Other than the toluene solution that I'm working on that will essentially free up horsepower by being able to raise the boost. The other method of improving horsepower is increasing the airflow of the cylinder heads. This low cost solution to this is buying camshafts. Camshafts are improved upon from their stock counterparts by raising the 'lift' and increasing the 'duration'.

Lift is raised by increasing the distance from the tip of the lobe to the camshaft centerline. This distance will ultimately cause the cylinder intake and/or exhaust valve to crack open and move a farther distance from its seat, potentially allowing more air into the cylinder easier (up to a certain point, that is). Duration, the icing of the cake, is really what sees the improvement. The duration represents the beginning of the flank of the lobe all the way to the tip and back. This represents when the intake and exhaust valves crack open and when they close. This duration is measured in degrees. Some of the popular durations are 264 degrees and 272 degrees; both of which are available for the 3000gt vr4. I've been trying to find some good hard evidence (dyno sheets particularly) of what kind of improvements I should see with each of those cams. Generally the more duration, the more power up top in the higher rpm band; but sometimes this isn't the case. I'm considering just going with the 264 intake and 264 exhaust, but I'm afraid I will have lost out on some decent horsepower if I don't go 272 intake 272 exhaust (which happens to be the same price, if minimal difference). If I find any real results in my research, I'll post up a follow up along with what I decide to go with and why.

HKS is a popular supplier of camshafts, alas, they have none for the 3000gt. I was a little bummed by this because people who use HKS cams generally see healthy horsepower gains. An example of this would be the supra guys, especially after they've switched to a high horsepower single turbo setup and follow up with camshafts. Funny enough, I did see some dyno sheets on HKS' site that would imply that 264 duration cams would do better than 272. The dyno sheet, however, is vague in the engine's setup, and seems a hair biased; but I could be wrong:

This represents a '2jz-gte' setup from a toyota supra.

So I'm not sure what to think. Alot of sources are saying that with 272 cams I'll also have to upgrade my valvetrain to handle it's aggressive lift and duration (titanium valve springs, retainers, and such), even if I don't plan on revving it higher than stock (7300 rpm), which I can't do anyways because I'm currently locked into the stock rev limiter.