Vtec Un-Control
I had an A'PEXi AFC Neo Fuel Computer installed on my S2000. The computer has a lot of functionality that the installer did nothing with, like VTEC controls. Can you provide some insight on how to best use the settings on this unit? I had the installer turn on the VTEC controller and set it at 4,500 rpm to kick in, but this just made the check engine light go on and little else. What settings did he miss that would make this feature usable and how can I get rid of the damned light?--Harleyvrod57, via importtuner.com forums
The AFC Neo is handy for quick analog adjustments, tweaks to the fuel curve and VTEC switchover points. However, fuel tuning and VTEC switchover points should be done on a dyno by a professional tuner. Why? Because a professional tuner knows what he's doing and if you're asking these questions, you don't. He has the expensive tools and equipment to help him safely make those adjustments. A dyno also helps to quantify the adjustments made to the fuel curve and VTEC switchover points. By setting the VTEC point too low without raising the engine's compression ratio, often times huge dips in the power curve will appear. On a stock compression car, you can drop the VTEC point several hundred rpm's as a rule of thumb and sometimes even more with cam timing changes (which should also be done on a dyno). As for the check engine light, your installer probably messed up on the VTin and VTout wires on the Neo. The Neo has a method of keeping the factory computer happy which will keep the check engine light off while the Neo controls the VTEC switchover point. Visit your local tuner and he can fix your problem.
STROKE JOB
I drive a '95 Civic coupe with a T3/T04E turbocharged B18C5 (USDM Integra Type-R) engine and five-speed LS transmission. I've always liked the high-revving, late power delivery of a highly boosted ITR engine (especially useful in FWD) but want to take it even further. Since the next step for my engine is a total build, I'm thinking about boring the block and having a custom crank machined to actually de-stroke the engine to a final displacement of around 1.6L. After that, I'd plate the deck and have custom rods machined to match to increase the rod ratio. The head would be fully rebuilt as well, to rev-friendly specs, but here are my questions: Will the decrease in stroke require custom-ground cams? And will the increase in deck height require them to be timed differently? Is the whole project worth the effort, or not at all?--FWDdragKiller68, via importtuner.com forums
Let me let you in on a little secret: It's called a B16A crank. You can probably find one on hondatech.com for $50 since most people are probably giving them away. You will need a custom long rod (143mm center to center) to match the deck height of the B18 block and the stroke of a B16 crank, but once you have everything dialed in you'll have an increased rod ratio (1.86). Of course custom pistons will have to be made to accommodate the shorter stroke to hit your target compression ratio. You'll end up with a 1.6L displacement since the B16 and B18 share the same bore (81mm). Keep in mind however, that higher rpm's mean exponentially higher wear on the engine parts including piston rings, piston skirts, etc. The shorter stroke will lower the piston speed, and the longer rod will reduce the side loading of the piston to the bore, but higher quality and lighter weight valve train parts will be needed to ensure valves don't drop or valve springs break.