Weird torque curve on dyno

[BigBeed]

Hello all!

I went to a dyno event today just to see what the car makes and the torque curve was weird. The first run it made 474hp / 375tq the the torque curve comes up, dips, and then comes back up again on the top end. Second run it made 481hp / 399tq and the torque curve shoots up to 399 and holds there until 6k rpm. I pulled fuse 62 for ABS so there shouldn't be any nannies involved and it was ran in track mode. 62 degrees and 90% humidity.

Mods are as follows.
MAK cat deletes
Custom resonated 3' H-pipe
K&N drop in on factory airbox with carbon trap removed and studs shaved off
Velossa Tech big mouth
PBD E85 tune

Not sure if it is a dyno issue or a tune issue but I figured I'd post the graphs and logs here before I sent them to PBD just in case it's not a tune isue. I fueled up the other day and it tested as E90. The logs are in the zip file as it would not allow me to upload a csv file.

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[markmurfie]

First pull looks like tire slip. Maybe TCC slip, but not likely.

Second pull looks better with out the slip. Both look like they could use a revision (or test the E85 for its true %) as its trending rich in the higher RPMS(6000+). It maybe a bit closer to 500 if not break that mark if fuel wasn't trending rich. There's a difference when its a flat 7-8% from the start to finish, and when it starts at 1-2% then works its way to 7-8%. That means the closed loop was not succeeding in meeting its target (.84-.85) and was having to continue to reduce the amount of fuel to stay there. I'm not a fan of a flat timing value like PBD usually does, but it works. I think there's torque left on the table in the lower RPMs, from this, but its safe. Some drag strip logs and 60ft times and they would probably start to work on that for you. It takes torque to get good 60ft times.

 

[BigBeed]

First pull looks like tire slip. Maybe TCC slip, but not likely.

Second pull looks better with out the slip. Both look like they could use a revision (or test the E85 for its true %) as its trending rich in the higher RPMS(6000+). It maybe a bit closer to 500 if not break that mark if fuel wasn't trending rich. There's a difference when its a flat 7-8% from the start to finish, and when it starts at 1-2% then works its way to 7-8%. That means the closed loop was not succeeding in meeting its target (.84-.85) and was having to continue to reduce the amount of fuel to stay there. I'm not a fan of a flat timing value like PBD usually does, but it works. I think there's torque left on the table in the lower RPMs, from this, but its safe. Some drag strip logs and 60ft times and they would probably start to work on that for you. It takes torque to get good 60ft times.

I forgot to mention that the first run was done with hood closed, second was hood open. When they did my final revision the E% was 84.6 according to the ngauge on the flex tune. That was running empty on 93 and filling up. They said that would be fine to tune on but the E I have been getting had been consistently testing at 90%. Could that be causing the rich condition? Also I guess I should have them do another revision?

 

[markmurfie]

A higher than E85% would make it read lean. But like I stated this isn't like it starts at 7-8% rich and stays there like a difference in E% would cause. This is actually trending rich, going from 1-2% and working its way to 7-8%. Its consistent in both pulls and on both banks. I also see your LTFT are showing a bank to bank difference when you go WOT. I would reset your KAM, and if it comes back the way it is now I would look into some new O2 sensors/ spark plugs. Seeing this you probably don't need a tune revision, just some maintenance.

I didn't think PBD did flex fuel tunes only dedicated E85, so I wouldn't trust what the PID on the ngauge is saying for that and assume they are using the stoich point for E85.

 

[BigBeed]

Ahhh ok I understand now. I mentioned to them that LTFT was off bank to bank and they said that was normal. I'll do a KAM reset and see what happens. I wouldn't think it needs O2 sensors or plugs as it only has 13k miles on it.

From my understanding they only do flex on 18+

 

[BigBeed]

Also what is that program you're using to view the data in a graph like that?

 

[xXoVrKiLLXx]

looks like datazap.me

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