Cold Air intake w/ Heat shield

#1

Since it’s the off-season and I have a little time on my hands I decided to look around the Internet to see what my choices were for a cold air intake. The short answer is not alot. BMP offers an adaptor and filter for around $100 bucks.
http://www.bmpdesign.com/product-exec/product_id/1048/category_id/43

So I put it on my Xmas list and Santa was nice enough to oblige.

I installed the kit but was unhappy that it did not contain a heat shield. So I went back to the trusted Internet and looked some more. After not finding a simple or inexpensive option I decided to fabricate one my self. With a quick trip to Home Depot (yea I’m a Tony Stewart fan) I acquired some thin zinc coated tin. After figuring out how to fab up a bracket and heat shield out of cardboard I transferred my design to the metal. With some tin snips I cut out the design. After some grinding work to smooth out and trim some edges it came together and bolted in like a champ.

Truth be told I don’t know if it makes a difference in performance, but it was a fun project to do. If anyone’s interested in getting a copy of the posterboard Templates just let me know and I’ll send you a set.

brain

Post edited by: brain, at: 2006/01/09 18:52

#2

I haven’t looked to see what it is yet, but I’ve heard the Reflectex, also from HD is a good material to use around a CAI.
thanks
bruce

#3

Brain,

I’ll definitely take you up on the offer for the template. I don’t know if it really makes a difference either, but I was at an autocross event at Virginia Beach yesterday (Pungo airfield) and all of the e36 guys had a heat shield around their intake systems.

Thanks,
Ed

#4

Hi Brain,

Thanks for the template. It helped a lot. I did have to make a few modifications as my layout - from the MAF intake to the radiator is a little different than in your picture (mine is an 87 325i). I lined it with Thermotec aluminized heat barrier - something I picked up from JEGs or Summit racing for my 240z.

Thanks again for the help with the template.
Ed

#5

Has anyone measured underhood temp at race speed?

(there does happen to be a temp probe for the OBC right about where the filter resides)

I did and found no appreciable difference from ambient.

At race pace there is some air moving thru the engine compartment.

Around town it WOULD make a difference, at least until the car started moving.

Ric

#6

Hi Ric,
so are you saying that a heatshield probably isn’t that critical on a race car?
thanks,
bruce

#7

30SpecE30 wrote:

[quote]Has anyone measured underhood temp at race speed?

(there does happen to be a temp probe for the OBC right about where the filter resides)

I did and found no appreciable difference from ambient.

At race pace there is some air moving thru the engine compartment.

Around town it WOULD make a difference, at least until the car started moving.

Ric[/quote]
The OBC temp probe is actually mounted under the bumper on the passenger side. The one in the AFM is intake air temp.

FYI, Aotozone sells an aluminum filter adapter that has the holes in a useable position to nount to the airbox on an E30 for something like 15 bux.

I have heard on the e30 boards elsewhere that dyno does not show any improvement with this setup but a big increase in intake noise/coolness factor

#8

[/quote]
The OBC temp probe is actually mounted under the bumper on the passenger side. The one in the AFM is intake air temp.
[/quote]

Should have been more clear. I pulled mine from its OEM spot and mounted it near the filter so I could clearly see underhood temps as I was considering a heat shield.

Temp at speed was not an issue once you were moving. It went up rapidly while sitting.

Easy to test yourself, or you can build a heat shield if you’d like…

Ric

P.S. I maybe recollecting this from my 1991 318is, which also saw track duty.

But I am 99% sure I did the same on my 87 325. Neither one of which I still own.