subaru wrx test drive/data logging

[randy 77zt]

kid next door gets a slightly used 2005 wrx.since these seem to be latest fad car to have of course he wants it faster.being normal for his age of course he has a laptop+obd2 cable.he had a program called enginuity on his laptop so we go for a spin in the country.we dialed up the the sensors i wanted to see-map sensor,rpms,injector duty cycle,ignition timing,speed,intake air temp,air fuel ratio.i drove-pulled onto the road easy-short shifted to 2nd at about 15mph and ran it at wot 2nd,3rd,4th.some interesting info gathered compared to tuning on my megasquirt turbo z.air fuel ratio stayed at 11.25 to 1.timing stayed at 13-14 btdc.boost maxed at 12-13 psi.injector duty cycle hit 92%.this tells me the engine is tuned to live a long time-unless some kid tries to screw it up with too much boost or timing.it wont take much more hp with out bigger injectors.when the cold air intake and complete exhaust system go on i will have to see if the a/f goes slightly leaner.i sent the boy home with homework-i told him to check some of the tuners like cobb to see what they do with a/f and igntion timing-as in get me the maps open so i could see them.meanwhile i need to take some timing out of the z-with 2960 stroker at 8.2-1 it likes race gas.at 10 psi i have about 26 btdc-it might have to goto 20 or 22 btdc.

[Pete84]

Where does the turbo on those cars loose efficiency?

[Mikelly]

Guy inhe track day video link I posted below in the blue WRX STi is running about 460BHP in that WRX. He has a front mount intercooler, big injectors, and an upgraded turbo. It's a pretty solid package. He's thinking of selling it and buying an M3 or Porsche 996.

 

Mike

[nbesheer]

I think you forgot the link. I heard that on the STI or maybe it was the EVO, that their so finely tuned from the factory that when people do "upgrades" it looses performance, but that is just what I heard, theres probably not much truth to that.

[randy 77zt]

mike-how is your porsche programmed-max boost,max injector duty cycle,ign timing at max boost/high rpm.trying to get some general knowledge as far as tuning stratigies that oem cars use.the suby was a standard wrx 2.0l .sti has a 2.5.

[Mikelly]

Randy, The injectors are sized to support over 700WHP from the factory. The intercoolers are the GT2 factory units and the turbos are Hybrid K16s with K24 internals. They used upsolute software to tune the PCM. What I'll do over the winter is have the computer sent to upsolute, the old tune written over with the factory program, then turn around and send it with a bunch of datalog files to Kevin at UMW.

 

I expect this car to be around 550WHP when Kevin's tune is done. What I especially love about this car is the way they built it. Everyone raves about the Toyota Supra motors, and these boxer motors are even better from the factory.

Mike

[randy 77zt]

mike-to make 700 hp with 6 injectors they would have to be 1000cc per injector at 80% duty cycle with bsfc assumed to be %65.your datalogs would be very interesting.most modern engines have cylinder heads that flow well-thats what keeps them wanting to turm more rpms.most people are smart enough not to turn 8000rpm with 20+ psi boost on a daily driver.if your porsche has a mass air flow sensor it would be nice to find out what cfm air flow is going through it.anyway you will probably get into it someday.

[Mikelly]

We run 7200RPM for redline/limiter and the car is pushing a little over 10:1 compression from the factory. It does use an MAFS and I could get you that data on what the CFMs are, but I'll have to dig thru some logs.

 

I have zero desire to mess with the tune from the custom tuner's parameters, and he locks them, giving me 3 settings, one for economy, one for track tune on pump gas and one on race gas. I recognize that I'm not smart enough to know what I'm doing with tuning software and leave it to the pros. At $28,000 for a replacement motor, I don't want to take that gamble.

 

Mike