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Discussion Starter · #1 ·
i know everyone tells us to upgrade to a 4 bar, well i found a 4.5 bar fuel pressure regulator, would that work or would it flood out the injectors on a 2.5 v6?
 

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t_buck09 said:
i know everyone tells us to upgrade to a 4 bar, well i found a 4.5 bar fuel pressure regulator, would that work or would it flood out the injectors on a 2.5 v6?
You're looking for an upgrade.. Linear or progressive? Stock injectors?
Stock injectors and 4bar fpr would max the injectors. With a linear that's 5bar fuel at 1bar.

You probably already know, but a linear 3bar fpr will have a fuel pressure at 2.5 bar when idling (normally -0,5 bar), and ofcourse 4 bar at 1.0bar boost.

The question is really how much fuel you need. 5.5 bar fuel pressure (with a 4bar fpr @ 1.5bar) is.. well, thats just plenty for both you and your neighbours car ;)
 

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Discussion Starter · #3 ·
lol actually you confused the **** outa me, looks like i need to learn something, i always heard about the upgrade to a 4 bar for quicker responce. i have a fully stock fuel system. this is the regulator i was looking at link so the 4 bar is like the max i could go?
 

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t_buck09 said:
lol actually you confused the **** outa me, looks like i need to learn something, i always heard about the upgrade to a 4 bar for quicker responce. i have a fully stock fuel system. this is the regulator i was looking at link so the 4 bar is like the max i could go?
I've never heard of someone upgrading only the fpr..
4bar frp with stock fuel system is overkill.. I'm using 630cc injectors on my 410hp/530nm 900, with stock fpr. Thinking about upgrading it now when the fuel is the threshold.
But if you're not planning to upgrader just the fpr, i'd say its unnecessary.
 

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t_buck - is this on your V6 engine, or a different car?

nine - you are talking about a 2L turbo, right?
 

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PMI said:
t_buck - is this on your V6 engine, or a different car?

nine - you are talking about a 2L turbo, right?
It's his V6. Thanks for reminding me, im got snowed in on the 2.0t for some reason. And yes, the mods i listed is on a 2.0t.

I still think that a 4bar fpr wont do any (much) good. Dont think the fuel pump's gonna be up to the task. The injectors might.

I cant see a reason to upgrade just the fpr, since the engine wont need the extra fuel in comparison to the stock fpr.

Correct me if im wrong!
 

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Depends on what he is trying to do. He lives in northern Wisconsin, there are a few cars up there running on ethanol... :cheesy:

The pump will work at higher pressure, but the max flow has to be derated. Basically, the higher the pressure, the lower the flow. I only have the table handy, but I will insert a graph into this thread later, easier to see the relationship. The flow numbers are in gallons per hour (sorry).


Pressure v. Flow for equivalent Walbro pump

At some pressure the injector will not close reliably. It will open, but because it closes on a mechanical spring, at some pressure it will start to fail.
 

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Discussion Starter · #8 ·
i live in southern wisconsin with a v6, ive heard from tboy and raggy that if you upgrade the fpr you gain quicker fuel responce? idk
 

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t_buck09 said:
i live in southern wisconsin with a v6, ive heard from tboy and raggy that if you upgrade the fpr you gain quicker fuel responce? idk
I thought you were up in the GB area, sorry. I don't quite understand that, :confused: , but Ragtop would know, ask him what pressure he recommends.
 

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Discussion Starter · #10 ·
i believe raggy is running a 4 bar, yea i live in racine county
 

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Im planning on running a 3.5 bar once I get my stg 4 software. im sure thats fine with stock injectors, but could I get away with a 4?
 

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9-3sleeper said:
Im planning on running a 3.5 bar once I get my stg 4 software. im sure thats fine with stock injectors, but could I get away with a 4?
You can probably look up the maximum pressure the injector is rated at. The NG900 and early 9-3 had Bosch EV1-3E (red) injectors. The injection time was 2.5 msec at idle, and 18 msec max. at wot (from the WIS) Note that after model yr. 2000, the injector changed.

Point is though, "Stage N" is usually a package deal, and the tuner assumes you have a known setup. I would not mess with that unless you discuss what you are doing with whoever reflashed your ecu.

I feel pretty safe playing with fuel pressure b/c I was not changing the max boost (or revving the engine to redline), but with modified boost control, high revs, and high fuel pressure, it might not take much to create an lean condition so quickly the ecu can't respond to it, and... boom, instant pile of scrap where your engine used to be.

( not saying it is not fun to play, if you don't have to depend on the same motor to get you to work on Monday...:cheesy: )
 

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PMI said:
You can probably look up the maximum pressure the injector is rated at. The NG900 and early 9-3 had Bosch EV1-3E (red) injectors. The injection time was 2.5 msec at idle, and 18 msec max. at wot (from the WIS) Note that after model yr. 2000, the injector changed.

Point is though, "Stage N" is usually a package deal, and the tuner assumes you have a known setup. I would not mess with that unless you discuss what you are doing with whoever reflashed your ecu.

I feel pretty safe playing with fuel pressure b/c I was not changing the max boost (or revving the engine to redline), but with modified boost control, high revs, and high fuel pressure, it might not take much to create an lean condition so quickly the ecu can't respond to it, and... boom, instant pile of scrap where your engine used to be.

( not saying it is not fun to play, if you don't have to depend on the same motor to get you to work on Monday...:cheesy: )
yeah, I surly dont want to push it, and I of course would talk to nick about adaptability before the tune is written. I am an '02 so I guess the injectors you listed are different from mine.
 

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was reading this thread and wanted to jump in with a quick question. will those regulators in the link above work on our Saabs? I have a 96 2.0t. the reason I am asking is because i am about to refresh my fuel system and have not pulled my old FPR out yet. I changed my filter and then the FPR went. The previous owner had a lot of crap in the tank.
 

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I'm a big fan of the 4 bar regulator,i put one on my V6 after having a chat to Raggy about it.

It wont give you any more power,but it does let you get up the revs a bit quicker and access what's there,in my case it also helped to get rid of that flat spot on the revs at about 2200/2500.

I would recommend giving the injectors a full ultrasonic clean at the same time as the new FPR goes on,that way you'll feel the full benefit of having a set of matched and flow tested injectors and the security of new seals and o rings...
 

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Discussion Starter · #17 ·
Still Pete67... said:
I'm a big fan of the 4 bar regulator,i put one on my V6 after having a chat to Raggy about it.

It wont give you any more power,but it does let you get up the revs a bit quicker and access what's there,in my case it also helped to get rid of that flat spot on the revs at about 2200/2500.

I would recommend giving the injectors a full ultrasonic clean at the same time as the new FPR goes on,that way you'll feel the full benefit of having a set of matched and flow tested injectors and the security of new seals and o rings...
how much does a cleaning usually run?
 

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t_buck09 said:
how much does a cleaning usually run?
I paid £11 per injector for a full strip down,clean and new seals and o rings,sent them in the post on Monday and they were back on the Thursday of the same week very well packaged with a full write up of the work they'd done,parts replaced and their flow rates.

If anybody's interested i'll dig out the paperwork and post the email address of the firm...
 

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Discussion Starter · #19 ·
damn if you wernt across the pond that would be GREAT i wonder if i could ship them out to them?? hmmmm
 

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I suppose you could ship them over,but there must be somebody in your area that will do a strip and clean?

Have a Google and see what you can find,Raggy advised me to look for Bosch service centres that normally clean the injectors on trucks but are more than happy to look after cars...
 
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