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Got my ECU yesterday after an absolute nightmare with UPS. Initial Results are that the car feels definately quicker, and much smoother in acceleration. Before the reflash I would get boost peak up to 1.02 BAR then it would drop like a rock down to about .93 BAR. With the new ECU this is virtually gone. I am seeing boost held right around 1.02/1.03 BAR, without using cobb restrictor hose. OVerall the car feels great, love it.
THE BAD:
From the delta dash logs it looks like I am running pretty high injector duty cycles , I was under the impression that this would not be a problem with just a stage 1 or 2, looks like a turboback or stage 2 won't be happening anytime soon. I was hoping that my midrange would be more improved than it has shown, before I would see a big dip in power at ~3100 RPM until ~3700 RPM it's still there and noticable, just not quite as bad as before. I thought that it was due to the drop in boost @ that RPM but apparantly that wasn't the whole story.
Delta Dash Road Dyno:
Midrange is surprisingly unchanged. I was expecting to see a little bit more peak HP, but still good results, but was surprised by the increase in the low end.
The following is Road Dyno graph, it's pretty consistent, all the runs were taken from the same starting point, roughly the same weather conditions. The numbers maybe aren't worth much compared to another car on a dyno, but they are very much comparable between different runs with the same car. This is on very heavy smoothing, the drop in torque in the midrange is not quite as noticable with the Very Heavy smoothing setting, but it is neccesary with three graphs and an auto tranny, which must be done in 2nd gear, but 3rd would be more desirable.
Blue: Catback only (maybe hacked silencer) Peak #s -157 HP , 155 Tq.
Green: Catback, STi Uppipe, Samco Intercooler hoses, Hacked Silencer, Grounding Mod - Peak #s -168 HP , 164 Tq.
Red: Same as green but w/ Cobb Stage 1 ECU - Peak #s -185 HP , 177 Tq.
The Delta Dash Road Dyno works by inputting the weight of the vehicle, in this case Slack's WRX, and monitoring a single-gear run spanning much of the RPM range. There may be other user input values but I don't have Delta Dash so I couldn't tell you.
It generates the torque graph based on how long it takes the vehicle RPM to increase over time. From the torque curve it generates the horsepower graph.
hp = torque * rpm / 5252
I have a g-tech pro competition meter which measures vehicle acceleration using three accelerometers and calculates the curves from that data.
Both methods should be fairly comparable in accuracy although not to each other in terms of numbers. Unlike an engine or a chassis dynamometer, both take into account effects of real world factors like ambient air conditions and wind resistance in the higher gears, but neither will compensate for wheelspin (even though the g-tech uses accelerometers, it warns against using data where wheelspin was encountered). Are these two systems better than a chassis dyno? No, the resolution isn't as great as a real dyno but they are still useful tools.
EDIT: I'm looking at the software analysis of hp runs with the g-tech and it's obvious that Delta Dash Road Dyno is much more sensitive to minute changes, even when curves are smoothed. I'm gonna have to pick up a laptop next year so I can use Delta Dash, too.
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0==WW==0
"…axles of evil…" - george w. bush
Last edited by Wingless Wonder; 12-07-2003 at 11:25 AM.
Originally posted by HTM WRX why are those numbers so low?...i thought stock was 170?
Quote:
Originally posted by Slack
The following is Road Dyno graph, it's pretty consistent, all the runs were taken from the same starting point, roughly the same weather conditions. The numbers maybe aren't worth much compared to another car on a dyno, but they are very much comparable between different runs with the same car.
It's utterly useless to compare these results to [enter chasis dyno of choice] results. Plus add on the 4eat factor, and lack of resolution due to being forced to use 2nd gear instead of 3rd.
Originally posted by Slack Most likely yes. Performance wise, it is worth it. The injector issue is a little bit worrying however.
Good information, Slack. Sorry for the Noob question, but what kind of problems result from having high Injector duty cycles? Are you worried about running rich, or maybe decreasing the injector's lifespan? I'm very interested to hear about issues like this before I plunk $555 for the Accessport in February.
Originally posted by DeepBlue Good information, Slack. Sorry for the Noob question, but what kind of problems result from having high Injector duty cycles? Are you worried about running rich, or maybe decreasing the injector's lifespan? I'm very interested to hear about issues like this before I plunk $555 for the Accessport in February.
The issue would be not being able to dump in enough fuel, the engine could run lean which could lead to detonation. At this point completely running out of injectors is most likely not going to happen but, it makes future mods a little more complicated and expensive, if I have to go out and get injectors.
Originally posted by Wingless Wonder Slack, if you want to log data from my car at a Saturday meet, it's okay with me if you want to compare IDC and other data. We have very similar mods.
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0==WW==0
"…axles of evil…" - george w. bush
I think Ill be at the Sac meet this week, so I'll bring my laptop along and, see what yours look like. You have a turbo back?
Linear Mode
