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Arvidw · Posted: Thu Jan 14, 2010 7:21 pm Post subject: Fuel pressure regulator

A while a go I bought a fuel rail with a FPR atached to it for my MegasquirtII conversion. Unfortunately the FPR is broken and a replacement part is jolly expensive.

Therefore I'm searching for an other FPR. I saw some of you are running those cheappy chineese FPR with a gauge which are quit easy to find at Ebay. Does anyone use the adjustability of the fuel pressure regulators, or is it a wiser choise to buy a solid simple non adjustable fpr with a raised fuel pressure (like this one, 3.5bar) Are you running higher pressure than this with those chineese FPR's ?

http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=300385214088&ssPageName=ADME:X:RTQ:DE:1123

The reason why I would like to have a slightly raised fuel pressure are my injectors. They can only flow 190cc/min (18lbs/hour) and I would like to use those in the period after my EFI conversion but before installing the supercharger. CIS can flow 210cc/min...

The fuel pressure regulator attached to my fuel rail does not have a manifold pressure feedback regulation. I'm going to supercharge my engine so I think this manifold pressure feedback could be usefull then?
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Porsche 924 2.0 Kompressor 136.1wHp @ 5650rpm / 201.9wNm @ 3900rpm (dyno @ dp-engineering.nl)

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

Absolutely, for a forced induction application, the manifold feedback is highly desirable, if not essential. There are even some NA applications that use this (only in reverse, of course, with the vacuum signal).
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erstwhile owner of just about every 924 variant ever made

Arvidw · Posted: Thu Jan 14, 2010 10:05 pm Post subject:

Okey, than I will narrow my search to FPR's wich have that manifold feedback

What is a wiser choice: A non adjustable FPR which was produiced for a long lasting car or an cheap aftermarket adjustable FPR which seems to work fine when looking at other EFI projects?
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Porsche 924 2.0 Kompressor 136.1wHp @ 5650rpm / 201.9wNm @ 3900rpm (dyno @ dp-engineering.nl)

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

I think adjustability is important. What is your budget? Surely there's a middle of the road option that will provide adjustability, manifold feedback, and not an exorbitant price?
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erstwhile owner of just about every 924 variant ever made

Arvidw · Posted: Thu Jan 14, 2010 10:25 pm Post subject:

My buget is 50euro including shiping costs, therefore ordering from ebay.com is no option because shipping + taxes will exceed my buget. I'm likely to order from ebay.de

I'm having doubts between these 2 fpr's
http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=180454325301&ssPageName=ADME:X:AAQ:DE:1123
http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=300385214088&ssPageName=ADME:X:RTQ:DE:1123

How high can you go with the fuel pressure ? 4bar? 5?
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Porsche 924 2.0 Kompressor 136.1wHp @ 5650rpm / 201.9wNm @ 3900rpm (dyno @ dp-engineering.nl)

Martijnus · Joined: 29 Dec 2006 Posts: 2019 Location: Netherlands

I've got the adjustable one. from Race Tech R. Cheap, and also directly sold in the Netherlands (bijv. marktplaats ofzo).
It works. Hasn't failed me yet. Can't say more, because I don't know if it's good or bad and when it's good or bad

It just works fine. and it does respond to pressure differences...so it really does work.

On the other hand, a simpler FPR could be better, faster, more accurate I guess... and there's no real reason to adjust FPR, you can tweak it with VE.
Unless you've got the wrong injectors (too much or too little cc/min) the fuel pressure from any EFI application should be fine... the injectors are designed for approximately 3 bar so why raise the pressure to 5 bar...?
_________________
"Rule: Turbo's make torque, and torque makes fun." (C. Bell)

924 "50-jahre", 1981.
MSII/extra, LPG, ITB's, 5lug.
To be turbo'ed in a while.
Killed her at the Nurburgring, Porscheless at the moment

fiat22turbo · Joined: 18 Jan 2006 Posts: 4040 Location: Portland, OR

Shouldn't really need an adjustable regulator if you size your injectors properly and tune appropriately within MS. It is nice to have, but could increase the amount of "fiddling" you get to do initially. use an air compressor to set the base pressure to somewhere around 45psi at first as a baseline.

The only concerns I've heard of with the cheapy Chinese knock offs is that their quality control is lacking, many have had to replace the internals (luckily since they are knock offs of a known brand, the internals from that brands regulator can be used for the diaphragm)

If you get one, carefully pull it apart make sure it is clean and that the diaphragm is not torn and that all of seals are in good shape, then make sure to use fuel safe locking compound on the threaded parts.

Good luck!
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Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

Arvidw · Posted: Sat Jan 16, 2010 7:29 am Post subject:

Thanks for the tips guys

Then I think i'm going for the ceap ass chinees one, it is supplied with some tubes. i'll check the diaphragm for tears immediately when I have received it.
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Porsche 924 2.0 Kompressor 136.1wHp @ 5650rpm / 201.9wNm @ 3900rpm (dyno @ dp-engineering.nl)

Rocco R16V · Joined: 03 May 2009 Posts: 497 Location: PNW

leadfoot · Posted: Sun Jan 17, 2010 10:17 am Post subject:

How much boost you planning on running through the supercharger??
at 19lb/hr think you are going to run out of injector when you supercharge.
at 10psi boost a 300cc / 28lb/hr injector will be maxed as the duty cycle will be getting up there too.
http://www.injectorsonline.com/indivprod.php?cid=74&scid=11
Stu.
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1981 ROW 924 Turbo -
carbon fiber GT mish mash
LS1 conversion in progress...

Arvidw · Posted: Sun Jan 17, 2010 8:37 pm Post subject:

I'm not quit sure about the boost, I have not done any proper research for the supercharger install except reading most 924supercharger threads at this forum.

I would be very happy with 150hp at the flywheel with the redline at 6000rpm so I don't need a lot of boost. My car is totally stock and I prefer not to break the gearbox, clutch, engine or other components.

I agree that I need new injectors and I've found some quit interresting injectors:

These will inject the fuel at the same place as the CIS injectors do, I think this will be better than short ones. (if they fit the through the hole)

Martijnus and Ideola wrote in another topic that using "short" injectores is not really a problem so maby i'm just creating my own problem wich is going to cost me a lot of money

Therefore I would like to try the 19lb/hr injectors first without a supercharger, I suppose they will be sufficient.

So now i'm not only searching for a FPR but also for 300cc/min injectors...
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Porsche 924 2.0 Kompressor 136.1wHp @ 5650rpm / 201.9wNm @ 3900rpm (dyno @ dp-engineering.nl)

Rocco R16V · Joined: 03 May 2009 Posts: 497 Location: PNW

Arvidw · Posted: Mon Jan 18, 2010 7:24 am Post subject:

Ah thanks, that 2spray injector style would indeed be a problem. The EV12 is only available in 15deg twin

My 19lb/hr injectors have got 4 holes however I don't think they where ment for a 8valves/cilinder engine. I don't think a mondeo does have these pistons:

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Porsche 924 2.0 Kompressor 136.1wHp @ 5650rpm / 201.9wNm @ 3900rpm (dyno @ dp-engineering.nl)

Min · Posted: Mon Jan 18, 2010 8:08 am Post subject:

Any fuel puddling issues you may have can be taken care of by software. X-tau/enhanced acceleration enrichment is based on the size of the fuel puddle in the intake system and how quickly its moving into the intake stream. Don't over think the simple stuff, you'll never get it running if you do. 19 pound injectors will work just fine for awhile.

Min
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Custom means it didn't come from a box.
1980 n/a with EDIS and Megasquirt II Injection. 7 different colors and counting.

Arvidw · Posted: Mon Jan 18, 2010 4:48 pm Post subject:

I don't quit understand what you are saying: What do you mean by simple stuff?

I shouldn't be worried about the injectors, they will work just fine and any problems with puddles can be solved with software, therefore no "long tip" injectors are neccesary?

That would be great.... and cheap

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Porsche 924 2.0 Kompressor 136.1wHp @ 5650rpm / 201.9wNm @ 3900rpm (dyno @ dp-engineering.nl)