Hey guys, posted this on the other board as well but I know there are a lot of tuners here on 6speed so I wanted to cross post. Cheers

I purchased the Cobb Accessport V3 for my 997.1 Turbo. I plan to have a professional tune done, but of course I wanted to load up an OTS map and do some datalogging right away - new toy needs to be played with...

Using the OTS maps I wanted to be conservative, so I loaded up the stage 2 91ACN map even though I am running 94 with 10% ethanol. Actually, there was about 1/8th of a tank of 91 0% ethanol remaining in my tank when I filled up with 94 this morning. I have a speedtech 3" catted x-pipe, everything else is stock.

http://datazap.me/u/cstyles/log-1498...?log=0&data=18

Check out the datalog on this quick 3rd gear pull. I am most interested in timing and knock, and I am hoping I can get some feedback from the experts here. You can see there is 0 knock up until 6k RPM, and then the knock sensors on each cylinder start registering some values up to 6500rpm where I let off the gas. From my research, -3 to -5 on the knock sensors seems to be about normal, and well within the -15 degrees the DME can pull in event of knock occurrence.

I want to play around with the regular 91 and then the 93 maps, but want to ensure the most conservative 91ACN map datalog looks ok first.

Appreciate any feedback. Thanks

 

Looks pretty good overall. Your car is flowing a good amount of air mass for the boost it is running. What mods do you have?

The Mezgers are extremely sensitive to knock, much more so than the newer DFI motors. They are particularly sensitive in the 5700 to 6k rpm range, as you also see in your logs. If my car is going to pull any timing when I'm on pump gas, it is usually in that area. You are pulling 5-6 deg, and your overall timing curve gets a little messy from 5700 rpm on up. 2-3 deg when on pump gas is a pretty normal amount of pull, but 5-6 is more than I like to see. Do you have access to E85? You can add a couple of gallons of it to your normal tank of 93, and usually that small octane bump is all you'll need to clean up your timing. Ultimately getting a custom tune is the way to go. You'll make more power and have better consistency than the off the shelf maps. Also, if you haven't already, get rid of the stock intercoolers. They are absolutely some of the worst performing units that I've ever seen on any car, much less a Porsche turbo.

 

Thanks for the feedback. My only performance mod, other than the Cobb AP, is a Speedtech 3" catted x-pipe.

I plan on loading the 'stock' map and doing a few logs, and comparing to see if it's better or worse than stage 2 91ACN. Then doing the same with the stage 1 maps.

 

Intecoolers need to be on the list in the short term. Intake air temps are very important when it comes to pump gas performance.