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Sweet2002 Sweet2002 is offline

Join Date: Oct 2014
Location: Florida
Age: 62
Posts: 194
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Default Re: I did a study of inlet pipe insulation and SUPRISE

Just starting to digest the math. Since we have a 4-cycle motor wouldn't the filling at 2000rpm be 500 and not 1000? Intake, compression, firing and exhaust. So recaculate?

engine intake is half or cyclinders per revolution, one revolution is one up and one down of piston or 1/2 of the 4 cycle.



IF the engine pistons WERE displacing 112 cubic feet it had better receive 112 cubic feet of air, minus the fuel volume. Since the intake manifolds are at 1/2 atmospheric, remember there are 2 of them, so the the motor is in fact taking in the 112 cubic feet per minute and not the 61 cubic feet stated, staying with the figures in the original post, but 61 cubes feet per inlet pipe, not about 30. So there are 60 CFM in EACH manifold/pipe.

See above, the intake air is also at 1/2 atmospheric density so the intake of atmospheric air volume is only 1/2 of air consumed , cause it expands in the manifold after the tb.

The 4th paragraph confuses me as it seems to take cubic feet and then they become linear. I estimate each inlet pipe at 4' long from my bed. that means each has 340 cubic inches of volume, divided by 1728, cubic inches be square feet equals .2 cubic feet rounded up from .19675. If indeed each pipe is drawing in 62 cubic feet a minute then that is roughly 1 cubic foot per second(62/60)Since the pipes volume is only .2 cubic feet we'll see that we have to multiply times 5 to get the 1 cubic foot of volume per second. That means 1/5 of a cubic foot can occupy the pipe in any given time, so the 1 cubic foot is sped up 5 times to all get through in 1 second. Then how fast would atmospheric move air through a 3" diameter pipe assuming no friction, much comes into play, physics.

inlet air velocity in the dcai pipe would be volume of flow divided by the cross section of the pipe. I stand on 30 cu ft and thus 30 cu ft x 1728 cu in / cu ft divided by the pipes area of 7sq in would give the air velocity in inches per minute divide by 12 is ft per min. which I figured to be 10 ft per min.

I could have done the speed conversion better. air speed in one of the DCAI tubes of about 10 feet per second or 5280 ft divided by 10 = 528 seconds per mile or 528 divide by 60 = about 9 miles per mile. = = fail it would be 9 minutes per mile and more calculations needed.

SO if 88 ft /second is 60 mph then, ( 10/88 ) x 60 = 6.8mph

What I am getting at here waldig is I believe the math is skewed and then we have the physics involved making mathematical assessments about a non-insulated pipe compared to an insulated pipe very difficult to determine. A datalog using uninsulated and then insulated pipes on the same day within the least amount of time on a warm motor would still be the best way to judge the value of the insulation. It's not just the amount of time the inlet air is in each pipe but how much the pipes inside diameter is transferring the heat. Again, much physics involved, especially if the car has that wonderful killer chiller. It's likely that it takes more heat(energy) to raise 1 cubic foot of air that is 60* Farenheit to start with 1*(put any figure here) then raising 1 cubic foot of air 1* that is 100* Farenheit.

I did the full test with one inlet insulated and the passenger inlet uninsulated at the same time, so there was a reading just before the supercharger inlet showed the difference in pipe temperatures to evaluate the insulation. I just insulated the passenger side last night and will have it on soon. the testing was to see if the pipes were going to profit from the insulation and to my suprise the pipes wernt being cooled much, why??

well the air is not going thru fast enough to scrub out much heat for the reasons stated.


I know the Cobra Mustangs measured inlet temps at the MAF, right after the filter and then in the compressor. There must have been some correlation that the ECU then determined was going on in the inlet air from start to near finish.

Our inlet air temp is at the outlet of the intercooler and thus way down from the intake manifold. I wanted to reduce or limit the temp of the incoming air to maximize the charge density going into the supercharger. Everything after that is fixed by the configuration of the sc and ic designs.

I know the temp of my braiin has increased, likely destroying or harming what good cells I have left after 62 years, many spent in abusing the brain!

Really the better media for a CAI is plastic or carbon fiber IMHO, mark

I agree and think a low conductivity carbon fiber pipe would be the deal, as it would be an insulator.

WW at 68 yrs.