Janis
True Classic
I’ll try to get someday laser thermomet to make these calculations, thanks!
Intake Manifold Thermal Reduction
- Thread starter Dr.Jeff
- Start date
Dr.Jeff
True Classic
Janis, I suspect there are a couple of things that you may need to improve.
First, the stock UT intercooler is a little small; it worked fine on a stock UT engine that was located in the front of the car with lots of airflow, but your engine is larger (which generates more heat), and located behind the cabin with little airflow. So you may benefit greatly from a larger (and more efficient) intercooler. Especially as the boost levels go up (as the other guys have said, it will get hotter not cooler). It seems a lot of discussion about IC size and efficiency is based on measuring the temperature of the air going into it vs the temperature of the air coming out of it, and comparing the exiting air with the ambient temperature surrounding the vehicle. The "ideal" condition would be a IC than can reduce the exiting air temp to the same as ambient (which is impossible to do). But the more the temperature can be reduced the better. That's why a bigger intercooler may be needed here. However it is not only size that matters, the efficiency of the IC design also matters.
Second, as mentioned there is not a lot of airflow in the X's engine bay. You did a nice job of adding a air duct to the IC, but it might need more help. Especially at slower vehicle speeds. Connecting the duct to your radiator fan (as you described) is good. Perhaps even better is to add a small fan directly on the IC.
Third, any additional insulation to separate the "hot" stuff from the "cold" stuff will greatly help. As suggested already things like ceramic coatings on the manifolds, heat shields, increased air circulation around the turbo, etc.
A couple things I've learned about this is the temperature inside the intake manifold increases when there is more "resistance" to airflow inside it and the rest of the engine (head and exhaust system). The easier it is for the air to flow into the turbo, through the IC, through the intake manifold, through the head, through the exhaust manifold, through the turbo, and through the downpipe/exhaust pipe, then there is less resistance (friction) and lower back pressure, so the temps are cooler. And the temp increases in a exponential way (multiple times greater as it rises) as pressures go up. So anything you can do to make the flows easier/smoother, the lower the charge temps will be. That might include things like the diameter of the air pipes that connect everything, the sharpness of any bends, porting of internal surfaces, bigger IC, etc.
First, the stock UT intercooler is a little small; it worked fine on a stock UT engine that was located in the front of the car with lots of airflow, but your engine is larger (which generates more heat), and located behind the cabin with little airflow. So you may benefit greatly from a larger (and more efficient) intercooler. Especially as the boost levels go up (as the other guys have said, it will get hotter not cooler). It seems a lot of discussion about IC size and efficiency is based on measuring the temperature of the air going into it vs the temperature of the air coming out of it, and comparing the exiting air with the ambient temperature surrounding the vehicle. The "ideal" condition would be a IC than can reduce the exiting air temp to the same as ambient (which is impossible to do). But the more the temperature can be reduced the better. That's why a bigger intercooler may be needed here. However it is not only size that matters, the efficiency of the IC design also matters.
Second, as mentioned there is not a lot of airflow in the X's engine bay. You did a nice job of adding a air duct to the IC, but it might need more help. Especially at slower vehicle speeds. Connecting the duct to your radiator fan (as you described) is good. Perhaps even better is to add a small fan directly on the IC.
Third, any additional insulation to separate the "hot" stuff from the "cold" stuff will greatly help. As suggested already things like ceramic coatings on the manifolds, heat shields, increased air circulation around the turbo, etc.
A couple things I've learned about this is the temperature inside the intake manifold increases when there is more "resistance" to airflow inside it and the rest of the engine (head and exhaust system). The easier it is for the air to flow into the turbo, through the IC, through the intake manifold, through the head, through the exhaust manifold, through the turbo, and through the downpipe/exhaust pipe, then there is less resistance (friction) and lower back pressure, so the temps are cooler. And the temp increases in a exponential way (multiple times greater as it rises) as pressures go up. So anything you can do to make the flows easier/smoother, the lower the charge temps will be. That might include things like the diameter of the air pipes that connect everything, the sharpness of any bends, porting of internal surfaces, bigger IC, etc.
Janis
True Classic
Was on spiritual drive before a moment ,mostly in 2nd and 3rd at ~3000-4200 rpm, temperatures was some without increase.
But on a way home had to take first exit on roundabout/viaduct = 270degrees right turn at ~45kmh in 2nd or 3rd, in these ~30 seconds air temperature in manifold dropped by 5 degrees C. Because of long right turn there was more airflow through the left sidescoop. So this is thing to start with - modifying leftsidescoop
But on a way home had to take first exit on roundabout/viaduct = 270degrees right turn at ~45kmh in 2nd or 3rd, in these ~30 seconds air temperature in manifold dropped by 5 degrees C. Because of long right turn there was more airflow through the left sidescoop. So this is thing to start with - modifying leftsidescoop
fiatfactory
Steve Cecchele
Are you still using the stock cooling system at the moment?
How much RWHP are you making again?
You know of course that the power the engine makes that turns the axles is subject to many losses on it's way to the wheels. The actual efficiency of the system is quite poor (in real terms) at about 30% or so of calorific input becomes enrgy that we want, the rest is lost... most as heat into the engines oiling and cooling systems.
Stock USA spec is what about 65rwhp, if you've tripled the RWHP, you also triple the energy your expecting the systems to dissapate / exchange heat so I've often wondered what the upper thermal limit of the stock system would be.
Personally I haven't had a problem with my own vehicles and cooling, but I've sure fixed a lot that have. You must be right on the tipping point (more or less) of maximum thermal input if it doesn't get hot "for some time" when you push it, which dispels the theory that the cooling system on the car is "marginal" in any way in the first place with the stock engine if it's maintained correctly, as you must be putting roughly three times the standard engines energy into the stock system..
SteveC
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Bjorn Nilson
True Classic
Yes I. Am still using the stock X1/9 radiator. Never had cooling issues with the 1500, but with the UT engine the temperature raises when pushing hard on track. No temperature problems when driving under "normal conditions". I also had to move the radiator in/backwards 30mm at lower side to make room for the IC heat exchanger which possibly reduced the air flow a little bit. And of course the airflow is a little bit warmer as well:
It is 205whp/267wNm in the car.
I have a brand new aluminum radiator and two fans to be installed and I hope that will solve the problem
Longitudinal
True Classic
The exhaust manifold well exceeds any temperature you will ever witness on any part of the cylinder head, so isolating the EM thermally from the head will have the effect of increasing the EM temp (albeit by a little, since I doubt that much heat is being conducted from the EM to the head. And that's not necessarily a bad thing, as any small difference in heat input to the head could net you a couple of degrees lower temperature on the back side of the combustion chambers. Increased EM temp also should translate to slightly higher exhaust velocity since the exhaust isn't being cooled as much. That's all just spitballing, though, and probably wouldn't amount to anything.
I don't know what you might make a spacer from that can take the heat AND is a poor conductor. Maybe carbon? I don't know how well carbon conducts heat. I know it is a poor electrical conductor, but thermal and electrical conductivity are not exactly one and the same.
Dr.Jeff
True Classic
I'd have to go back to see what I posted earlier, in this thread or elsewhere. But I've since decided not to include both manifolds with the heat insulator - for several reasons. That was merely a passing thought to avoid the issue caused by having the two manifolds sit at different heights (i.e. the intake spaced out with a insulator but not the exhaust). What I ended up deciding is to put insulators between the intake runners and the head. Then add half round spacers to the exhaust manifold mounting tabs to make them the same level as the intake's. The thought of placing them between the runners and plenum has also been eliminated for other reasons. The material I have for this is a phenolic type, like what was once referred to as "bakelite". The same material is used widely for this application. I've collected everything but haven't finished cutting the insulators out.