Anybody else run the LS7 maf?

ZephTheChef

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So on the twincharged car, I have been playing with my LS7 MAF (100mm housing) and the numbers just aren't adding up. I have been scaling back my injector size in the tune as well as the MAF chart to get some more resolution (since originally it was maxxing out the values in the maf chart at around 9,000hz) and so far, I have been able to hit right around 10,000hz. I have gotten pretty close to getting the 67.7 max allowed value right at the 11,500hz max position in the table.

My issue/question now relates to things not adding up. Even looking at a stock LS7 tune in HP Tuners, 10,000hz is maxxed out at over 67.7 lb/min airflow. Let alone in the bigger housing I have. The car is not making anywhere near the power that would equate to. I mean it's pulling pretty good, but I think we're in the low 400hp range right now...it does not quite pull like my S600 @ approximately 600 crank hp, and they should be a similar weight. BWs matchbot calculator has me between 400-500hp depending on what intercooler efficiency value I put in (my chiller loop is not running right now, but the intercoolers are still full of water so will pull some heat out of the charge anyway). Which jives with my butt dyno. So what's up? Why am I getting so close to maxxing out this MAF at half the HP I thought it would be capable of measuring? Any ideas or experience?

The car runs smooth even at idle, the maf operation appears to be smooth and consistent. It does still have honeycomb and is maybe 4" from my intercooler outlet and has a good 6" of straight pipe off the backside. I haven't gotten the car leaned out to be able to accurately calculate what kind of power it is making from IDC and wideband reading, but I am pretty sure it's not in the 650+HP range that an airflow that high would indicate.
 

ZephTheChef

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I am somewhat wondering if going from 3.5" intercooler outlet to 4" MAF housing is defeating the purpose of running a 4" MAF housing? I could certainly pull the intercooler and cut and weld a 4" outlet end tank...but I don't want to go through the trouble if I'm not pretty sure that's the problem. It would be a huge pain to pull that intercooler since the fittings and lines and intake pipes are all really crammed in there and would have to be removed and re-installed.
 

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