New 4150 style Sniper EFI

Got the new 4150 style Holley Sniper EFI setup today. Looks pretty good. It has a standard throttle linkage and dual fuel inlet so it should fit a lot of applications without mods.

cool, i like the radiused entry better than the design before. They even put in the float adjusting screws....looks nice. Anything else different to the existing sniper 650?

Michael

How does the "carb style" effect the cost? IMO this is the way they should have come to market with the sniper. It looks really good which is hurdle that lots of people couldn't overcome about the throttle body systems.

HP capabilities?

Agreed! I would have preferred mine to look like a 4150 instead of a weird, anodized Thermoquad pancake looking thing!

Holley says 870 CFM; 650 HP NA with 4 100# injectors.

It would be interesting if they come out with a bigger 4150 Stealth model. I like this style better than the original Sniper design, although I don't know if they're functionally equivalent.

Is that a 1-to-1 linkage, or progressive?

I would expect that they'll release a version with the 120 lb/hr injectors which is what you would need for your engine. I don't have any inside info but it just makes sense for them to do that. The linkage is 1:1 out of the box. It can be changed over to progressive but then the unit has to be reprogrammed. I run mine in 1:1 mode. I tried progressive but decided to go back to 1:1 linkage.

Do most of these bolt on FI units still have issues with large cams that produce low vacuum?

Just depends on how low the vacuum is. If vacuum at idle is really low then you have to run open loop at idle and go closed loop at 1500 or 2000 rpm. The Sniper doesn't have any problem handling race cams or even open headers but you have to adjust the tune. The out of the box tune won't work. If you know what you're doing it only takes a few minutes to dial in the tune. If you don't know what you're doing then it could take much longer.

I'm trying to imagine driving on the street, staging, and launching off a foot-brake using a 1-to-1 linkage...

I'd be in the second category. LOL

I used to convert all my carbs to 1:1 linkage. The one I'm using now isn't, but it's just a linkage adjustment.

And soon, it will be 1:1 as well, I just need to do some other stuff first.

They now have HOLLEY SUPER SNIPER STEALTH 4150 - 1250HP one on there site.

I recently programmed a tune for my friends Charger with the non-stealth style of Sniper on a 446 with a 6 speed.

The one-to-one linkage was a non-issue driving the car around in traffic with his combo.

Not for naturally aspirated; that's still limited to a claimed 650 HP. Probably sometime, though.

This is NA 4150 800 hp

Yeah the 1:1 ratio setup works fine in my car too. Maybe a tiny bit too sensitive right off idle but that is it. Holley does sell a longer throttle arm which slows down the speed of the throttle opening so that can be tried. I like the 1:1 setup in terms of how the mixture gets pointed into the intake. I've had trouble with the progressive linkage on a Sniper with the mixture being pushed to the front of the intake at part throttle.

I do not have any experience with the 1:1 linkage and a two step. I'm sure people are doing it but I haven't talked to anyone who runs that setup.