scotty305

iTrader: (2)

Hey all, my first project with this car will be replacing my fuel filter with the OEM filter from a Porsche 911 Turbo. Thanks to all who have posted instructions on these forums, they helped a lot. I am lucky enough to have a friend with a lift, so I was able to get some decent pictures of the area:



Here are instructions I found on these boards, posted by Flyebye:Here ya go. I copied it from Brian's site for ya.

Mazda recommends the fuel filter to be replaced every 60,000 miles or 60 months. However, most people change it at least every 25,000 miles to be safe. Before working on components of the fuel system you need to release the fuel pressure.

1. Start the engine.
2. Remove the circuit opening relay (picture 1).
3. After the engine stalls, remove the key from the ignition.
4. Install the circuit opening relay.



The fuel filter is located above the differential (picture 2).

1. Raise the rear of the car on a lift, ramps, or jack stands.
2. Remove the undercover.

Here's a pic looking up from behind the car:

scotty305

iTrader: (2)

Here's what you can see once you remove that cover.


This view is looking up from the front-passenger side of the car.



3. Remove the two bolts holding the fuel filter. I used a ratchet with a long extender and swivel on the end (picture 3).
4. Slide back the clamps holding the fuel lines on the fuel filter.
5. Carefully remove the fuel lines from the fuel filter. FUEL WILL SPILL. Use a towel to absorb any leaking fuel from the filter.
6. Replace in the order removed.

The filter is located in a hard to reach spot and space is tight. Take your time when trying to get the fuel lines off the filter. It's not hard to do, but it will take some time and patience.

Since you released the fuel pressure when changing the fuel filter, the system needs to be primed. This will avoid excessive cranking when trying to start the engine.

1. Use a jumper wire to short the F/P and GND terminals.
2. Turn the ignition ON for 10 seconds and check for fuel leaks.
3. Turn the ignition OFF and remove the jumper wire.

Start the car and have fun.

clayne

Nice pics Scotty.

They will help people out who are trying to figure out how to remove the filter.

If you thought the filter was hard, try to remove the differential mount bracket, sometime. Total PITA.

scotty305

iTrader: (2)

Thanks man, actually I haven't gotten around to completely removing the filter yet. I took the bracket off to see if the Porsche fuel filter will fit in the same space as the OEM Mazda one. It looks like there will be enough room, but I'll need to make a new bracket to hold it on, because the Porsche filter is a much larger diameter.

Here's the filter I plan on using:
--------------------------------------------
Purolator part# F64607 , In Line Fuel Filter for '97 Porsche 911 Turbo
Height: 6.63
O.D.: 3.25
Outlet: M16x1-5-6G
Inlet: M16x1.5-6H
Price $25

----------------------- Compare this to their application for our car, '94 RX-7: ----------------------

Purolator part# F54803 , In Line Fuel Filter for '94 Mazda RX-7
Height: 5.20
O.D.: 2.80
Inlet/Outlet: 0.31
Price (didn't ask, probably $20-25)

Scrub

iTrader: (25)

Good luck, I'd like to see the outcome of this project.

scotty305

iTrader: (2)

As of right now, there is one thing that I could really use some help with. I would like to know the flow rate for the '97 Porsche 911 Turbo's fuel pump, and possibly the diameter of their fuel lines going into the fuel filter. If anyone has Porsche connections , or knows of good websites, please speak up. Search engines are nearly worthless these days, all I find is "buy Porsche fuel pump flow ratings at www.autoparts.com " , and then their site doesn't even have pics or descriptions... If anyone can get me a factory service manual, that would be great.

For reference, our Mazda fuel pump puts out 490-740 kPa ( 5.0-7.5 kgl/cm^2 , 71.1 -106.2 psi), hopefully the Porsche fuel pump is similar.


-scott-

Mahjik

iTrader: (1)

Brightened up the pic a little.

SPOautos

I've been trying to find out what lbs/min the stock filter is good for? I know it can take the pressure, but how many lbs/min can flow thru it at say 80psi of pressure?

You have any info on that?

Thanks,
STEPHEN

clayne

Scotty,

I would contact the people at:

http://www.smartracingproducts.com

How to get a hold of us...
408.369.9997 phone
408.369.9741 fax

-----------------------------------------------------------------

info@smartracingproducts.com
Smart Racing Products
491 McGlincey Lane #4
Campbell, CA 95008 USA



They know their stuff and make great products as well.

scotty305

iTrader: (2)

Thanks for the info, Clayne, but I emailed that guy and he said he "didn't know." My guess is he either doesn't work with Porsche's that new, or doesn't want to talk to me because I'm not buying anything from him.

Stephen/SPOAutos, I could plug some numbers into a few Physics formulas and tell you how fast fluid would be flowing through the openings in the fuel filter at 80psi. Give me a few days, I've got some other stuff going on right now. Service manual says our stock fuel pump flows between 71-106psi, so you should be fine at 80psi.

That's why I'm trying to find how fast the Porsche pump is shooting gas into the Porsche filter; if it's flowing twice as much as our Mazda pump, the Porsche filter might not work at the slower speeds that we could be dealing with. Hopefully the flow rates are pretty similar...


Anyone else out there have access to some good Porsche tech info? I searched a couple of the Porsche club websites, they've got lots of nice photos of racecars, but not much data...

-scott-

scotty305

iTrader: (2)

Well, I got some adapter fittings and a had pipe bent, the new filter is almost ready to go on the car. It's a bit huge, but I think it should barely fit in there:

scotty305

iTrader: (2)

I'm really not satisfied with having to use so many brass adapter fittings, though. One of them has an inner diameter that's a bit too small, I think I'm going to bore it out a little:

BRADYMAHONEY

My rubber lines were glued on and were a biatch to get off. I was in the grass with a regular jack so it sucked very much badly. I think it took a couple hours to change that thing out. If I would have known it was that hard I would have looked into relocating it while I was at it.

NukeGenius

My fuel filter is relocated to the engine bay. It makes it a lot easier to deal with. K+N makes a tiny in-line one that works awesome, and you dont have to put it back by the tank.

turbojeff

iTrader: (30)

Why change it out with a 911 filter vs. stock?

The fuel filter doesn't need to be changed that often, even at 25-30K intervals it isn't that big of job. Relocating the fuel filter to the crowded, fire prone engine bay isn't ideal either IMHO. The stock filter location sucks, but in reality there aren't many better places for it.

spoolin

extend the hoses, make a bracket and mount it to the back of the car frame behind the diff. look at the 1st pic....see wher the red square is, i have mine mounted to the sub frame or whatever you want to call it

scotty305

iTrader: (2)

Why use 911 filter vs. stock? I had seen a few people comment that the stock fuel filter is too small (same as Miata). The fuel filter from my Subaru 2.5RS was larger, and that car shouldn't need nearly as much fuel as a twin-turbo RX-7.

It's the same reasoning as using a larger Mazda MX-6 or FC oil filter, it will have more filter surface area, so you run less risk of getting it clogged between changes and restricting flow.

Simply put, I trust Porsche engineers to definitely build a sufficient filter, vs. Mazda engineers who might have been forced to cut corners in order to meet budget requirements. Maybe it's a little paranoid, but it's a one-time $15 price premium getting all the fittings and having that pipe bent, so I don't mind going to the extra trouble to have the extra peace of mind (and screw-type removal for the future). And I'm not making any changes to the car that can't be undone easily, so if I change my mind about it later, no problem.




NukeGenius & spoolin, I don't mind the stock filter location, if you have access to a lift it's pretty simple to get at it. Relocating the filter might put it in harm's way, the stock mounting point tucks it up away from any debris or off-road dangers (which this car should never see anyway, but better safe than sorry with fuel).

-scott-

jspecracer7

Maybe in a stock car. My car is FAR from fire prone.

PVerdieck

A couple comments. I did my filter today (or most of it, I had help).

Anyways, removing those hoses is a pain. I removed the hose connected to "U" shaped end. What I did, was try to work loose the end of that hose, by usint my finger to push against the end of the hose, and pull it out, away from the fitting. I repeated this around the circumference of the hose. I would alternate just trying to push/pull the hose as well. After continuing this process, the line started to slide off. First an eighth, then a quarter, then about a half inch was pushed off. At that point you are almost there. Grab something to use to plug of the line, possible a Bic-type ball point pen cap, if you have nothing else. Grab a rag towl and place it over the diff so it will soak up excess gas.

Then remove the line the rest of the way and cap it.

RTS3GEN

I have a good system down, everytime I break an axle or blow up a tranny, or replace a clutch, I just replace the filter then when everything is out of the car. Over the last 4 years that's about every 4500 miles!
Art

skunks

why areyou using a porsche 911 filter instead of a mazda filter? it should cost the same amount and you dont need to fab up anything... also, it will be gaurenteed to work right and flow enuf

RonKMiller

Maybe I am missing something here - but what's the whole point of this exercise?

Is it because it is a CHINESE (that's what it says on your filter) filter that just happens to fit a Porsche that makes you believe it is better? I have no clue what brand Porsche uses as OEM but I can pretty much guarantee you that it is German (probably Bosch) in origin - and it probably retails for at least $50.00 and probably more.

China makes GREAT STUFF!

Is it due to your belief that Mazda OEM fuel filters are inherently poorly designed?

Do you think you are going to get a performance gain since you will be "flowing" more fuel with a "larger" filter?

Do you think you can extend the change interval with another filter vs. the OEM?

Do you really think changing out the OEM fuel filter is that hard? Once the rear is off the ground and with the proper tools I can do it 5 mintes AND not get a drop of gas on me - think "large cheap hemostats at Harbor Freight to clamp the fuel lines".

Oh, btw, the fuel line hose in that picure is not 5/16", it is METRIC and needs to be METRIC in order to seal properly with the METRIC metal nipple....

HMMMM??

scotty305

iTrader: (2)

There are a few reasons I've chosen to go with this particular filter. I'm pretty sure I mentioned them earlier in this thread, but here goes again:

1. Greater volume of fuel being filtered at any given moment. Autocrossers who aren't allowed to upgrade their fuel pumps used to use a larger filter, the effects are said to be similar to a surge tank. Eventually this was banned by most sanctioning bodies, I'm assuming this is because it made a noticeable difference / unfair advantage?

2. Factory filter is almost identical to the one used in the Miata (which was first released a few years before the FD3S , correct?). Either the Miata filter is big-time overengineered, or the RX-7 unit might be too small. This might explain why so many people are finding that their stock filters are clogged when they go to replace them. Do you want to take that chance? I trust that Porsche spared no expense with regard to this, I'm assuming they designed their filters for performance, rather than using what they could find from the parts bin.

I'm not looking for increased HP, but I'm hoping this will be an extra safeguard against running lean. The only downside I can imagine would be due to the non-factory parts I need to use for adapters. I still haven't gotten on the lift to install everything, but I'll be sure to check that a few times over and make sure there aren't any leaks or anything.

It might be possible to extend filter change interval vs. OEM, but I'd rather be safe than sorry, I'll probably continue to do it every 15-20K miles, or every year or two.

The brand of filter I bought is Wix , they are pretty reputable as far as filters go. I wish I had some better resources for finding Porsche info, the Rennsport forums were tough to sift through, and didn't contain much tech info regarding something as mundane as the factory fuel filter. Most Japanese automakers use Purolator filters as OEM, and Wix is said to be equal quality (sometimes better, depending on who you ask).




^^ that line isn't 5/16" ? Crap, someone on here said it was...Bummer.
-s-

SPOautos

Just because its larger doesnt mean it flows more. Its really up to the material design inside not the actual size of the filter.

BTW - When I ditched all my emmissions BS I removed the charcoal canister....man thats a GREAT spot to put a fuel filter(s).

BTW - How much is that 911 Turbo filter and is it designed for any particular year model?

STEPHEN

scotty305

iTrader: (2)