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Fuel pressure regulator question
clairetoo - 28/4/12 at 06:49 PM

I've been looking for a regulator for my V6 project , and something has occurred to me - do I really need an adjustable reg. , or would any production car one do ?
I'm looking for one to screw into the fuel rail - anyone think eBay - The UK's Online Marketplace would do ?

jacko - 28/4/12 at 07:14 PM

How about a cosworth regulator ?there adjustable of a sierra

HowardB - 28/4/12 at 07:22 PM

a fixed one is less prone to accidentaly changing pressures when least required. That is a simple looking bit of kit, and as long as it fixed at the pressure you want I would suggest it out to be ok.

will121 - 28/4/12 at 08:23 PM

as said above, i can only see main benefit of adjustable one is to compensate for mis match in injector flow/power output scaling. i had a cheap ebay adjustable one and it was constantly changing pressure, ended up fitting a decent one

paulf - 28/4/12 at 08:55 PM

In my opinion a good quality fixed regulator is better than an adjustable one that may not retain a stable pressure in use.I made a housing to take a Bosch regulator capsule from a zetec fuel rail.The Webber fuel regs look to use much the same regulator unit and I made a copy of one of them by boring a bit of alloy to match the inside dimensions of the fuel rail and then fitted a couple of hose tails.
Paul

hicost - 29/4/12 at 08:45 AM

Personally I would not bother with any form of cheap regulator, especially some of the adjustable rising rate regulators found on EBay, they are just copies of proper regulators but about as much use as a “chocolate fireguard”.

Fuelling has to be the number one factor of any smooth running engine from both a performance and driveability point of view.

If you are using custom inlet or custom injection then at some point you will want to know and maintain your optimum fuel pressure.

What is the point in spending hours mapping a car if you either don’t know what your fuel pressure is, or it is not sustainable. Think of the AFR issues that arise from an up and down rate.

So I would spend the extra and purchase an adjustable regulator with a either mechanical or a electronic pressure sensor.

Fit and forget and adjust if needed.

But this is just my opinion!

BaileyPerformance - 30/4/12 at 01:55 PM

quote:
Originally posted by clairetoo
I've been looking for a regulator for my V6 project , and something has occurred to me - do I really need an adjustable reg. , or would any production car one do ?
I'm looking for one to screw into the fuel rail - anyone think eBay - The UK's Online Marketplace would do ?


Hi Claire,

Why can't you just use the standard fuel regulator? assuming your engine is near stock (not force fed) the stock reg and injectors should be fine.
Assuming you will use aftermarket engine management i would leave the vacuum pipe disconnected from the reg and map accordingly. We have found this to produce better throttle response. (more stable fuel pressure).

Otherwise, if you really want an adjustable aftermarket reg we use Weber Alpha ones WEBER ALPHA INJECTION REGULATOR ADJUSTABLE 0-5 BAR WFR505 | eBay

Steer clear of FSE "power boost valves" we have removed several of them due to fluctuating fuel pressure, thay are rubbish.

clairetoo - 30/4/12 at 03:38 PM

quote:
Originally posted by BaileyPerformance
quote:
Originally posted by clairetoo
I've been looking for a regulator for my V6 project , and something has occurred to me - do I really need an adjustable reg. , or would any production car one do ?
I'm looking for one to screw into the fuel rail - anyone think eBay - The UK's Online Marketplace would do ?


Hi Claire,

Why can't you just use the standard fuel regulator? assuming your engine is near stock (not force fed) the stock reg and injectors should be fine.
Assuming you will use aftermarket engine management i would leave the vacuum pipe disconnected from the reg and map accordingly. We have found this to produce better throttle response. (more stable fuel pressure).

Otherwise, if you really want an adjustable aftermarket reg we use Weber Alpha ones WEBER ALPHA INJECTION REGULATOR ADJUSTABLE 0-5 BAR WFR505 | eBay

Steer clear of FSE "power boost valves" we have removed several of them due to fluctuating fuel pressure, thay are rubbish.

I cant use the standard regulator - I'm running bike throttle bodies , with new billet fuel rails and different injectors - also I think I will need to upgrade the fuel pump as the stock 1.6 Mx5 one may not cope with a 2.5 V6 !
I'll add a pressure take-off to check , but I've decided to give that ebay one a try - after all , its for a similar sized engine .

BaileyPerformance - 30/4/12 at 04:19 PM

quote:
Originally posted by clairetoo
quote:
Originally posted by BaileyPerformance
quote:
Originally posted by clairetoo
I've been looking for a regulator for my V6 project , and something has occurred to me - do I really need an adjustable reg. , or would any production car one do ?
I'm looking for one to screw into the fuel rail - anyone think eBay - The UK's Online Marketplace would do ?


Hi Claire,

Why can't you just use the standard fuel regulator? assuming your engine is near stock (not force fed) the stock reg and injectors should be fine.
Assuming you will use aftermarket engine management i would leave the vacuum pipe disconnected from the reg and map accordingly. We have found this to produce better throttle response. (more stable fuel pressure).

Otherwise, if you really want an adjustable aftermarket reg we use Weber Alpha ones WEBER ALPHA INJECTION REGULATOR ADJUSTABLE 0-5 BAR WFR505 | eBay

Steer clear of FSE "power boost valves" we have removed several of them due to fluctuating fuel pressure, thay are rubbish.

I cant use the standard regulator - I'm running bike throttle bodies , with new billet fuel rails and different injectors - also I think I will need to upgrade the fuel pump as the stock 1.6 Mx5 one may not cope with a 2.5 V6 !
I'll add a pressure take-off to check , but I've decided to give that ebay one a try - after all , its for a similar sized engine .


Your right about the pump, may struggle with the higher power output engine. As you said measure the fuel pressure at full load full throttle high RPM to make sure it does not drop.
What size are your injectors? the jag regulator on ebay is probably only 2.5Bar, so you will need to calculate the injector flow rate at 2.5Bar to confirm they are big enough for the 220+BHP your engine will produce.

We would probably run 4.0Bar pressure on an conversion like yours to make sure we didn't run out of injector when mapping (unless your injectors are very big) plus better fuel atomisation at higher pressure can help power.

clairetoo - 30/4/12 at 04:29 PM

One small (but very relevant) point...................I'm not looking for as much power as I can get , and any full throttle use will be for seconds at a time - a full run through the gears gets me to well over 150 in no more than half a mile , which is something I have done just once in four years of use..........to be honest , its way to fast for the sort of roads I enjoy driving on !

Its highly unlikely it will ever see a rolling road - squeezing out that last couple of horsepower is just not important to me (its just not worth the expense - decent economy at light load is way more important to me , which I can get using auto-tune )

BaileyPerformance - 30/4/12 at 06:01 PM

quote:
Originally posted by clairetoo
One small (but very relevant) point...................I'm not looking for as much power as I can get , and any full throttle use will be for seconds at a time - a full run through the gears gets me to well over 150 in no more than half a mile , which is something I have done just once in four years of use..........to be honest , its way to fast for the sort of roads I enjoy driving on !

Its highly unlikely it will ever see a rolling road - squeezing out that last couple of horsepower is just not important to me (its just not worth the expense - decent economy at light load is way more important to me , which I can get using auto-tune )


Humm... i do see what you mean but before we got the rollers we used to tune on the road, but you can never get it tuned 100%. The rolling road is not just about full throttle, you can alter engine load at all RPM and throttle positions making it quick and easy to map. Plus autotune wont sort out the timing.
The only way you can get it right is on the dyno, it will be cheaper than all the fuel you will use driving around on autotune!

If you are looking for more drivablity than power, have you got room for the stock inlet manifold? if so no reason to use throttle bodies, just stick with the factory manifold, injectors and fuel reg, will be easier to map and slow speed driving will be better.

clairetoo - 30/4/12 at 07:44 PM

quote:

If you are looking for more drivablity than power, have you got room for the stock inlet manifold? if so no reason to use throttle bodies, just stick with the factory manifold, injectors and fuel reg, will be easier to map and slow speed driving will be better.

Drivabilty isnt an issue with my current (home mapped) set-up , it will tickover at 650 RPM , pull away in second gear at less that a thousand , and pull clean all the way to 8000 - and it will do over 40 MPG cruising........ I know its not completely right at full throttle , but its near enough .

I cant use the stock manifold and injectors - this engine is in an Mx5 , and the stock setup would put the throttle body right where the servo and clutch cylinder sit.......plus it is very heavy and restrictive (ITB's give about a 40 BHP boost !)

Its also being done on a very low budget

BaileyPerformance - 1/5/12 at 09:01 AM

If its driving well and you are seeing 40MPG you must have it set up close to optimum at part throttle, getting the throttle's balanced is the key to a good idle and slow speed progression, again - you must be close! Fair Play!

coozer - 1/5/12 at 09:15 AM

Will BaileyPerformance be at Stoneleigh perchance?

BaileyPerformance - 1/5/12 at 11:10 AM

quote:
Originally posted by coozer
Will BaileyPerformance be at Stoneleigh perchance?


Hi coozer, no we wont but we probably should be!

coozer - 1/5/12 at 11:16 AM

Shame, i wanted to pick your brains v my turbo project...

BaileyPerformance - 1/5/12 at 11:20 AM

quote:
Originally posted by coozer
Shame, i wanted to pick your brains v my turbo project...


you can U2U me or email dale.bladen@orange.net. or use the contact page on our website if ya like. www.baileyperformance.co.uk