For the guys still playing with the stock bottom but have a heads/cam setup; how much are you spraying? I heard that since you are already moving more air/fuel thru the engine with the heads/cam that a 150 shot would be more deadly than on a stock engine, obviously with a supporting fuel system. How often are you spraying and how many miles are on your bottom end?

I've talked to Lloyd Elliot about a LE2 heads/cam setup and he ball parks that combo with supporting mods in the ~400rwhp range. Add a 150 shot thats ~550rwhp thru an M6 which comes to ~600hp at the flywheel. Is that really pushing the limits on the stock bottom end, especially the pistons. Or is this pretty common?

 

Actually a 150 shot won't get you 150 to the ground. You will have to tune it on a dyno with the jets to get 150 rwhp.

On my old hot cammed ported heads I sprayed an ocassiona 150 shot without problems. I wouldn't be comftorable spraying any higher on a stock bottom end. I usually sprayed a 125 or a 100 shot.

ZMAN

 

Having seen this question asked a few times I can tell you that the general consensus is that 125-150 is about the safe limit.

Having said that, there are apparently several people running as much as 200.

However, people running that big a shot are being very careful to keep a close eye on how the engine is reacting and they have made the appropriate upgrades in terms of fuel pump, injectors and wiring harness.

 

So, even though more air/fuel is being moved before the nitrous, the added nitrous shouldn't be a problem with all the safety equipment and fuel system? Or since there is already upgraded heads/cam on the car nitrous should be bumped down to a 'safer' level 100-125?

 

there are many heads,cam,150 shot guys on stock shortblocks. if you have a great dyno tune, fuel system and are pulling enough timing things should last for a while. The rods in our motors are only rated to 450hp. Many people go way past this number and are fine. Some blow up motors with only n2o. I cannot tell you what will happen with your combo. Is it safe? no, but then again you could easily spin a bearing with the top end package alone. So there is not real answer to if it is going to blow or not. Could you afford a rebuild? if you can't maybe you should not even use the n2o at all. if you really want to do i,t dyno tune with the jets your going to use, get a scanmaster and always run race gas when spraying.

 

I ran the 200 shot on a stock shortblock for 2 years and the only problems I have are an insane number of oil leaks. I am not telling you to do what I did. I started like everyone else and had the 100,s in, then the 150's, then the 175's and finally went to the 200 n and 175 fuel jet. Stock fuel pump, zero timing pulled and 110,xxx miles and a stock 10 bolt. It can be done but I wouldn't risk a nice top end set-up. I had home ported heads and a baby nitrous cam.

 

with that setup your talking about it sounds like a tune would be everything. a good one and you could be ok and make some real power, a bad one or none at all and you'll be hitting the parts for sale board.