Got Sniper Running. Need Help with Parameters

[jayfire]

Thanks for everyone’s help in getting my Sniper wired up on my 426 hemi with 6-71 supercharger. Now, here’s where I spout some dumb questions. With this setup, what should I set as my initial timing, cruise timing and WOT timing? Digging out my timing light now. What about my AFR at 0 boost? How much should it offset per 7 lbs of boost? Trying to get me to a good starting point and learn what each one means in relation to how the car is performing. Thanks

 

[rmchrgr]

Have you considered getting a tune from somewhere? A blown hemi is an expensive piece of equipment to be guessing about.

That said, what would your timing curve look like if you didn't have a Sniper? EFI does not change basic parameters just cause it's software driven, still have to be an active participant.

What's the rest of the setup? Did you get the Hyperspark ignition and distributor so you can control timing?

 

[69 GeeTeeX]

For your application I’d suggest contacting Richard.

https://www.fastmanefi.com/about

Get the USB cable from summit to connect a laptop computer to your sniper system and Richard will do a remote connection to your computer and teach you / tune your system. It’s well worth the small fee he charges and teaches you how to do it at the same time.

 

[jayfire]

Have you considered getting a tune from somewhere? A blown hemi is an expensive piece of equipment to be guessing about.

That said, what would your timing curve look like if you didn't have a Sniper? EFI does not change basic parameters just cause it's software driven, still have to be an active participant.

What's the rest of the setup? Did you get the Hyperspark ignition and distributor so you can control timing?

Yes, Hyperspark distributor and ignition box. I have no idea about the timing curve. I haven’t had the car long, and the previous owner only put 30 miles on this setup (minus the EFI) in 31 years! I was hoping someone had a similar setup that I could snag some info from. I just don’t know where to start. Obviously, I got it started on 15 degrees initial timing or close to it. I’m trying to understand AFR as well.

 

[jayfire]

For your application I’d suggest contacting Richard.

https://www.fastmanefi.com/about

Get the USB cable from summit to connect a laptop computer to your sniper system and Richard will do a remote connection to your computer and teach you / tune your system. It’s well worth the small fee he charges and teaches you how to do it at the same time.

Thanks, I will do that. The Sniper came with that cable, so I’m that much closer.

 

[Wietse]

I've got no experience with a supercharger attached on it, though i setup the stealth sniper on my 440.
With regards to the AFR, i found that you just have to find the sweet spot for a nice idle.
At idle, in a perfect world would be running at 14.7, though i found that setting it a little rich helps the idle quality.
My engine has quite poor vacuum at idle so it needs some extra vitamins to keep it going round smooth.
I played with it and found i got the most decent idle with 13.8, any richer did not help and going leaner it starts to run poor and wants to stall.
At cruising speeds i have it at 14.4, here the same, if i go leaner it will stumble when accelerating.
I even played with the "pump shot" to give it a bit more but did not work out. (whats it called in the settings? accelerator fueling or so)
Going WOT i think it would be same, supercharger or not, at a 12.8-13.0 but some others will know more about that.

 

[diesel_lv]

I run 12.5:1 AFR WOT on naturally aspirated engine. On my turbo engine, I run 11.5:1. Most pushrod engines take about 1° of timing out per lb of boost after they hit 2 lbs. Only real way to tell is spend the money. You have a blown 426 hemi, if you can afford that, you can afford to get it on a dyno and tuned properly.