Sniper 2 EFI Swap Stroker

[El.Padrino]

Hey!

Considering swapping from carb to EFI on my BB stroker 68 B-body.

It's a 489 stroker with 10.5:1 CR, ported aluminum cylinder heads, hydr flat tappet in/ex 242/246 110 LSA, headers, 2.5" x-pipe, EDE Performer RPM intake, full MSD ignition (dist, coil, CD), electric fans, electric fuel pump. 727 trans and 3.54 gears.

The car has tons of power. Just want to overcome (cold) start issues and improve driveability. It is a street car only.

I am leaning towards the Sniper 2 or the Sniper Stealth 4150 (flows a bit more about 870cfm).

Holley claims their Sniper 2 EFI handles up to 650hp. Will this be sufficient for my engine combo? Unfortunately I do not have any numbers to the engine so far.
People report running this EFI with dyno numbers of 750+hp without any issues.


I would pretty much just need to change out the fuel pump and fuel pressure regulator and do the rotor phasing kit on my pro-billet distributor along with the MSD 6AL.

Anyone running their MSD ignition with the EFI for timing control?

 

[493 Mike]

Hey!

Considering swapping from carb to EFI on my BB stroker 68 B-body.

It's a 489 stroker with 10.5:1 CR, ported aluminum cylinder heads, hydr flat tappet in/ex 242/246 110 LSA, headers, 2.5" x-pipe, EDE Performer RPM intake, full MSD ignition (dist, coil, CD), electric fans, electric fuel pump. 727 trans and 3.54 gears.

The car has tons of power. Just want to overcome (cold) start issues and improve driveability. It is a street car only.

I am leaning towards the Sniper 2 not the Sniper Stealth 4150 bc of its price point.
Holley claims their Sniper 2 EFI handles up to 650hp. Will this be sufficient for my engine combo? Unfortunately I do not have any numbers to the engine so far.
People report running this EFI with dyno numbers of 750+hp without any issues.


I would pretty much just need to change out the fuel pump and fuel pressure regulator and do the rotor phasing kit on my pro-billet distributor along with the MSD 6AL.

Anyone running their MSD ignition with the EFI for timing control?

Yes. I am using FAST 2.0 EFI system.
Mike

 

[beanhead]

Without knowing exactly what your engine makes, it's hard to say if you'll hit the limit of the sniper but if it feels like you are, you can crank the fuel pressure up a little more as long as your fuel system's capable.
The MSD can be made to work but "if it was me" I wouldn't use it. Sell it and get the Hyperspark setup. It's a hall-effect distributor and designed for the Sniper. Having full control of the timing is one of the best things about EFI.

 

[El.Padrino]

Without knowing exactly what your engine makes, it's hard to say if you'll hit the limit of the sniper but if it feels like you are, you can crank the fuel pressure up a little more as long as your fuel system's capable.
The MSD can be made to work but "if it was me" I wouldn't use it. Sell it and get the Hyperspark setup. It's a hall-effect distributor and designed for the Sniper. Having full control of the timing is one of the best things about EFI.

Well, you mean I should rather step up to the Stealth 4500 or Super Sniper 1250?
The Sniper XFlow would be an option with 800hp? It just seems to be discontinued. Not available anywhere but Holley still lists it on their website.

I understand, the Hyperspark ignition would be most benefical. What features would I miss going with the phased billet distributor and 6AL?

 

[beanhead]

Well, you mean I should rather step up to the Stealth 4500 or Super Sniper 1250?
The Sniper XFlow would be an option with 800hp? It just seems to be discontinued. Not available anywhere but Holley still lists it on their website.

I understand, the Hyperspark ignition would be most benefical. What features would I miss going with the phased billet distributor and 6AL?

Judging by the combo you posted I'd say a 650 kit will be perfectly fine.
If you were able to upgrade to something a little better, I'd skip all the Sniper stuff and look at Terminator X...a little more involved installation, but a much better ECU and it can mounted in the cabin instead of on the engine.
As far as the MSD distributor, you'd be limited to a mechanical pre-set timing curve which isn't all that great with those units to begin with plus the Hyperspark uses a Hall-effect pickup that generates a digital signal to the ECU...more accurate and much less RFI/noise factor.
Being able to plot your timing curve at every RPM point (as well as adjust it from a laptop, without having to remove the distibutor and change parts every time) makes it a must-have for me, but you can always get it going with a standard distributor and upgrade later..

 

[gkent]

How often do you think you'll get close to using that full 650 hp ? Exactly ! In your case I would opt for the Sniper 2 as opposed to the Stealth simply because its newer with more bells and whistles. (it also supports 650 hp). The MSD dist can be made to work. The downside of the Holley Sniper distributors is they're so damn short and close to the valve cover that running the plug wires can be a PITA. Is the 5" display available with it yet ??

 

[El.Padrino]

How often do you think you'll get close to using that full 650 hp ? Exactly ! In your case I would opt for the Sniper 2 as opposed to the Stealth simply because its newer with more bells and whistles. (it also supports 650 hp). The MSD dist can be made to work. The downside of the Holley Sniper distributors is they're so damn short and close to the valve cover that running the plug wires can be a PITA. Is the 5" display available with it yet ??

Exactly.

What about the Stealth 4150 with its 870CFM rating vs the Sniper 2?
My fuel line routing with the Stealth would be exactly the same as now with the current carb.

 

[Jonas Nordstrom]

What carb is on there now?
If it is only cold starts and driveability you want to improve then an electronic choke and a carb with small primary venturis is one way to go.

 

[gkent]

Why are you so concerned about CFM ? The Sniper 2 supports 650 hp - that's all you need to know. You're never going to need it for the simple reason that - at risk of damaging your ego - you're not making anywhere close to that.