Cheap Fuel Pressure Regulators?

[drummerdave]

I'd be interested in fitting a fuel pressure regulator on my M7, because I have no idea what the pressure even is, and I'd like the ability to adjust it if its way off. But Im not so sure I want to pay $150 for something I might not even really need, when money is already tight, and I have other sled parts I need to buy.

I can get universal FPRs on Ebay and Amazon for cheap. If I were to calibrate it against something that is known to be correct, is there any reason I couldnt just put one of those on?
Im not planning to run the ragged edge of fuel pressures here so hopefully running lean wont be too much of a risk. But I do understand if you run too lean you'll burn your engine down, and I would definitely prefer that not happen.


I know Im not the only one to come up with this as Ive found a few people commenting that they've put them on:
http://www.snowest.com/forum/showthread.php?t=207528
http://www.snowest.com/forum/showthread.php?t-51932.html

But I dont see much else.

Can I get your thoughts?

 

[montananate]

No free lunch!

Are you running mods or planning to in the future? If you answered yes to the previous question spend the money on getting a quality unit. Had a bikeman on my m1000 it was cheap and it bit me in the azz big time. Went tits up on a fresh pow day and went rich had to ride with it pinned for most of the day to keep her from washing out. Fuel pressure is foundation of good tuning in my opinion. If you go cheap it is only a matter of time before it bites you either in a burn down or at the least a disappointing day on the mountain. I started a post when I was looking for a replacement and I had a list of regulators currently on the market and grabbed some input from the guys on here on which one to buy. Ended up with a BDX and love it. Backcountryislife handles BDX parts and might be able to swing you a deal on one. Just my two cents?

 

[drummerdave]

Are you running mods or planning to in the future? If you answered yes to the previous question spend the money on getting a quality unit.

No, not really.
It's got a can on it, but that's it. I doubt I'll ever do any significant engine mods.
I just know the M7s tend to run fat, and would like to see what mine is up to and maybe correct that. That's pretty much it.

 

[ultrasks700]

No, not really.
It's got a can on it, but that's it. I doubt I'll ever do any significant engine mods.
I just know the M7s tend to run fat, and would like to see what mine is up to and maybe correct that. That's pretty much it.

You may not want to hear this...but...I had a M7 that came with a snostuff can, and it ran TERRIBLE with it. Put the stocker back on and made a 100% difference. If you have never ran it with the stock muffler you might want to give it a try just for a baseline

 

[drummerdave]

You may not want to hear this...but...I had a M7 that came with a snostuff can, and it ran TERRIBLE with it. Put the stocker back on and made a 100% difference. If you have never ran it with the stock muffler you might want to give it a try just for a baseline

I did buy it with the (MBRP) can already installled, and it didnt come w/ the stocker, so I dont have a lot of choice unless I buy something. HOWEVER, it seems to run really well with the can that's on it. So if it continues to do so, I'll probably leave well enough alone.

Mostly, like I said, Im just looking to find out what my current pressure is, and if it's too high (46 - 49ish), adjust it down a few psi (41-43ish), which should improve my fuel mileage, and give me a few extra hp to boot.

Here's a question:
If a cheap regulator were to fail, what are the chances that it would fail by reducing pressure? If it failed by allowing the pressure to go unregulated, it would be the same as stock, right? So no issue.
The only potential issue I can see is if somehow it were to fail by over-reducing the pressure. IS that even possible?

 

[drummerdave]

Oh, and as a point of reference, given there are cheap regulators of different prices, I didnt think I ought to get the cheapest thing I can buy.
I was thinking of this which runs about $80 shipped, in case that has some effect on your opinions:

http://www.ebay.com/itm/FITS-SUBARU...KIT-/400538981075?vxp=mtr&hash=item5d41fbd2d3

 

[jim]

I would leave it alone and spend the money to freshen up the clutching. New springs and some bushings maybe. Clean them up. My experience with guys playing with fuel pressures...no gains...or only losses. Only reason to do this is if you have mods that need more fuel...otherwise you are just adding another thing that can fail on your sled. Run it. Stay on top of maintenance.

 

[drummerdave]

I would leave it alone and spend the money to freshen up the clutching. New springs and some bushings maybe. Clean them up. My experience with guys playing with fuel pressures...no gains...or only losses. Only reason to do this is if you have mods that need more fuel...otherwise you are just adding another thing that can fail on your sled. Run it. Stay on top of maintenance.

You put regulators on the M7 to reduce fuel pressure, not add it.
From the factory many (not all) M7s ran really rich. The fix to this is to reduce the fuel pressure.
There are 2 ways to do it:
1) A Fuel restrictor - Basically a carb jet in the fuel line that reduces fuel flow at WOT. Here is an example of one of those: http://bikemanperformance.com/inline-fuel-reducer.html
2) A fuel regulator. Instead of being a WOT only solution, this is used to reduce fuel pressure throughout the throttle range. Which to do depends on mods, current pressure, etc.

Consensus is that reducing the pressures (again, if that particular sled's fuel pressure is too high) also can net gains of anywhere from 5-15 hp.

 

[jim]

Yep...understand that you can lean stuff out as well. Just my opinion. Going lean can also burn you down. My theory is that if something runs well from a jetting perspective i leave it alone. Seen many motors melt down chasing a few HP by leaning it down. And those burn downs happen during those rare times when you have it wide open a long time or if the stock fuel curve experiences rare conditions (mid range lean or very cold, etc.). Just my input.

 

[0neoldfart]

Just a thought...

Why not test your fuel pressure prior to purchasing a regulator? Maybe you don't need it at all, will save you the expense and possibly headache of a regulator failing. A decent gauge is reasonably inexpensive.