Port Injection Fuel Pressure Regulators

[RICE RACING]

Never really liked the Sytec regs though. I've never particularly tested them, but always thought they looked cheap.

I am pretty easy going, been dragged by the nose over this for weeks nothing from them at all admitting they stuffed up. A mate of mine in UK ordered another 1.7:1 and tore it down (this is a Malpassi unit) and its as different as you can imagine internally, single disk, different configuration on bottom assembly, inverted disk orientation, you get the idea.

So I say I will just send him a link after he says I should have contacted them to supply the right part cause their own web site listed it as 1.7:1 then they told me on email it was 1.7:1 and been supply for years and I am the first one ever to report otherwise (that old classic) last thing I wanted to be doing is wasting my time on FPR testing Anyway I digress, go to look on their site https://www.glencoeltd.co.uk/malpassi-s ... regulator/ just now to send to my friend and just like that "it gone" but they are still all over ebay so took a few happy snaps for history sake

Moral is Stevie not so much that they look cheap but I guess I had to prove the function of it. The principle has merits, just need a unit that does the rising rate as per the advice and all will be good. Will get some of the right part number to test no doubt, don't think it will come from these people at a guess............

Just putting this here for others information cause I guess in time there will still be some kicking about or being sold on E-Bay, just don't get it expecting that it will be a 1.7:1 enrichment rate, hope this helps.

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[stevieturbo]

The advert says 1:1:7 whatever that even means.

I think some early adverts said it responded 1.7x faster. There were lots of advertising over the years, but other than n/a cars, I don't think I ever actually used one, and I never measured fuel pressure with one.

[RICE RACING]

^ I am a bit the same, just never really cared unless a car ran like crap and needed to look into it to sort out why.
Would not have dreamed I would give a FF about fpr's. It is interesting though once you test it, and I have a base now across a sample of two of a -1.45:1 to around 1.3:1 (vacuum to 4000mB map). Will work on a few permutations and see what is better, not really interested in throwing someone under the bus but would be good to see if the other one does what it claims ?

[stevieturbo]

Even a lot of 1:1 may not always offer true 1:1 in use, but then there are lots of install variables.

Say I fit a small 1:1 reg, then fire 1000LPH of fuel pump at it. At idle that's a shit ton of fuel to deal with, and I'll probably have it adjusted wide open to achieve target of say 50psi as it's maybe seeing 1000LPH, and returning 999LPH.

Then maybe at full load if engine is consuming say 700LPH, with only 300 returning....the reg adjustment is probably too open, and that would have a knock on effect of further reducing the regs ability to maintain 1:1

Everything in the system needs balanced. Pump flow, regs flow abilities etc.

I've had a Magnafuel and Edelbrock on my own car and both were just ok....they did drop a little under high load. Some leaked a little air via the adjustment screw which wouldnt help either.
But PWM'ing the fuel pumps so at low load the pumps flow less...reg only has to deal with a smaller volume. And ramp them up at high load. So overall, reg is flowing and returning more consistent amounts of fuel, despite what the engine is consuming.

On some I've used the little Turbosmart FPR, and have to say it works superb over a wide range, very consistent without variable pump flow.

[RICE RACING]

The advert says 1:1:7 whatever that even means.

Boxes for the Sytec SBV units I have are printed 1.7:1, you can image my shock when they tested at 0.97:1 once on boost

They are talking about rate of rise
IE: 20psi gauge boost would give (20*1.7) = 34psi increase in fuel pressure
But is it a flat rate of rise or even increasing rate of rise, when does it happen, all of these details are sadly lacking from the current crop of vendors/makers as I am finding out. Does it apply in Vacuum? is that flat or curved? I have found out on the as delivered unit and the RR enhanced versions which work pretty much what I think is a good fit. There are many permutations though.

The way I have it currently is a almost identical to what you see on a large cam driven mechanical fuel pump fitted to a high power density single turbo drag type engine. They roughly give a 1.3:1 rising rate at ~50psi gauge boost 8000rpm (rises based on engine speed in this case), the (un) intended? benefits of this are many like an effective variable injector size based on power demand.

[RICE RACING]

My 'gut' feeling is that all of these in stock form maybe are only applying a rising rate in vacuum, and on boost are 1:1 (or there abouts)
See the original test (on boost) clearly 1:1 rate, in video I show its only rate change happens in vacuum region, maybe this is what they intended? wont know till I get other models and test them an plot the curves.

25psi 1 to 1 V 1.2 to 1 YO.jpg (910.14 KiB) Viewed 37293 times

Here is a close up of my modified reg, very smooth in response to step changes, and is true rising rate in boost, picked normal levels of boost people use typically as example range.

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[RICE RACING]

Well this gets more entertaining by the minute!
My friend I was telling you about who told me I should have rang them to get the right part (lol) seems like he has the wrong part as well !
https://www.glencoeltd.co.uk/pub/media/ ... 171019.pdf

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[RICE RACING]

FYI a "power boost valve 384" and Sytec "SBV" is the same shit only difference is a changed top hat some longer bolts and nuts on bottom to hold it together all else is identical, listed as 1.7:1 rising rate which we know is bullshit cause I tested two of them and they showed 0.97:1 rate in boost.

Here is what my mate ordered pulled down.
Little technical explanation there is no way in hell it can be a rising rate in boost cause as assembled the larger area of the disk points down and matched the area size on the fuel chamber side so any imparted force cancels out the fuel side, there is no multiple so indeed it will be 1:1 (as they list on their own PDF) but they still sold it to him as a 1.7:1?????????

Stevie is seems was right about this company lucky for me I made my own after working it out myself with zero help from them or Malpassi

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[RICE RACING]

So its safe to say if you have a original Malpassi 384 'power boost valve' or the doctored (blue hat) Sytec branded 'SBV', then it wont be as advertised in any way shape of form, if you want it modified to be a documented rate in vacuum and boost as per the graphs I provided you can send my your regulator/s and I will modify them so they work properly.

[RICE RACING]

Some more comedy gold below
384 type is not 1.5:1 or 1.7:1 (or 1.2:1 in one ad)...... just pick a number out of thin air and sell it lol
473 type is 1:1 not 1.7:1

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LOL 1.5 to 1 wtf.jpg (625.4 KiB) Viewed 37252 times

LOL 1.2 to 1 wtf.jpg (245.53 KiB) Viewed 37252 times