MFI with watershield air filters

jkeyzer · jkeyzer's Garage

Would anyone like to comment on running an MFI engine with watershield style air filters? Obviously this is going to change the airflow a bit but is it enough that the MFI pump is going to have problems? I am looking for louder intake music and a more open engine bay.

Oh, and if anyone has a set of K&N watershields around they'd like to sell, send me an e-mail.

Bobboloo · Bobboloo's Garage

Jeff,
You probably already know but just in case. You'll have to do some modification to make them fit. They won't bolt on to the plastic stacks like they do on the magnesium stacks which had the same bolt pattern as Webers.

Bobby

michel richard · 04-29-2002, 03:30 AM

Also, the driver sider watershield will foul the pump: the atmospheric pressure sensor and the fuel lines. In my case, I managed to cut the shield and re-form a lip to clear that stuff.

I'm still in the process of dialing everything and I have'nt gotten it to run correctly, yet. This is a new engine for me, so that It probably is not a matter of the intake, just a new injection system on a new engine that needs to be set up from scratch. I therefore can't comment on what impact the intake has on the injection.

Michel Richard

70flatsix · 70flatsix's Garage

I have a 70E with original MFI fuel system with the magniseum stacks.

From what you guys are saying, with modifications, I could adapt K&N watershield air filters designed for weber carbs to fit on my MFI powered motor?!

Anyone have a picture to post showing this setup?

Does anyone else offer watershield air filters to fit my MFI powered motor?

Oh boy!

NYSCAR · 04-29-2002, 05:14 AM

I was looking into this a while back, wanted them primarily for the cool intake sound that is muffled by the stock MFI airbox. Gave up on it because I figured I'd have all kinds of clearance problems with the rear lid (it's tight with a simple engine lid, but my engine lid also has an AC condensor mounted on it). Do a search for ITG filters, someone has figured out a way to use the ITG foam filters (supposedly better than K&N at filtering).

Brad

Keith S · 04-29-2002, 06:43 AM

I have ITG foam filters on the carrera w/o rain shields – even in the rainy ol' UK. There is no problem with rain ingress as they are well shielded when the deck-lid is closed. If the filters are correctly 'oiled' with the spray provided, they are pretty well impervious to water anyway. Any rain just sits on top of the foam – none gets through.

Fitting them to a MFI engine is not straightforward and there are no 'off the shelf' filters available. You'll need to modify some blank baseplates specially. Deck-lid clearance will be a major issue with rain-shroud K&Ns – it's tight even with the shallow ITGs.

pwd72s · 04-29-2002, 08:01 AM

Keith...curious here...did you have to modify the injector lines to get the filters to clear?

Keith S · 04-29-2002, 10:02 AM

Quote:

Originally posted by pwd72s
Keith...curious here...did you have to modify the injector lines to get the filters to clear?

No, all I had to do was offset the baseplates by about 1/8 inch and then use a Dremel tool to notch the plastic surround on the filter by a fraction. Cheaper than RSR flexible hoses!

jkeyzer · jkeyzer's Garage

Thanks for all the info guys!

I was aware I'd have to do some custom work to bolt them onto the intakes and clear the pump, but I didn't realize there would be clearance issues with the rest of the engine compartment.

If I can find a set for cheap I'll see what I can do.

I've also seen some carb'd 911s with foam filters stuck directly into each of the 6 intakes. Seemed like an interesting idea and probably the least restrictive filter of all.

Bobboloo · Bobboloo's Garage

70 Flatsix,
With the magnesium stacks no mods are necessary. They just bolt on. Take a look at Kurts' new motor.http://www.starnes.com/images/105-0589_IMG.JPG

Bobby

michel richard · 04-29-2002, 12:52 PM

I forgot to add, earlier:

You also need to modify the idle microswitch. It fouls.

Michel Richard

Kevin G. · 04-29-2002, 01:34 PM

Is there a website for the manufacturer of the IMG filters?

Paul Thomas · 04-29-2002, 04:31 PM

Here are some pics of the mods mentioned. Not a big deal if you have a Dremel

jkeyzer · jkeyzer's Garage

Paul - Looks simple enough. I really like the look of the plated linkages and painted throttle bodies/intake stacks. Is that how they come back from Eurometrix or did you do anything more to them?

Bobboloo · Bobboloo's Garage

I stand corrected on the watersheds on magnesium stacks. (i.e. Paul Thomas' motor) In Kurt Starnes motor he doesn't have the watershed. He just has the K&N filters.

Paul is that your cold start setup on the top of the filters?

Also what heads did you start with?
I'm curious how you adapted the MFI injectors.

Bobby

jkeyzer · jkeyzer's Garage

I found the non-watershield type that K&N sells (the ones on Kurt's car). You can see them at http://www.knfilters.com/Racing/customcarb.htm model #56-1246. I looked at the online resellers and these puppies sell for over $120 EACH!!! (retail $200)

Umm... excuse me?

CamB · CamB's Garage

Don't forget another ~ $125 for the rainshields.

Or - it could be worse:

http://www.wolfert.com/information.html

And it could be like Keith has:

http://www.itgairfilters.com/megaflow_jc90.asp

TWM used to be the US agent, but I see they aren't anymore. I asked ITG about the price once. They weren't cheap either.

Paul Thomas · 04-30-2002, 09:10 PM

Jeff,
The throttle bodies and linkages are as they came from Matt at Eurometrix. He does fantastic work. The manifolds are the color magnesium is after you have them bead blasted, i added 3 coats of clear laquer. The cross bar and velocity stacks i had re-plated at a cost of about $20.

Bobby,
The heads were SC heads twin plugged and tapped for MFI injectors.

Paul