dyno sheets and questions
dyno sheets and questions
I recently took the evo down to Birmingham because Next Level has a new AWD dyno (Dynapack). Anyway, all I did was get a few runs to get a baseline for the car. I'm currently running BR "stage 1" (3" TBE, intake and MBC) with a dynoflash (not the "buschurflash"). It seems the VDO boost gauge I have reads high. I had it adjusted to peak at around 21 and drop to around 19. However, once it was set up on the dyno I was only hitting about 18 and dropping to 16. As we ran the tests we upped the boost until the dyno was reading approx 20 and dropping to 18.
Anyway, I'm no expert at reading the data so I'd like opinions. I noticed a dip in hp/torque at 6K RPM that only seems to be on the last two runs. There is a corresponding dip in AFR but no decrease in boost so I'm not sure why. Heat? Air leak? Gremlins?
I'm also not sure how to compare the numbers to "other" dynos since the dynapack measures at the axle. (I know you can't compare numbers really, just ballpark figures.) It does seem that my evo is somewhat low compared to another owner I was talking with. Of course, he is blessed with a factory mutant. Lucky bastard. 
Anyway, I'm no expert at reading the data so I'd like opinions. I noticed a dip in hp/torque at 6K RPM that only seems to be on the last two runs. There is a corresponding dip in AFR but no decrease in boost so I'm not sure why. Heat? Air leak? Gremlins?
I'm also not sure how to compare the numbers to "other" dynos since the dynapack measures at the axle. (I know you can't compare numbers really, just ballpark figures.) It does seem that my evo is somewhat low compared to another owner I was talking with. Of course, he is blessed with a factory mutant. Lucky bastard.
I gave Al a call to get his input on these results. Before I get into that I gotta say that I should have called him when the car was on the dyno! I guess I'm just not used to that kind of customer service, nor was I prepared for the level of detail needed to get a good diagnosis. I'll also say that this has convinced me to look into getting some data logging capability since awd dynos are very rare around here. Besides, I won't have to worry about what the dyno's settings are or variances between dynos.
Obviously the main fault was that my boost was set too low. My boost gauge reads high so when I thought I was hitting 20-21 PSI peak dropping to 19, I was really getting a bit over 18 and dropping to 16. Even though we were increasing the boost for each run, it was still only peaking at 20.2 on the last run. I had five runs on the dyno with minimal cool down between runs, so by the last run I'm sure the car was quite hot. (I don't know the actual temps but with only a fan blowing on the radiator and intercooler it must have been hot.) This is also a factor and could we be why there were odd "dips" in the torque/hp curves at 6K RPM. I do know the runs were made in 4th gear but couldn't tell you what the settings were for the dynapack.
I'm also not running the latest version of the reflash for my mods and Al offered to give me the upgrade and see if it makes a difference. He also offered to update the flash to include my walbro fuel pump which I have in my garage but haven't installed. I'm also going to double-check all my hoses and connections since I think my boost is tapering a bit too much. I might have a small leak that is only apparent at higher pressures. Thanks again for the help Al.
Obviously the main fault was that my boost was set too low. My boost gauge reads high so when I thought I was hitting 20-21 PSI peak dropping to 19, I was really getting a bit over 18 and dropping to 16. Even though we were increasing the boost for each run, it was still only peaking at 20.2 on the last run. I had five runs on the dyno with minimal cool down between runs, so by the last run I'm sure the car was quite hot. (I don't know the actual temps but with only a fan blowing on the radiator and intercooler it must have been hot.) This is also a factor and could we be why there were odd "dips" in the torque/hp curves at 6K RPM. I do know the runs were made in 4th gear but couldn't tell you what the settings were for the dynapack.
I'm also not running the latest version of the reflash for my mods and Al offered to give me the upgrade and see if it makes a difference. He also offered to update the flash to include my walbro fuel pump which I have in my garage but haven't installed. I'm also going to double-check all my hoses and connections since I think my boost is tapering a bit too much. I might have a small leak that is only apparent at higher pressures. Thanks again for the help Al.