Road Dyno: Cobb Stage 2 with and without Accessport
Road Dyno: Cobb Stage 2 with and without Accessport
The following is Road Dyno graph, it's pretty consistent, the runs were taken from the same starting point, roughly the same weather conditions. The numbers 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, on an auto tranny the dyno must be done in 2nd gear, but 3rd would be more desirable, the results are still very consistent.
The blue graph is with the Stage 2 91 HWG map. The yellow is on the stock ECU(unmarried AP)
I assume it's because of a lack of learning, the road dyno and loggings on the Cobb ECU were done right after the reflash so no learning. Stock ECU ran more timing across all RPM, between 5-6.5 degrees more above 5000 RPM. Knock Correction was higher on the Stock ECU than the Cobb across all RPMs.
Stock ECU 173/167 HP/TQ
Cobb ECU 192/180 HP/TQ
The blue graph is with the Stage 2 91 HWG map. The yellow is on the stock ECU(unmarried AP)
I assume it's because of a lack of learning, the road dyno and loggings on the Cobb ECU were done right after the reflash so no learning. Stock ECU ran more timing across all RPM, between 5-6.5 degrees more above 5000 RPM. Knock Correction was higher on the Stock ECU than the Cobb across all RPMs.
Stock ECU 173/167 HP/TQ
Cobb ECU 192/180 HP/TQ
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Originally Posted by Slack
The blue graph is with the Stage 2 91 HWG map. The yellow is on the stock ECU(unmarried AP)
I assume it's because of a lack of learning, the road dyno and loggings on the Cobb ECU were done right after the reflash so no learning. Stock ECU ran more timing across all RPM, between 5-6.5 degrees more above 5000 RPM. Knock Correction was higher on the Stock ECU than the Cobb across all RPMs.
Stock ECU 173/167 HP/TQ
Cobb ECU 192/180 HP/TQ
With the 91 map, the car would pull timing no matter what. Seems like cobb might not have put enough time into tuning for 91.
IMHO, the 91 map is bogus.
Registered User
Joined: Dec 2002
Posts: 32
From: Phoenix, AZ
Car Info: 2002 Black WRX Sedan
So you are running a Stage 2 93 octane map with 91 gas Razorlab? What difference did you notice between the two. I am currently running stage 2 91 but only have a up/dp and haven't come close to 15 psi. I think partially because it is hot as a **** in AZ and also because it isn't a full TBE.
It's just how the road dyno is, it doesn't have the resolution of a real dyno, and I have to run in 2nd gear as opposed to 3rd so that makes it less smooth as well.
Redid the runs after the ECU had a chance to do it's learning, results are pretty much the same, maybe a bit more on the top end, but the weather was cooler today so learning didnt change much.
I almost got nailed by a CHP out on my test strip today, I noticed someone coming up pretty fast when I was just starting a run to doing some logging, I let of at about 70 cause of this car coming up on my ***, turned out to be a CHP thank god I didn't go up to 100+ like I was going to.
I almost got nailed by a CHP out on my test strip today, I noticed someone coming up pretty fast when I was just starting a run to doing some logging, I let of at about 70 cause of this car coming up on my ***, turned out to be a CHP thank god I didn't go up to 100+ like I was going to.
Last edited by Slack; Aug 12, 2004 at 11:05 PM.
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What is with that dip in torque between 3500 and 4000 rpm? It seems pretty substantial, and present with both the stock and Cobb plots so it doesn't seem like a flaw with the programming. Is there an AT shift there, or something as simple as a bump in the road?
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From: Santa Rosa, CA
Car Info: 02 Subaru WRX w/ JDM Spec C
Originally Posted by Slack
Redid the runs after the ECU had a chance to do it's learning, results are pretty much the same, maybe a bit more on the top end, but the weather was cooler today so learning didnt change much.
I almost got nailed by a CHP out on my test strip today, I noticed someone coming up pretty fast when I was just starting a run to doing some logging, I let of at about 70 cause of this car coming up on my ***, turned out to be a CHP thank god I didn't go up to 100+ like I was going to.
I almost got nailed by a CHP out on my test strip today, I noticed someone coming up pretty fast when I was just starting a run to doing some logging, I let of at about 70 cause of this car coming up on my ***, turned out to be a CHP thank god I didn't go up to 100+ like I was going to.
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Originally Posted by _mike_
What is with that dip in torque between 3500 and 4000 rpm? It seems pretty substantial, and present with both the stock and Cobb plots so it doesn't seem like a flaw with the programming. Is there an AT shift there, or something as simple as a bump in the road?
-- Ed
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I wouldn't necessarily say that it's because of the automatic transmission. I think it has something to do with the way boost reacts to a long pull in 2nd. seems to run up to peak boost very quickly, taper off a bit, then climb up a little again. too bad DD won't allow logging when dynoing. maybe i'll do back to back 2nd gear pulls, 1 run logged, one run dyno'd.
anyway, here's a comparison. red line is a VF34 in my car that would hold rock solid 17.5 to 18psi from peak to shift. notice how similar the dyno curve looks to what a manual would be. the yellow line is a setup similar to slack's but with an ecutek tune. has the same dip. probably because of the turbo. both setups on my car were tuned by the same tuner, and the DD graphs bear some resemblance to the charts I would get from the chassis dyno.
on a side note, the stock turbo graph of my car looks VERY similar to Slack's. different tuner, different exhaust, extremely close #'s. there was more power available in my car, but i like it tuned to be very safe and conservative.
anyway, here's a comparison. red line is a VF34 in my car that would hold rock solid 17.5 to 18psi from peak to shift. notice how similar the dyno curve looks to what a manual would be. the yellow line is a setup similar to slack's but with an ecutek tune. has the same dip. probably because of the turbo. both setups on my car were tuned by the same tuner, and the DD graphs bear some resemblance to the charts I would get from the chassis dyno.
on a side note, the stock turbo graph of my car looks VERY similar to Slack's. different tuner, different exhaust, extremely close #'s. there was more power available in my car, but i like it tuned to be very safe and conservative.
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Joined: Jul 2003
Posts: 25
Originally Posted by razorlab
care to do an experiment? load the stage 2 93 map in and see how much timing , knock and what your EGT's are. Post the graph. You might be suprised. I did something on a hunch and now I am much happier with my cobb Stage 2, only i'm not running a 91 map, but still running 91 octane.
With the 91 map, the car would pull timing no matter what. Seems like cobb might not have put enough time into tuning for 91.
IMHO, the 91 map is bogus.
With the 91 map, the car would pull timing no matter what. Seems like cobb might not have put enough time into tuning for 91.
IMHO, the 91 map is bogus.
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