Posted: 02/28/11 11:41 AM
New to this site and I,m looking for any clues or info about resolving an issue in tuning a j-series with a high scavenge exhaust and 80mm throttle body. The setup actually works well but I can see some more potential in it. Of course the car has problems related to the fact that it needs finishing work like powdercoat and a cleaner oil pan. The pan leaks so v-tec fails when the level is too low which has reveiled some questions about tuning on and off v-tec through the high rpm range.
Naturally when the v-tec works it delivers as expected and when not it cuts out anywhere from 4200 to 5800 depending on ambient air temp but in the rain and no v-tec the engine will slam the 7200 rev limit begging for more of course when the v-tec works there are no problems in any conditions but it does not so much slam the rev limit on dry days with v-tec on. There are signs that the cylinder pressure is high similar to a boost issue in light of the rain performance. I don't think water injection is a practical solution and my tuning software is not dynamic enough to accurately adjust timing for humidity plus air and engine temp. So I've considered an intercooler (remember it's n/a) but the whole thing is a squeeze for my car and I probably couldn't fit an effective cooler in there anyway. Any suggestions or insights would be greatly appreciated also if anyone has observed any other idiosycrosis with high induction n/a engines feel free to mention them as there may be clues there as well. I'm don't want to pour fuel on it just to cool the charge either.