I know all about the retarding for nitrous but my question is would it be safe to run about 10.5-11:1 compression on about a 150 shot of nitrous. I plan on gettin a 383 but want to build it for possilble nitrous. It has 4340 H-beam rods, and a 4340 no twist forged crank. I am probably gonna have to get forged pistons too I would guess. Thanks for any info.

 

You can get away with a 10.5:1 with a 150 shot on an aluminum headed motor on pump gas. If your running iron heads you my want to be a little more conservative. The amount of overlap your cam has will also effect the compression. If your running a cam with a lot of overlap,you can get by with a little more compression without detonation. Yes, go with forged pistons if you plan to spray 150 shot.

 

For a 150 shot, you could get away with decent forged pistons, stock rods and a scat or other aftermarket steel crank for a good combo. You don't have to have 4340 everything to spray. The only reason I went the 4340 route is because I plan on a 2 stage 400 shot. There are guys around here that are spraying 250 shots on stock cranks, with better rods and pistons with 2-bolt blocks. It all depends on the total car setup. They are running 116 gas though with a lot of timing pulled out, total timing is around 28 degrees or less.

Compression doesn't matter. With higher compression, you just have to run richer on the fuel, higher octane, pull more timing, or all of the above. You won't know what the motor wants until you read the plugs or get to a dyno.