To answer this question, you need to think about what you are going to need your car to do.
While the cam itself might not be very expensive, the install is very labor intensive, so please choose your cam carefully so that you don’t regret your choice later.
The VS cam is currently the most aggressive cam on the market that behaves similar to your factory cam. It does not set SES codes or require any valve train changes, it also does not require any special PCM programming, and it will not significantly reduce the life of any of the engine components. Gas mileage is close to stock. With very little overlap, the VS cam puts down massive torque numbers which make it an excellent choice for cars with a stock torque converter or stock gearing. We were able to get 342 WHP and run 11.79 with the VS cam in our 97 GTP. Digital Ken hit 400WHP with the VS cam on his CSC’d 97 GTP. Most people dyno 300WHP with the VS cam and intercooler before tuning with stock timing. With tuning, people are reporting back averages of 320-330WHP. Peak power is 5800-6100. Most people run a 3.2″ pulley non-intercooled. 3.1 and 3.0 are possible with other mods such as P&P heads and/or headers. ZZP intercooler users can run 2.6″ pulleys. Pulley sizes listed are for 93 octane without KR.
To move up in cam size means that a few things are now changing with the way your car needs to be setup. Longer duration than the VS cam means that gas mileage is now going to drop, and idle will have some lope to it. If you are running stock heads you will want new springs and retainers (stock springs and retainers are only good for ~.515 lift or so). It will set the P0300 misfire code if not programmed out of the PCM. The XP cam is what we recommend to our customers who feel the VS cam is a little too small for their goals. Users who do not plan on running an intercooler but want to run small pulleys might want to run the XP because of its KR reducing capabilities. Torque numbers are very high, in fact peak torque is higher than the VS, but low end (below 3k) will be reduced from the VS cam. Cars running the XP cam can expect around 10HP more than the VS. With a cam like this, you will want a DHP PCM or a custom. Raised shift points will help to see gains over a smaller cam. 3.1″ pulley with no KR is average on 93 octane. 3.0” pulley is possible with other mods such as P&P heads and/or headers. ZZP intercooler users can run 2.6″ pulley with raised timing on 93 octane. The XP can be used with stock or 3000 stall torque converter. Users with 2.92, 3.29 and 3.69 gears have had good luck with track times.
The XPZ cam moves up in size from the XP. To run the XPZ you will need 130# valve springs, which means a double roller timing chain. You will need P&P heads with clearance enough to run .570 lift. The XPZ idle and behavior is very close to the XP. Custom PCM programming is required for P0300 code, raised shift points, and raised idle speed. With the HP levels over 350 or rpms over 6400 the stock converter can balloon and fail. We recommend an after-market converter with a stall speed around 3000. 3.29 and 3.69 gears are also recommended with single chain conversion. The stock chains will not hold the power that your car will be putting down for more than 1 racing season. 2.9-3.0 pulleys can be used with 93 octane non-intercooled. 2.5″ pulleys with raised compression and/or raised timing can be used on ZZP intercooled applications. Currently we are running the XPZ in our 500HP, M90 powered GTP. If you’re looking to get to levels of 400WHP without changing power adders, the XPZ is the only cam available to help you meet those goals.
The NIC cam has more duration than any cam we offer. The lift is low so it can be used with stock heads. We recommend springs and retainers for RPMs over 6200. With long duration and lots of overlap the cam performs very well without the use of an intercooler. Unfortunately this makes the cam very hard to tune and a wideband O2 sensor is recommended for fuel tuning. The NIC cam can be used with an intercooler but the potential for performance is not as high as the XP or XPZ. The overlap of a large cam doesn’t maximize the use of the intake air for HP. While peak HP is good, the low and mid- range suffers from the use of high duration lobes. It will see gains, and perform well with an intercooler but we recommend the XP or XPZ if you plan on intercooling.
Some things to keep in mind when selecting a cam:
- The larger your cam, the worse your gas mileage and street-ability will be.
- Your car will be harder to start, especially in colder climates
- At idle the car will smell like unburned fuel, and tuning in the car will require a dyno with a wide band O2 sensor.
- You’re Ltrims in Atap will be off and you will have to retune your WOT O2 values.
- A mini-AFC, Tuner, or ICCU might be needed for fuel adjustment
- In applications requiring stiffer springs, valve train life will be reduced. Remember the stiffer the springs you install, the harder your valves will be smacking the heads, and the less life you will get out of your valve seats. Stiffer springs and higher lifts wear the dampener out quickly. Your timing chain will stretch a lot sooner, and the chain tensioner will have to be replaced more frequently.
Please Email if you have any further questions on which cam might be best for you.