Join Date: Jan 2004
Location: Winston Salem, NC
Re: Super Sniper EFI with Hyperspark install
I had the same thought process. I always wanted EFI some day but multi port was way too expensive and throttle body either didn't support boost or didn't support my HP level (about 750 at the crank). Then I heard about the Super Sniper 1250. It supports up to 1250 HP and boost. I loved my carb but the thing was dead rich at cruise. I basically had to set it up for the AFR I wanted at WOT and it stayed the same at cruise. I also wanted something that could adjust to the wild weather swings I experience. I am sure some will chime in and say "you could tune the carb". I don't disagree but it is not as easy as it sounds. What put me over the top was watching the Steve Morris video where he says if you buy from him he will sell you the tune for $99.
I ordered the system and the fun began. lol. I was a step ahead of the game because due to being boosted I already had an EFI capable fuel system. Sumped fuel tank, electric pump capable of high pressure, return style regulator, etc. All I had to do was get a high pressure spring for my regulator and I was good to go for the fuel system.
The thing I can't stress enough is the EFI systems are very particular to wiring and electro magnetic interference (EMI). In order to give myself the best chance of success and keep it as simple as possible I removed a perfectly good MSD box and went with the whole Hyperspark ignition system. That includes a CD box, coil and Hall affect distributor. The wiring is all plug and play. Technically you can use a mag distributor, but they are problematic for EMI.
Most of us hot rodders are scared to death of wiring...me included. But I took my time....it took weeks to get it installed. I spent a lot of time thinking about wire routing, etc. I spent 50% of the time just staring at the engine bay for the first day or two. Invest in some decent crimpers and wire strippers before you get started and follow the directions to the letter.
I did have one major hiccup. I got the system all installed and wired and the first time I turned the key I heard size, pop and an cloud of smoke rose from the engine bay. The unit had a skinned wire and a dead short in the factory harness. Not my fault at all....defective product. I sent it back to Holley and they replaced it right away.
Along the way I ran into some install bumps. The throttle lever ratio is different on the Sniper and all 4 blades moves at the same time. It is not progressive like a carb so the right foot experience is stiff and hard to control, especially with a stick. I read a lot and learned you should install a Demon Carb throttle lever extension to keep a good pedal feel. Once mine arrived I found out the factory throttle rod linkage on my Camaro would not work but I found a Mr. Gasket linkage bushing kit to remedy that. All of it had to be ground down a bit to fit and if anyone has the same issue I can get them part numbers and pictures.
So i got the new unit on, ran the startup wizard on the handheld then loaded the Steve Morris tune using the laptop. The thing fired on the first rotation...and it was about 30 degrees! I was so excited. After it got up to temp it would randomly stumble, almost shut off, then recover but the idle would race to 2,000 then fall back. Then, when I turned the key off....the car kept running! I had to disconnect the fuel pump relay to get it to shut off. I saved a data log and sure enough, EMI all over the place when it stumbled.
Hmmm.... i called Holley and they said to wire the trigger wires for the ECU, CD box and distributor to a relay with clean 12V power rather then connect it at the IGN spade on the fuse panel like their video shows. I did that....and it still wouldn't turn off until I disconnected the fuel pump relay.
I then called a buddy of mine and he immediately said "oh, you need to install the MSD diode if you have run on. I have to do that on all my cars". Well, I had an MSD on it before and never had run on. But I still had the diode that came with the kit so I gave it a try. Man, that was the huge breakthrough. The car immediately ran smoother, no stumbles and it turned off with the key!
The interesting thing is no one at Holley support seemed to know anything about the diodes but I am going to recommend it to anyone installing the Sniper. It sure cleaned mine up. No more EMI in the logs.
Sorry for the novel, but I hope it will help the next guy. I wish I had found some of this advice out there. Especially about the diode.
As I said, I am still very early on. To date I have just been garage tuning. The weather has been bad so no test drives and certainly no track time yet, but that will come soon.
69 Camaro, 3650lbs., 400ci, TH400, Coan 10" converter, 3.50 gear
D1SC, pump gas, street car, Water/Meth injection
1.302 60', 5.956 @ 116.4 Super Sniper EFI 2019