How VTEC Works
HCF Member
Joined: Jan 2006
Posts: 340
From:
Actually, i may have been wrong with the AEM EMS being able to adjust the vtec point, i think you have to do something to it but i can't find out what.
anyways, it wasn't the RSX, but the TSX that was tested on the December 2006 issue #93 of Import Tuner. they sent back the ecu to have hondata reflash it to change it to the best cam profiles where they shifted the vtec point to 4850 instead of 6000 rpms. with this change, the torque line truely was smooth and linear. during the vtec kick in, there was a gain of 38 hp and 34 lb-ft but they mention that the drawback is that the driver can no longer feel nor hear the vtec activate, disapointing many drivers.
anyways, it wasn't the RSX, but the TSX that was tested on the December 2006 issue #93 of Import Tuner. they sent back the ecu to have hondata reflash it to change it to the best cam profiles where they shifted the vtec point to 4850 instead of 6000 rpms. with this change, the torque line truely was smooth and linear. during the vtec kick in, there was a gain of 38 hp and 34 lb-ft but they mention that the drawback is that the driver can no longer feel nor hear the vtec activate, disapointing many drivers.
HCF Member
Joined: Mar 2009
Posts: 48
someone had asked about I-VTEC earlier. As far as i know I-VTEC is completely different from regular VTEC in d-b-h series engines. Its not 2 different cam lobe profiles for intake and exhaust but instead its just variable timing, intelligent variable timing.
upon boning up on my wikipedia i remembered i have an old issue of honda civic tuning that goes through, in detail for about 4 pages on vtec, i-vtec and a little on honda's latest they are still developing, a-vtec.
if i can find the issue i will photocopy it for you guys, its way worth the read.
upon boning up on my wikipedia i remembered i have an old issue of honda civic tuning that goes through, in detail for about 4 pages on vtec, i-vtec and a little on honda's latest they are still developing, a-vtec.
if i can find the issue i will photocopy it for you guys, its way worth the read.
Junior Member
Joined: Jul 2009
Posts: 6
From: Nokesville, Va
If you look at the dyno chart, VTEC kicks in at a "notch" where the torque made from the low cam equals the torque made from the high cam. If you set it to turn on earlier, you will lose torque, but if you let it kick in later, you will get a sudden bump of torque. Neither one is good, because that can really screw you over when accelerating in a turn. At the very least an improperly tuned VTEC will make for a rough transition in power between low cam and high cam.
The only reason to change VTEC is 1: It's not tuned right and it engages rough, 2: Your torque curve changed from some kind of strange performance mod and it engages rough.
The only reason to change VTEC is 1: It's not tuned right and it engages rough, 2: Your torque curve changed from some kind of strange performance mod and it engages rough.
Also another thing with vtec controllers is that when you set the vtec to kick in at a lower rpm you are losing fuel economy. If you want the best fuel economy then set it at a high rpm so that it doesnt kick in at all. but also as everyone else said if your vtec is not properly tuned then it can mess you up motor wise. an easy way around that would be to get a hondata ecu and a laptop so that you can change your fuel maps and all that on the fly.