ITB and intake temps

[Magpie]

Here is the Pipercross it has its own foam air filter.

[project.r.racing]

project.r.racing I agree that many people have done the same test and proven the same thing, however few people make available on these sort of forums their results/proof.

With ITB's that get air from the engine bay it is more of an issue. Further, at least for us RHD cars we are restricted in trumpet and filter size unless the brake package is redesigned to be boosterless. In addition, there are different ways that people have installed the air intake for ITB's, sailaholics is different to mine (pipercross dome filter) and whilst gslender is using Jenveys he has chosen to use sockfilters.

Again with the setups of sailaholic, gslender and myself we all have different radiators so again, hence if other people are interested in installing ITB's it is hoped (at least by me) that this thread will assist in making informed decisions.

The purpose of this thread is to exchange ideas and solutions to a problem,

Do what everyone else in the past has done and used and airbox and ducted it to outside the engine bay.

[Magpie]

project.r.racing already working on that. However for RHD cars there are fitment issues at least for NA6/8's and this, among other things makes the length of the trumpets a compromise. The best length, at least for my engine is 100mm however only 40mm can be used. Practical solutions with photos would be appreciated!

Collected a wide range of data today and of the 32,668 data points collected, at least for me there is no correlation between coolant temp and air temp. I looked at the percent change for both the water and air temp and they were moving independently. The data was collected in the morning and afternoon, car idling with the bonnet up and closed, some hard acceleration some normal.

[Dupain]

Have you tried replacing the front indicators with a straight through afternarket item and lifting the bonnet slightly with spacers to get more air into the bay?

Just basic fluid dynamics.

[sailaholic]

I've got turn signal intakes yes but I haven't looked at the data logs.

[Magpie]

Dupain yes it is basic fluid dynamics.

With the turn signal intakes there is a risk of air being sucked out due to the high pressure zone in front of the radiator, The air will find the path of least resistance and go out the duct rather than in. It maybe a solution to have tubing placed on the turn signal intake duct and direct it to where it is needed, but again this would be a pain to run due to pop up headlights etc. Then you run into the other issue of equalising the pressure inside the engine bay and hence no air will flow through. The airflow through a radiator doesn’t depend on the pressure in front of the core; it depends on the pressure difference across the core, hence the engine bay needs to have a lower pressure.

I have a set of turn signal indicators at home, however have not installed them yet. My focus is going to be on radiator ducting and then getting the air out of the engine bay and hence increasing the pressure differential across the radiator as well as getting as colder air as possible to the ITB's. By increasing the efficencey of getting the air out of the engine bay more air will be drawn in for the ITB's. However this needs to be done by reducing drag!

Raising the bonnet is a similar issue. For the NA6/8's there is a reason why it is suggested to cut a hole in the firewall near the windscreen because it is a great place for CAI, simply it is a high pressure zone. By lifting the bonnet you will be sucking air back into the engine bay and reducing the efficencey of the air being drawn through the radiator. Knowing the differential pressures above and below the bonnet will make this easier to decide on what to do, basic fluid dynamics.

[Dupain]

Just leave it. ITBs look great and you are not going to get much more kws by enclosing it and running a CAI.

Have you seen the Autoexe intakes where they draw the air from the firewall, built something like that so the mouth of the intake is near the ITBs.

[Nevyn72]

Just leave it. ITBs look great and you are not going to get much more kws by enclosing it and running a CAI.

Have you seen the Autoexe intakes where they draw the air from the firewall, built something like that so the mouth of the intake is near the ITBs.

Better yet, you could have some sort of fan type arrangement that would blow air onto the ITBs via a tube from a cold air source location.
This 'fan' could be powered by some sort of crank dríven belt or perhaps even the exhaust air pressure!

[sailaholic]

Just leave it. ITBs look great and you are not going to get much more kws by enclosing it and running a CAI.

Disagree unless you have some testing to prove otherwise. Sure you might only get 3-5 hp from the air temp drop but combined with the better flow from removing filter socks the improvement should be significant.

If you set the airbox up to make the best use of ram air effect there is a bit more to be had again.

[Magpie]

sailaholic you replied before I did

The other issue is drawing air from the hot side firewall and then moving it to the cold side, ala Mania style CAI will allow heat soak unless you either ceramic coat the duct or use gold reflective wrap. The LHD MX5's are much easier because of where the booster etc is located (hot side). There is not that much on the internet about ITB's on RHD MX5's.

Ram effect provided it goes straight into an air box could work, but a ram box increases drag

Anyway I still have the hole in my firewall from when I had a Mania CAI installed, time for some testing to see if air is coming in the hole and decreasing the flow through the radiator or if air is comming out. It should be as simple as test, then tape over the hole and test again.

[sailaholic]

Yup, if the air pressure blows the tape off you know it's coming in. Could also use streamers taped over the hole and a go pro. Just because.

[Dupain]

sailaholic you replied before I did

The other issue is drawing air from the hot side firewall and then moving it to the cold side, ala Mania style CAI will allow heat soak unless you either ceramic coat the duct or use gold reflective wrap. The LHD MX5's are much easier because of where the booster etc is located (hot side). There is not that much on the internet about ITB's on RHD MX5's.

Ram effect provided it goes straight into an air box could work, but a ram box increases drag

Anyway I still have the hole in my firewall from when I had a Mania CAI installed, time for some testing to see if air is coming in the hole and decreasing the flow through the radiator or if air is comming out. It should be as simple as test, then tape over the hole and test again.

[Dupain]

sailaholic you replied before I did

The other issue is drawing air from the hot side firewall and then moving it to the cold side, ala Mania style CAI will allow heat soak unless you either ceramic coat the duct or use gold reflective wrap. The LHD MX5's are much easier because of where the booster etc is located (hot side). There is not that much on the internet about ITB's on RHD MX5's.

Ram effect provided it goes straight into an air box could work, but a ram box increases drag

Anyway I still have the hole in my firewall from when I had a Mania CAI installed, time for some testing to see if air is coming in the hole and decreasing the flow through the radiator or if air is comming out. It should be as simple as test, then tape over the hole and test again.

Where are you and sailaholic located? Would love to see/hear these urban assault vehicles that you are building. In the end it's a street car and unless you are a professional racer, I don't think it would matter much. No problems being a perfectionist though.

Magpie, have you thought of computational modelling? Beats doing all those runs for data.

[Dupain]

You've got a stack of data already. Take more at the location that you are interested in over a range. Get your differential equations from these results. Once you have that, you can play with the variables.

[Dupain]

Computational Fluid Dynamics





Using years of applied experience and a proprietary software code, Pratt & Miller uses Computational Fluid Dynamics (CFD) to solve airflow related problems. CFD is a branch of fluid mechanics that uses numerical methods and algorithms to solve and analyze problems that involve fluid flows. Computers are used to perform the calculations required to simulate the interaction of liquids and gases with surfaces defined by boundary conditions. The CFD modeling and simulation can be used to reduce drag over a vehicle body, optimize engine cooling, predict heating and air conditioning performance inside a vehicle, and develop strategies to manage temperatures in an engine bay.

Capabilities & Technology:

Established processes to generate high-quality grids rapidly on complex configurations
Proprietary tools to improve overall grid quality and increase local grid refinement
Proprietary flow solver software and post-processing tools to simplify the analysis of large 3D datasets
Access to one of the largest, privately owned super-computing systems in the U.S. used to conduct large-scale full-3D calculations
Test execution including component prototyping, scale and full size wind tunnel testing, and on-road testing
Applications:

Drag reduction for fuel economy
Down force management for performance
Airflow through radiator, coolers, brake ducts
Engine bay temperature management
Underbody air flow
Interior heating and cooling performance

[Close]