ok so i have a 383 lt1 w/ heads, cam, intake, etc..see my signature. im running right around 12:1 compression. I am considering running like a 100-150 shot(wet) through it. I am told that it can be done and will see descent results w/ high compression, but the error margins are alot tighter. Im asking you guys if it would be safe to do this and if anyone else is running some spray through theyre high CR engine. I plan on having a shop that installs n20 systems frequently and is capable of dyno tuning install the system. I just dont want to see $4500 go down the drain on the first time i spray this engine, but i guess thats part of racing..

 

A friend of mine has a 385 LT1 with 12.5:1 and he sprays it 150.

 

12:1 isn't really that high of compression. How confident are you in the tune up? Make sure you have good gas, and start small, working your way up

 

So your saying run 100+ octane fuel..and start with like a 75 shot? Does anybody know what the best/most forgiving setup would be for a street/strip lt1?

 

Safest thing to do would be to just go with a stand alone fuel system, put 116 in the small cell, and you'll be fine. 1 degree for every 25 hp plus 1 for every 100, (so 5 for a 100 hit) to start... that should put it in a safe safe range (be able to put some back I'm sure, but better not to burn it down right off the bat)

150 hit on a 12 to 1 motor I wouldn't worry about. I was putting that to a 13.5 to 1 motor on my last build... and it loved it. Granted the motor was built for 350 hp worth, but still. The added compression is fine, it just makes good race fuel a must.

 

My biggest concern is how well build is the motor? You will need to make sure your tune is spot on but high compression and nitrous makes great power. Therfore your bottom end needs to be able to handle it.

 

bottom end is totally forged..it has a SCAT forged crank..idk how much it will take but i think i would be satisfied w/ a 100 shot. that would probably put it around 600 hp at the flywheel.

 

Dude take a look at the cars you see at the track. All the fast nitrous cars squeek like something is loos. That my friend is compression 15 to 1 or better. I know that is a different world but the same principles apply. Usually you would buy a kit and install it. Then you would make short pass's (say 1st gear only) checking a couple plugs after each pass. You would be looking for color or pits in the electrodes of the plugs to indicate a lean condition of and possibly overheating the electrodes causing pieces to literally blow off. And you would take things forward from there.

Now move forward 40 years. You have companys with years of nitrous experience you have a infinately tune able pcm. That pcm reads air fuel ratios it detects knocks it even does its best to compensate for bad conditions.

You still might want to check a plug or two from time to time but if you are gonna have this thing dyno tuned the guess work is almost eliminated. And with spot on kits these days that are on the market you can almost be guaranteed to be really close no matter what setup you are running. I've seen a tnt power ring with three different sets of jets straight out of the box pull the same 11.2 to 1 air fuel ratio on a cam'd ls1 with 100, 150, and 200 jets straight from the box. With a stock fuel pump btw. Ive also installed a NOS kit on a stock tpi corvette (which shares alot of similarities to a lt1) with 150 shot plate kit and the kit itself from NOS called for absolutely no change in timing. NONE!

Just remember if you are tuning your car right now when its hot out things will be different in the fall when its cooler and thats when you might want to start thinking about higher octane.

Hope I didn't bore anyone just some things to think about.