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Posted by Nismo87SE (91 se-r) on August 23, 2002 at 16:10:54:
In Reply to: Taking Maxima tuning to the next step. posted by Matt on August 23, 2002 at 14:00:00:
That isn't entirely true. Anyone can go out and buy a stand alone, however for just bolt ons why even bother? : So, I got to thinking about what has the potential to be the best “bang for the buck” upgrade that can act as a stepping stone to the more serious modifications. It seems to be that real engine management has the potential to make the most out of our current mods, and paves the way for future “big power” modifications such as forced induction. This is true, however JWT has been tuning nissan engines for the last 20+ years. At some point the engine is going to hit the *wall* with bolt on mods on a stock engine. Also it isn't for the timid too. : The benefits are pretty obvious, in the current issue of SCC they gain ~9hp and a smoother torque curve on their mildly modded project Civic by engine tuning through a HondaData ecu upgrade. I've seen a maxima gain 8hp/9tq from a JWT ECU also. The “big 3” WRX aftermarket tuners base their staged upgrades around the Unichip piggy-back ECU. This device is inserted inline between the engine sensors and the factory ECU and modifies the sensor readings in order to fool the factory ECU into changing the timing or fuel settings. In the Vishnu Stage 0 kit (http://www.vishnuperformance.com) the Unichip is responsible for roughly half of the 40 whp gains while retaining all factory emissions control, cold start operation, and knock prevention ability. Well I'm sure the SGP stage chart for the Z32TT is very simular to this ;). Stage I is intake, stage II is intake + exhaust or I/E, stage III is I/E + ECU. : Now we enter theoretical land, and I’m not saying I’m going to do this, I’m just spitting out some ideas. : Most of us have Maximas with mild modifications, but we are not using them to their full potential. I’d be really interested to see the gains a properly dyno-tuned Unichip system would give on a 3rd Generation Maxima, I’m guessing it would be pretty significant. Based on SCC’s improvement of +9hp for a ~150 whp car, we could reasonably expect similar or greater gains on our more powerful engines. Yes it would be good for the 3rd gen but how much does it cost for dyno tuning? I know the ECU itself is like $400-600 and usually its installed + dynoed for $900-1300. That is kinda pricey,where as one can buy a $600 ECU and spend $45-70 on dyno pulls before and after. : What gets really interesting is the turning potential of the VE engine. With the VTC system (when it decides to work) and the dual-length intake manifold (5spd only) the VE30DE has two other parameters that can be optimized for power. It would be a matter of simply wiring the Unichip to control the VTC and manifold vacuum line and then doing dyno pulls to get readings with and without the VTC and with the short and long intake runners. Using the resulting 4 curves you could determine the optimal switch over points and program them into the Unichip. I believe Matt93se tried messing with the IM power valve. No matter when it was opened it lost power vs what it is set for from the factory. As for the VTC, a simple rpm switch could adjust when they decrease the overlap. : For those who are going to install forced induction (cause the VG30DETT is a direct transplant right?) they are going to require some kind of engine management, and this might be a good choice. I know several of you are working on turbo projects, and must be looking at engine management solutions. That is true however I have confidence in JWT's tuning, to date there havn't been many if any blown motors due to JWT specifically tuning. True they would make a conservative program but it would be reliable and have room to expand. For example anyone with a VE or VG could call JWT and say they want a custom turbo program with 4 bar fuel pressure and 370cc or bigger injectors. Once the car is on the dyno then one can bump the timing or trim the fuel curve. Especially with turbo cars you can find the limit of power that can be made on pump gas and race gas. : So, there’s my 2 cents for this morning, I’d be interested in hearing other people’s opinions on the subject. Who knows, perhaps somebody has the time and money to look into this. The y-pipe was an enthusiast created upgrade that was eventually picked up by the big tuners, perhaps this could be one too (if this happens, you can send to royalties to me). : - Matt No problem man, its all good BTW how is the WRX treatin' ya? P.S. That VG30DETT swap thing would have gotten you flammed if you were a newbie, but since your from the old school you get a :p.
We all know the Maxima community is relatively small and therefore doesn’t garner much aftermarket attention. You can purchase all of the “basic” bolt-ons, intake, exhaust components, clutches, and ecu chips, but the more serious upgrades like forced induction, headers, cams, and real engine management are commercially non-existent.