CAI Heat Shield/Filter Box

[jrcook320]

Very nice! I have always wanted to do this after seeing the work Jeff did using acrylic (you don't even notice the shield separating the block from the intake). I should start thinking about doing this as well.

I thought about doing a lexan lid so that I didn't have to contour to the hood but I liked the idea of it being open when the hood is up. Lexan would be a great alternative material that would probably insulate better. I'd have a harder time bending it without a break though.

Josh,
Can't say it enough. The best CAI box I've seen for an E21. I'm not surprised that it came from you.To finish this off... do you have any thermocouples to do some temp readings? It'd be fun to read temps pre and post turbo, and post intercooler. Might give you some more info on tuning stuff as well. My friend did this on his water to air setup on his Mk1 4-Runner.

You think the template would fit on a 17x11? You could do an AutoCAD drawing and make it a PDF on 17x11, then folks could just print and trace if they could find a large format printer.

Thanks. That's a great idea but I don't have access to that kind of hardware. Without that I'll just have to use common sense and an understanding of heat transfer. My turbo spread sheet does calculate turbo outlet temp based on inlet temp, pressure change and compressor efficiency and intercooler outlet temp based on intercooler efficiency. From those numbers I'm calculating lbs of air per minute into the motor using the ideal gas law. For example, if ambient temp is 75 degrees and I estimate turbo inlet temp at 80 degrees, at 14 lbs of boost the turbo outlet will be 236*, with a 60% efficient intercooler the outlet temp will be 142* based on ambient temp. I hope thoughtful use of heat sheilding will minimize the discrepancy between ideal calculations and reality.

It is larger than a 17x11, but it could be printed off on a couple pages and taped together as long as it prints to scale.

I'm using a similar but less elegant version of this same CAI on my NA engine and it reduced the intake air temp by up to 20 or 30 degrees F depending on outside air temp and driving speed. At any speed over about 30 miles an hour the intake air was within a few degrees F of ambient.

This makes a difference you can feel on EFI where colder intake air equals more fuel. I'm not sure how big a difference it will make on kjet which does not compensate for intake air temp.

- Steve

Having actual data is invaluable. Good to know. Where was your temp sensor located? In the manifold? I'll have to check out your web site again to see exactly how your intake is routed, it's nice to know you were only gaining a few degrees from ambient to manifold. Given the layout of my system, do you think I would benefit from wrapping my intake pipe with reflective insulated heat wrap? It runs just behind the radiator and it does get hot. The turbo inlet runs about 4" away from the manifold so I am definately going to wrap a heat shield of some sort around the manifold and possibly around the turbo inlet pipe. I'm undecided about the CAI pipe. I've thought about covering the filter box and cold air intake pipe with this:

motorarmor


On a turbo motor anything I can do to control heat just adds to the reliability of the system as a whole. A 20 degree drop in turbo inlet temp is going to equal close to a 20 degree drop in my intercooler outlet temp. Aside from being less likely to knock in high heat, I don't know how much I can utilize the denser air with in CIS. I do know that I notice a marked difference in the performance of my car on a 90 degree day vs. a 60 degree day. On a cool day the car will be nasty and spin the tires in 2nd. On a hot day it doesn't pull as hard. In the summer heat my AFR drops to 11.9 when I hit boost and tapers off to ~12.5 by 7000 rpm depending on conditions. In very cold weather it does run slightly leaner but in the cool I'm not worried about knock. After the heat shield if I actually see a leaner mixture on a regular basis I can just tune for it and bump it up a tad. Either way, I'm probably already so rich it actually makes a little more power when it leans out some. It's just safer to run extra fat.

I was just curious because I know that air is more dense when cold, and that the K-jet sytem measures air density. or so i would think

The CIS air flow meter measures air volume only. It does not take into account air density which changes with temperature and pressure. The volume flowing through the meter does not change with temp or pressure. This is why the a turbo must suck through the AFM and not blow through it, it is designed to work at atmospheric pressure.

[pthm]

oh, I thought the density of air would cause the ability of the air to lift the plate to vary

[shauer]

My IAT sensor is mounted in the intake plenum in front of the air horns. It is a pretty accurate indication of what is entering the ITBs. Mounting the temp sensor on the aluminum intake manifold opens up a bunch of issues with heat soaking and conducted heat through the manifold. IMHO mounting the IAT sensor in my fiberglass intake plenum was the better trade-off.

That's a tough call on insulating the intake pipe behind the radiator. Any little bit of temp reduction helps so might as well try it and see. Also consider the heat soaking of the intake pipe from the engine compartment heat. An insulated pipe is more quickly cooled back down with the cold intake air. I think these would be very small gains though.

- Steve

[TKO383]

lol JEG's. and maybe a Lingenfelter sticker across the windshield..

I see what you did there...... Are you saying I'm rice?

[jrcook320]

if the shoe fits...



haha, jk. Since you actually have a lingenfelter 383 it is not rice. Plus, your sticker is small, period correct and hardly noticable. I was more thinking of the kid in van wert with a 305 tbi and teh 4 foot wide lingenfelter sticker.

[jrcook320]

Just an update so this is all in one thread, I eventually added heat reflective matting (from summit racing) to the outside of the heat shield. I also installed some heat reflective tape (also from summit) to the bottom of the intake tube since it runs behind the radiator and taped up the turbo inlet pipe since it runs close to the intake manifold to keep as much engine heat out of the intake as possible.

[bmac320i]

great work as all ways.

[Baldini]

Your car is freakin' amazing - a fantastic and shining example of what a 320 can be - she's everything mine would aspire to be and more. Time and money... Time and money...

[jrcook320]

Thanks Baldini, and welcome to the forums. For me it's mostly time. I do everything on the cheap. The car is built with ebay and forum swap parts.