Holley Sniper Tuning 500hp 383 Stroker

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Tenhorse

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To help fuel in the idle areas, warm up the engine to 160 .. then I like to set the idle at 2500rpms then let it learn for a while.. then set it at 700. Let her learn...then 2400. Then 800. All the way to 1700 or whatever. Let it learn on each area. Give it 15 minutes. If it's still not close, give it 10 more. It takes time, but it will learn the idle and low rpm airflow characteristics and not die when you go for your first drive. My truck has a smaller cam so I can set the idle to as low as 400 and she'll lope along. You have to adjust the throttle for the iac to be 2-10%, but keep at her. It will learn what it needs, rather than guessing based on a generic table for "wild" cams. When you're done, set the idle where you want it on the touchscreen and adjust the idle screw so that the iac motor shows in the single digits.
Also, I'd be interested to know what your total timing is.. your tuner doesn't want you to hook up the vacuum advance? He's an idiot. Get a timing light and hold it to 3000rpms and see what your timing is. It should be in the mid 30s range. My head manufacturer recommended 36-38⁰. Your heads will vary. I've heard vortec heads like 36⁰. Your heads will vary but that will give you a general idea of where you're at. Typically more efficient chambers like less timing. . And less efficient chambers prefer more timing. LS motors are rare to see past 28⁰ or 29⁰.
Hook up your vacuum advance to full vacuum, not ported vacuum... it's any manifold vacuum in your intake manifold.. ported vacuum closes when idling and opens when your throttle opens. Just stay away from the vacuum ports on the actual throttle body and you won't mess it up.
My truck makes peak vacuum at 30 degrees of timing. It idles between 25 and 30kpa. If I get on the throttle, it shows load (increased kpa)... and the vacuum drops, lessening the spark advance. 16⁰ at idle seems awful low. You won't see a lot of vacuum with that big cam, but you should see some.. and you'll see a little spark advance from it. Vacuum advance is always good for drivability and mileage. Drag race guys are the only ones that don't hook it up. The only time you'll really advance timing with vacuum advance is when you're part throttle. Full throttle timing won't be affected so I don't know why your builder/tuner was against it.
 

L31MaxExpress

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What's the duration on that cam @ .050? 245+? A 383 cammed up to make 500hp/tq is probably going to need to idle around 1k. Maybe a little less but probably not going to see 750rpm. 500hp 383 is pretty stout

Mine idles 650 rpm with 19 in/hg vacuum. 26° of idle timing. Makes right at 500 hp and 500 tq. Cam is a 218/228 @ .050 with 0.578 lift. Heads flow nearly 300 cfm. It does have Rhoads V-Max lifters. 11:1 compression cranks at 210 psi.
 

Tenhorse

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Liberty heads. You said your builder blamed the intake coolant leak on the aluminum/iron? So you're running iron heads? Or an iron Weiand intake?
What type of lifter are you running? I can't find your cam specs in the lunati catalog. There is an HR LT1-LT4 voodoo cam that is 294/302 but none of their other stuff shows anything close. They recommend that cam for 2800-6800 and for serious bracket racers only. That cam shows 243/[email protected]". It might not idle at 750 with that much overlap and erratic air:fuel and map values jumping around at idle.
I like my idle at 850 so I can have a little better tip-in torque. I've got a way smaller cam. 252/264 advertised, 202/[email protected]". 113lsa. .550"/.546". I can roast the **** out of the tires off idle with my little 355.
You may have to set a small area in open loop around your idle area. You'll have to set it manually once you get a good fuel to keep her running. Leave a few hundred rpm area in your fuel table and a decent sized map area that covers your entire map at idle.. however much it jumps around at idle.. Set those areas to 0% learn and tune the fuel table manually.
 

Erik the Awful

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The Lunati catalog doesn't list a lot of camshafts that are available. That's another reason you want to call the cam company instead of just ordering from what Summit shows you. Lunati actually looked into Summit's inventory for me and recommended my cam, which didn't appear when I was surfing Summit's website.
 

Hipster

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Mine idles 650 rpm with 19 in/hg vacuum. 26° of idle timing. Makes right at 500 hp and 500 tq. Cam is a 218/228 @ .050 with 0.578 lift. Heads flow nearly 300 cfm. It does have Rhoads V-Max lifters. 11:1 compression cranks at 210 psi.
Cool, but he didn't say that's what he has. Hence why I asked.
 
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I dont know anything more about my cam than what i posted in the title post. I do know its a 2800-6000 cam, but im definitely having questions on the build. I dont know if i have any vacuum ports on my intake. I certainly didnt see any before i dressed the motor and dropped it in. I feel a little bit of buyers remorse creeping in. I wanted a bunch of HP and torque but 2800 and up kind of sucks for a 4x4 that is used as a 4x4. It absolutely screams at 3000 and up but in 5th gear at 65 it wont pull at all in 5th because it sits at such a low rpm. Id much rather sacrifice top end for low end. The secondary linkage has helped a lot with driveability. It doesnt want to rip my head off at stop lights now and 1st gear is much easier.

I did two Learns for about 15 miles each. One Learn of regular ol' driving, second Learn mostly normal driving with some WOT pulls mixed in. I drove 15 miles to a gas station. Applied learn table to base. Then 20 miles or so and applied the learn to base.


https://photos.app.goo.gl/RHbWH8PUgqjWVx6b7

The link is to an album of screen caps from the Config File within the EFI software. If anyone sees anything that stands out as wrong or odd, please let me know. I screwed the pooch and didn't datalog the drives. Hopefully I'll remember the next time I take it out.

If i do indeed have a vacuum port on my intake I will hook up the advance and see what she does.
 

LC2NLS6

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I have the hyperspark so the holley controls the timing, and playing with timing I for sure know it's a dog with low timing at low rpm - need timing down low to get torque. I bet once you get the vac advance hooked up and 15 deg more timing at vac, it'll feel much better at low throttle.
 
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Sorry ive been dealing with some crap. I had to pull the intake manifold and re gasket/seal it was leaking oil out the back and down the bell housing had me worried my rear main was fubar. Anyhow i dicked with the mechanical and vacuum advance for a good long while and never was satisfied and math is not my strong point so i said **** it and got the hyperspark setup. I just installed it yesterday and got it fired up. Seems to run worse so I figured i needed to adjust my tune some, specifically in the timing table and other spark/ignition options. Im now trying to figure out what a good table would be but im not sure what my limit is. I dont want to blow anything up. So im dealing with that now. I appreciate all yalls help and advice though. I will report back when i get this thing figured.
 

PlayingWithTBI

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Seems to run worse so I figured i needed to adjust my tune some, specifically in the timing table and other spark/ignition options. Im now trying to figure out what a good table would be but im not sure what my limit is
Here's a thread where 84Elky worked out a spreadsheet to help set up your SA table(s). He didn't design it for the hyperspark but, you should be able to modify it. The Excel spreadsheet is on the bottom of post #3. HTH
 

LC2NLS6

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With hyperspark, did you use the factory aligner? Sure the wires are on in the right order and they ohm out as good? There is a timing procedure, set it locked to 15* on the tuner, then use a light to verify it is also 15* mechanically, if the timing mark is right on the balancer that is.
 
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