I have spare Thermostats laying around, and they don't make aftermarket ones for our cars. I have little to lose, and the tools to monitor the temps. If it makes no difference then no loss. IF it does it great, noone else seems to have tried it yet, and I have lead the way on other ideas before.

 

Just for future reference....
people who resort to personal insults in any form of disagreement, tend to make their argument look weak, because they have to result to childish highschool quips.

You and I both know that your "formula" added 1 significant variable to the situation we are talking about....which is pressure.

technically, both of our standpoints are correct, but we are looking at different parts of the system.
Im looking at the intake recieving an increase in temperature, due to the heatsoaked air around it.

that has nothing to do with pressure.
You are looking at the effect of the air coming through the BLOWER, after being heated, and then calculating the BLOWERS heat...on top of that.

the blowers heat has nothing to do with the efficiency of the heat wrap on the intake.

Im sure someone who can snap off equations such as you did, knows that cold air will absorb more latent heat from the engine bay, than warm air does....
thats a very basic fluid dynamics principle.

The same as I can accept that in the blower, under pressure, the situation changes.

but the fact is....the heat wrap isnt on the blower, its on the intake....and we are discussing what that heat wrap can do for the temperature of the air going through that intake.

its a closed system as far as this argument is concerned..

Basically, we both have sound principles, that are pointing at different parts of the open system...

So Im more than happy to conceed your facts about POST blower temps.
hopefully you can do the same for PRE blower temps.


Notice how I didnt once insult you with childish quips during the discussion?
please feel free to do the same in future.

 

I assume you are responding to:

Quote: Originally Posted by an0malouseven when my IATs are up over 160, and the car is heatsoaking...
the intake pipe never feels hot.
warm at the very worst.
it may help....but IMO, not enough to warrant the cost.


"You sound like some kind of matamatical jeanyus or something. I bow to you.

Here's the forumla, plug in some numbers and prove yourself wrong.

deltaT = absolute intake temp (intake temp in degrees of Rankin) x [{pressure ratio^0.238}-1]
_________________________________________________
compressor efficiency

Now I would think that an intraweb wizard jeanyus like yourself would be able to plug in some numbers and self-own, but I'll help you out with it just in case.

Let's pick an intake temperature. We'll say 140*F since you think that pulling hot air in doesn't matter. Add 460* to that to convert to Rankin temp, and you have 600*R.

Pick a boost pressure, we'll say 15psi. Convert it to pressure ratio. (15 + 14.7) / 14.7 = 2.02PR

Now we need a compressor efficiency. We'll say 65% because roots blowers suck a nut.

deltaT = 600 x (2.02^0.238 -1)
_________________
0.65

That gives a temperature increase of 168* Add that to the original intake temp of 140* and we now have a compressor discharge temp of 308*F.


Ok so let's try this again. We'll change nothing but the temperature of the intake air.
This time we'll say it takes in 100*F air. Converted to Rankin that gives 560*R.

deltaT = 560 x (2.02^0.238 -1)
__________________
0.65

This gives a temperature increase of 156*, that's 12* LESS OF AN INCREASE than with the 140* air. Add that to the original 100* intake air and we now have a compressor dicharge temp of 256*F, which happens to be 52*F lower than previous. Keep in mind, that's 40*F drop in intake temp, yielding a 56*F drop in compressor discharge temp. Do you see how that works now, jeanyus boi?"

I believe what the gentleman immediately above in quotes is trying to say, in response to the short post above that with regard to whether cooler IAT's benefit engine performance, and even more importantly engine longevity, is that the cooler the air is going into the S/C the lower the temperature the air coming out of the S/C and into the I/C is. It fits that if the I/C has a given effectiveness, and can only remove a given amout of heat from the S/C air, the lower the S/C air the better. This is valid, and I have found on my 2006 Cobalt SS S/C, Stage II, w/2.8", extrude honed exhaust, performance C/Back, CIA through K&N factory filter/w/opened up factory housing, it definately helps my Cobalt's performance to use the CAI wrap discussed.

Unfortunately, it appears the gentleman with the formula has been banned and cannot defend himself, however, I did notice that his numbers and formula are as flawed as his spelling. He goes from the correct 52* drop to incorrect 56* drop in the second to the last last sentence in his last paragraph. He also goes from -1 outside the parands in the first formula to -1 inside the parands in the following two lower formulas, which yields a completly different result.

His results appear otherwise to be in the right relationship.

The point is for each + 1* hotter air going into the S/C = about + 5* hotter air coming out after being compressed by the S/C, or vice versa, if minus or cooler temperature. So the cooler the air going into the S/C the better, as the temperature of that air when compressed (ending up at about a ratio of about 5* to 1*, whether plus or minus, of the air going into the S/C), makes a significant difference when going into the I/C. So about + 11* (hotter) air going into the S/C comes out at about + 52*/55* (hotter). That equates to a loss of about 5% or more H/P. On a 300 H/P engine that would be about a 15 H/P or more loss. If lowering the corresponding temperatures the same ratio, the previous loss of power due to increased heat then becomes a performance gain, because of lower heat, or a 15 H/P or more gain.

Sorry to ressurect this thread, but I was searching for data with regard to the CAI wrap, and saw this thread was left hanging. I am anything but a mathametician, so please forgive any unintentional errors on my part, but the concept of the CAI wrap is sound.

I hope some of this makes sense. It is easy to inadvertently get things juxtaposed.

Doc

 

Going back to original post:
Trying to keep it simple. Cooler air into engine is better than warmer air. Air into intake from wheelwell is cooler than air in engine compartment. Heat around engine warms CAI tube which warms air passing through it. Insulating CAI tube will keep air cooler.

Will it make any difference? Maybe a few degrees. Could you tell it made a difference? Probably not.

Just my 2 cents.

 

with it. Remember, a few, say 2* going into the S/C is 10* coming out. That is 1% H/P. Might seem small, but small improvements add up to major performance differences. On the surface that may not seem like a lot, but if you consider you were losing 1% and are now gaining 1%, which is a 2% swing. On a 300 H/P engine that would be going from 297 H/P to 303 H/P, using the small 2* above. In all reality it may well be 4* or 5* or even more, which when doubled as above, could be a very significant performance increase over what you had prior. Keep in mind that depending upon a few variables such as ambient temp, altitude etc., 10# of S/C boost creates approximately 120* temperature rise. Excess heat is the worst enemy of all engines/performance, especially those with turbos and S/C's. Every * you can lose counts toward engine longevity and higher performance in the long run.

I used the small heat tape (1 1/2") first all around the tube, as far as I could go-not around the accordion section (where it connects to the throttle body) or lower than where it joins the tube going under the fender. Then I used the CAI wrap to cover it all, including the accordion part, and covered the showing part of tube that goes through the fender. When you have the tube off to wrap it, it is a perfect opportunity to clean the throttle body. I have 6000 miles on my Cobalt, use the best fuel/additives, and the throttle body was filthy.

While I was at it, also taped off the entire fuel line from the fuel rail/log, including the fuel pulse dampener, extending to as far down the firewall as I could reach. Not only did GM Engineers choose to route the fuel line/rail/log across the top and right next to the engine, (and route the rest of the fuel line over the engine and down the back of the engine by the firewall where it too can thoroughly heat soak), just in case the fuel line/rail/log didn't get heat soaked enough from the engine heat, they also routed the coolant return line right next to and parallel with both the fuel line/rail/log. Wonderful performance engineering? Not.

In addition I have removed the engine cover, held on by two screws (which only serves to keep the heat around the fuel line/rail/log like a little oven, thus promoting more heat soak), and the rear hood seal (to facilitate hot engine air passing out through the back of the hood under the w/s rather than keeping it sealed in - like the cheapest heat extractor you will ever not have to even purchase).

It now takes much longer for my car to warm up and runs 10*/15* cooler once warmed up, and the temperature cycles up and down much faster in the normal course of driving. It also cools off much quicker when parked for short times, rather than getting more heat soaked from sitting, as all the hot air escapes under the rear of the hood, much like heat extractors would allow it to do. Instead of the engine temperature being in the 200+*, it is now like 170*/180*. Overheating your engine or supercharger will damage both.

On a couple of occasions when my car was hot, before my modifications described above, 200+*, after I parked it and it thoroughly heat soaked, when I restarted it and took off down the road, the engine went into the limp mode. It did not throw a code, but ran on two cylinders until I shut it off and restarted it, after limping along putting the clutch in and trying to keep the rpm's up for 5 miles in and out of traffic and stop lights, as I was afraid if I shut if off it would not restart. Being cooler at that point, it ran fine once restarted. It has not done that since I made the mods above. Not having that pain in the ass to deal with when restarting the car after parking for short periods in the hot months is worth the price and effort of the mods if nothing else. When the engine internals swell up with 200+* after sitting short periods, then restarting, makes you wonder what that does to things like bearing clearances etc. "Engine temperatures of 160* to 200* have been the accepted "safe" range by engineers for the last 100 years. The higher temperatures should be avoided because excess coolant temperature expands the pistons, thereby reducing the piston to bore clearance to a critical '0'. The piston then scores and/or seizes in the cylinders. Excessive heat will also cause the rotors to expand and score the supercharger case, and/or seize the rotors" - Kenne Bell. Anyone whose engine temperature is getting well into the mid to high 200* range is asking for expensive trouble. Supercharged engines do not like excess heat.

Prior to the improvements/changes I made above, the car was running to hot for my liking in the summer, getting up into the 200*+ range. I also noticed that my engine was making less boost. It went from 16 1/4# boost in the cold months, down to 15# boost in the summer months, which is a sizeable horsepower loss. Now it rarely gets above 190* in the summer, moving from 180* to 190*, on 90+ degree days outside, and is back at 16 1/4# boost. In the past during the cold months it ran like a scalded cat. It runs like that during the summer months as well now.


Doc

 

thermostats. My drag car for example doesn't even have one. However, with a daily driver, if you get the coolant going through your cooling system too fast, it then doesn't have a chance to properly cool while in the radiator. Ideally the coolant regularily/consistently cycles back and forth between the engine and radiator manitaining a reasonably consistent temperature dictated by the thermostat. If it goes through your cooling system before it has a chance to cool properly, your car can actually run hotter and at an inconsistent, unpredictable temperature. These engines already have a 180* thermostat. If you want it to run cooler, consider programming a lower fan on temperature into your ECM.

Doc

 

GM did this on their Time Attack Cobalt,( using the stock intake pipe) they also wrapped the coolant resovoirs as well. Speaking of which you should that car. I think I needed a tissue.

 

with the heat barrier tape, but decided against it.

The whole concept of the reflective heat barrier tape is to reflect radiant heat, so it did not make sense to me to tape up the coolant overflow reservoir. I have the air tube covered with the reflective heat barrier tape, and that is the only thing in the vicinity of the COR, which could absorb some of it's heat. The coolant is in the COR already 180*+ and it isn't going anywhere while the car is running, so it didn't make sense to me to protect it from the comparable 180*/190*/200* underhood heat. Rather it seemed to me like the tape might in fact insulate the heat already in the COR, which might diffuse some of it's heat if left uncovered, with moving air blowing over it.

Pretty much seemed like a waste of tape, and something which might even hurt more than help manage underhood heat.

Doc