Nitrous with Crower

system · July 19, 2004, 7:44pm

Does anyone know of this set up being done ?
Crower Cams, PR3 pistons, Zex Nitrous Kit

I thinking about getting the 404 or 403 cams but i dont know how well they will do with nitrous. Or if they can handle nitrous. Has anyone used the crower cams with nitrous ? Also would you recommend other cams instead ?

system · July 19, 2004, 8:03pm

im going to be using the rocket motorsports L21 regrind cams in my 2.0L ported head nitrous motor. they are a little bigger than 403’s. either of those cams should do fine with nitrous. remember, imports arent like domestics where you have to get the cam timing right the first time. you can adjust the cam gears to make the cams work better with nitrous, then adjust them back to regain your n/a power curve. try opening the exhaust valves sooner. that always helps.

system · July 20, 2004, 12:57am

Try crowers’ “high lift, low duration” cams. they are great. You wanna get all that nitrous in there fast (high lift) and get it combusted and out fast.(low duration) Hope that helps out. Also adjustable gears as stated.

Steve

Armed_Ferret · July 20, 2004, 2:00am

mid lift flow is more important than high-lift flow.

system · July 20, 2004, 2:04am

Why?

Armed_Ferret · July 20, 2004, 2:06am

i’m so glad you asked.

http://m24x.zeroforum.com/zerothread?id=147

rocket martin:

With the current preoccupation about big flow numbers like the magical 300CFM number on the BVTEC intake ports at say 0.500" lift at 28"H20 test pressure, I would like to give you some thoughts as to why low/mid lift flow is important.

Before flow at high lift occurs, you need flow at low to mid lifts. The more your flowing at low/mid lifts the more air will flow thru the ports at higher lifts when the car is running.

High lift flow occurs at “one” point where as low/mid lift occurs before and after high lift so its “twice” as important. (" " used as emphasis and not meant to be exact).

As your rpms increases there is less time for the air/fuel to react and move due to inertia, so having the flow earlier in cycle helps greatly. This is reasoning behind longer duration cams for higher rpm usage and that most NA cam phasing likes to be advance 2 - 6 degrees.

Also to this effect is scavenging from the header during vavle overlap. This is to pull on the intake charge earlier in the intake valve timing event.