Engine BBK Cold Air Kit Rework

AeroCoupe

lube between the nut and the face
Founding Member
Oct 28, 2001
2,417
1,383
153
Claremore, OK
So many years ago I bought a BBK cold air induction kit (CAI) in chrome and it has hung around on the car since then.

1557-1_2_1024x.jpg


At that time it was bought and installed the car a 75mm Pro-M Bullet MAF so the kit worked pretty well. Several years down the road I sold the Pro-M and 24 lb/hr injectors and installed a 80mm MAF off of a 2001 Mustang GT and 42 lb/hr injectors. To do this I had to get a flange adapter for the upstream side of the 80mm MAF so I could couple the elbow that goes into the inner fender to it. Works well and the ID's matched up really well. However, to get the 3" tube between the MAF and the throttle body to seal at the MAF it needed a ring of one of the smaller ID silicone couplers on the tube and then slide a larger ID coupler over that so it would fit the 80mm MAF. The 3" tube has a 60 degree bend in it (you can see it in the picture above) and the alignment is total crap with the throttle body and the tube can just about fit into the ID of the throttle body. I swore that when the 331 went in the car I would address this and now that is happening.

I ordered a straight piece of 3.5" tube, two 3.5" silicone couplers, and one 3.5" to 3" 60 silicone reducer. Getting rid of the blue couplers and making the CAI all 3.5" up to the throttle body. Hoping to get this knocked out this week but work and helping a buddy out this weekend at his lake property will most likely take up most of my time.

This is what the current setup looks like in the car (this was when the 331 went in the car and it hasn't changed):

IMG_2267_zps7d823399.jpg
 
  • Sponsors (?)


Well its been a minute since I started this project but I think I finally have all the pieces to put it together. Ended up ordering some parts and out of them this is what will make up the CAI :
(1) 3.5" x 3" silicone 60 degree elbow - throttle body to 3.5" aluminum tube
(1) 12" x 3.5" piece of aluminum tubing - goes between the 60 deg elbow and the MAF coupler
(1) 3.5" silicone coupler - aluminum tube to MAF
(1) 4" x 3.5" silicone coupler - 3.5" inner fender pipe to 4" adapter on MAF

All of which have delivered except the 4" x 3.5" coupler which should be here today. I also went to the parts store and got the following:
(1) 3.5" hose clamp - throttle body to 60 deg elbow
(3) 4" hose clamps - 60 deg elbow to aluminum tube, aluminum tube to MAF outlet, and 3.5" inner fender pipe to 3.5" side of 4" x 3.5" coupler
(1) 4-1/2" hose clamp - 4" side of 3.5" x 4" coupler to 4" adapter on inlet of MAF

Where I ended up with a couple extra parts is I forgot how I got the 2001 Mustang GT MAF in the BBK CAI kit back in 2007ish. I had to order an adapter for the inlet of the MAF due to it being a flat four bolt flange as they bolt directly to the stock air box. What I ended up using was a tapered adapter that was 3" on the inlet side and then matched the opening on the MAF which is right at 3.5". Looks like this:

C9C022C8-C69D-44A5-A0CF-69E4712CF8AB.jpg


The blue BBK silicone coupler was a 3.5" and it fit the inner fender pipe but I had to slide it all the way up to the flange on the silver adapter and tighten the hose clamp. Looking back on this it was not a good solution but it worked at the time as my tuner said the Pro-M bullet was running out of room and I need to switch to an 80mm or 90mm MAF so this is what I did to make what I had work. Got the car retuned and gained hp and torque across the board on the 306 so I was happy.

The 4" adapter for the inlet of the MAF was in my stash of parts and the only reason I think I have this is from a buddy that got out of the Mustang game and just gave me all the crap he did not sell with his cars. Its a plastic injection mold piece but all I can seem to find now are metal like this one:

MAF_Adapter_wnqD3aMGJTuWyPPGbvK8DM.jpg


So a side by side comparison of the metal one I had in the car and the 4" one shows that the old one was a problem:

D6073743-2652-4497-9B96-DDBFB50DF8BF.jpg


The 4" adapter is a fat 1/16" larger all the way around than the opening on the inlet side of the MAF. The sampling tube opening is super close to that hard edge so I wanted to knock that down and reduce the turbulence.

I bolted it up and scribed a line around the inside of the adapter onto the MAF. Removed the adapter and took a round rasp and knocked the edge off and laid it back just a little. I then used a find round file and cleaned up the rough in and followed that with 400 and 600 grit wet sand paper. Here is the before and after shots (left one is my spare and the right one is the one going in the car):

B41144D1-F41F-4597-A92C-0310BE94933B.jpg


Square edge:
CBDEF343-6090-4210-87AB-3FA76B389D0B.jpg


Rounded off edge:
A48F9CDA-3013-4FAE-8B89-BE3B33DE0815.jpg


I ended up using an exacto knife and trimmed the gasket in the ID of the adapter/MAF combo as there was a bulge right in front of where the air enters the sampling tube.

Will post up what the final assembly looks like later today or tomorrow depending on when the 4" x 3.5" coupler gets here....
 
  • Like
Reactions: 1 user
Decided to work on my truck yesterday and swap out the front camera washer. Evidently there was a TSB on it due to a potential for an o-ring to leak. Mine did it under warranty a couple of times but I just chalked it up to cold weather. Would dribble the washer fluid out and overnight it would take a full washer fluid tank down about 1/3 to 1/2 way down. Stumbled across the TSB looking for something else and bought the camera washer for $30 delivered. Thing they don’t mention is having to remove the entire grill and then separating the active shutter from the grill. Not terrible with some YouTube help but the one thing I could not find was how to remove the camera washer. Said F it and just worked the problem and got it figured out. About an hour and a half total time and hopefully this mofo quits draining my washer tank.

Tear down complete:
AB231827-2BBF-4002-89DE-D7059397D342.jpg


Pile of parts:
6AB58EC6-26A0-4C8C-BC19-5FB0C53443A0.jpg


The $30 piece that needed to be replaced:
D39356AA-87E9-4A54-BB2D-632A4F9C8F12.jpg


Back together:
722A5119-88EF-40DF-BF72-E8D0CD093A19.jpg


Anyhow after that mess we took my dad down to a local watering hole and had some tacos, chips & salsa, and adult beverages.
 
Last edited:
  • Like
Reactions: 1 users
So this morning I got back on the CAI as the 4” x 3.5” coupler finally delivered at 8:30 last night. Got that installed and cut the aluminum 3.5” tube down to 6”. Ended up taping up the section I was going to put in the car with a couple of layers of blue painters tape, drilled a couple holes, and used the jig saw to make the cuts. Hand filed the OD and ID of the pipe ends and started the battle of getting all the larger pipe and fittings into place. Needless to say it’s F’n tight but it fits.

This is the difference in the pipe between the MAF and the throttle body:
3B145773-365D-446B-A679-DBF5EDE2B2CE.jpg


This is the finished install:
6AB99CB0-2F27-4EFD-8923-9834E86ED648.jpg


I’m good with it and that should fix any further air issues. Tuner said I was running out so hopefully this will give me a little more cushion.

Definitely like the black silicone fittings vs the BBK blue ones.
 
Last edited:
  • Like
Reactions: 1 users
I case anyone wanted part numbers they are as follows:

3" x 3.5" 60 Elbow - got this from AGP Turbo (https://agpturbo.com/silicone-elbow-transition-3-50-3-00-60-degree-extra-ply/), P/N AGP-901-278
3.5" Aluminum Tube - got this from Silicone Intakes (https://www.siliconeintakes.com/?searchstring=SIL000619), P/N SIL000619
3.5" Coupler - got this from Silicone Intakes (https://www.siliconeintakes.com/?searchstring=SIL000279), P/N SIL000279
3.5 x 4" Coupler - got this from Amazon (Amazon product ASIN B095HNCK8N
View: https://www.amazon.com/dp/B095HNCK8N?psc=1&ref=ppx_yo2ov_dt_b_product_details), P/N ID89-102
4" MAF Inlet Adapter - buddy deal on this one so I have no idea who made it or where it came from
3.5" Inner Fender Cold Air Pipe and Plate - from BBK 1557 cold air kit (could most likely make the plate and the pipe is a 3.5" 60 degree elbow)
K&N Filter - do not remember when I bought this but the BBK one was garbage. Believe the P/N is RU-1033.

I searched for a bit for the reducing 60 degree elbow and finally just gave up and paid the $40 for the one from AGP. Probably could be had for less but time is money. I ended up cutting the 12" aluminum pipe down to 6" for my application. I am running a 1" spacer between the intakes to clear the valve covers and will say if that was not in there this would have fit a little easier. The MAF is from a 2001 GT Mustang so it goes without saying the tune takes this into account.

The proper size and quantity of hose clamps are in post #2.