Are there any plans to make a polished system? I love the way it looks but the black piping doesnt do anything for me and was wondering if anything was in the works for a nice polished system.

Since I don't have one I can't be sure but I believe they are made of plastic. Which is a good thermal barrier. Polished metal would absorb alot more heat, I would think.

Since I don't have one I can't be sure but I believe they are made of plastic. Which is a good thermal barrier. Polished metal would absorb alot more heat, I would think.

Yes, heat soak! :whine:

Are there any plans to make a polished system? I love the way it looks but the black piping doesnt do anything for me and was wondering if anything was in the works for a nice polished system.

Heat is the issue. Aluminum and stainless steel are better heat exchangers than plastic. With metal inlet tubes, heat from the engine and radiator warm up the inlet tube and the heat is quickly transferred to the inner wall of the tube. The incoming air then picks up that heat as it moves towards your engine. The same thing happens with plastic, just at a much slower rate. To test, just fill a plastic cup and a metal cup with hot water and feel the outside of the cups. All of this sounds a little elementary, but it's worth explaining since at least one air intake company is claiming the opposite.
In reality, there are two primary advantages to using metal tubes for air intakes. First, you can polish them. Second (and more common), an air intake can be developed with virtually no tooling costs since mandrel bent tubing is readily available. Setting all of that aside, I think a polished inlet tube would look awesome with our intake!:)
Mike

Thoughts....
On the other side of the coin, it takes the plastic longer to get hot but once the plastic gets hot (say from sitting in traffic), doesn't it take more time for the incoming air to cool it back down than if it was metal?

I found this troublesome on my GP GTP where the IAT sensor built into the MAF would heat soak and report hotter air than actually entering the throttle body because it took so long for the plastic body of the MAF to cool from incoming air. Couple this with the very slow response time of the OEM MAF IAT sensor and the ECM was pulling timing because it thought the air was hotter and it actually was. The response time of the IAT sensor built into the MAF was several seconds and didn't start accurately reporting the actual intake air temp until most of the way through a 1/4 mile run.

I think, at idle, the air already in the airbox, MAF and intake tube has time to warm up from heat soaked surroundings. Once you go WOT the air is replaced quickly with cooler air (assuming Roto-Fab intake or other CAI) and there is little time for the air to gain much heat from the intake system. The reported air temp however can be high because of a heat soaked, slow responding IAT sensor.

On my GTP, I replaced the IAT sensor with a remote, faster, unit from VMS. I could monitor the IAT and timing with my DHP Power Tuner and see the temp of the incoming air drop much quicker that previously reported. The result was more accurate metering of fuel and less pulled timing which gave better performance.

Some kind of metal would look better then a big plastic tube that looks like it came from Lowe's. Then take some metal polish and make it look almost like chrome. Just something to dress the engine bay up and make the intake really stand out.

PAINT your plastic one!!!!!!!!! der ya go!!!

what silver? lol that would look a little funny i think

Thoughts....
On the other side of the coin, it takes the plastic longer to get hot but once the plastic gets hot (say from sitting in traffic), doesn't it take more time for the incoming air to cool it back down than if it was metal?


you're misunderstanding...the plastic is a better heat insulator, meaning it won't transmit heat as easily as metal...also meaning it won't hold as much thermal energy (heat soak)...since metal has a much larger thermal capacity, it takes longer to reach that capacity than plastic...therefore the plastic will heat up faster, but it's holding much less heat...this also means that plastic will cool down faster (say between 1/4 mile runs)...

Are there any plans to make a polished system? I love the way it looks but the black piping doesnt do anything for me and was wondering if anything was in the works for a nice polished system.

for performance, you want a thermal barrier between intake air and engine compartment.

plastic is better.

wrapping it with owens corning insulation is even better than that.
sometimes looks and performance are opposite

Thoughts....
On the other side of the coin, it takes the plastic longer to get hot but once the plastic gets hot (say from sitting in traffic), doesn't it take more time for the incoming air to cool it back down than if it was metal?

I found this troublesome on my GP GTP where the IAT sensor built into the MAF would heat soak and report hotter air than actually entering the throttle body because it took so long for the plastic body of the MAF to cool from incoming air. Couple this with the very slow response time of the OEM MAF IAT sensor and the ECM was pulling timing because it thought the air was hotter and it actually was. The response time of the IAT sensor built into the MAF was several seconds and didn't start accurately reporting the actual intake air temp until most of the way through a 1/4 mile run.

I think, at idle, the air already in the airbox, MAF and intake tube has time to warm up from heat soaked surroundings. Once you go WOT the air is replaced quickly with cooler air (assuming Roto-Fab intake or other CAI) and there is little time for the air to gain much heat from the intake system. The reported air temp however can be high because of a heat soaked, slow responding IAT sensor.

On my GTP, I replaced the IAT sensor with a remote, faster, unit from VMS. I could monitor the IAT and timing with my DHP Power Tuner and see the temp of the incoming air drop much quicker that previously reported. The result was more accurate metering of fuel and less pulled timing which gave better performance.


Hopefully VMS will come out will a heat soak reduction kit, like they have for the LS2's............. :)

Thoughts....
On the other side of the coin, it takes the plastic longer to get hot but once the plastic gets hot (say from sitting in traffic), doesn't it take more time for the incoming air to cool it back down than if it was metal?

I found this troublesome on my GP GTP where the IAT sensor built into the MAF would heat soak and report hotter air than actually entering the throttle body because it took so long for the plastic body of the MAF to cool from incoming air. Couple this with the very slow response time of the OEM MAF IAT sensor and the ECM was pulling timing because it thought the air was hotter and it actually was. The response time of the IAT sensor built into the MAF was several seconds and didn't start accurately reporting the actual intake air temp until most of the way through a 1/4 mile run.

I think, at idle, the air already in the airbox, MAF and intake tube has time to warm up from heat soaked surroundings. Once you go WOT the air is replaced quickly with cooler air (assuming Roto-Fab intake or other CAI) and there is little time for the air to gain much heat from the intake system. The reported air temp however can be high because of a heat soaked, slow responding IAT sensor.

On my GTP, I replaced the IAT sensor with a remote, faster, unit from VMS. I could monitor the IAT and timing with my DHP Power Tuner and see the temp of the incoming air drop much quicker that previously reported. The result was more accurate metering of fuel and less pulled timing which gave better performance.

I agree with this in principle. It doesn't matter what intake you have if the MAF starts getting heat soaked.

you're misunderstanding...the plastic is a better heat insulator, meaning it won't transmit heat as easily as metal...also meaning it won't hold as much thermal energy (heat soak)...since metal has a much larger thermal capacity, it takes longer to reach that capacity than plastic...therefore the plastic will heat up faster, but it's holding much less heat...this also means that plastic will cool down faster (say between 1/4 mile runs)...

Before i buy into your comments, what are your credentials? I'm an engineer and for 30+ years have dealt with thermal issues, heat sink designs and heat transfer problems. Most of the 'facts' you presented are not supported by the science but before I expand, I would like to know if you figured this out on your own or actually have some education or scientific training in thermodynamics to back up your theories. No offense intended. I just want to find a starting point.

Hopefully VMS will come out will a heat soak reduction kit, like they have for the LS2's............. :)


This will make more difference than a metal or plastic intake duct, IMO.

Before i buy into your comments, what are your credentials? I'm an engineer and for 30+ years have dealt with thermal issues, heat sink designs and heat transfer problems. Most of the 'facts' you presented are not supported by the science but before I expand, I would like to know if you figured this out on your own or actually have some education or scientific training in thermodynamics to back up your theories. No offense intended. I just want to find a starting point.

I can't answer where he got his information from, but I can say this. Think simple. What are heat sinks made of, metal or plastic? Metal. Why? Because it conducts heat better than plastic. This heat conduction is exactly what we want to avoid.

I can't answer where he got his information from, but I can say this. Think simple. What are heat sinks made of, metal or plastic? Metal. Why? Because it conducts heat better than plastic. This heat conduction is exactly what we want to avoid.

true...

Before i buy into your comments, what are your credentials? I'm an engineer and for 30+ years have dealt with thermal issues, heat sink designs and heat transfer problems. Most of the 'facts' you presented are not supported by the science but before I expand, I would like to know if you figured this out on your own or actually have some education or scientific training in thermodynamics to back up your theories. No offense intended. I just want to find a starting point.

i have a bachelor's degree in mechanical engineering from the speed scientific school at the university of louisville...if that pleases you...

i had two semesters of thermo...in which i learned that the material that has a higher thermal conductivity will transfer more heat, while the one with a lower thermal conductivity will transfer less heat...thermal insulation is a measure of how easily heat can move from a hotter area (engine bay) to a cooler area (intake air)...so tell me again how this is not supported by science?

true...



i have a bachelor's degree in mechanical engineering from the speed scientific school at the university of louisville...if that pleases you...

i had two semesters of thermo...in which i learned that the material that has a higher thermal conductivity will transfer more heat, while the one with a lower thermal conductivity will transfer less heat...thermal insulation is a measure of how easily heat can move from a hotter area (engine bay) to a cooler area (intake air)...so tell me again how this is not supported by science?


i have to agree here. i am a chemical engineer with more thermo. plastic is the best choice to avoid heat issues. as said before metals will conduct heat and store it longer than plastics. i dont think that this a major issue however due to the high velocity of air, the short intake tubing, and the temps that are coming in. now if you were in between runs at the track metal would probably get a lot hotter due to waiting and low velocity, but hey everyone has there preference ( looks or performance)

Shouldda,
No offense indended but the problem is that, pound for pound many of not most plastics have a higher thermal capacity than many metals, including aluminum. Some very good thermal insulators, like bricks, make great heat storage devices. Pound for pound, the plastic tubes used for intakes will take longer to heat up than the aluminum tubes used the same way. By the same token, once hot, plastic will take longer to cool down than the same weight of metal heated to the same temp.
Thermal conductivity and thermal capacity are not the same and for our discussion are not directly related.

I never said plastics were not better insulators than metal. I never said plastics transfered heat better than or as good as metal. I'm saying if you give plastic the time to heat up to the same temp as metal and then flow air through the tube, metal will cool off faster than plastic if the tubes weigh the same. It will take a lot longer to heat up the plastic tube than the metal tube. The best heat storage material is hydrogen at about 3.4 BTU/lb F*. Water is 1 BTU/lb F*. Steel is 0.115. Aluminum is 0.215 and a number of plastics are 0.27-0.42. These are approx and there are a lot of variations available. They are from memory so I hope i didn't mess them up too much.

Blanket statements that metal is better than plastic or the oposite can be misleading and I wanted to point out that generalities may not apply.

I think a bigger problem is the IAT sensor. What is more important is being able to accurately measure and report the true IAT. The mixture and timing used are a function of IAT.

The IAT sensors used by car makers, for the most part, have time constansts of 7 to 10 seconds. This means it takes them 1 time
constant to report to 66% of a step change. You can be through the 1/4 mile before the IAT sensor is really telling the ECM what temp
the IA really is. Add to these slow time constants the fact that the MAF (where the IAT sensor is located) heat soaks just like the
ducts. The heated MAF can affect the reported temp. There are faster IAT sensor available. I think their time constant was something
like 2 seconds. It could also be located remotely, like in the portion of the duct inside the CAI box going to the K&N.

I'm sorry if i ruffled feather and when I re-read my earlier comments, i wished I had stated it differently.:slap:

Hopefully VMS will come out will a heat soak reduction kit, like they have for the LS2's............. :)

This will make more difference than a metal or plastic intake duct, IMO.

ETA ~2 Weeks ;)

ETA ~2 Weeks ;)


Will it fit my existing VMS intake I bought from you; and if so will we be allowed to buy first as we already have your system?

Please?:whine:

Will it fit my existing VMS intake I bought from you; and if so will we be allowed to buy first as we already have your system?

Please?:whine:

Yes it will work with the Roto-Fab system we sell, these will be first come first serve but you should have no problem getting one.

Shouldda,
No offense indended but the problem is that, pound for pound many of not most plastics have a higher thermal capacity than many metals, including aluminum. Some very good thermal insulators, like bricks, make great heat storage devices. Pound for pound, the plastic tubes used for intakes will take longer to heat up than the aluminum tubes used the same way. By the same token, once hot, plastic will take longer to cool down than the same weight of metal heated to the same temp.
Thermal conductivity and thermal capacity are not the same and for our discussion are not directly related.

I never said plastics were not better insulators than metal. I never said plastics transfered heat better than or as good as metal. I'm saying if you give plastic the time to heat up to the same temp as metal and then flow air through the tube, metal will cool off faster than plastic if the tubes weigh the same. It will take a lot longer to heat up the plastic tube than the metal tube. The best heat storage material is hydrogen at about 3.4 BTU/lb F*. Water is 1 BTU/lb F*. Steel is 0.115. Aluminum is 0.215 and a number of plastics are 0.27-0.42. These are approx and there are a lot of variations available. They are from memory so I hope i didn't mess them up too much.

Blanket statements that metal is better than plastic or the oposite can be misleading and I wanted to point out that generalities may not apply.

I think a bigger problem is the IAT sensor. What is more important is being able to accurately measure and report the true IAT. The mixture and timing used are a function of IAT.

The IAT sensors used by car makers, for the most part, have time constansts of 7 to 10 seconds. This means it takes them 1 time
constant to report to 66% of a step change. You can be through the 1/4 mile before the IAT sensor is really telling the ECM what temp
the IA really is. Add to these slow time constants the fact that the MAF (where the IAT sensor is located) heat soaks just like the
ducts. The heated MAF can affect the reported temp. There are faster IAT sensor available. I think their time constant was something
like 2 seconds. It could also be located remotely, like in the portion of the duct inside the CAI box going to the K&N.

I'm sorry if i ruffled feather and when I re-read my earlier comments, i wished I had stated it differently.:slap:

no harm no foul, but you are talking lb for lb...a plastic intake of the same dimensions as steel or even aluminum should have significantly less mass, correct?

Yes it will work with the Roto-Fab system we sell, these will be first come first serve but you should have no problem getting one.

Awesome.... I'm totally getting one... :)

Awesome.... I'm totally getting one... :)

+1 .

no harm no foul, but you are talking lb for lb...a plastic intake of the same dimensions as steel or even aluminum should have significantly less mass, correct?

The Roto-fab tube is thicker than most of the aluminum tubes I've seen so I assumed that maybe they weigh about the same. Maybe the actual weights are such that they perform about the same as far as specific heat is concerned. No doubt about the plastic insulating better.

Awesome.... I'm totally getting one... :)

I put one in my 04 GTP Comp G and the increase in IAT response was fantastic. With my Power Tuner I could see that the PCM was not pulling the timing like it was with the slow sensor. Even with a heat soaked engine you could see the IAT start to drop almost as soon as you went WOT.

I put one in my 04 GTP Comp G and the increase in IAT response was fantastic. With my Power Tuner I could see that the PCM was not pulling the timing like it was with the slow sensor. Even with a heat soaked engine you could see the IAT start to drop almost as soon as you went WOT.

G8V8: Thanks for the info! Good to know. I had a 2004 GTP Comp G as well. I totally miss that supercharger whine.

G8V8: Thanks for the info! Good to know. I had a 2004 GTP Comp G as well. I totally miss that supercharger whine.

I know what you mean. However, the sound of a G8 with the Roto-Fab intake is pretty intoxicating in its own right!

doesnt the HSRK trick the engine into thinking its getting cool air??? we wrapped me SS up with A/C duct insulation and saw IAT's drop dramatically, and in some cases more so than the trucks with the HSRK...

doesnt the HSRK trick the engine into thinking its getting cool air??? we wrapped me SS up with A/C duct insulation and saw IAT's drop dramatically, and in some cases more so than the trucks with the HSRK...

No, the stock IAT sensor get heat soaked, giving the PCM incorrect data on intake temps. We need a faster sensor.

Back to dressing up the plastic part. You can get it chromed:

http://www.cvvacuumplaters.com/