Spraying 2 Plates

[stroker1]

Having thoughts of adding another plate, if my Cheater doesn't do what I'm looking to do. Right now I have a 383 with 13.3:1 and Performer RPM heads, solid roller 256/268 .640"/.640" on 106 LSA, 4.56 gear w/28" tire, PG with no brake, Cheater kit on a 190ish?? shot 73N/71F @ 8.5 psi. (Still rich but getting better, pressure fluctuations don't bother it as much with more fuel pressure).

Going up to the Profiler 210 heads, nitrous cam, and 29.5 tire. I'm wondering how is the best way to add a plate for a smaller shot after I get it rolling? Do I need to run a 2" spacer and separate the plates for better distribution? Also, which plate do I need on top and bottom? IF my money was right I could just get a bigger plate shot and do a progressive.

[stroker1]

Uh, OK then. Well I know I'm not the only one who has done or thought about doing this. I searched thru some posts but didn't find much about this that was helpful. I wish it was a 4500 series, I would just turn them 90 degrees apart and stack them. But since I cant do that with 4150 stuff I thought do they need to be spaced apart? Also, would the larger shot be better on top or bottom?

I have a informant that sneaked a peak of a local grudge racer that is using 2 plates. He has a 4500 style intake with 4500 plate shot. Then an adapter spacer with a 4150 plate on top, beneath a 950HP carb. Seems to work OK, that's where I got the question do they need to be spaced apart. Oh, and mine is all 4150 stuff.

[John_Heard]

Never tried stacking plates myself, but I don't see a big difference between that and doublecross - except with 4150 style plates since you can't clock the 2nd plate sideways. Sounds to me like it might be a good time for you to upgrade the plate to a Big shot or something and add a progressive. If you try stacking two cheaters the bars will be above each other, might not be a problem? But that's not how 2 stage plates/double cross plates are typically designed.

[mytmouz]

I've stacked them both ways, but with the cross stack, I had to run a spacer between the plates and the carb to clear. If you just want to make one bigger stage, I would do like John said, and upgrade to a big shot. You just need a plate and a nitrous 'noid. The plates in line were fine at the time, but I didn't know any better back then. Since all of the 2 stage plates are cross bars, I'm sure there is a reason for it...

[stroker1]

Question1: What all do I need to upgrade to a Big Shot? A plate, a nitrous noid, and a fuel noid?


Question2: How far can I go with the cheater with square jetting? I'm pretty sure I could go maybe 210. But I don't think I should square jet a 250 shot for fear that one noid might be at max flow and the other not. I have 2 each of these sizes: 63,71,73,82,91,93,102 Right now I'm running a 73N/71F. What is the biggest size you would recomend to go squaring it up? I really like to run fuel pressure a little higher than recomended because it is not so sensitive to pressure change. So, with that I don't want to go to the NOS recomended jetting and drop my fuel pressure down for that.

[mytmouz]

On the upgrade, the fuel solenoid is the same for both the cheater and the big shot. You need the plate and the nos 'noid. I also prefer to feed the big shot from the bottle with 6an stuff...

[stroker1]

Oh,.....OK thanks mouse. So I don't have to worry about the fuel noid being big enough.

So does that mean I could probably try a square jetting on a 250 shot with the cheater plate before I go to the Big Shot?

[mytmouz]

I honestly don't know. I never tried to square jet a cheater that high. I was worried that the nos 'noid wouldn't carry enough and it would be way too fat...

[John_Heard]

There's some flow limits with the cheater, can't remember how high they can go but before you try that you need to flow test it first, or talk to someone that has. Mr. Watson aka Darth Watson has played with one of those in the past and found some limits, maybe he will chime in here.

[stroker1]

NOS recomends 93N/102F for the 250 shot. So I dunno, I thought maybe with the 102 jet it would be kinda rich. I was hoping to try 93N/93F. I guess I'll just have to try the recomendewd jetting and read plugs from there. Too bad though, I was kinda looking forward to using higher fuel pressure. Seems to like it, not as moody on the tune up.

[John_Heard]

For the most part the NOS tune ups need to be thrown out the window, typically they are pig fat. The deal is with that plate there are flow limitations when you start to reach it's max potential which means it won't flow what jets you put in it. The solonoid/s or the spray bar will start to become the restriction. That's why I sugguest waiting on figuring out your tune up until someone with some history with maxing that plate out can chime in. I know Craig found where the limits are, but don't recall what they were.

So stand by...

[Craig W.]

All my tune-ups on the Cheater plate were with a 2 jet spread. I ran a bunch of runs with a 73N/71F tune-up. 950 psi in the bottle and 6 psi on the fuel. This was not a ragged edge tune-up at all.

I didn't really find the limit of the Cheater plate as I couldn't get down the track under much more power. But I can tell you the nitrous solenoid will be the limit long before the fuel solenoid.

Also, just changing to the Big Shot plate was a big jump in power with the same nitrous jet. The tune-up changed to squared jets with 5.5 psi of fuel pressure.

As for the 2-stage plate, what I've played with is two "Y" fittings on each end of a Big Shot plate. Didn't seem to effect the power of the first stage at all and I was able to easily plumb in a small second shot. I brought it in using the timer wire on my 7531 box. I never got any good runs out of it as it broke the tires loose when the small 2nd hit came in every time I tried it. I'll play with that more one of these days.

On thing I have learned is to use the same size lines from the solenoids to the plate. At one time, I had a #4 on the fuel and a #3 on the nitrous and it really screwed with the tune-up until I figured out the NOS #3 line has about a .071 hole in it.

Hope this helps.

[stroker1]

Thanks Craig. That's some very useful information.