To answer your questions: It's big money to develop a camshaft for a specific engine design. I would suggest trying some of the more popular grinds and concentrate on cam timing to achieve your desired powerband. Whenever something is changed in an engine, cam timing should always be re-optimized for the intended purpose of the engine and gearing. Is it worth the effort? On street cars, I always subscribe to the old adage, "There's no replacement for displacement." However, I never discourage anybody from trying something different. Good luck.
The Right Combo
I have a '95 Mitsubishi Eclipse GSX that I plan to build for big power. I've seen 400-plus whp on stock block 4G63s running pump gas and was wondering what their recipe was for reliable power. I've heard that if you don't do it right that you'll get crank walk and blow your motor. I can't remember what I read, but it was something about having to mix and match engine parts from different generations. Does this make sense? What's the right way to go?--Sammy Jones, Providence, R.I.
Wow it's been years since I've worked on an Eclipse, but back in the day, to get 400 whp on a stock bottom end, we would bolt on a first-generation Eclipse head, intake manifold, and throttle body because of the significantly larger intake ports, larger plenum volume, and larger throttle plate. We would also send the throttle body out to RC Engineering to have them work their magic and stuff a larger throttle plate in there. With the right turbo, intercooler, 272 cams, and good tuning, 400 whp wasn't a problem.
Crank walk is generally a result of using too heavy of a clutch pressure plate and/or too tight of a thrust clearance. Single diaphragm clutches with 2,600 pounds of pressure tend to piss-off the thrust bearing and you end up with crank walk. I recommend you use a twin-plate clutch that uses surface area over pressure to keep your engine from crank walking. Remember, there's a 100 ways to skin a cat. This is the way I used to skin the cat for a 400 whp Eclipse.
Running Wild
I accidentally ran off the road in my '96 Prelude the other day and took out a couple of orange barrels. Afterwards, I took it to a shop and learned it was running rich. As long as I've owned the car, I've never had this problem and am wondering if it has anything to do with my little wreck, and if so, what could have been damaged to cause this problem. I also thought I smelled burning wires, and the alternator seems to be fried.--Vitukovawild, via importtuner.com forums
Chances are, if the problem came about after the wreck, the problems were caused by the wreck. Diagnosing the fuel system and electrical system is better left to a professional. Asking questions to a magazine will do nothing for you since I'm not psychic. Take it to the body shop and repair the body and then have a mechanic do the rest.
Legal Supra Power?
I'm in the middle of building a '94 Supra Turbo. I'll be swapping out the stock turbos for twin HKS GT2835s, adding all the goodies and plan to tune it with an HKS F-Con V-Pro and 1,000cc injectors. It sounds funny, but I still want to keep the car street legal. I want to retain a catalytic converter and have the car be able to pass emissions on pump gas and a low-boost setting. The problem for high-boost tuning is that all the necessary fuels are leaded which (I'm told) will ruin my cat. Is this true? Are there any high-octane, unleaded fuels available that I can tune with? And why are high-octane fuels leaded anyway?--Ediya Ree, San Jose, Calif.