read if you have the metal turbo to ic pipe for the stock turbo

[91blazins10]

I was driving around doing some datamaster runs because it was around 80° today and I wanted to see how high my ic temps were getting at wot on a hot day with stock boost. Anyways a few months ago I covered my ic pipe with some stick on heat shielding material thinking it would help out a little, well it turns out it helped out alot more than I thought it would. Before on a very hot day say around 85° I would see IA temps around 155°, now just with wrapping that pipe nothing else there all the way down to 125°. Now that’s no comparison for when im running methanol at 22psi and I see IA temps around 75° :lol: , but if your having problems with high IA temps I would give that a try it may help out a little. I plan on ditching the stock setup in favor of a/a sometime in future though.

 

[Six-is-Enough]

Re: read if you have the metal turbo to ic pipe for the stock turbo

Could ya post some pics please?

 

[91blazins10]

Re: read if you have the metal turbo to ic pipe for the stock turbo

Ive always had my ic wrapped with this stuff and that seemed to help out alot as well. I actaully added another layer since I took this pic but you can get the idea.


http://i160.photobucket.com/albums/t170/91blazins10/159_5951.jpg

 

[Six-is-Enough]

Re: read if you have the metal turbo to ic pipe for the stock turbo

Ive always had my ic wrapped with this stuff and that seemed to help out alot as well. I actaully added another layer since I took this pic but you can get the idea.


http://i160.photobucket.com/albums/t170/91blazins10/159_5951.jpg

Thanks:tup: . Do you still only have it on the bottom side of the pipe? I know that is were it will do the most good, but figured you would go all the way around.

 

[91blazins10]

Re: read if you have the metal turbo to ic pipe for the stock turbo

I wrapped the whole thing now.

 

[91blazins10]

Re: read if you have the metal turbo to ic pipe for the stock turbo

another thing I forgot is I have a one of those infared temp guns and the bottom of that pipe would be over 300°.

 

[allwheeldriven]

Re: read if you have the metal turbo to ic pipe for the stock turbo

the air inside the pipe coming out of the turbo is moving at super sonic speeds that air shouldn't have enough time or surface contact to have any effect at all on air temp while the air is within that pipe.

intercoolers only work because the cores have fins inside them to improve the surface contact with the air, if you take those fins out it won't cool anything.

Smoothing the airflow out would help but as far as wrapping or coating a turbo out or intrercooler pipe, in theory you should be able to get those pipes red hot and not see a drastic change in temperature while under boost.

same idea as sticking your hand in to boiling water as long as you pull your hand out quick enough you won't get burned.

the water doesn't have time to heat your hand up.

 

[91blazins10]

Re: read if you have the metal turbo to ic pipe for the stock turbo

:dunno: didn’t change anything else, maybe the pipe was transferring heat to the intercooler itself?

 

['JustDreamin']

Re: read if you have the metal turbo to ic pipe for the stock turbo

the air inside the pipe coming out of the turbo is moving at super sonic speeds that air shouldn't have enough time or surface contact to have any effect at all on air temp while the air is within that pipe.

Are you sure about that speed? I would doubt highly that the air in those tubes is flowing in excess of 600mph (ie, super sonic). By my math, its going a whole lot slower than that.

Here's the example I looked at:
Lets say 600 cfm (cubic feet per minute) through a 3" diam pipe.
3" pipe has an area of 7.06" square inches (pie r squared) = 0.589 square feet.

To flow 600 cfm though .589 area we need a velocity of 1019 feet per minute (fpm).

1019 feet / min = 11.5 miles per hour.

600mph = 52,800 feet per minute. For a 3" tube, we'd need to be flowing 32,000 cubic feet a minute (cfm).


So, help me understand. Either I'm making some huge math errors (possible) or the flow is no where near super sonic.

'JustDreamin'

 

[T-Bone]

Re: read if you have the metal turbo to ic pipe for the stock turbo

same idea as sticking your hand in to boiling water as long as you pull your hand out quick enough you won't get burned.

Come on!!! I'd like to see this theory proved......using someone elses hand, of course.

 

[turbodig]

Re: read if you have the metal turbo to ic pipe for the stock turbo

So, help me understand. Either I'm making some huge math errors (possible) or the flow is no where near super sonic.

'JustDreamin'

I'd say you're right on. If you've got an inlet to a pipe that goes sonic, you'll know it. So will your neighbors.

I've got some video of the GM flowbench running a test piece at sonic velocities. It's positively deafening, even on tape.

They're also driving the bench with huge roots-style blowers and it takes a *lot* of HP to make it happen.

 

[2kwik4u]

Re: read if you have the metal turbo to ic pipe for the stock turbo

Are you sure about that speed? I would doubt highly that the air in those tubes is flowing in excess of 600mph (ie, super sonic). By my math, its going a whole lot slower than that.

Here's the example I looked at:
Lets say 600 cfm (cubic feet per minute) through a 3" diam pipe.
3" pipe has an area of 7.06" square inches (pie r squared) = 0.589 square feet.

To flow 600 cfm though .589 area we need a velocity of 1019 feet per minute (fpm).

1019 feet / min = 11.5 miles per hour.

600mph = 52,800 feet per minute. For a 3" tube, we'd need to be flowing 32,000 cubic feet a minute (cfm).


So, help me understand. Either I'm making some huge math errors (possible) or the flow is no where near super sonic.

'JustDreamin'

Even at only 11.5mph it's only in the tube for less than a second assuming you have a 6" length of tube.

1019 ft/min = 16.98 in/sec in the same 3" tube with a surface area of ~56.5 sq/in........I don't think it's in there long enough to make a real difference.

At the same time. If you made no changes on the same day with the exception of coating that pipe with heat wrap, and you measured a 30* difference. Testing > Theory anyday of the week.

 

[allwheeldriven]

Re: read if you have the metal turbo to ic pipe for the stock turbo

My information came from a conversation I had years ago with a guy at Corky Bell's shop here in San Antonio while I was doing some work for them.
I can't remember his name but he was an engineer that came from Ferrari to work for Corky who is a pioneer in turbo charging, Corky knows his shit
If that guy says wrapping or coating a turbo pipe is a waste of time them I am going to assume he knows wtf he is talking about.
:rotf:

 

[91blazins10]

Re: read if you have the metal turbo to ic pipe for the stock turbo

I bought his book, didnt get that far into it yet, he might talk about this in it though.

 

[vortecfiero]

Re: read if you have the metal turbo to ic pipe for the stock turbo

My information came from a conversation I had years ago with a guy at Corky Bell's shop here in San Antonio while I was doing some work for them.
I can't remember his name but he was an engineer that came from Ferrari to work for Corky who is a pioneer in turbo charging, Corky knows his shit
If that guy says wrapping or coating a turbo pipe is a waste of time them I am going to assume he knows wtf he is talking about.

corkys book uses a percentage of mach numbers to determine if a given tube diameter
will easily flow a given cfm. If the flow approaches his figure of 400 ft/sec its starting to
cause enough of a restriction to consider increasing the diameter.

for exhaust tubes he recomends 250 ft/sec

so using his math
a 2.5 dia. intake tube from turbo to whatever will allow flow up to around 800 cfm
a 90 deg bend will reduce that by 5% appox

i created a lotus 123 spread sheet to play with diameters etc to see what i really
needed for my build.

 

[James Thomas]

Re: read if you have the metal turbo to ic pipe for the stock turbo

I tend agree that the air will not be heated enough to make a big difference if at all with the under hood temps what they are. I can pass my hand through a cutting torch fast enough not to get burned as far as the boiling water example goes. I contacted a company that makes modular plastic cold air intake tubes and asked if we could buy "parts" to build I/C pipes so as not to use metal and avoid "heat soaking" the intake charge air. I got a reply from the their engineering department (not sales) that said about the same thing as allwheeldriven said above and that they use plastic due to cost only, not the anti heat properties. Think about it from the aftermarket side also, if it did make a difference (big one anyway) wouldn't they be all over it like white on rice for the turbo guys?

Just a thought. If two tubes are under a hood for the same period of time at the same temp. (200 deg.+??) and one is plastic and the other metal / alum. Won't they be the same temp? I think so.

____________
James

 

['JustDreamin']

Re: read if you have the metal turbo to ic pipe for the stock turbo

Just a thought. If two tubes are under a hood for the same period of time at the same temp. (200 deg.+??) and one is plastic and the other metal / alum. Won't they be the same temp? I think so.

Yes, in a "heat soaked" condition, they should be the same temperature.

But the question that would be most appropriate is "what material has the least negative impact upon intake air temperature under those conditions?" I would expect the plastic to have the advantage under heat soak because it doesn't transfer heat as well (meaning the air could get through without picking up as much heat energy) but I'm not sure that it would be best in all conditions.

Even at only 11.5mph it's only in the tube for less than a second assuming you have a 6" length of tube.

That may be, but exhaust gas isn't in the tubes of headers for any real length of time either and there's still more than enough heat transfer going on for the pipes to get damn hot. But my basic point was that the air flowing through the pipes wasn't ANYWHERE near supersonic.

At the same time. If you made no changes on the same day with the exception of coating that pipe with heat wrap, and you measured a 30* difference. Testing > Theory anyday of the week.

Now that's something I agree with. Test Test Test. And only change 1 variable at a time if you can.


'JustDreamin'