EFI w/Dual plane manifold ?? - Team Camaro Tech
EFI in your modern Classic EFI conversions in early Camaros

 1Likes
  • 1 Post By Cunning69
 
LinkBack Thread Tools Display Modes
post #1 of 10 (permalink) Old Jun 5th, 18, 06:13 AM Thread Starter
Gold Lifetime Member
Mark
 
67 455 Bird ragtop's Avatar
 
Join Date: May 2003
Location: Melbourne, FL
Posts: 686
EFI w/Dual plane manifold ??

I've read a few posts that the new EFI systems, Sniper/EFITech don't really like a dual plane manifold. I currently have an Edelbrock Performer RPM which is a dual plane manifold. What are my option?? Or is this not really an issue with the RPM ??

67 'Bird vert 455 JW TH400 KRE d-port 310 cfm heads H-beam rods Comp Cam 305-AH-8 cam w/1.65 rockers Ford 9" 3.55 Detroit Locker M/T Radials 31x18x15 on Convo Pro 15x15s
67 455 Bird ragtop is offline  
Sponsored Links
Advertisement
 
post #2 of 10 (permalink) Old Jun 5th, 18, 06:39 AM
Tech Team
Robert
 
Join Date: Nov 2013
Location: maryland, US
Posts: 87
Re: EFI w/Dual plane manifold ??

Last weekend I installed the Sniper system on my Camaro with an LS engine. I also have the RPM dual plane manifold. So far acceleration and idle are very good, but I have only drove it about 100 miles since installation, it's still learning.

Couple things to note, I have not fixed any of these yet:
I get a whistling noise at about 30% throttle, seems this happens to a lot of people. The fix is to install a 1/4 inch or larger 4 hole spacer under the unit. It's not clear if this only happens on dual plane manifolds. https://www.efisystempro.com/sniper/...le-300-4004QFT


It is real touchy off idle, all four barrels open a once. The fix is a replacement piece of linkage that will give you progressive opening. Holley sells this for about $15. https://www.efisystempro.com/sniper/...ve-linkage-kit

My air cleaner has a drop base and it hit the fuel line. I think this will only happen if you use one of the two front fuel feed options. I had to do some cutting to get it to fit. Holley sells a modified drop base for 14 inch air cleaners that will work. https://www.efisystempro.com/sniper/...-black-120-511
Smitty68 likes this.
Cunning69 is offline  
post #3 of 10 (permalink) Old Jun 5th, 18, 06:47 AM
Senior Tech
Dave
 
Join Date: Dec 2005
Location: Tampa, Florida
Posts: 4,752
Re: EFI w/Dual plane manifold ??

It isn't an issue. Diesels, which where the first fuel injected engines, have nothing but a big open plenum with a throttle plate located somewhere to control the flow of incoming air. At wide open throttle they are open to the atmosphere, hence the need to provide a mechanical or an electric powered vacuum pump if you want vacuum for anything.

A carb requires vacuum pulses to work. the longer the runner the more torque you make down low, the shorter the more horse power you make up top. The RPM Air gap was designed to flow within 4% of a Victor Jr single plane while still retaining the advantages of the longer runners.

Direct injection or port injection will not be affected by manifold shape or runner length. If it is a Throttle Body containing the Injectors it is still just an electronic carb as the runners in the manifold are wet, not dry. As such it behaves like a carb, just a lot more expensive. Consider the Hilborn or Crower mechanical injection system used straight stacks for each port that were not connected in any way other than a throttle shaft with blades.

Big Dave
Larger Dave is offline  
 
post #4 of 10 (permalink) Old Jun 5th, 18, 08:23 AM Thread Starter
Gold Lifetime Member
Mark
 
67 455 Bird ragtop's Avatar
 
Join Date: May 2003
Location: Melbourne, FL
Posts: 686
Re: EFI w/Dual plane manifold ??

Thanks for the feedback ..

67 'Bird vert 455 JW TH400 KRE d-port 310 cfm heads H-beam rods Comp Cam 305-AH-8 cam w/1.65 rockers Ford 9" 3.55 Detroit Locker M/T Radials 31x18x15 on Convo Pro 15x15s
67 455 Bird ragtop is offline  
post #5 of 10 (permalink) Old Jun 5th, 18, 08:40 AM
Gold Lifetime Member
Robert
 
rtchaney's Avatar
 
Join Date: Jan 2007
Location: 85340
Posts: 320
Garage
I have about 3k miles on my Sniper system. Running and Edelbrock EPS with a 1" tapered 4 hole spacer. She's happy. I've seen vids online and had friends "mill" the plenum divider if they had issues and that seemed to rectify the problem. Simple dremmel mod.

1968, 5 speed, Vintage Air Gen IV, American Auto Wire Update Series, Champion 4 Core Rad, BMR front w/ Koni's, BP Roller 383, Posi 8.2", Solid Frame Bushings
rtchaney is offline  
post #6 of 10 (permalink) Old Jun 5th, 18, 09:07 AM
Gold Lifetime Member
Darin
 
ilikeike's Avatar
 
Join Date: Jun 2013
Location: Stanislaus Co. Ca.
Posts: 1,609
Re: EFI w/Dual plane manifold ??

The Edelbrock RPM should have the notch in the divider so the MAP sensor port is getting good signal from both sides. I think some of the issues that were happening were on the dual plane manifolds with solid dividers and the the sensor location on some of the throttle body EFIs weren't getting good consistent signals or were getting pulses,reversion...
If you have room,throw a 1/2" open spacer on there.

1968 Butternut Coupe,
421" Dart SHP block
TKO 600 RR
Dutchman 9" w/3.70
Speedtech torque arm,Ridetech HQ coilovers
Global West arms
Budnik wheels

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
ilikeike is offline  
post #7 of 10 (permalink) Old Jun 5th, 18, 12:32 PM Thread Starter
Gold Lifetime Member
Mark
 
67 455 Bird ragtop's Avatar
 
Join Date: May 2003
Location: Melbourne, FL
Posts: 686
Re: EFI w/Dual plane manifold ??

Quote:
Originally Posted by ilikeike View Post
The Edelbrock RPM should have the notch in the divider so the MAP sensor port is getting good signal from both sides. I think some of the issues that were happening were on the dual plane manifolds with solid dividers and the the sensor location on some of the throttle body EFIs weren't getting good consistent signals or were getting pulses,reversion...
If you have room,throw a 1/2" open spacer on there.
Or cut a notch between the two sides while the intake is still off the car ??

67 'Bird vert 455 JW TH400 KRE d-port 310 cfm heads H-beam rods Comp Cam 305-AH-8 cam w/1.65 rockers Ford 9" 3.55 Detroit Locker M/T Radials 31x18x15 on Convo Pro 15x15s
67 455 Bird ragtop is offline  
post #8 of 10 (permalink) Old Jun 5th, 18, 01:31 PM
Gold Lifetime Member
Darin
 
ilikeike's Avatar
 
Join Date: Jun 2013
Location: Stanislaus Co. Ca.
Posts: 1,609
Re: EFI w/Dual plane manifold ??

Quote:
Originally Posted by 67 455 Bird ragtop View Post
Or cut a notch between the two sides while the intake is still off the car ??
If it doesn't have one yes.

Proven to be a good idea on the dyno. And why Edelbrock does it.

1968 Butternut Coupe,
421" Dart SHP block
TKO 600 RR
Dutchman 9" w/3.70
Speedtech torque arm,Ridetech HQ coilovers
Global West arms
Budnik wheels

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
ilikeike is offline  
post #9 of 10 (permalink) Old Jun 5th, 18, 01:56 PM
Moderator
John
 
Vega$69's Avatar
 
Join Date: Sep 2010
Location: Vegas NV/Wesley Chapel FL
Posts: 13,326
Garage
Re: EFI w/Dual plane manifold ??

Quote:
Originally Posted by ilikeike View Post
If it doesn't have one yes.

Proven to be a good idea on the dyno. And why Edelbrock does it.
Yes. Even if carbed

2017 Corvette ZO6 with ZO7 Option
66 Chevelle Protour LS3/525(SOLD AT Mecum 2018)
69 SS396 Cortez Silver(SOLD)
69 Z28(Sold)
69 Pro Tour - LS3/T56
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
(SOLD)
69 Pro Tour - LS7/T56 (SOLD)
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

69 Z28/RS Tribute355/5 Speed (SOLD)
69 RS Clone 427/TH400 (SOLD)
67 RSZZ502/5 Speed (SOLD)
69 Camaro 406 SBC/TH400 (SOLD)
Vega$69 is offline  
post #10 of 10 (permalink) Old Jun 5th, 18, 05:21 PM
Senior Tech
Rufas
 
Join Date: Oct 2012
Location: USA
Posts: 585
Re: EFI w/Dual plane manifold ??

Just remember a couple of things about EFI, manifold vacuum is less of an issue than with a carb, and, the single plane manifolds of olden days actually benefit from EFI, even throttle body type EFI systems. EFI must use the heat crossover passage, or, a water cooled plate under the throttle body, EFI doesn't like "cold" manifolds, or throttle bodies.
dave ray is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome