Max SAFE shot??

[GEARS]

I have a broken-in HT3.4 crate motor with the iron heads, along with a 400 cfm Holley TBI, Edelbrock TES, ported manifold, MSD coil... and I just ordered a NOS TBI kit for it, along wih a MSD timing controller, and I was wondering what you guys think the max SAFE shot is on these motors??

I was going to go a 50 shot to start, and would like to end up at a 75 shot. Will it take a 75 safely?? Compression ratio is 9:1, with the crate motor cast crank, rods, and slugs.

I will be retarding as necessary and will gap the plugs down to 40" from the recommended 45".

Thanks guys!!

[pocket-rocket]

I remember reading some time ago the safe norm on a stock engine is something like 30% of your already max power. So if you had 200hp, 60 would be considered safe, or along those lines. I've also read that a 75 shot should be safe on my engine, but mine produced 200-210 from the factory, so be cautious with a 75 shot on yours as I have no idea what yours produced from the factory.

[timg]

Remember, there really isn't a safe shot. Improper fueling/timing can blow a motor even on a small shot. Starting at 50 and moving to 75 sounds like a reasonable plan.

Tim

[payback]

Don't know a whole lot about nitrous but I would have to say it's really a question of WHERE you want the hit too. I would never spray my motor down low...then again I have a 4t60e lol.

[GEARS]

I would only use it at abouve 3200 rpm at WOT... and would use a RPM/TPS window switch to do that for me.

[3400-95-Modified]

I sprayed a jetted 100 shot for a few years on my stock 3400... I had issues with Fel Pro headgaskets though, but nothing else broke. Also I should note I always sprayed that with the bottle at ambient temp so around 600 PSI, so I think it was equivalent to around a 60 shot since thats what I dynoed the change at. Stock run was 144 and the spray put it up to 206.

I'm now running a 100 shot with the proper bottle pressure 950-1050psi and the engine still has all stock lower end internals, and is probably around 9.15:1 CR and so far has survived 4 runs at the strip spraying that. I keep it quite rich though to prevent knock so I'm sure that helps some.

I may tune it back to the 75 shot this year since it will be my first with the bottle warmer and pressure gauge to get the bottle to 950... once I feel comfortable with that and don't notice any tune issues I'll probably put the 100 jets back in.