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This is the best of 3 pulls... I have Alta turbo back, FMIC, Hot side boost tube and CAI. It hit about 15.5 psi. No ECU tune. It's Lower than I expected. But were they bad pulls? The curves crossing point was not consistent. Also not at 5,250 rpm like the others i see posted. The one pictured is about 4,700 rpm. Another was at 4,900 rpm. Thoughts? Suggestions?
Automatic if it makes a difference.
Thanks
Last edited by guitfiddler; 10-29-2009 at 06:17 PM.
The curves crossing point was not consistent. Also not at 5,250 rpm like the others i see posted. The one pictured is about 4,700 rpm. Another was at 4,900 rpm. Thoughts?
If you notice, power and torque are not plotted equally.
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A tune certainly would help! I think if you could see your air/fuel ratios, it would look very lean compared to stock, since your intake and exhaust are wide open. The fuel injectors and ECU mapping aren't keeping up and the ECU is backing off timing down low. Also, you should be seeing boost from 2K-3.5K, with a little dip, then the bigger boost above, but it seems like you have nothing until 3.5K. Maybe you need to be heavier on the gas pedal at the low end of the pull? Also if you hit the floor pretty quickly you get the overboost, which doesn't seem to be happening here. The intercooler may also be playing a part, causing higher loss in boost pressure through the core, though if I remember right Alta claims there is less loss than OEM. There are a few things to diagnose, or you can just add a tune and see how it goes. The stock dyno results I've seen usually show around 155-160HP at the wheels, so there is an improvement here, it just seems a little low.
Those are not bad numbers for an AUTO on the MD. Ask your operator to do the following:
- force identical scaling on the two graphs
- do 'Trace Graph' instead of 'power curves'
- plot the AFR along with your graphs
