Cam's LSA effect on nitrous
 

does the LSA of a cam have a great affect on how it runs on nitrous. I have a 110lsa(227/233 @0.050) cam in my car I was recently told that if I sprayed it I wouldn't get very good results and that I needed a 112lsa or more for a sprayed motor.

A wider LSA with an otherwise same cam means less overlap which can help with supercharged or nitrous induced power BUT can come at the cost od some NA power. IMO go ahead and spray away just understand the cam is not optomized for spray though it definetely will work.

What you need for best results using a healty shot is earlier exhaust valve opening, to dump all that extra gas (can be a 50% or more increase). A longer exhaust duration (as much as 15 degrees), combined with a wide LCA and installed maybe 6 degrees advanced gives you this, at a modest loss of 'just motor' power. A good nitrous cam cam give you almost 300 HP from a "200 HP" calibration, with no increase in internal stresses (well except on the flywheel end of the crank...)

i know guys running 106 cams with a 300 shot of nitrous with no problems out of it at all. its a 69 camaro, but it runs like hell....but its mostly a track car and some street... i say spray away to the motors limits

This what I find funny. N20 does not make VE (volumetic efficency) exceed 100%, it increases it compared to N/A trim but doesnt over charge the cylinder to the point where it creates pounds of boost.

So in essence it shouldnt really matter if the LSA is 107 through 116 When the n20 is used. BUT in normal N/A form the LSA does have a great effect on how a motor runs. My buddy runs a decent cam with a 114 LSA in anticipation of a blower but for now he Lost alot of torque and his power band shift forward alot to the point of negating the better power band from 3,500 rpms and up.

The cam I will be running n/a on my 383 and with n2o its far different in the LSA catagory and I will anticipate when I run juice it will run great!

The main thing you need to worry about is compression, nitrous loves compression.

i spray a 100 shot on a 224 236 502 510 on a 108LSA...and i love it i have not seen any downfalls from it but i have alwys had this cam in my car with spray also for my car i knew i wound not be sprying 100 % of the tiem so why get a nitrious based cam..get a good N/A cam and then spray the hell outof it..and have fun... ....and my buddy sprays a 200shot on a 106LSA...just my .02

Yea, the only time I would get a nitrous specific grind cam is for a trailered car or a car that I would primairily race on the juice, becuase its designed for it and thats the purpous.

As I understand it, higher numeric LSA is better for larger shots.

Nitrous is pulled into the cylinder with the normal air/fuel mixture. At this point your have a given amount of nitrous being pulled in and for explanation sake lets say its a 300 shot. One cylinder would thus be recieving a 37.5 shot. When N20/fuel is pulled in for a short time the exhuast valve is also open (LSA). During this period some of the N20 will get pulled out. That 37 shot in the cylinder will have say 5-10% pulled out the exhaust.

With a small shot (say 150) a smaller amount would be pulled out of the cylinder than would a 300 shot at the same amount of overlap. The benefit of running a higher numerical LSA is that less N20 (much like boost) is pulled out when both valves are open.

Changing the LSA usually benefits larger shots, because more N20 is lost. A 150 shot at 110lsa may lose 5% (7.5 hp) to the LSA. A 300 shot at 110LSA would loose 5% but 15hp. Thus changing the LSA improves/lowers the amount lost. Boost suffers a similar but more prominent loss due to lower numeric LSA.

In general a higher LSA would be better for motors running large shots. A 300+ shot would generally perform better on a higher LSA than a lower. At the same time, you could always just pill up and make your desired power. If your 300 shot made 250whp...pill it up until it makes 300 at the wheels.

I'm not saying it hasn't, won't or can't be done with a lower LSA, just that higher LSAs keep more N20 in the cylinder (as I understand it). All of those numbers were just for explanation purposes and not specific to our motors.

Feel free to correct me if I'm mistaken.

The whole principal that guides motors who creates boost, i.e. turbo and supercharge motors require the over pressurization of the cylinder to create a dynamic compression ratio that makes the power. Hence compression makes power be it mechanical (static) or dynamic (blower/turbo)

Nitrous helps the combustion process, it makes it happen quicker, but doesnt overcharge the cylinder, hence VE does not exceed 100% like a turbo or blower motor would.

A higher LSA may make the difference of 10-15 peak horses but again for the street, what is practical, would having a set up that uses the juice like 10 percent of the time be better off 90% of the time with a nitrous friendly cam vs a nitrous specific cam.... thats really the decision that needs to be made.