Wrapped my intake tubes with heat reflective tape.
08-19-2010, 10:39 AM
#122
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I must be doing something wrong, as I'm getting no detectable difference whatsoever running with or without tubes on 16V or 32V, let alone insulated ones.
And I think that's my aunt Janey in the avatar. But she's 66 now.
Maleficio, try hard not to mess that car up, ok? Its gotta rank up there with value-of-the year. Nice shape. Uber-classic, clean and preserved.
And I think that's my aunt Janey in the avatar. But she's 66 now.
Maleficio, try hard not to mess that car up, ok? Its gotta rank up there with value-of-the year. Nice shape. Uber-classic, clean and preserved.
08-19-2010, 11:27 AM
#123
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08-19-2010, 12:23 PM
#124
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08-19-2010, 08:44 PM
#125
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I used the last bit of the roll to wrap up the topside of the airbox. I plan on buying one more roll.
So far, so good. No degraded driveability.
So far, so good. No degraded driveability.
08-20-2010, 06:07 AM
#127
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08-22-2010, 12:04 AM
#128
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I busted the coolant return line to the reservoir as I was stuffing the wrapped tube back in, now I've got a slight coolant leak, but nothing major. Should be an easy fix.
08-22-2010, 05:13 AM
#129
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If you ever feel like replacing the stock expansion tank, I can thoroughly recommend the aluminium one from 928 Motorsports...looks great, plus it's stronger and CHEAPER than Porscheplastic.....
08-22-2010, 09:50 AM
#130
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regards the original premis: the relationship of intake air temperature to HP, the power varies essentially as the square root of the change in ABSOLUTE temperature.....
example;
HP output at 0 deg F (-17.78 deg C)=138.1hp
HP output at 30 deg F (-1.11deg C)=133.8hp
HP output at 80 deg F (26.67 deg C)=127.4hp
HP output at 100 deg F=37.78 deg C=125.1 HP
HP output at 140 deg F=60 deg C=120.9 HP
So, as we know, air intake temperatures do vary HP considerably. But, to the point raised by several people, how much is the air temp influenced by the time it spends in the intake system before combustion, and how much can we influance it? That remains the big question. Just a guess on my part but unless we go to an ice water cooled and very efficent intercooler, the answer would be NOT MUCH. A degree or two reduction is hardly worth the effort....air flow rates, pressures, and volumes would have to be understood as well as coefficents of heat transfer and the like......and I am not a thermodynamics engineer......
references:
High Speed Combustion Engines by P. M. Heldt, 16th edition, p.638
The Design and Tuning of Competition Engines by Philip H. Smith, 5th edition, p.370-71.
example;
HP output at 0 deg F (-17.78 deg C)=138.1hp
HP output at 30 deg F (-1.11deg C)=133.8hp
HP output at 80 deg F (26.67 deg C)=127.4hp
HP output at 100 deg F=37.78 deg C=125.1 HP
HP output at 140 deg F=60 deg C=120.9 HP
So, as we know, air intake temperatures do vary HP considerably. But, to the point raised by several people, how much is the air temp influenced by the time it spends in the intake system before combustion, and how much can we influance it? That remains the big question. Just a guess on my part but unless we go to an ice water cooled and very efficent intercooler, the answer would be NOT MUCH. A degree or two reduction is hardly worth the effort....air flow rates, pressures, and volumes would have to be understood as well as coefficents of heat transfer and the like......and I am not a thermodynamics engineer......
references:
High Speed Combustion Engines by P. M. Heldt, 16th edition, p.638
The Design and Tuning of Competition Engines by Philip H. Smith, 5th edition, p.370-71.
08-22-2010, 10:29 AM
#131
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If you haven't done it yet, you might want to replace ALL the cooling hoses. They are odd-sized, molded and virtually impossible to cobble-up and still fit in the tight space allocated for them. So you need to buy them specifically for the car and there are a number of them.
You did replace all the fuel lines, right?? I don't want to read about you in the newspaper.
You did replace all the fuel lines, right?? I don't want to read about you in the newspaper.
08-22-2010, 12:29 PM
#132
anyone ever thick Silicone tubing for the intake tubes? i have one on my turbo diesel and it helped turbo temps alot by keeping engine heat out. but, i can tell you the under hood temps on my Cummins are ALOT cooler then my 928....
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Kevinfschultz (01-18-2020)
08-22-2010, 05:03 PM
#133
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yes, I suppose you could wrap the intake tubes and insulate them from getting any heat over several hours if you were creative, BUT, for what gain. Again, it all boils down to the air flow, mass and volume being so great and the surface area being so little, that NO measurable effect will be felt at full throttle and less effects under part throttle, due to it really doesnt matter. In fact, there might be a fair debate that hoter air might create better fuel mileage.
I cant believe you guys are still talking about this. Its such a silly idea with absolutely no imaginable gains.
If you really want some gains, try the electric supercharger. it has the effect of lowering the intake air temp to about 60 degrees, but it does it with vacuum reduction and slight pressure in the air box.
. THAT I do have DYNO proof for!
I cant believe you guys are still talking about this. Its such a silly idea with absolutely no imaginable gains.
If you really want some gains, try the electric supercharger. it has the effect of lowering the intake air temp to about 60 degrees, but it does it with vacuum reduction and slight pressure in the air box.
. THAT I do have DYNO proof for! To go back to my idea about the Kevlar wrap on the intake tubes...
Mark seems to be saying that no matter what you wrap the tubes with,
they will still absorb heat.
I disagree.
If you wrap the tubes with Kevlar, with adequate thickness, I could take a
propane torch to those tubes and not melt the plastic underneath. Kevlar really
*is* fire resistant. I agree that the aluminum wrap will only give you a minimal
decrease in temp, and will transmit radiant heat, just like any metal will. As
some people mentioned, the plastic tubes might transfer less heat than aluminum
would. So I am not saying the original wrapping idea is the best answer.
But I honestly think wrapping the tubes in Kevlar WOULD in fact reduce the amount
of heat transferred to the air inside. Take it a step further. Wrap the intake tubes in
10" thick of Kevlar. Or concrete. You really think the tube inside will be just as hot?
"Insulation" as a concept, does in fact work. If you put a good insulating material,
like Kevlar, the temp inside the tubes should be reduced.
Mark seems to be saying that no matter what you wrap the tubes with,
they will still absorb heat.
I disagree.
If you wrap the tubes with Kevlar, with adequate thickness, I could take a
propane torch to those tubes and not melt the plastic underneath. Kevlar really
*is* fire resistant. I agree that the aluminum wrap will only give you a minimal
decrease in temp, and will transmit radiant heat, just like any metal will. As
some people mentioned, the plastic tubes might transfer less heat than aluminum
would. So I am not saying the original wrapping idea is the best answer.
But I honestly think wrapping the tubes in Kevlar WOULD in fact reduce the amount
of heat transferred to the air inside. Take it a step further. Wrap the intake tubes in
10" thick of Kevlar. Or concrete. You really think the tube inside will be just as hot?
"Insulation" as a concept, does in fact work. If you put a good insulating material,
like Kevlar, the temp inside the tubes should be reduced.
08-22-2010, 05:25 PM
#134
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Mark, you keep talking about gains, but gains is not what this thread is about. I'm just trying to keep things normalized, and this wrapping has helped very much. I'm not sure what the weather is like where you are, but here in Va Beach it's freaking miserable because of the high humidity. This high heat and humidity makes my car run weakly, and this wrapping has helped. I'm not going to propose exactly why it's helped, I just know it has.
08-22-2010, 05:53 PM
#135
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If you haven't done it yet, you might want to replace ALL the cooling hoses. They are odd-sized, molded and virtually impossible to cobble-up and still fit in the tight space allocated for them. So you need to buy them specifically for the car and there are a number of them.
You did replace all the fuel lines, right?? I don't want to read about you in the newspaper.
You did replace all the fuel lines, right?? I don't want to read about you in the newspaper.
I hear ya. I did buy a fire extinguisher.
