Anybody have any trouble running an RPM Air-Gap (Big Block) with a Nitrous plate system? I'd like to use the plate setup, but don't want to lose the Air Gap intake. I did a search, but no real answers to this question. Thanks guys.

I run an NOS 125 shot plate on a Big Block Edelbrock Perf. RPM intake. I have never had any problem, the spray comes out at a 45° angle and sprays right into each side of the plenum.

That's what I thought. Thanks alot, Bob.

NOS says not to spray over 150 in a dual plane. I have a brand new air-gap in a box and a Big Shot. The air-gap is going back for a single plane.
I was wondering about the ends of the spray bars, they are over the partly closed areas of the intake (the points between each primary and secondary). I was wondering about spraying down into this solid area. What about machining this area a little?

I have been looking into this a little and have not found an answer, but what happens if you DO spray over 150 hp shot with a dual plane, lets say 175 or 200 hp shot, what will happen? (if the motor, fuel & ign. system can handle the additional amount)

Will it just not make the additional horsepower or will it actually be harmful in some way to the motor? :confused:

My understanding of this is, that fuel and nitrous oxide flow differently in the intake, and because of the usual runner shape and length of dual plane intakes fuel could drop out and cause a lean condition. I am thinking about the same thing, I have a RPM Air Gap, which I would like to use but have a BigShot plate too. I think I will customize my intake a little to clean it up around the plenum divider where the thick areas are, and try incrementally go higher with nitrous, and just watch my plugs really close...I think the cut plenum divider of the AirGap helps a bit with distribution, but I dont know how much... I did run a 275 shot on a smallblock with a Performer and it worked OK, but I didn't care if I blow it up or not. This engine is different, more costly, will have to be careful this time, but there is a chance it could work. If not, I would go to direct port before I go to a Victor, for a street oriented car...

tommytt
Keep us posted on that, I have the same situation, air-gap, big shot and a motor I want to be careful with.
I haven't finished installing these together yet but was planning on giving up some streetability and going to a single plane so I wouldn't damage anything.
Anyone else spray a dual plane with more than 150?

I'm running a RPM AirGap and a NOS Super PowerShot.

I recently installed a billet aluminium 1/2" spacer under the NOS plate (to help with the distribution) and am going to experiment with the 175 hp jets. Hopefully I wont have any problems. ;)

I sprayed a 210 shot on a sbc with a RPM performer with no troubles. I did switch to a vic jr as i plan to spray 250 , but i have talked to several local guys that have sprayed a 225 on the dual plane and they said a 1" spacer made all the difference they needed. If i loose too much driveability with the single plane i'll put my dual plane back on and cut the divider a bout 1/2" and install a 1" spacer and try that.


As stated in an above post, good fuel, good ign and safe timing, go in small steps and read ALL 8 plugs. The spacer will help.


Hot rod had an article about 600 HP plate systems with suggestions from Musi, Sharoff, and many others and they all said the dual plane was good to 200 level.

i ran the 125 and 150 hp jets in my adjustable set up a few years back on my bbc's.........and was using the performer intake for a while......150 hp jets gave me a 2.3 second faster run......with about 13 mph on top end........on the super power shot systems the 175 hp jets dont really make much difference.....less then .10 e.t wise and traps speeds was hard to say if anything was being made extra.....this was with a single plane......the soleniods are pretty much at max flow with 150 jets....this is on the super power shot with the small soleniods.......i never did convert any of my nitrous plates to the bigger soleniods to really get the full effect of the 175 hp jets......

dual plane i didnt have any problems with 150 hp shot.........one thing thru the years running nitrous the engines respond a lot better to low rpm shift points....on the engines running 7000 rpm N/A...... with nitrous ran faster and more mph at a lower 5500- 6000 rpm shift point......


this might make one think about using a single plane if your motor really dont need it...... using a single plane just for nitrous is the wrong thinking......build the motor for best performance n/a......use the nitrous as the performance enhancer not as the performance maker.......if the engine runs best with say an rpm intake and shift points are good to 6300 rpms.....the nitrous will respond better to say 5500 rpm shifts......so why stick the single plane on there no need for it.....the way i see it if your going thru all the trouble to run nitrous and want more then 200 shot its best to fog it in direct port it.......i really think the engine should be as stout as it can be hp wise.....the nitrous just should be for kicks and not heavly relied on for the mass of the hp..........ok maybe im just rambling now.......jmo guys......

Have you checked out the ZEX kit. It spray out of the perimeter of the plate, no bars.

nitrous HP peak will always be 600-800 RPM lower than N/A.

ddeennis, I rely more on nitrous HP at the track to run a good ET, i prefer this because i can keep the motor very very tame for daily driving. I'll let you guys know what happens on my combo going from the dual plane to single plane.