winders

I am looking for an adjustable fuel pressure regulator for my 964-based race engine. It needs to fit the stock location and plumbing.

What options do I have? What pressure ranges do they support? How well do they work?

Thanks!!

winders

Does this one work okay?

http://www.lindseyracing.com/LR/Pors.../911-4501.html

From talking with Dave at Lindsey, it adjusts to as low as 30 psi (2 bar) all the way up to 80 or 90 psi (5.5 or 6.2 bar). Stock is about 3.8 bar (55 psi).

onceover

I should have bought that rather than spending close to $200 for my Bosch unit!

Vandit

Looks like a nice piece of kit.

R6XTERRA

Having a gauge indicator would be a nice touch as well.

Vandit

^it wouldn't be very accessible given where the FPR resides under the plenum. There is an unused fitting on the bank 1 fuel rail that is better suited for a gauge.

R6XTERRA

Vandit,

I was thinking the same thing about being accessible but assume you can use a relocate with braided lines. I guess, why bother when its super simple to run it off the fuel rail.

I am wanting to add to my car. Do you have any sort of recommendation for decent guage?

J richard

This is the one I've used, it is a one time set and forget item so ongoing access to it really isn't all that critical


https://m.automotion.com/high-perfor...1989-1995.html

ThomasC2

A stupid question. How do you know how to adjust it? What is a correct setup/values?

Thomas

winders

If you need an adjustable fuel pressure regulator, there is no one correct pressure. You typically get an adjustable fuel pressure regulator because the stock fixed pressure unit has either too much or too little pressure.

One wouldn't want to adjust the fuel pressure without being able to read and adjust the air/fuel mixture. It certainly does not hurt to have a fuel pressure gauge somewhere inline so you know what pressure you are using. But that is not really important compared to the air/fuel ratio.

J richard

More importantly than just the fixed pressure is the adjustables are also rising rate regulators. The stock one has some attenuation but are basically limited to one pressure set at low rpm or at power, it is therefore a compromise at either end. The adjustable rising rates allow for a more linear matching between vacuum and power levels as well as a higher ultimate pressure. This makes for better throttle response as well as better A/F matching. They are generally ok out of the box but as winders has said it can be optimized on the dyno with F/A levels.

Roque

Can someone shed some light on an adjustable FPR with good reviews. Looking for comments on performance, design, durability, etc.

Thanks,
Carlos

onceover

What are you trying to accomplish? Have you gone big bore? Running too lean/rich?

Roque

Hi Onceover! I got to replace my oem FPR that fail to hold pressure. I would like to finetune fuel pressure and AFM to target desired AFR.

For sure the FPR location is a challenge in terms of on the fly adjustments, but possibly thinking of using a temporary remote adjuster similar to the ones available in the market for shocks or brake bias.




Thanks in advance for your input.

Carlos

-nick

Changing the fuel pressure is an awful way to affect the afr. Tune the chip or use an aftermarket system. Fuel pressure changes everything, everywhere. Adjustments are only useful when balancing injector size and duty cycle before tuning everything else.