I got a Diablo Predator a couple weeks ago from RPMOutlet and installed the performance tune. My only modification is a K&N Aircharger #63-1051. The car has run fine since.
I went to a dyno day Saturday organized by Dynoperformance.com at (www.NEDyno.com) New England Dyno here in Worcester, MA. My first pull the car gained 40HP and 38lb of torque over my stock #'s of a month earlier. Needless to say I was very happy with the results.
My next pull resulted in very similar #'s but they noticed that my car went lean right at 6200 rpm and went off the charts above that. They looked closer at my first run and noticed it did the same. They told me to try it again to make sure I wasn't pulling off the throttle (I wasn't)before redline even though you could see the graphs didn't match by several hundred RPM where the lines of the HP and torque went down and the AF went up. Same results, the car leaned out after 6100.
I then pulled the performance tune out and reinstalled the stock tune. Even though my peak HP #'s(397 peak) actually improved slightly between 5500 and 6500 rpm I lost torque and power through out the lower portion of the rpm range. In regards to the A/F the graphs matched up going lean when I let off the throttle right at the rev limiter and the torque and hp lines on the graph going down at the same rpm. The AF ratio stayed OK (even though it was leaner from about 2700-6100 than the performance tune) until I hit the rev limiter and let off the throttle. Most importantly it was below 11 to 1 at 6600 rpm.
With the performance tune the A/F was good at 10.2 at 5400 stayed at 10 from 5500 until it went to 10.4 at 6100. Then went to 12.2 at 6200 to 17.4 at 6300 and up to 18.0 and off the chart at 6400-6600. The A/F looks better with the performance tune up to 6100 but after that it seems like the EEC is turning off the fuel pumps(?) and leaning the car out for some reason. There was another Cobra there with a Predator and the performance tune his mods were a Magnaflow catback and a Steeda CAI. His AF stayed good right up to redline.
I e-mailed this information to Diablo but haven't heard from them yet. Any thoughts?
John
I went to a dyno day Saturday organized by Dynoperformance.com at (www.NEDyno.com) New England Dyno here in Worcester, MA. My first pull the car gained 40HP and 38lb of torque over my stock #'s of a month earlier. Needless to say I was very happy with the results.
My next pull resulted in very similar #'s but they noticed that my car went lean right at 6200 rpm and went off the charts above that. They looked closer at my first run and noticed it did the same. They told me to try it again to make sure I wasn't pulling off the throttle (I wasn't)before redline even though you could see the graphs didn't match by several hundred RPM where the lines of the HP and torque went down and the AF went up. Same results, the car leaned out after 6100.
I then pulled the performance tune out and reinstalled the stock tune. Even though my peak HP #'s(397 peak) actually improved slightly between 5500 and 6500 rpm I lost torque and power through out the lower portion of the rpm range. In regards to the A/F the graphs matched up going lean when I let off the throttle right at the rev limiter and the torque and hp lines on the graph going down at the same rpm. The AF ratio stayed OK (even though it was leaner from about 2700-6100 than the performance tune) until I hit the rev limiter and let off the throttle. Most importantly it was below 11 to 1 at 6600 rpm.
With the performance tune the A/F was good at 10.2 at 5400 stayed at 10 from 5500 until it went to 10.4 at 6100. Then went to 12.2 at 6200 to 17.4 at 6300 and up to 18.0 and off the chart at 6400-6600. The A/F looks better with the performance tune up to 6100 but after that it seems like the EEC is turning off the fuel pumps(?) and leaning the car out for some reason. There was another Cobra there with a Predator and the performance tune his mods were a Magnaflow catback and a Steeda CAI. His AF stayed good right up to redline.
I e-mailed this information to Diablo but haven't heard from them yet. Any thoughts?
John
