zex perimeter plate 200hp pump fuel ?

[victtor]

HI have to say this site is awsome very good info,my question is i have zex perimeter plate which have been using last 18months on 100-150 hp with BP ultimate 98 pump fuel no problems just been on very soft stock tune as not the best plug reader in the world.
The settings is n74/f64 for the 200hp shot with 8 degress retard on my digi 6 do you guys see any proplems with this tune,,vic jnr mainfold, plugs are ngk vpower-8 ,motor is zz454 9.6 comp 230/236 @ 50 ,the jet formula zex uses is very intresting i notice nitrous works uses nos jet higher than fuel jets as well,but NOS allways has fuel jet higher than their nos jet can anyone exlpane the big diffrence in jetting sizes for same hp rating we talked about this for years ,i know nos sets theres up rich 4 slight safter factor but the it goes complete opposite, you would think zex kit would make motor run lean,but me and 4 off me mates run same kit no engine meltdowns thanks victtor ,new zealand http://www.zex.com/Base/Instructions/ZEX145.pdf

[victtor]

Woops for got to say fuel pressure i have set at 6psi flowing if click on link at bottom your will see what i mean about massive diffrence in jetting which should make kit run mega lean but never has on mine or any other zex kit my freinds use thanks

[John_Heard]

Many times the differences in jetting are due to other flow restrictions than the jets, for example the Nitrous solenoid may be approaching it's flow capacity or the plate may have flow restrictions, so they will bump up the jet size on that side. In most cases on a store bought kit using the solonoids that came with it, it's probably best to start at the mfg's sugguested tuneups then adjust from there. Only by flow testing the entire system on both the nitrous and fuel side will you be able to tell for sure what the capacity is on the kit.

[supernova]

I run a Zex plate on D/R tire (275-60-15 MT) 200 shot on a 525 ci bbc. My motor makes approx. 1000hp with a 200 shot. It works great but like you I wasn't sure about the jet set-up. I called the Zex people and asked. Heres what I was told.

The standered spray bar type plate has the nitrous going straight thru to the orifices in the bar so you see lower jet sizes. With the Zex plate the nitrous has to circulate around the body of the plate to be delivered. There for the bigger jet size. Plus it has more delivery orifices and needs more nitrous to help keep the pressure right. It's a great concept and works well.
I would stay with the Zex tunning for a while and learning everything about the system before tunning outside the box.

I have a buddy that has a new Speed-Tech plate I am going to try with the 200hp pills. Lets see which one works the better.