Technical: Fender Mounted MAFs and Filters

[Mustang007]

Tuning shouldn't be used to fix bad hardware. Do you have the stock CAI? you could put that back on and verify the KN is the problem.

Yes, I do. I just need to get a filter for it. I'll swap it out tomorrow once I get a filter to see if it corrects the problem.

 

[PballSqu*id69]

if i dont have mah stock intake...and i switch form the fenderwell bbk cai to jus like a short arm does ne1 think that could help
?

 

[Mustang007]

if i dont have mah stock intake...and i switch form the fenderwell bbk cai to jus like a short arm does ne1 think that could help
?

No that wouldn't help. The K&N FIPK2 is a "short ram" CAI and I have the same problem. It would be worse since the incoming air travels somewhat of a distance before it reaches the MAF with a fenderwell CAI as opposed to the K&N which is inches before the MAF.

See pics below-

K&N- http://www.v6mustangstuff.com/images/57-2532.jpg

MAC- http://www.v6mustangstuff.com/images/MAC9903cai.jpg

The incoming air has more time to stabilize before it reaches the MAF with a fenderwell CAI as opposed to a straight shot CAI.

I was going to buy a fenderwell CAI but after seeing that they induce the same problem i'm at a loss. The stock induction would be the best choice since the air filter is completly inclosed to protect it from turbulent air. I was going to do the switch tomorrow but I figured out I couldn't install my shark nozzle for my nitrous into the stock induction tubing because it's flexible rubber. I don't think it would be safe. This sucks .

 

[PballSqu*id69]

the bbk and the mac one in the second pic are identical so idk what to do? Im gonna see if i got all the stock stuff somewhere and try and put that on....

 

[Mustang007]

UPDATE





Problem solved .

I brainstormed all night about how to fix this and it hit me. In the stock induction there is a aluminum screen (it's circular in shape and made out of aluminum screen). I thought if I loosend the K&N and attached the aluminum screen before the MAF it would be enough to diffuse/stabilize the incoming air. I was right . It might be a slight restriction but it's worth it.

I drove around for a hour. I took it up to about 50-60mph and then took my foot off the gas and cruised. Usually it would buck multiple times until I would put my foot back on the gas but not anymore. I did this around 30-40 times.

This could also be a solution for fenderwell mounted CAI's. Anybody want to try it out?

 

[Justin@VMP]

You mean aluminum screen, not silencer.

Its a good idea in general to have before an MAF.

 

[Mustang007]

You mean aluminum screen, not silencer.

Its a good idea in general to have before an MAF.

Yep. Thats what I mean . I'll edit it.

 

[PballSqu*id69]

wow that sounds good.....im def gonna try it

 

[load]

UPDATE





Problem solved .

I brainstormed all night about how to fix this and it hit me. In the stock induction there is a aluminum screen (it's circular in shape and made out of aluminum screen). I thought if I loosend the K&N and attached the air silencer before the MAF it would be enough to diffuse/stabilize the incoming air. I was right . It might be a slight restriction but it's worth it.

I drove around for a hour. I took it up to about 50-60mph and then took my foot off the gas and cruised. Usually it would buck multiple times until I would put my foot back on the gas but not anymore. I did this around 30-40 times.

This could also be a solution for fenderwell mounted CAI's. Anybody want to try it out?

You bet your sweet ride I will!!!!!!! I was kinda wondering why that was there...my friends helped me install the K&N (its always better to do car stuff with friends), and we were wonderning what the heck that screen was for! Good thing i saved it!! yay I will go try as soon as I can!

 

[load]

here's a pic of the screen
http://i47.photobucket.com/albums/f167/chris512/screen.jpg

 

[Mustang007]

here's a pic of the screen
http://i47.photobucket.com/albums/f167/chris512/screen.jpg

Yep. Thats it.

Now take off the air filter and take out 3 of the 4 bolts on the back of the heat shield. The bolts attach the round black plastic piece that attaches the air filter to the heat shield. I just loosened the bottom left bolt because it was hard to access. After that, pry the round black plastic piece back and install the aluminum screen behind it. The screen should be inbetween the round black plastic piece and the heat shield. Tighten everything back up and your good to go. I must note that I had my brother hold the aluminum screen steady while I tightened the bolts.

If any of you are confused just let me know and i'll take some pics.

 

[PballSqu*id69]

thankz alot mustang007, everythan worked out great for me also car drives way better, idles better, etc.

Just a sidenote if only one person is there to put screen in i would undo three bolts and keep the last one on the bottom lossened like half way....worked great for me....

 

[load]

Well I put that screen back in, and the car now performs flawlessly!!

Excellent, excellent work Mustang007!!

Although I wasn't really sure exactly where I should put the screen...so here's a layout of what I did.

Throttle body <- K&N pipe <- MAF <- gasket <- heat shield <- screen <- gasket <- weird donut shaped thing <- air filter

 

[Mustang007]

Throttle body <- K&N pipe <- MAF <- gasket <- heat shield <- screen <- gasket <- weird donut shaped thing <- air filter

Thats it .

Much thanks to SteveC. If he hadn't posted this information I would've never even thought that was the problem.

 

[PballSqu*id69]

ya thankz again stevec and mustang007

 

[Shadow Burner]

Sweet!!!!!!!!, can't wait to try this out in the spring when it warms up enough for me to work on my car and re-install the FIPK II again.

 

[skidmark]

good write up, and thank you, i was having a fiew issues with it my self

 

[stangboyv6]

haha i put that screen thing in my toolbox and forgot about it. guess I need to put it back in also. Question about these "gaskets"... I don't believe I have any gaskets on my intake. I have the "half" densecharger intake setup. the only gasket like things that I have are a screen with a rubber piece all the way around the edge. I put it in between the MAF and the plastic tube going into my fenderwell. Is there anywhere I can get these gaskets(auto store/hardware store) or is it not a big deal?

 

[blainestang]

Some more tech info from the guys at Fordchip...

Jerry made a post on Modular Depot about this.... I figure its worth repeating here as well especially after seeing the issues on my car.

Most blower kits relocate the MAF and filter to inside the fenderwell. Most of the time this works OK but can be the cause of some driveability issues. We have seem some cars that had a decel stall problem or a fluctuating idle when you depress the clutch and coast while coming to a stop. My car had the issue. After looking at several cars with the same issue we figured out that its actually caused by an erratic signal at the MAF and filter caused by air passing through the filter at speed. The issue is worse in a car with no foglights since you will allow more directly at the filter and MAF vs a car with a foglight filling the hole. This could also cause cruise "bucking" and other wierd probs while driving.

To test the solution I simply put a piece of cardboard into the fascia to act as a shield for the MAF and filter. The idle is perfect now and no more stalling. We have seen the same improvement in other cars that had the initial prob.

This should not be an issue with cars that have CAIs since the air will most likely stabilize before getting to the MAF. I could see a similar issue with Ram-Air set-ups though.

Turbulent air through a filter mounted right ot the MAF is never a good idea. So plan on using some sort of shield around any filter mounted in an exposed position.

EXACTLY the same problem we had w/ the Bullitt after installing the Vortech... because the Bullitt has no foglights.

So, I bought a piece of vinyl siding, sprayed it black, and taped it in the hole. It's not noticeable, and the problem is virtually non-existent now.

Good info, Steve.


***Wow... thought this was a few days old (10/28). Guess it's 3 YEARS old

 

[Infntrystud325]

Ok so I'm stuck here in Iraq trying to fix my car's shuddering problem... I've had a CAI for bout 6 months now, and up until now the only difference I've noticed was the sound and the fact that my idle was rough... REALLY rough right after starting her up. Figured that was normal though so didn't give it another thought. Then I deployed to Iraq (the first time) for four months, and when I came home my car had the shudders really bad on accel and when letting my foot off the gas. I thought it was a fuel delivery problem initially, then a friend of mine pointed out that perhaps the spark plugs went bad while I was gone. But after reading this, I am 90% sure that the stupid little screen is causing my problems! But I'm stuck in Iraq (for the second time) and the person that is watching my car has no problem fixing it if I pay for repairs. Is there anywhere I can get a replacement screen? Or even possibly make one out of a certain type of mesh? One more question, would this shuddering problem due to the MAF generate a check engine code? Cuz I got one about 6 days after developing the shudders, and about two days before I deployed again... Thanks for all the sweet info, probably saved me hundreds. I'll keep you guys updated cuz I know you all hate a sick pony just as much as the next guy!

SPC Cody Portz
US ARMY