Thoughts...Pros....Cons ? .................Something better ?

Been toying with the idea for a while (+5 years)

When I went LS, I had no FI stuff with the motor, but did already have the carb fuel system (electric pump and so on) so it was a no brainer since all I needed was an intake.

 

It depends on where you want to make power at.

Your post is lacking some important information.

 

What you need to know ?
2005 6.0L w/ LS3 heads and an aftermarket cam topped with a Vic Jr intake.
Street-strip car (more strip)
TH350 FMVB
5000 stall
4.10's
Right now has a 750 Mighty Demon...

 

Cool opportunity, Be able to compare the drivability and power with just the carb > EFI swap.
Which Sniper setup are you leaning towards?
Crosslflow sniper PART# 550-541 is 900CFM,,
Stealth PART# 550-842 looks like a old Dominator Carb..

Toys..

 

Was actually looking at Part# 550-511 ....but I really do like that X-flow.

 

I had a "professionally modded" Quick Fuel on my old big block Chevelle.
Setup by pro in Florida, then tweaked & tuned (by me) for cruise and WOT (Dragstrip) using a wideband.
Had fine tuned it for about 2 seasons...Drag Race Log Book FTW.
Car was a legitimate STREET car, with FUNCTIONAL A/C, a 439ci engine and weighed 4200#
Went best of 11.32@118 (4.10 gears), usually pulling the driver front tire, 11.50-11.60 with less rear gear (3.90), and 11.80's with 3.08's...lol

When the Fitech EFI/TBI first came out, there was literally ONE YouTube video, and most had never heard of the company...including me, LOL. I wanted the NEW HOLLEY SNIPER, but typical Holley...they kept pushing the release date back further and further...I guess there really is a "slow boat from China"...

With the Fitech...Took 10 MONTHS, of dicking around with it, just to get it to EQUAL the drivability AND dragstrip performance of my well tuned carb.

Sent it back 2 or 3 times, dealing with their incompetent "tech" people, and finally...FINALLY, HOLLEY came out with their SNIPER, which I immediately bought. Same as Doug posted, but in polished version, as that's all they had available the day they released them...

Literally swapped TBI units, and immediately the car sounded better.
Drove it from Middle River to Cecil County Dragway, (just to get some "fuel learning" done)
Raced a guy at the local dump road on the way home, and the next day took it to the track, and bettered my best ever carb ET and MPH

Holley had a video on YT showing how to use the Sniper's IGNITION function with an MSD distributor and ignition box...which I proved only worked CORRECTLY on an engine stand, and not in a REAL WORLD (on a car that is driven) scenario. They then oddly enough deleted the video, and reposted an updated version, recommending you buy their $450 distributor.

The throttle body and it's ECU worked GREAT controlling FUEL ONLY...
If you already have the ignition dialed in...LEAVE IT BE...

I was able to resell all of the no longer needed "carb" stuff, which made the update to EFI a no-brainer cost-wise.

Also, be aware...you will absolutely NEED either an EFI conversion fuel tank w/internal pump for your car, or a fuel cell with EFI pressured external pump. I only tried the Fitech originally, because they offered a low pressure to high pressure EFI "Fual Command Center", which was a surge tank that did NOT work...

I miss the old tank every once in a while...I can drive my TA like a Grandma and the big block Chevelle still got MUCH better gas mileage.


And, YES, I had a DUAL PLANE intake (Weiand Stealth), which all the Famous Videos say doesn't/can't/won't work with the TBI/EFI...

 

Just based on observing a lot of EFI upgraded cars, for street cars, in tanks fuel pumps are the way to go.
The external in line pumps just fail more often.. Usually seem to be heat related, with a cell if you
mount the pump supports to the cell cover its SOOO easy to swap pump check things etc..
Plus they are way less noisy.. The wine of an Aeromotive HP pump gets annoying if you drive it on the street a lot..

 

No doubt. Once I swapped in a TanksInc EFI tank, with intank pump, I never had another issue, ever...

 

Thanks Bob, great to hear this, exactly what I'm looking for, real world info.
Yes, I was going to go the whole EFI set-up too...$2000-ish. Don't really have that kind of $$$ to just throw away.

https://images.holley.com/12-300_0117339.jpg
https://www.holley.com/products/parts/19-501
https://www.holley.com/products/parts/550-540