1974 From Carb to Finally Sniper EFI - Page 2 - CorvetteForum - Chevrolet Corvette Forum Discussion

Notices
C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette

1974 From Carb to Finally Sniper EFI

Old 01-26-2018, 02:40 PM
  #21  
Black04Vert
CF Senior Member
 
Member Since: May 2004
Location: Dallas TX
Posts: 968
Thanked 10 Times in 10 Posts
Default

Do you have your EFI unit controlling timing? If so, what distributor + ignition source did you go with?
Black04Vert is offline  
Old 01-26-2018, 03:01 PM
  #22  
redcruz1120
CF Senior Member
Thread Starter
 
redcruz1120's Avatar
 
Member Since: Feb 2007
Location: Pearland Texas
Posts: 1,346
Thanked 88 Times in 69 Posts
St. Jude Donor '09
Default

Originally Posted by Black04Vert View Post
Do you have your EFI unit controlling timing? If so, what distributor + ignition source did you go with?
Im not planning on changing the distributor unless I really have to. I'm going to fire it up and see what it does. Im currently running the big cap style HEI gm distributor.
redcruz1120 is offline  
Old 01-26-2018, 03:44 PM
  #23  
flyeri
CF Senior Member
 
flyeri's Avatar
 
Member Since: Mar 2011
Location: Kernersville NC
Posts: 1,196
Thanked 74 Times in 66 Posts
Default

Originally Posted by redcruz1120 View Post
Yes it does have a built in regulator but my return line would be too small and I want to minimize the use of hose all the way from engine to the tank.. this way it spills back to tank from about a foot away via Steel tubing.
Ok, I get that. To clarify, you will have no return line from engine to tank? I have a 1/4" return line now and I don't really want to run a 3/8" line for the return either. If you are also returning from the engine via a smaller existing line could you please explain that plumbing further? Thanks
flyeri is offline  
Old 01-27-2018, 12:47 AM
  #24  
OldCarBum
CF Senior Member
 
Member Since: Mar 2016
Location: Napa California
Posts: 1,773
Thanked 285 Times in 242 Posts
Default

Originally Posted by flyeri View Post
Ok, I get that. To clarify, you will have no return line from engine to tank? I have a 1/4" return line now and I don't really want to run a 3/8" line for the return either. If you are also returning from the engine via a smaller existing line could you please explain that plumbing further? Thanks
My 73 and I'm assuming the 74's did not come equipped from the factory with a return line from the engine (fuel filter) back to the tank.
OldCarBum is offline  
Old 01-27-2018, 01:08 AM
  #25  
Stingre'
CF Senior Member
 
Stingre''s Avatar
 
Member Since: Mar 2017
Location: Torrance Ca
Posts: 147
Thanked 11 Times in 11 Posts
Default

I'm doing the same upgrade, I'm using the Holley Distributor, plug and play. I'll be lurking here also
Attached Images  
Stingre' is offline  
Old 01-27-2018, 03:12 AM
  #26  
gwgwgw
CF Senior Member
 
gwgwgw's Avatar
 
Member Since: Jun 2004
Location: La Mesa CA
Posts: 1,346
Thanked 74 Times in 71 Posts
Default

Looks great
Following
gwgwgw is offline  
Old 01-27-2018, 01:04 PM
  #27  
redcruz1120
CF Senior Member
Thread Starter
 
redcruz1120's Avatar
 
Member Since: Feb 2007
Location: Pearland Texas
Posts: 1,346
Thanked 88 Times in 69 Posts
St. Jude Donor '09
Default

Originally Posted by OldCarBum View Post
My 73 and I'm assuming the 74's did not come equipped from the factory with a return line from the engine (fuel filter) back to the tank.
74s did come with a return line from the fuel pump back to the tank. It's just to small in diameter for a return line for the sniper system according to the recommended set up. I was originally going to have to run a 3/8s return hose back to the tank but then I saw a picture from a forum member that had the Ls filter /regulator with it plumbed directly back to the tank and Holley said I could just block off regulator at the unit. So I went with it. I put a compression AN fitting at both ends of the line as to be able to connect AN fittings to An filter, then to Unit up front then another hose from rear of line to filter/regulator at back. I might have maybe 2 feet of hose total



redcruz1120 is offline  
Old 01-27-2018, 02:59 PM
  #28  
redcruz1120
CF Senior Member
Thread Starter
 
redcruz1120's Avatar
 
Member Since: Feb 2007
Location: Pearland Texas
Posts: 1,346
Thanked 88 Times in 69 Posts
St. Jude Donor '09
Default Bad Pump

Update: there will be no results this weekend. I got ahold of a bad pump and will have to call Tanks Inc. for warranty tomorrow morning. Hope they ship me Another ASAP.... . I guess it's a good thing this happened for warranty review purposes. I'm sure they will honor the warranty 100%.

Last edited by redcruz1120; 01-28-2018 at 03:39 PM.
redcruz1120 is offline  
The Following User Says Thank You to redcruz1120 For This Useful Post:
gwgwgw (02-02-2018)
Old 02-02-2018, 06:01 PM
  #29  
Bigeddie
CF Senior Member
 
Bigeddie's Avatar
 
Member Since: Jun 2013
Location: salinas CA
Posts: 698
Thanked 12 Times in 12 Posts
Default

Well I bought the holley sniper and their efi tank. cannot wait to get it and also to read your full review!!!!cmon its been 6 days or so lol whats the update?
Bigeddie is offline  
Old 02-03-2018, 10:58 AM
  #30  
Johnnypegs
CF Senior Member
 
Johnnypegs's Avatar
 
Member Since: Mar 2017
Location: Boca Raton Florida
Posts: 242
Thanked 14 Times in 14 Posts
Default

Originally Posted by Stingre' View Post
I'm doing the same upgrade, I'm using the Holley Distributor, plug and play. I'll be lurking here also
That makes 3 of us!
Johnnypegs is offline  
The Following User Says Thank You to Johnnypegs For This Useful Post:
Stingre' (05-03-2018)
Old 02-03-2018, 01:00 PM
  #31  
wendellp601
CF Senior Member
 
wendellp601's Avatar
 
Member Since: Apr 2015
Location: Jackson MS
Posts: 1,796
Thanked 78 Times in 71 Posts
Default

Originally Posted by redcruz1120 View Post
it will. it's turning out easier than what I expected. the hardest part was finding someone to weld the oxygen bung,


I'm considering adding EFI on my '77 this spring.
My car also has side pipes, so I am interested in your 02 sensor bung.
Do you have more pics to share?
wendellp601 is offline  
Old 02-03-2018, 09:57 PM
  #32  
73ls1
CF Senior Member
 
73ls1's Avatar
 
Member Since: Nov 2004
Location: Bismarck IL.
Posts: 511
Thanks: 0
Thanked 4 Times in 4 Posts
Default vent valve

I bought the tank to use with my LS1. Old tank was leaking. Where did you mount your vent valve? Looks great,thanks Charlie.
73ls1 is offline  
Old 02-04-2018, 07:10 AM
  #33  
terrys6t8roadster
CF Senior Member
 
terrys6t8roadster's Avatar
 
Member Since: May 2012
Location: Allenton Wisconsin
Posts: 1,679
Thanked 159 Times in 156 Posts
Default

Originally Posted by wendellp601 View Post


I'm considering adding EFI on my '77 this spring.
My car also has side pipes, so I am interested in your 02 sensor bung.
Do you have more pics to share?
If you watch the Holley Sniper install 'You tube' video the kit also includes the O2 sensor hardware that does not require welding in a bung. T
terrys6t8roadster is offline  
Old 02-04-2018, 07:20 AM
  #34  
wendellp601
CF Senior Member
 
wendellp601's Avatar
 
Member Since: Apr 2015
Location: Jackson MS
Posts: 1,796
Thanked 78 Times in 71 Posts
Default

Originally Posted by terrys6t8roadster View Post
If you watch the Holley Sniper install 'You tube' video the kit also includes the O2 sensor hardware that does not require welding in a bung. T
That no-weld bung does not appear to have the correct radius for 4 inch side pipes.
wendellp601 is offline  
Old 02-06-2018, 05:50 AM
  #35  
dembo
CF Senior Member
 
dembo's Avatar
 
Member Since: May 2007
Location: Lokeren, Belgium
Posts: 1,022
Thanked 28 Times in 26 Posts
Default

Hi Redcruz,

Glad I could be of some help with the pictures or idea for the FPR. I must say that this weekend I swapped out the C5 regulator with a 'regular' Holley one. It's still mounted at the tank using the same hard lines but with some fittings. So still no rubber from front to rear.
I don't know how the sniper will behave but for my application (read engine) +Teminator efi, 65-67psi from the C5 regulator is putting out was just too much for the engine and I was always running rich and couldn't tune it out. It drove ok but not wow. With the new regulator at 45 psi my engine is alot happier.

So take it into consideration before bolting everything back up as the tank is out to change the fuel pump. There are alot of people on the Holley forum running the C5 FPR without issues as well. My engine is the 330hp crate with vortec heads.

Nick

Last edited by dembo; 02-06-2018 at 05:52 AM.
dembo is offline  
The Following User Says Thank You to dembo For This Useful Post:
redcruz1120 (02-06-2018)
Old 02-06-2018, 11:06 AM
  #36  
LT1M21Vette
CF Senior Member
 
LT1M21Vette's Avatar
 
Member Since: Nov 2014
Location: Foothills of the Adirondacks.
Posts: 632
Thanked 39 Times in 37 Posts
Default

Originally Posted by redcruz1120 View Post
Whoa, is that one of those Star Wars saber thing?
LT1M21Vette is offline  
Old 02-06-2018, 03:00 PM
  #37  
redcruz1120
CF Senior Member
Thread Starter
 
redcruz1120's Avatar
 
Member Since: Feb 2007
Location: Pearland Texas
Posts: 1,346
Thanked 88 Times in 69 Posts
St. Jude Donor '09
Default

Originally Posted by Bigeddie View Post
Well I bought the holley sniper and their efi tank. cannot wait to get it and also to read your full review!!!!cmon its been 6 days or so lol whats the update?

I want to apologize for the delay with the update. It hasn't been good so far. Tanks inc. Sent me a second pump that I installed last Friday. I finished the complete set up and the Sniper roared to life immediately!!!.....for like 10 minutes , then it died and lost all communication with ECU. after talking with Holley tech most of Friday afternoon which I must say they are very, Very helpful they recommended me take the complete unit back to where I purchased it and get another since it was a most likely a big issue. I took it back Saturday and installed the second unit yesterday and when I went to run the initial Wizard to establish communication with ECU there was no software to load. Talked to Holley Tech this morning and they are sending me another SD card with the right program to run the wizard. They said that will Fix the communication Issue. card should be here by end of week.. stand by I will update as soon as I get my card in. Hopefully it'' be Friday.

redcruz1120 is offline  
Old 02-06-2018, 03:05 PM
  #38  
redcruz1120
CF Senior Member
Thread Starter
 
redcruz1120's Avatar
 
Member Since: Feb 2007
Location: Pearland Texas
Posts: 1,346
Thanked 88 Times in 69 Posts
St. Jude Donor '09
Default

Originally Posted by dembo View Post
Hi Redcruz,

Glad I could be of some help with the pictures or idea for the FPR. I must say that this weekend I swapped out the C5 regulator with a 'regular' Holley one. It's still mounted at the tank using the same hard lines but with some fittings. So still no rubber from front to rear.
I don't know how the sniper will behave but for my application (read engine) +Teminator efi, 65-67psi from the C5 regulator is putting out was just too much for the engine and I was always running rich and couldn't tune it out. It drove ok but not wow. With the new regulator at 45 psi my engine is alot happier.

So take it into consideration before bolting everything back up as the tank is out to change the fuel pump. There are alot of people on the Holley forum running the C5 FPR without issues as well. My engine is the 330hp crate with vortec heads.

Nick
Thanks Dembo. That gives me something to look out for. If you get a chance can you get the part # for me just in case?.. Thanks!!
redcruz1120 is offline  
Old 02-06-2018, 03:09 PM
  #39  
rcread
CF Senior Member
 
rcread's Avatar
 
Member Since: Aug 2004
Location: Duvall, WA
Posts: 10,429
Thanked 70 Times in 62 Posts
Default

I got a Sniper EFI for Christmas, for my '72 LeMans and am debating whether to go with the Tanks fuel tank and pump or just go with Holley's tank and pump. What made you pick Tanks?
rcread is offline  
Old 02-06-2018, 03:14 PM
  #40  
redcruz1120
CF Senior Member
Thread Starter
 
redcruz1120's Avatar
 
Member Since: Feb 2007
Location: Pearland Texas
Posts: 1,346
Thanked 88 Times in 69 Posts
St. Jude Donor '09
Default

Thats right.! I stopped ny my local muffler shop and purchased a bung and had it welded in place. I drilled a 1" hole and it fit properly on the lip of the bung. Although I didnt try them, the clamps for the included O.Sensor plate seem too small to wrap around the sidepipe collector..

Originally Posted by wendellp601 View Post
That no-weld bung does not appear to have the correct radius for 4 inch side pipes.
This is what I used to cut the 1 inch hole

Last edited by redcruz1120; 02-07-2018 at 01:21 AM.
redcruz1120 is offline  
The Following User Says Thank You to redcruz1120 For This Useful Post:
wendellp601 (02-07-2018)

Thread Tools
Search this Thread
Quick Reply: 1974 From Carb to Finally Sniper EFI


Sponsored Ads
Vendor Directory

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2018 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: