C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Adjustable Fuel Pressure Regulator

Thread Tools
 
Search this Thread
 
Old Sep 14, 2014 | 11:15 AM
  #1  
Johninator's Avatar
Johninator
Thread Starter
Intermediate
 
Joined: Apr 2014
Posts: 48
Likes: 0
Default Adjustable Fuel Pressure Regulator

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?
Reply
Old Sep 14, 2014 | 11:40 AM
  #2  
playsdixie's Avatar
playsdixie
Drifting
 
Joined: Jun 2013
Posts: 1,590
Likes: 60
From: ft myers FL/Munising MI
Default

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...
Reply
Old Sep 14, 2014 | 12:25 PM
  #3  
383vett's Avatar
383vett
Race Director
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Apr 2003
Posts: 17,699
Likes: 1,667
From: moraga ca
Default

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.

Reply
Old Sep 14, 2014 | 12:33 PM
  #4  
Johninator's Avatar
Johninator
Thread Starter
Intermediate
 
Joined: Apr 2014
Posts: 48
Likes: 0
Default

Originally Posted by 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...

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.
Reply
Old Sep 15, 2014 | 06:03 AM
  #5  
65Z01's Avatar
65Z01
Team Owner
20 Year Member
 
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Default

Earlier this year I purchased the BBK AFPR from Summit. It comes with neither the diaphram nor the security Torx bit.
Reply
Old Sep 15, 2014 | 07:18 PM
  #6  
blackozvet's Avatar
blackozvet
Safety Car
Conversation Starter
Liked
Loved
Community Favorite
 
Joined: Nov 2009
Posts: 3,973
Likes: 341
From: Adelaide South Australia
Default

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/
Reply
Old Sep 15, 2014 | 08:34 PM
  #7  
Johninator's Avatar
Johninator
Thread Starter
Intermediate
 
Joined: Apr 2014
Posts: 48
Likes: 0
Default

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.
Reply
Old Sep 15, 2014 | 09:58 PM
  #8  
Tizzle's Avatar
Tizzle
Intermediate
 
Joined: Jun 2014
Posts: 35
Likes: 0
From: Melbourne Australia
Default

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

The Best of Corvette for Corvette Enthusiasts

story-0

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-1

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-2

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
story-3

Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

 Joe Kucinski
story-4

Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

 Verdad Gallardo
story-5

Top 10 Corvettes Coming to Mecum Indy 2026!

 Brett Foote
story-6

Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

 Michael S. Palmer
story-7

10 Revolutionary 'Corvette Firsts' Most People Don't Know

 Joe Kucinski
story-8

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
story-9

2027 Corvette vs The World: Every C8 vs Its Closest Competitor

 Joe Kucinski
Old Sep 16, 2014 | 02:08 AM
  #9  
blackozvet's Avatar
blackozvet
Safety Car
Conversation Starter
Liked
Loved
Community Favorite
 
Joined: Nov 2009
Posts: 3,973
Likes: 341
From: Adelaide South Australia
Default

Originally Posted by Tizzle
are these adjustable regs worth it on a basically stock L98 TPI? been thinking of getting one for my 87' C4.
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.
Reply
Old Sep 16, 2014 | 08:47 AM
  #10  
ghoastrider1's Avatar
ghoastrider1
Le Mans Master
15 Year Member
 
Joined: May 2006
Posts: 7,708
Likes: 266
From: indy indiana
Default

with everything stock, I just dont see the need for an ajustable reg. nor the extra expense. That wouldbe kinda like having one header.
Reply
Old Sep 16, 2014 | 08:56 AM
  #11  
MrWillys's Avatar
MrWillys
Drifting
 
Joined: May 2013
Posts: 1,736
Likes: 31
From: Reno Nevada
Default

Originally Posted by 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.
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.
Reply
Old Sep 16, 2014 | 12:43 PM
  #12  
Johninator's Avatar
Johninator
Thread Starter
Intermediate
 
Joined: Apr 2014
Posts: 48
Likes: 0
Default

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.
Reply

Get notified of new replies

To Adjustable Fuel Pressure Regulator





All times are GMT -4. The time now is 05:44 PM.

story-0
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-1
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-2
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE
story-3
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-4
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-5
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-6
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-7
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-8
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-9
2027 Corvette vs The World: Every C8 vs Its Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-24 16:12:42


VIEW MORE