The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > Engine & Drivetrain > LSx Swaps

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 05-14-2018, 12:06 PM   #1
davepl
Registered User
 
davepl's Avatar
 
Join Date: Aug 2006
Location: Redmond, WA
Posts: 6,332
Holley Sniper Timing Control - Worth it on ZZ502?

I have a ZZ502 that I am putting a Holley Sniper EFI unit on. I'm wondering if the car would actually benefit much from ECM timing control. Right now I'm not planning on it, and will just continue with the mechanical distributor.

The cam in the ZZ502 is 224/234. In theory, the computer should be able to "smooth" the idle out by advancing/retarding individual spark pulses.

What I don't know is how well it does that and whether it's worth it on a motor with this cam.

Would I like it to idle smoother? Sure, I suppose I would. But I have no idea what kind of difference if any, it would make. Has anyone experimented with enabling/disabling computer control of the timing to see what difference it makes?
__________________
1970 GMC Sierra Grande Custom Camper - Built, not Bought
1969 Pontiac 2+2 427/390 4-speed Coupe
1969 Pontiac 2+2 427/390 4-speed Convertible
davepl is offline   Reply With Quote
Old 05-15-2018, 07:05 AM   #2
homemade87
Registered User
 
Join Date: Apr 2010
Location: Guntersville Alabama
Posts: 1,073
Re: Holley Sniper Timing Control - Worth it on ZZ502?

I have a msd controller 6010 on my carbed ls . It has the idle control but I do not know if anyone uses it . It always caused more problems ( surge ). Do not know if it is do to the larger cams in most of the motors this controller is used on . I have no problem controlling my idle .

I would have to say if only concerned with the idle control my vote would be no . I have no experience with the sniper . Just the msd . I do have plans for a Terminator stealth EFI in my future .
homemade87 is offline   Reply With Quote
Old 05-15-2018, 07:19 AM   #3
PGSigns
Senior Member
 
PGSigns's Avatar
 
Join Date: Jan 2011
Location: Hayes Va
Posts: 4,569
Re: Holley Sniper Timing Control - Worth it on ZZ502?

With a good distributor and good information on what timing the engine needs and when it can be a benefit. I ran my sniper at first with the program generated curve and it was horrible at best. Then sat down with my race engine builder and picked a curve we thought would work and rewrote the timing table. This takes a bit of time to do. Then after a bit of tweeking added vacuum timing to the table. That worked pretty good but with the ECU having brain issues we never got it fully worked out. You can not enable/disable the timing control as it takes a distributor change to go from one to the other. After 3 months of working with Holley on the problems and the thing shutting off in traffic running 60 and almost causing a big wreck I pulled it and sent it back. Carb is back on the truck.
Jimmy
__________________
60 to 66 Chevy and GMC window decals
http://67-72chevytrucks.com/vboard/s...d.php?t=661131
Good friends, good food and a hotrod what else do you need?
1966 BBW long fleet Daily driver
1965 BBW short fleet Sold and going to a good home
1965 Suburban
2003 3500 Duramax
2005 Ultra Classic
PGSigns is offline   Reply With Quote
Old 05-15-2018, 09:49 AM   #4
davepl
Registered User
 
davepl's Avatar
 
Join Date: Aug 2006
Location: Redmond, WA
Posts: 6,332
Re: Holley Sniper Timing Control - Worth it on ZZ502?

Sounds like I will stick with the distributor for now if it runs well enough. I've got an MSD dual sync that has the purple and green wires for the magnetic pickup but I don't know if I can make it work with the Holley or not.

For now, I'll run the mechanical distributor!

Too bad you can't go back and forth between timing trigger method. As you note, you can't. Also you'd blow up the Sniper, apparently, if you hooked up the coil sense line while running in CD mode.
__________________
1970 GMC Sierra Grande Custom Camper - Built, not Bought
1969 Pontiac 2+2 427/390 4-speed Coupe
1969 Pontiac 2+2 427/390 4-speed Convertible
davepl is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not 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

Forum Jump


All times are GMT -4. The time now is 01:53 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com