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SVT Shelby GT500
3L+ blower guys what intake setup you running?
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<blockquote data-quote="Catmonkey" data-source="post: 16134452" data-attributes="member: 124025"><p>This is not really an airflow restriction issue. A 123 mm tube will outflow just about any throttle body that will bolt onto the supercharger. The problem with a smaller tube is that it's maxing out the MAF transfer function and can no longer monitor airflow once it's pegged. On an analog MAF (2010 or earlier) maxing out the 5.0 v limit is going to happen somewhere north of the 700 rwhp range with a 5" tube on pump gas. Putting the MAF sensor inside of a larger tube changes the charcteristics of airflow through the sensor, so the MAF transfer function can be calibrated to correlate to the revised airflow to change how the PCM interprets the voltage reading. Starting in 2011, Ford went to a frequency based MAF which can be calibrated for a higher range of airflow than an analog MAF, so the same limitations don't apply. I think most tuners end up going to a larger tube once you get in 800 rwhp territory. Even JLT's Super Big air tube is 6" at the MAF, but necks down to 5.5" at the throttle body. So there's no way it can outflow a 140 mm cobrajet, not by a significant margin anyway, but the signal at the MAF will not have the same calibration. The bigger tube might have some idle issues because the airflow stream is pretty weak at low load, low rpm. </p><p></p><p>To illustrate, the area of a 5" circle is 19.63 sq. in. The area of (2) 75 mm circles (think KB twin) is 13.70 sq. in. The area of a 168 x 79 elongated circle (think 168 mm mono) is 18.50 sq. in. Put them on a flow bench and I'm sure the round tube will walk away from the throttle body by virtue of the throttle shaft and blades. The moral is log your car if your running an analog MAF. If your voltage is in the high 4 v range, you may need a bigger MAF. If you see 5 v, you're there. I have yet to see the frequency limit of the later MAF. I think the limiting factor may be how far your tuner wants to push it. </p><p></p><p>As far as metal or aluminum vs injection molded plastic, certainly metal would be more the more consistent media, but I can't imagine a plastic tube has that much variation as to give adaptive controls fits. I do think a bell mouth at the entrance of the tube will flow better than a flat edge, but well may be splitting hairs.</p></blockquote><p></p>
[QUOTE="Catmonkey, post: 16134452, member: 124025"] This is not really an airflow restriction issue. A 123 mm tube will outflow just about any throttle body that will bolt onto the supercharger. The problem with a smaller tube is that it's maxing out the MAF transfer function and can no longer monitor airflow once it's pegged. On an analog MAF (2010 or earlier) maxing out the 5.0 v limit is going to happen somewhere north of the 700 rwhp range with a 5" tube on pump gas. Putting the MAF sensor inside of a larger tube changes the charcteristics of airflow through the sensor, so the MAF transfer function can be calibrated to correlate to the revised airflow to change how the PCM interprets the voltage reading. Starting in 2011, Ford went to a frequency based MAF which can be calibrated for a higher range of airflow than an analog MAF, so the same limitations don't apply. I think most tuners end up going to a larger tube once you get in 800 rwhp territory. Even JLT's Super Big air tube is 6" at the MAF, but necks down to 5.5" at the throttle body. So there's no way it can outflow a 140 mm cobrajet, not by a significant margin anyway, but the signal at the MAF will not have the same calibration. The bigger tube might have some idle issues because the airflow stream is pretty weak at low load, low rpm. To illustrate, the area of a 5" circle is 19.63 sq. in. The area of (2) 75 mm circles (think KB twin) is 13.70 sq. in. The area of a 168 x 79 elongated circle (think 168 mm mono) is 18.50 sq. in. Put them on a flow bench and I'm sure the round tube will walk away from the throttle body by virtue of the throttle shaft and blades. The moral is log your car if your running an analog MAF. If your voltage is in the high 4 v range, you may need a bigger MAF. If you see 5 v, you're there. I have yet to see the frequency limit of the later MAF. I think the limiting factor may be how far your tuner wants to push it. As far as metal or aluminum vs injection molded plastic, certainly metal would be more the more consistent media, but I can't imagine a plastic tube has that much variation as to give adaptive controls fits. I do think a bell mouth at the entrance of the tube will flow better than a flat edge, but well may be splitting hairs. [/QUOTE]
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3L+ blower guys what intake setup you running?
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