RRFPR/FMU choices

[FSAEracer03]

I'm looking at both rising rate FPRs and FMUs (vastly different in application, but I have my reasons) and was wondering if you guys know which manufacturers of each make units that replicate the OE Bosch port.

Thanks,
Kevin

[russc]

I know of no units that replicate(drop in) to the stock loctation. There is one that says it does, but it is not available yet. There all externally mounted and work in conjunction with the stock unit.

See this thread for the one that in theory replaces the stocker:
http://www.mye28.com/viewtopic.php?t=21 ... hlight=fmu

RussC

[FSAEracer03]

For the time beig, externally mounted is the only option, got it. Thanks, Russ. That new one looks slick, btw.

[Tjn182]

I dunno but I think this is pretty dandy:

EBAY

[Duke]

I know of no units that replicate(drop in) to the stock loctation. There is one that says it does, but it is not available yet. There all externally mounted and work in conjunction with the stock unit.

I know of one and it is on my engine right now -




$200 from BAVARIAN Autosport - Get more power and better throttle response from your BMW. This adjustable rising rate fuel pressure regulator enriches the fuel mixture as you accelerate to increase power and improve mid-range throttle response. Maintains stock fuel mixtures at idle.

[Shawn D.]

I dunno but I think this is pretty dandy:

EBAY

Uhh... why is it dandy? It's just an in-line regulator. I don't see how it's "specially designed for the BMW E30 and BMW E28 cars" and the statement "This is nice so it will not hit your hood" is rather curious.

[smackmybutter535i]

I know of no units that replicate(drop in) to the stock loctation. There is one that says it does, but it is not available yet. There all externally mounted and work in conjunction with the stock unit.

I know of one and it is on my engine right now -




$200 from BAVARIAN Autosport - Get more power and better throttle response from your BMW. This adjustable rising rate fuel pressure regulator enriches the fuel mixture as you accelerate to increase power and improve mid-range throttle response. Maintains stock fuel mixtures at idle.

I have that one, so I don't have to run my cartech RRFPR if I just use the bavauto RRFPR????

[russc]

Duke,
That FPR is not a RRFPR as the BEGI unit or Vortech. It doesn't have the capability to raise pressure at an exponential rate, ie more than 1psi fuel pressure for 1psi of boost. The classic RRFPR(or FMU) can be set to raise fuel pressure at more than 1psi/psi boost. So more like 2-5psi fuel pressure per psi of boost.

So Smackybutter, yes, you will need either a BEGI unit or the Vortech unit.

RussC

[vance]

Here are a couple of options for the stock location:
http://cgi.ebay.com/ebaymotors/E30-E28- ... 0002074307

http://www.synapseengineering.com/produ ... sc002.html

[Shawn D.]

http://www.synapseengineering.com/produ ... sc002.html

We've eliminated (these) problems by linearizing the response of the FPR via friction.

Sounds iffy and unreliable to me.

[Duke]

Duke,
That FPR is not a RRFPR as the BEGI unit or Vortech.

Directly quated from the BAV Auto site - "Get more power and better throttle response from your BMW. This adjustable rising rate fuel pressure regulator enriches the fuel mixture as you accelerate to increase power and improve mid-range throttle response. Maintains stock fuel mixtures at idle. "

So are they FOS?

[russc]

Duke,
that add is not FOS, it just dosen't tell the whole story. It does rise with pressure, but in a "linear" way, ie, 1psi to 1psi. This is not what you need for a turbo/forced induction setup, where you want a "non-linear" rise of pressure. Say 4psi for every psi of boost!

RussC

[Duke]

Duke,
that add is not FOS, it just dosen't tell the whole story. It does rise with pressure, but in a "linear" way, ie, 1psi to 1psi. This is not what you need for a turbo/forced induction setup, where you want a "non-linear" rise of pressure. Say 4psi for every psi of boost!

RussC

From my understanding, that is just fine. 1 psi of fuel for 1 psi of boost. That way the fuel injectors keep up the flow even under say 20 psi of boost. Why is 4 psi per pound of boost needed? I would be over 100 psi of fuel preasure and could pressure lock the injectors. Edumicate me please.

[DMNaskale]

Why is 4 psi per pound of boost needed? I would be over 100 psi of fuel preasure and could pressure lock the injectors.

You don't need it, you have big hairy injectors that can keep up with your engine, and a programmable ECU. Little sissy injectors and stock based engine management need the kluge to keep up with the fuel flow demands of higher horsepower than they were designed for.

[russc]

Why is 4 psi per pound of boost needed? I would be over 100 psi of fuel preasure and could pressure lock the injectors.

You don't need it, you have big hairy injectors that can keep up with your engine, and a programmable ECU. Little sissy injectors and stock based engine management need the kluge to keep up with the fuel flow demands of higher horsepower than they were designed for.

So right,
The RRFPR is a cludge, and is for using smaller injs for bigger power. This is usally for non-programmable ECUs, like the stock BMWs. This way you can run boost to ~10psi on a M30 with injs that will still idle OK with a 059 ECU. You can apply this theory to any other car/ECU combo.

RussC

[FSAEracer03]

Duke,
That FPR is not a RRFPR as the BEGI unit or Vortech. It doesn't have the capability to raise pressure at an exponential rate, ie more than 1psi fuel pressure for 1psi of boost. The classic RRFPR(or FMU) can be set to raise fuel pressure at more than 1psi/psi boost. So more like 2-5psi fuel pressure per psi of boost.

So Smackybutter, yes, you will need either a BEGI unit or the Vortech unit.

RussC

To clear up the confusion, I used RRFPR in the barest sense of the term; one that simply rises the rate equal to positive pressure.

FMU I'm using as everyone knows it; a linearly increasing, adjustable (ratio) fuel pressure regulator.

Thanks for all the info guys! Keep it coming in.

[AsphaltJungle]

I know of no units that replicate(drop in) to the stock loctation. There is one that says it does, but it is not available yet. There all externally mounted and work in conjunction with the stock unit.

I know of one and it is on my engine right now -




$200 from BAVARIAN Autosport - Get more power and better throttle response from your BMW. This adjustable rising rate fuel pressure regulator enriches the fuel mixture as you accelerate to increase power and improve mid-range throttle response. Maintains stock fuel mixtures at idle.

That is the same one I have!