I had installed K&N Cold Air Intake kit for my '99 C2. I am satisfied with intake sound, but I feel that intake air temperature is too high when starting after some idle in particular, because response of accelerate is bad.
So I have made heat shield for intake by aluminum board and heat shield sheet.
First of all, I investigated where was more hot after some ride. Then bottom of original K&N shield was the worst and either Snorkel and intake pipe was hot too.
Next I stuck shield sheets on original K&N shield, snorkel and intake pipe. I am sorry but there are a lot of patcheries for a seat and the appearance is dirty.


Last, I made the box which covers intake room in order not to heated air get in and is fixed with rivet and lock fastener.
I do not have diagnostic tool so do not know how much this mod affects but believe the intake air temperature must become lower.

 

Very Nicely done. In the first few pictures I didn't see the top cover you made and thought you did all of that work for not as most of the hot air is coming from the fact that the intake doesn't seal with the deck lid of the car yet is open at the top.

...but very well done. I think you addressed the real shortcoming of that intake. I took the same intake off of my old car because I could really tell at the track that the thing would heat soak after a few laps and then continue to suck in hot air after that.

 

Where did you get the Aluminum material?

 

Thanks Audi.
It's clear that warm air is being breathed. A plain example is that idling becomes unstable when engine is restarted after stopping a while after long drive. I think it is because of ignition timing retarded.

Is is just .5mm aluminum board which could be get in DIY shop or somewhere. I only cut and bent it to be fit, and made a hole for hood catch

 

I did something very similar on the intake of my preious car.

It was dubbed my "Baked Potatoe Intake Mod"........

 

Have you noticed any significant difference yet?

 

isn't that an aluminum fabric though? the material around the round plastic intake pipe?

 

I has feeled that torque when starting (low speed range of course) has strengthened obviously, even after long stop with signals.

my996
Yes, this is fiberglass cloth alminum deposited. But since I bought this cloth in Japan where I live, I do not know where to be got in US sorry...

 

I was just trying to figure out what kind of materials you were using. So it seems its just regular aluminum sheet metal and aluminum deposited fiberglass cloth. And maybe some Velcro. Anything else? Have you noticed any throttle response improvements after the long idle?

 

All you enumerate is what I used. In relation to aluminum deposited fiberglass cloth, I searched net and Thermo-Tec Aluminized Heat Barrier sheets seemed to similar to.

Yes after long idol, I have feeled much response.
Given air temperature which exceeds 50 degrees even with OEM air filter box while DYNO (engine food is kept opened and atmospheric temperature is 25 degrees), it is easily imaginable that there is an appreciable effect.

 

My "01 996 has a cold air intake and I have sealed it, but not to the extent that you have. I plan to attempt your mod on my car. I also covered the openings on the underside of the air box. Can you let me know your opinion on this mod? I have heard both opinions: leave these holes open and close them. Thanks!

 

I saw that the air box at the bottom of my 2003 carrera has a hole, the 997 also have larger holes, you'd better close them?

 

The holes in the bottom of the box should be for drainage. Due to the design of the air intake, water can come into the air intake off the rear decklid. The holes in the box are to make sure that you do not generated standing water in the bottom of the box. The hot air from the engine bay coming through the holes in the bottom of the box is not a strong enough influence on the air intake temp. IMO I would take the safety of having the holes in the box and not being concerned driving in the rain vs. running the risk of hydro-lock.

One thing that has always turned me away from modifications like this, yes the reflective material will help keep hot temperatures from the engine bay influencing the temperature of the air box (hot air box, higher ambient temp in the box= hotter air in the intake) One thing to consider as well is that what was done here was also acting as an insulator material. So in certain conditions, if the air box is getting hot, it will stay hotter, longer because it is insulated as opposed to an air box that is not.