JLT vs. Stock intake restriction

[65sohc]

I just finished the comparison. I ran a piece of silicone tubing from the breather fitting on the intake elbow into the cockpit where I connected the other end to a water column manometer. I then did several WOT accelerations to 7500 in second gear while my wife took the pressure readings. The results:

stock: 21 inches of water
JLT: 12.5 inches of water

To put this in perspective, a difference of 8.5 inches of water equals .02 atmospheres.

.02x526hp=10.5hp This would be the gain one could expect as a result of the reduced pumping loss.

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[65sohc]

BTW I removed the filter element from the stock tube for the first time and ran my hand inside. There is a nice bellmouth-ish entry to the maf housing, but after that it gets pretty ugly. There are very prominent sharp ridges at both ends of the flexible section. It is obvious that everything past the maf was designed with ease of assembly and packaging as the top priority.

 

[chops44]

Well Holy Sh**, an actual real world test....Well done sir!!

 

[65sohc]

Well Holy Sh**, an actual real world test....Well done sir!!

Thanks. I found the results surprising. The stocker was more restrictive than I expected but, frankly, so was the JLT. I tested both a Steeda and a C&L on my Boss and both came in around 6-8 inches which is essentially no restriction. Those units utilize a beautifully machined velocity stack ahead of the maf. The JLT is simply a straight tube. Previous JLT models had issues with MAF signal instability. The current model employs a screen inside the filter to straighten airflow and presents a clean signal. It is possible that this may restrict airflow a bit or it may be that this engine just has a huge appetite for air. In any case I think this amount of restriction is insignificant as far as power is concerned. PMAS also uses a velocity stack. It would be interesting to test one of those. They were supposed to send me one for this purpose but never followed through. The last message I received was that they thought the PCV hose was not lining up correctly.

 

[Zitrosounds]

Well Holy Sh**, an actual real world test....Well done sir!!

It is awesome! Was the JLT CAI test with tune? Because if it is, most if not all the gains are really made by the tune. 1. the car will not run right on the JLT CAI without a tune. 2. Stock CAI with tune yields similar results of the JLT CAI with tune, at least from what I have read.

 

[65sohc]

I did not measure horsepower (no dyno). What I measured was the pressure drop in front of the throttlebody, in essence how hard the engine has to work to suck air through the CAI. An analogy would be sucking a milkshake through a straw. You would have to suck harder, ie. expend more energy, to suck the same amount of shake in the same length of time through a small straw than a big one and the negative pressure inside the small straw would be greater. The horsepower number I gave was a calculation based on the fact that if you increase the amount of air by one atmosphere, eg. with a supercharger, you essentially double the horsepower. Increase by half an atmosphere and power increases by 50%. In this case the net pressure in the JLT was "less negative" by .02 atm. Therefore:.02atm.x526hp=10.52hp increase.
For the purposes of measuring negative pressure inside the intake the tune doesn't enter into it. I do have a Lund flex tune for both JLT and factory CAI.

 

[VUDUGT350]

Good stuff Ken!

 

[Zitrosounds]

I did not measure horsepower (no dyno). What I measured was the pressure drop in front of the throttlebody, in essence how hard the engine has to work to suck air through the CAI. An analogy would be sucking a milkshake through a straw. You would have to suck harder, ie. expend more energy, to suck the same amount of shake in the same length of time through a small straw than a big one and the negative pressure inside the small straw would be greater. The horsepower number I gave was a calculation based on the fact that if you increase the amount of air by one atmosphere, eg. with a supercharger, you essentially double the horsepower. Increase by half an atmosphere and power increases by 50%. In this case the net pressure in the JLT was "less negative" by .02 atm. Therefore:.02atm.x526hp=10.52hp increase.
For the purposes of measuring negative pressure inside the intake the tune doesn't enter into it. I do have a Lund flex tune for both JLT and factory CAI.

I completely understand the experiment and its results. All I am saying is 10 horsepower for CAI is an insignificant gain in terms HP. The tune is really what does it fir this car. Thanks for the experiment and it has solidified my decision not to buy an aftermarket CAI

 

[wildcatgoal]

The Steeda CAI, GT 350 CAI, and the ugly-as-fuuu PMAS are the only intakes that have mad flow. If you are concerned about IAT, get the aFe or similar closed box design.

JLT intake... first to market, first to be beaten.

 

[65sohc]

I completely understand the experiment and its results. All I am saying is 10 horsepower for CAI is an insignificant gain in terms HP. The tune is really what does it fir this car. Thanks for the experiment and it has solidified my decision not to buy an aftermarket CAI

The main reason I did it was to satisfy my own curiosity. I agree that 10 hp is not a lot, about the same as deleting the cats, but it's better than zero and small gains do add up.

 

[TRAC WPN]

Thank you, much more informative than a dyno claim

 

[65sohc]

I finally heard from PMAS again. Hopefully they will provide me with a unit so I can add it to the mix. I agree with your comment on the dyno. When we're talking about small power differences an intake could easily fall within the margin of error. On the other hand, pressure drop is the same every single time and sensitive to minute differences.

 

[Lexluther]

I am very skeptical.. I also own a Hellcat which has a similar bend and accordion type elbow. Guys are running the factory intake up to 1200 wheel horsepower. The car stock runs 707hp at the crank so power is doubled yes NOS is involved. A forced induction motor has a mechanical advantage sucking air than natural aspirated but I am still doubting JLT gaining 10hp. There's been a few dyno results showing no gain or 1-3hp which is in the margin of error on a GT350. The same results showed up on Hellcat's with several different brands of intakes and were talking a lot more air involved on those.

I agree the JLT is more efficient than stock but that doesn't directly equate to hp as one would think. Sure the available air is increased but the engine will only suck in as much as it needs or is capable of. Thats why superchargers are called forced induction. Using the same analogy from above post one can say they have a 4" round straw for their drink the pressure is decreased but only so much can flow on demand.

The JLT piece looks phenomenal especially painted and perhaps makes a few hp but in my mind can not be offset by cost of parts and tune per hp. It can be justified if you want to make your engine compartment look awesome. Just my opinion which is subjective you guys can believe what you want just giving my 2cents.

Ford Motorsports doesn't have an upgraded kit but do offer a filter element M-9601-G which I think is well worth the cost I bought mine from the dealer for $66- MSRP was 89-. Its rated for 30k miles for a lot less cash than the stocker replacements which is dry. Re-tuning isn't required and its 50 state legal.

Motorsports also offers a cobra jet intake for around 300 which shows some potential for the GT350. The cobra jet has an oval throttle body and without holding the part I don't know how malleable the plastic is to couple to a GT350 round throttle body. A silicone adapter would be needed as the radius bend is different between the two to the throttle body. There is an oval to round aluminum conversion piece you could buy but again seems complicated for very little gain.

You also have to remember the relationship both Ford and Shelby have with Roush and the spin off Roush Yates. The GT4, GT350r-c and FR350s all have engines sourced from Roush Yates. And one can not dismiss the striking similarities between the factory GT350 air filter intake vs. Roush S550 air filter intake which also has the accordion connector. Roush being aftermarket could have coupled their filter with a straight coupler but choose not to and i'm sure that went testing during development. The GT4, GT350r-c and FR350s race cars all use the factory air filter intake system. Ford could have used any air filter design to homologate (make legal) the intake for racing as a stock part buy simply putting it in the low production GT350R option package but choose not to and run the same air filter design as we do for racing.

Ford performance sources their air filters from Airaid who do offer the straight connector type filter system which you can buy for the GT500 from Ford Performance but this style is not in the catalog for the GT350 nor that type of design was incorporated for the GT350.

I know stock sucks and it bugs me to but sometimes they do get it right and the pennies saved for production costs argument can't be stretched to trigger justification. The GT350 is very good out of the box there isn't much improvement to be had outside of a tune removing emission and mpg compliance and gain more hp.

 

[Zitrosounds]

The main reason I did it was to satisfy my own curiosity. I agree that 10 hp is not a lot, about the same as deleting the cats, but it's better than zero and small gains do add up.

If your chasing HP numbers, SURE! But I am looking at the cost per HP and that is a stretch. I did however go with aftermarket Borla Atak and although the HP per dollar ratio is not great I also had the added benefit of the weight reduction and sound. I would like to increase induction noise but hesitant to pull the trigger on the CAI alone and not quite ready to use a tune.

 

[65sohc]

I am very skeptical.. I also own a Hellcat which has a similar bend and accordion type elbow. Guys are running the factory intake up to 1200 wheel horsepower. The car stock runs 707hp at the crank so power is doubled yes NOS is involved. A forced induction motor has a mechanical advantage sucking air than natural aspirated but I am still doubting JLT gaining 10hp. There's been a few dyno results showing no gain or 1-3hp which is in the margin of error on a GT350. The same results showed up on Hellcat's with several different brands of intakes and were talking a lot more air involved on those.

I agree the JLT is more efficient than stock but that doesn't directly equate to hp as one would think. Sure the available air is increased but the engine will only suck in as much as it needs or is capable of. Thats why superchargers are called forced induction. Using the same analogy from above post one can say they have a 4" round straw for their drink the pressure is decreased but only so much can flow on demand.

The JLT piece looks phenomenal especially painted and perhaps makes a few hp but in my mind can not be offset by cost of parts and tune per hp. It can be justified if you want to make your engine compartment look awesome. Just my opinion which is subjective you guys can believe what you want just giving my 2cents.

Ford Motorsports doesn't have an upgraded kit but do offer a filter element M-9601-G which I think is well worth the cost I bought mine from the dealer for $66- MSRP was 89-. Its rated for 30k miles for a lot less cash than the stocker replacements which is dry. Re-tuning isn't required and its 50 state legal.

Motorsports also offers a cobra jet intake for around 300 which shows some potential for the GT350. The cobra jet has an oval throttle body and without holding the part I don't know how malleable the plastic is to couple to a GT350 round throttle body. A silicone adapter would be needed as the radius bend is different between the two to the throttle body. There is an oval to round aluminum conversion piece you could buy but again seems complicated for very little gain.

You also have to remember the relationship both Ford and Shelby have with Roush and the spin off Roush Yates. The GT4, GT350r-c and FR350s all have engines sourced from Roush Yates. And one can not dismiss the striking similarities between the factory GT350 air filter intake vs. Roush S550 air filter intake which also has the accordion connector. Roush being aftermarket could have coupled their filter with a straight coupler but choose not to and i'm sure that went testing during development. The GT4, GT350r-c and FR350s race cars all use the factory air filter intake system. Ford could have used any air filter design to homologate (make legal) the intake for racing as a stock part buy simply putting it in the low production GT350R option package but choose not to and run the same air filter design as we do for racing.

Ford performance sources their air filters from Airaid who do offer the straight connector type filter system which you can buy for the GT500 from Ford Performance but this style is not in the catalog for the GT350 nor that type of design was incorporated for the GT350.

I know stock sucks and it bugs me to but sometimes they do get it right and the pennies saved for production costs argument can't be stretched to trigger justification. The GT350 is very good out of the box there isn't much improvement to be had outside of a tune removing emission and mpg compliance and gain more hp.

As long as there is a vacuum ahead of the throttle body the engine is wasting energy to pump air that otherwise would go into accelerating the car, just like any other parasitic loss. As far as the factory race cars, they are fitted with small throttle bodies to begin with to limit power to barely over 400 so a more efficient intake would serve no purpose.

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