Johninator

I am getting a new diaphragm from TPIS.com and i am also going to purchase the adjustable unit while im at it. My question is, which one do i go with? I know there is a few on summitracing, the TPIS one says it is out of stock until July 15th, which it is well past then. Maybe the website hasnt been updated, i'll have to call them on that one.

Anyways, which one is recommended?

playsdixie

most of the major sites sell them...summit, jegs, corvette central...don't know why youre getting the diaphragm and the unit....a new adjustable fuel pressure regualtor would have one in it....don't really think one is better from the other....i'm sure someone here will chime in with a preference...

383vett

I'm using a Holley which is a nice billet unit. It has a large "dial" on top which can be marked like a timing mark on a harmonic balancer for making small repeatable adjustments.

Johninator

All the ones I've looked at on summit and other sites says it uses the stock internals. Doesn't give you a new diaphragm.

I've seen some for $40, other brands for $80.

65Z01

Earlier this year I purchased the BBK AFPR from Summit. It comes with neither the diaphram nor the security Torx bit.

blackozvet

the usual alloy housing adjustable regulators dont normally come with the diaphragm, unless you specify it and pay the extra,

I had issues with the SouthBay fuel injectors reg and diaphragm i bought, Im sure the inside clearance of the housing is too small for the diaphragm, had min 60 psi pressure, eventually solved the problem by putting the old diaphragm in (it had a slightly shorter spring because of age) and got it back to 44 psi.
Had no issues with the old adjustable unit, similiar to that offered on e bay by tpi parts.

I would consider the Holley as suggested by 383vett,it comes with diaphragm/ spring and can be adjusted by hand.
the housings with the adjustable screw on top are a pain to get to under the tpi plenum.

http://www.summitracing.com/int/part...-501/overview/

Johninator

I ended up ordering the TPIS diaphragm and adjustable unit from their website. I'll take some pictures when I get them. To show the quality or (hopefully not) lack of quality. It's was $69.99 plus $41.95 for the diaphragm.

Tizzle

are these adjustable regs worth it on a basically stock L98 TPI? been thinking of getting one for my 87' C4.

blackozvet

best to check your fuel pressure first and see where its at,

buy or borrow a gauge first, if your pressure is ok then you wont need one.

ghoastrider1

with everything stock, I just dont see the need for an ajustable reg. nor the extra expense. That wouldbe kinda like having one header.

MrWillys

An adjustable regulator allows you to adjust pressure based on observed blm counts. Let's say using your scanner it reads counts above 128 that shows a lean condition? Turn up the pressure until they read 128, or a bit lower. With rich readings you turn pressure down. It can be very helpful when changing injectors too.

Johninator

Mostly if you plan on just keeping your car stock and not ever doing any performance with it, then yes, it probably isn't worth it for you. But for me and many others I have plans in the future to expand in the performance. So, while I'm replacing the diaphragm, I figured I might as well put the adjustable unit in there so I don't have to take the regulator apart twice.