A quick question ...fuel regulators

[andy graham]

Just looking for some advice:
Following a recent "health" check (93 4.0)it has come to light I have slightly low fuel pressure (30psi)
So time for a new one I guess! It was recommended to get an after market rising rate regulator, have been reading through thr RPI website and what they promise seems great, however other publications seem to contradict this their effectiveness on a standard Chim/Griff
Anyone have any experience on these?? Seems I will be buying a new regulator, but a standard one, or believe the hype?????
Any suggestions ???
Andy

[chassis 33]

To all intents and purposes a standard regulator will do the job, not everyone has found the aftermarket ones to be 100% reliable.

Regards
Iain

[andy graham]

"To all intents and purposes a standard regulator will do the job, not everyone has found the aftermarket ones to be 100% reliable."

In what way are they not reliable, and were there any gains from the rising rate reg??
Andy

[chassis 33]

It is known for diaphrams to split causing a loss in fuel pressure after a relatively short life under a TVR bonnet whether its an application issue that's to do with heat build up under the TVR bonnets or a more fundamental flaw I couldn't say.

The idea of the "rising rate" regulator is that as revs increase (meaning there is less time to squirt fuel through the injectors), the fuel pressure increases to help, done via the vacuum pipe, however without re-maps etc to make use of this it's kinda pointless, and in my experience the rising rate bit doesn't work anyway.

The original unit works perfectly well, if you're having to up the fuel pressure beyond 34-36psi to get the car to run properly then the chances are you're treating the symptoms not the cause.

Regards
Iain

[andy graham]

Thanks for your comments, was just getting engine checked over / set up correctly last weekend and is running fine now....just one of the checks was fuel pressure which appeared a bit low at 30psi...then the can of worms got opened with the mention of a rising rate regulator. think I will probably just replace like for like though.
Am I right in thinking fuel pressure should be closer to high 30's?
Like I said car is driving fine, just having been given the info that pressure is on the low side I feel compelled to spend some more money to get it right

[GreenV8S]

andy graham said:

Am I right in thinking fuel pressure should be closer to high 30's?

They're usually set to run at a nominal 2.5 bar (37 psi ish) with no vacuum.

[midlifecrisis]

Just fitted a rising rate to my 95 400 chim today. Ran it on a rolling road found the best
setting for mine at 40 PSI. I gained 5bhp and 10ft/lb. The extra torque is nice low down and response is smoother.