the headlight as possible.

Yes, a heat shield is a good idea. Cold is always better than hot, especially if we're supercharged already. You're just not going to have a huge performance increase from it.
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Old 02-08-2003, 04:21 AM   #5
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You're determined to get this, and I'm curious to see what you find. If I end up being wrong, I'll buy the beer and swallow the pride......or buy the pride and swallow the beer. Something like that.

Here'* my suggestion. Hook an ohmmeter up to the contacts on the IAT. Run extension wires if you have to, just get the meter where you can read it. I have a chart that tells me what temps produce what resistances. I can scan it and email it to you if you want.

Try it that way with and without your heat shield. It'll most likely produce very different results.
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Old 02-08-2003, 04:22 AM   #6
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Quote:
Don't misunderstand me.....I'm not flaming you. Just speaking from the perspective of many performance shops for many years......you won't see 20hp from a heat shield. Period. You probably won't see 5hp. The surrounding surfaces in the area are what you're reading. The ambient air as it travels through this area is not as hot as the surfaces while in motion. I have the same gun you do. If you blow air across the top of your toaster, the air doesn't automatically become the same temperature as the heating coils in the appliance. Your heat gun is picking up the hottest temperature it can find along it'* detection axis.....a very thin, precise line projected from the IR pickup. The last surface it hits will be a hot surface. Hotter than the ambient air.
Please don't misunderstand me.
I'm not saying that I gained 20 hp.
I'm saying that I gained about 10 net hp for the addition of the Cold Air Inlet Cone Filter, but that I would have lost 20 hp if I had been satisfied with a simple under hood cone.
So the under hood cone would have been a net loss of about 10 hp due to hot air.

I really don't buy your theory. Remember that it'* the air that'* heating the cone not the radiant heat. I've already shielded it from that.
The toaster reference is different because the toaster element is the heat generator not the ambient air.

The heat gun takes a conical reading and averages the temperature within the cone.
You know why the car manufacturers use a simple thermistor instead of an infra red detector that costs $400.
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Old 02-08-2003, 04:33 AM   #7
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Ok, I'll throw another wrench for good measure

I like your style....you're tenacious and you do **** just to prove it can be done. Where do you think my water injection came from?

Watch out, here comes the wrench!

Unshielded intakes have been dyno'd for performance gains across the country on a daily basis. The sheer volume of air delivered is more important than the air temp, within reason. This is why 99% of the custom intakes out there don't have heat shields. It'* been proven to not make that much of a difference, at least not worth the cost of the CAI.

Yours is different. You did it with material you already had on hand. If you gain 5hp, it'* worth it. Even the famed Thrasher CAI only claims 7-10hp. All custom intakes with cone filters gain hp over stock, but no more than 10 hp on an engine like ours. That'* a grand total of 20 for the whole shebang under the BEST of circumstances. That heat isn't costing you what you think it is!

That won't stop me from doing the same thing. I've already got some polycarbonate sheets here for that purpose. Every little bit helps. To give you some credit, I misunderstood your original post and thought you said you'd gain 20hp from the bubble ALONE! I stand humbled and corrected, and will read twice before replying next time I promise!

Yes, 20hp is possible from the combination of custom intake and CAI, especially since you're already over-boosted.

BTW, my heat gun doesn't do an average of a cone. It has a visible wavelength laser built in, and measures right along that sight line. Very narrow. It'* for getting temps of something as small of an area of a tenth of an inch.
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Old 02-08-2003, 04:54 AM   #8
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Quote:
You're determined to get this, and I'm curious to see what you find. If I end up being wrong, I'll buy the beer and swallow the pride......or buy the pride and swallow the beer. Something like that.

Here'* my suggestion. Hook an ohmmeter up to the contacts on the IAT. Run extension wires if you have to, just get the meter where you can read it. I have a chart that tells me what temps produce what resistances. I can scan it and email it to you if you want.

Try it that way with and without your heat shield. It'll most likely produce very different results.
I just might take you up on the beer, Will.

That'* a good suggestion using the ohmmeter on the IAT. I should have done that before I taped up the bubble sheild. It would take longer to remove it now than just to test the real world performance difference. I just can't wait.

I will use 0-60 test runs to try and gauge performance gain.
I know that when I tested with the open unsheilded cone I was getting 6.8 secs from a stock box time of 6.9 sec.
I am anticipating a time of 6.7 sec or better.....

I have seen the claims of the K&N with heat shields ---- 20 hp

The ram air cold air box on my Firebird gained me 25 hp. I have time slips to prove that one.

I'm just telling you that I can feel it in the seat of the pants and my testing will prove it to me.

I'll let you know tomorrow.
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Old 02-08-2003, 05:04 AM   #9
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Yes, I can admit when I screw up. Ok, I didn't screw up. I can't give you that much, too humiliating. I MISUNDERSTOOD. Let it be known the evils of alcohol dulled my wits to the point I actually missed something. No more drunken tranny cooler install lectures with Allmachtige and Vze for me. Mark this day on the calendar.

Ram air....now you're talking a totally different animal. Especially on a non-SC car. Yes, you're force feeding it that way. I don't think you'd see anywhere near that kind of gain on a car that'* already force-inducted like ours. But there would still be a gain.

But to get back on topic......you ever hear of "survival of the fittest"? That'* why I drink. Kill off all the weak brain cells so only the strong ones can breed. Makes the herd stronger, faster, and.......slightly less capable of driving.
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Old 02-08-2003, 08:26 PM   #10
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I am just curious, but did you guys forget you have Eaton superchargers that are hot no matter what temperature the incoming air is? CAI'* for roots blowers are worthless. The only thing you need for it is a bigger intake so it can suck more air, not really cold air. You guys are arguing the wrong battle. N/A cars are affected by temperature entering the engine. A roots */C, nope, get an intercooler and that will be your CAI. Just trying to break this up before you forget that you are trying to do N/A tuning when you have */C cars...... Catchin my drift...
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