Q&A: Matt Patrick, Zex Performance Products
CHP: What is Zex's main market?
Matt Patrick: We mostly sell to the modern-performance, late-model EFI guys. We've also got a whole new line of products for trucks. It's an emerging segment. If a guy doesn't want a used Camaro, a pickup truck is a convenient platform, and a Gen III-style truck motor can handle a lot of nitrous.
CHP: What kind of things do you look at when developing these kits?
MP: People tend to go for the thing that's engineered for their vehicle. When all cars had MAF systems, they ran 40 psi fuel pressure. That's not the case anymore, and GM uses 58 psi. If we don't adjust for that customer, they won't have an optimized tuneup. The OEM is also using crimped-together plastic lines, which has forced us to engineer more specific kits and adapters. We also size all our braided lines to the chassis, which is especially important on a late F-body.
CHP: What kind of power levels do you recommend?
MP: On average, most people run 100-125 hp. We think 125 hp is fairly safe on the stock long-block. When you push things to 150-175 hp, you've used up the safety margin and should consider better pistons, rods, etc.
CHP: What type of system do you sell more of, wet or dry?
MP: Eighty-five percent of what we sell is wet. The nice thing is that they supply their own source of fuel. They're very universal and bolt onto anything. And the charge takes care of itself. A dry kit is a simple install, with a different injector. We bleed off nitrous to trick the fuel regulator into thinking it has a stiffer spring. They don't fit newer cars that use returnless fuel systems, though.
CHP: Where else is Zex seeing action?
MP: Sales of our our perimeter-plate carb systems, which optimize distribution so you don't have lean cylinders, are through the roof. People want the latest in technology, but the great thing is seeing the performance gains.
CHP: What kind of problems do you commonly see?
MP: A number of customers aren't taking enough concern about timing. Our installation instructions say to retard the timing 2 degrees per 50 hp. But this is assuming the base timing has already been optimized without nitrous. You go as far as you can, then back off a few degrees. And it's best if you retard the timing only when the nitrous is engaged.
CHP: Anything else?
MP: Spark plugs-the gap needs to be closed 0.010-0.015, and the plugs need to be 1-2 step colder. But the biggest trend we see is too much timing.
Q&A: Steve Johnson, Induction Solutions
CHP: So, what does Induction Solutions do?
Steve Johnson: We are primarily into installing nitrous systems and plumbing intakes, and I blueprint and wet-flow the systems for proper calibration. I also provide a baseline tuneup and phone or racetrack support 24/7.
CHP: What do you do when you blueprint a system?
SJ: Whether it's a plate or direct-port system, the primary areas I focus on are the solenoids, nozzles, and jets, the three most important parts of the system.
CHP: Is that really necessary?
SJ: Even though things are brand-new, everyone's human; even a CNC machine can have programming errors or worn tooling. Solenoids are just like anything else; there's a tolerance, so I go through each one, measure the orifices, and correct them if necessary. With jets, I make sure each is properly marked, and check the orifice and consistency of machining. I don't take it for granted that everything's done right. When I'm trying to tune an engine, I want consistency.
Maintain proper nitrous and fuel pressure levels for optimum performance-and also to make sure air/fuel ratios stay in the safety zone. NOS' Racer's Nitrous and Fuel Pressure Gauge kits come with Schrader valve fittings, which can be plumbed into your system to facilitate quick and accurate pressure checks.