Just finished writing up the results of Intake Manifold tests on my '04.
Enjoy!

Testing 3 Hot Manifolds on a 2004 Dodge


Have you done the basics? Installed your exhaust, cold-air intake and power programmer? Looking for just a little extra (aren’t we all)? We have been seeing new Intake Manifolds that are claiming impressive power gains, but just like with anything, we were skeptical. So whaddaya do? Strap some poor test truck to the dyno and start testing!

Premier Performance asked Adam Winslett from WINspeed to test out the ATS, aFe and CFM+ manifolds on a 5.9 Common Rail truck. Adam turned to the crew at Tri-Valley Performance in Dublin, CA for the testing on their DynoJet Load Dyno. When Adam’s test truck couldn’t make it, Erik Lind (one of TVP’s owners) volunteered his 2004 Ram for the tests.

Erik’s truck has the aFe Cold-Air Intake, Torque Tube, a custom 4” exhaust, boost elbow and fooler, WINspeed heater grid delete, and a Smarty running on 7. The fuel system is stock except for a modified CP3 pump. Previous runs with this setup netted 379/779. Baselines with the stock manifold were consistent with earlier numbers, delivering 383/781.

For the test, each setup would get two runs, starting at roughly the same RPM with a 10% load applied to help get the boost up. Numbers are uncorrected. Peak numbers are without smoothing on, but we did put smoothing on 5 for the purposes of determining the results at 1900 and 2150 rpm. This eliminated freak peaks or valleys that can skew the numbers and don’t represent what the truck really feels.

First up was the ATS Arc-Flow aluminum intake. This is a sweet piece of equipment. There are FIVE tapped holes just begging for N20, water meth, hobbs switches, you name it! After plugging all the holes, Erik swapped in the manifold in about 10 minutes using the supplied hardware and gaskets. After two runs, the results were in, and the ATS netted 395/795. A very nice start, indeed! Those numbers are really only part of the story, however. Power above 2600rpm was up just a bit (10-12 HP&TQ), but the power down low was astounding! At 1900rpm, the ATS delivered 48.55 HP and 134.27 lb/ft of torque. Moving up to 2150rpm, power evens out, but the gains are still sweet at 23.74HP and 57.88 lb/ft. This is right where you can feel it!

Second on the rollers was the aFe Blade Runner aluminum intake manifold. Like the ATS, this manifold had several ports and drillable bosses for goodies. Installation was a little less straightforward and a little odd, to be honest. It requires you to drop the outer bolts down through the manifold, then cap the holes with supplied plugs. Strange, but it seemed to work fine. The aFe put down 396/788, with very similar top-end performance to the aFe. At the same 1900rpm, the aFe added an impressive 38.61HP and 106.75lb-ft of torque. The 2150rpm mark dropped the gains to just 4.14HP and 10.11 lb/ft.

Last in line was the composite manifold from CFM+. This piece is the lightest of the bunch, and promises even better heat insulation than the aluminum units. The manifold we tested did not have extra ports built in, but we are told that one is in the works. Installation required the use of supplied studs and nuts, so it took a bit more time than the others, but it was still only a 20 minute install. Peak power results were 393/791, so the CFM unit was right in line with the other intake manifolds. The CFM really shines down low. At the 1900rpm mark, the CFM+ manifold delivered a whopping 57.7HP & 159.53lb/ft! 2150rpm showed 23.65hp and 57.88 lb/ft of torque.

Can you guess which manifold never got taken off of Erik’s truck? Yup, the CFM+ is staying on there! The bottom line is that for between $315 and $360 you can add a trick manifold to your rig that adds a boatload of low-end torque and HP, gives you ports to play with, and looks great doing it. Our guess is that the top end improvements might be greater on more modified trucks. We’ll test the CFM+ again when Erik gets the FASS installed on his truck.

 

great post thanks ...

am i reading the graphs correctly?

do all the aftermarket intakes make less hp than the stock from 2600 rpms up?

 

Excellent results and actually better than expected. It's also nice to see results that go along with the general theory on the subject. The theory being that air under low boost is more sensitive to flow restrictions than air at under pressure (high boost).

"Everyone" says the manifold brings in better driveability to the trucks and here we can see it on the dyno. So for anyone out there trying to clear up their smoke at low RPM and build more power at low rpm, you may have found your answer.

 

2broke - the dyno results show the aftermarket intakes with hp and torque numbers above the stock manifold at all rpm, blue line above the green line, the difference just isn't as much when you get to the high rpm levels.

Also, of note, the actual boost pressure reading may go down a few psi after installing this mod because it reduces the restriction to flow, this should correspond to a moderate drop in EGT as well.

 

The graphs that start to fall off after 2600 are the before and after torque. There are 2 runs there with HP and TQ for each run. The highest of each was with the aftermarket manifold over the stocker.

 

got it ...

nothing like asking a stupid question in front of a few thousand freinds

 

... don't worry about it ... i've been there many times

 

Little skeptical on checking the results because I just put the CFM+ on mine; but glad I did. Finally did something right.

 

To be honest those numbers down low just don't seem right. If they are they're very impressive.

 

pt, were you refering to one intake over another, or just the results in general? Just curious ...

 

Geat post you just answer a lot of the qestions i was searching for! thanks.

 

Thats kinda what I was thinking, but I guess you never know...

 

I was referring to the gains from the aftermarket units as compared to the baseline with the factory intake. Gains of 50+ hp and 100+ lb-ft seem to good to be true.

 

Trust me, they didnt seem right to me either. Thats why each got two runs under almost identical cool down conditions. I did the work and the runs myself on a dyno that we own and have been using for almost 5 years. The load unit was just calibrated a couple of weeks ago. Perhaps my truck is an anomoly, but numbers are numbers.

I will say that with the CFM in place, the low end propensity to spin the tires is silly. And its raining now, so its even worse. May have to dial the Smarty down!

 

Firstly all these products are intake horns...a manifold takes one or a few inlet sources and distributes it to more outlets...these are just curved inlet pipes which we call horns. There are but one or two intake manifolds available on the market, ZZ Fab or Hellman. I for one have been a doubting dora on intake Horn's forever....the math just doesn't necessarily work and knowing the air is just getting into a dump zone of an intake manifold and then being squeezed through very constricted roughly cast holes in the stock head...just doesn't make that much sense.

That said.....at lower boost levels there is much less energy in the intake air so that any increase in volume or lessening of friction or restriction makes a bigger difference...for higher boost levels the difference is much less and should be negligible so even up in the rpms the results are that much more surprising.

Porting and Smoothing my head made a huge difference in the performance of my twin turbo set up on spool up so I guess I left some hp on the floor by not using an aftermarket intake.

If doing that again I guess a 4 inch intercooler and lines will help out even more. I think I'll mod my own intake horn though as if these units do this well with stock delivery hoses than a full 4" will make a huge difference.

Thanks for the diligent work on this report. Kerry