93 K2500 Suburban 454 Holley Sniper Upgrade

[LC2NLS6]

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Holley Sniper EFI w/Hyperspark
Weiand 8122WND intake
1 inch Phenolic carb spacer
Comp Cams K11-302-4 212/218 .503/.503 on 112 FT Hyd
Hooker super comp long tubes (torch and hammer time I'm sure)

Plan is to wire the TPS and tach leads up and let the factory computer control the 4L80E.

Got everything (I think) except an adapter to plug the factory temp sensor into the 1/2 npt hole in the front of the manifold. I forget which of the temp sensors is gauge or ecm, just going to hook it all back up.

Other random parts, fuel line orings for those GM lines. I have GM 14 and 16 mm x 1.5 straight 6AN adapters to either 45 or 90's to bend to the Sniper inputs on the back(male 6AN). I also have a fuel rated schrader valve output on the inline 6AN for easy fuel pressure testing, got it from some obscure diesel shop online for my twin 350 vortec fuel injected boats years ago.

I'm going to trim the timing cover and silicone it back on since the engine is in the truck and I'm not dropping the oil pan just yet, because 4x4...

Currently new cam is in, no lifters in, and time to start swapping valve springs this weekend. Then the intake and front cover can go back on.

I think I'll break the cam in on the stock exhaust manifolds first. I have Comp Cams break in oil, and 6 zddp bottles for later oil changes.

I already upgraded the fuel pump to a later model vortec one that should be enough.

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[OutlawDrifter]

Sounds like you've got a plan. Typically the sensor for the temp gauge runs out of the head, and the ECU runs off the sensor in the intake manifold.

 

[Erik the Awful]

If you can get an O2 bung, I welded one into my header instead of using the stupid clamp-on piece they included. This system is really sensitive to exhaust leaks.

 

[LC2NLS6]

My long tubes have the 02 already setup from Hooker, they are supposed to just drop in, but I'm sure the blue wrench will be needed.

The tricky part is removing the old 02 sensor, its rusted in solid, might be original...again, torch and pb blaster. IF I want to break cam in on the manifolds, else the LT's will have to go in to run the wideband.

 

[bluex]

The O2 goes 6-10" after the header pipes merge. You won't get a good reading with it in the collector. If you're going to run converters it has to go before it also. The factory tbi location won't work well for a wide band sesnor.

Keep all your sniper wiring away from spark plug wires. If the must be close or pass each other try to keep them at a 90* angle. It's very sensitive to electrical noise when controlling timing.

Speaking of timing, an the afr table after you get it running you need switch over to the advanced tables to make it run the best it can. Contrary to the marking, it is not self learning for everything, just the base fuel table. The rest is up to you.


For some back ground on my suggestions, I'm holley teir 2 certified. I personally have 2 sniper systems, one with 15k miles on it in my 78 C10. The other in a 95 C1500 5 spd that I ditched the factory tbi in. I've installed an worked on many others at my shop. Most of the time the issues are from the install or an underlying problem that wasn't noticed with a carb.

Anyway my .02. read the manual, then go download the full tuning manual off the holley web site. Don't take short cuts, the manual says what it says for good reasons. I'll help if I can, there tech support is SWAMPED currently....

 

[bluex]

oh an put the sniper temp sensor in the head, it works better there for warm ups/cold starts in my experience.

If you can find/ borrow an hei for your cam break in that will be better as well. If you have issues with the hyperspark an getting it set correctly you could wipe the cam before you realize it.

Splicing into the tps harness is a bad idea. At the least buy a break out harness but I've seen missed results with those as well.

 

[LC2NLS6]

Thanks bluex!

I installed Holley HP EFI on my 87 TurboBuick 3 summers ago, I'm all about full tuning. Yes I understand power and ground direct to battery, follow instructions etc. TPS is only thing I'm up in the air about. My neighborhood is very hilly so I know I need to drop the learn % way down out of the gate and manually set my base out on flat ground.

I have the breakout TPS harness from Caspers. I was only going to connect the blue wire, not try to connect the 5v and grd as the sensor already has that. If that doesn't work I'll get the $200 remote TPS setup overnighted from summit along with a flat to small 3 pin adapter, ugh.

The hyperspark has the clear cap kit to set and forget on install. Since I'm doing the cam, I'll know its not 180 out and at tdc as close as the dots on the timing cover can be. I've watched all the sniper and hyperspark videos, seems like I should be able to handle that.

My headers are Hooker 2461HKR. The o2 is in the collector. I was going to run true duals. I doubt I'll get the stock o2 out to break cam in with the manifolds, removing that thing would put me in line for next King of England.

The factory heads have a temp sensor on each side, I'll just move the stock wiring to pull from manifold for trans control temp and dash gauge. I think both my heads have a temp sensor plus a manifold sensor.

 

[CrustyJunker]

Sub'd for fun. I've been curious to how the TBI 454 would respond to headers and that cam! They're not fast from the factory, but you sure can load them down.

 

[LC2NLS6]

Holdener did an episode kinda like that, made pretty good power, though he bumped the compression up, then said just get heads instead of new pistons for the effort.

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[bluex]

Sounds like you got it then man. I have my sniper rants preloaded because everyone always seems to be trash talking them lol.

They have high expectations an the system is capable but they lack the follow through because they think it should do it all for them from the self-learning marketing mumbo-jumbo.

I'll be watching maybe I'll learn a thing or two as well!