I finally decided on my new FI setup, I'll be using the Holley Super Sniper system, but now I need to figure out if I go with the 650 or the 1250, the motor is a 5.9 Magnum (360 ci) with a small cam and intake upgrade, stock heads, should be about 310-320 hp NA, 3.90 gears with built A518 trans. I'm running 5 PSI of boost until I get some running and driving time on the engine to make sure I don't kill anything then I plan to up it to 10 PSI after I'm comfortable with the way everything is going with this setup. What do you guys think for the FI 650 or 1250?

 

320x1.68=537HP. In theory the 650 would be enough. How big of a deal is the $300+/- price difference? Will you want more later?

 

Go big, it'll give you options down the road.

 

What he said. The 650 will be marginal at best.

 

I know the 650 will do the job, but I may end up building up the motor a bit more, I'd like to go 408 stroker and aluminum heads when money allows, my main worry about going big is will it perform ok with the setup now, kind of like if you go to big on a carb the response goes in the toilet, I don't wanna run into that.

 

It'll be fine. Unlike the carb, you're not relying on air movement to draw fuel. The only real downside could possibly be idle quality, but modern fuel management, and injectors have really minimized if not eliminated that on 1200 hp worth of injector. The ability to run E85, or upgrade later would be the deciding factor for me.

 

Thanks for the help, think I'll be going with the 1250, so I can do some upgrades a little later, E85 isn't a real good option for me, there aren't a lot of stations around me that have it.

 

Pulled the trigger on the 1250 super sniper system, when my wife asked why I needed to spend the extra 400.00 for the larger system I told her for later upgrades, I got the best what do you mean other upgrades later look.

 

They always think that’s it!

 

Just tell her it’s so you can run cheaper fuel (e85) lol

 

I got the kit over the weekend, it looks pretty straight forward, I made sure to get the polished throttle body so I could get crap form her about buying my car jewelry. I still need to order a few odds and ends things but hopefully by the end of next week I have the car back on the road again. I also discovered an oil leak out of the turbo so now I need to figure out where its coming from and what I need to do to fix it.

 

i dont think any SNIPER unit works with E85 regardless
thats why i consider a terminator X universal on my BBC build , it gives more tunability , you can run a Hyperspark Dizzy or other ignitions and you can run e85 injectors.

if you do the math after buying a EFI Intake a 90 Elbow a 102mm LS style TB you are basically equal pricing as the 1250 Stealth .

 

Plenty of peeps with e85 running through snipers.
And there are a couple different larger injectors that can be swapped in.

 

Oh really i wasnt aware... with the the stock injectors??
you ll loose round about 30% of the advertised HP rating with E85, means a 650hp unit actually supports 450 ish' on e85 if im not mistaken

 

yup

 

I started looking into an E85 setup for it, but I'm going to stick to gas for the time being, I am using parts that are E85 compatible though in case I want to switch later. Its my understanding that E85 causes corrosion if left sitting for to long and that may be a problem as I don't always use the car, I try to take it out once a month at a minimum but I'm not sure thats enough to keep it from getting all chunky inside.

 

good approach , get the right fuel lines etc. otherwise not much different

 

e85 corrosion really depends on typical humidity level where you live. Peeps in florida struggle with letting stuff sit.
Also, carbs having a vent tube will get water absorbed in the bowl. Sniper is sealed.

 

I know the Sniper is sealed, but I do get a lot of humidity during the summer months, and that's when the car typically sits for longer periods of time because I'm not driving a car with no AC in 120 degree temps.

 

Finally got everything running, but I'm having a problem with the idle, it surges. I'm now trying to find out why and how to fix it, I know it has to do with the IAC so we'll see what happens, it was nice to hear her running again, its been a while.