20 september 2008
Trådstartare
Tjo.
Läser lite på en sida om trimmning av denna motor. Kan någo förklara vad dom menar med detta och vad det är, fattar nada :S
The intake manifold and TVIS were designed to provide good low end torque and high top end flow using a dual runner per port setup with a set of butterfly valves kept closed at low RPMs to increase air velocity into the port and open at higher RPMs to increase flow capacity. The proper TVIS opening point lowers as VE improves (better exhaust, turbo, valves or cams). The ECU keeps a fixed opening point around 4200RPMs which is too high for modified engines. Consequently, there will be a torque dip from around 3800 RPMs to 4200 RPMs. The ECU also uses the TVIS to reduce engine VE if it has detected knock in the recent past. This can cause variations in performance for no apparent reason. The TVIS be kept functional as long as you continue to use the stock intake manifold but you should control the TVIS with an MSD RPM switch. You will need to purchase an MSD 8950 along with an appropriate RPM module, which is going to be included in wither the MSD 8743 (for even 100 RPMs) or MSD 87431 (for odd 100 RPMs) opening points. Alternatively, you can make your own fully adjustable RPM module. Most modified 3S-GTEs will need to open the TVIS between 3600 and 3900 RPMs. The only way to know for sure is to do a dyno pull to 4500RPMs with the TVIS open and another one with the TVIS closed keeping everything else the same. Then, the point at which the two torque curves cross is your best opening point.
