Anyone running the PMAS 120? I know they have the DD149 out, but was wondering if anyone knows how a 120mm would fair on the larger blower setups. I know Whipple has a 4.0L kit that ships with a 123mm MAF housing.
Restriction above 750-800rwhp.
Pretty much JLT 148 or DD 149 your best options, also adapting the 140mm CJ could work.
I run the no longer made 155 JLT, and will compare it to the DD149 this spring.
-J
3.4
FRPP mono-blade ( 65 x 147mm )
JDM zip tube
FRPP 140mm MAF
Owner modified stock air box
FRPP air filter
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.@1 Alibi 2 , do you think there is any advantage to the FR 140 SCJ Maf housing you have over say a PMAS? I definitely like your intake setup!
With my 4.0 liter (not maxed out) Jdm motor combo I see 4.8 maf volts. Important to keep this in mind so you don’t peg the maf. I don’t know what the limit of the 140mm maf is but I think it’s too small for me. View attachment 1552806
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With my 4.0 liter (not maxed out) Jdm motor combo I see 4.8 maf volts. Important to keep this in mind so you don’t peg the maf. I don’t know what the limit of the 140mm maf is but I think it’s too small for me. View attachment 1552806
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I only know what I read here about the Pmas, & they have a 149mm, which would provide more adjustment. On the down side, you're forced to use " their " filter. My set-up has been on the car since 2014. If you could find someone who upsized from 140 to 149mm, they would be the one to ask.
It also has to do with what your goals are, for me, my current set-up will support any future mods I may do................good luck.
..... Ill take the DD 149 Haha, I have no bad animosity toward JLT. But I just dont see how a blow molded intake has the same quality and precision of a machined aluminum MAF housing. No regrets ditching my JLT 123mm in favor of my PMAS 120mm.Well if you can wait I’ll do a JLT 155 vs DD149 comparison. My tuner likes JLT so it’ll be interesting on a 1000rwhp combo.
I’ll sell you whichever makes less
-J
..... Ill take the DD 149 Haha, I have no bad animosity toward JLT. But I just dont see how a blow molded intake has the same quality and precision of a machined aluminum MAF housing. No regrets ditching my JLT 123mm in favor of my PMAS 120mm.
I dont doubt your experiences with JLT at all. I just had drivability quirks with the one I bought when installed on my car. It improved greatly switching to Lund racing for my tunes. Completely cleared up when I installed the PMAS.Years ago I did a "Plastic" JLT vs a aluminum Intake. Same car, same dyno, same day, 3 pulls about an hour apart. The JLT consistently had more power than the metal intake. Ever since then I was a JLT fan until I had to start making my own for my off the wall builds.
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.
Lord almighty, KB makes some pretty Monoblades...Thanks for the input. I am on a pre-2010 slot style MAF with a MAFia on it to convert it to my electronics. I have the Kenne Bell big single blade. I am trying to make sure I have adequate air flow plus block off all the engine heat that I can. They of course make nothing for my car so I have to wing it and piece together parts.
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