Testing of 3 intakes CFM+ AFE ATS

[BHolm]

I know that I really like my CFM+. I have fairly mild mods, but that intake boosted midrange respone in a big way, you could easily feel the difference. It dropped my EGT's almost 200* F on long pulls. It made the highest setting on my fuelling box usable instead of just a dream.

 

[ENafziger]

I was thinking that they were all equivalent based on top end performance, but after looking at your data again, I can see that the aFe is significantly less effective at 1900 and 2150 RPM. I sure would like to see where the GDP stacks up in the rankings.

Top End (ranked by HP)
aFe 396/788
ATS 395/795
CFM 393/791

That's an interesting way that you presented this comparison Drury. I noticed the truck used was not a heavily modded truck. He was running a stock turbo if I remember right.

It's obvious that at low cfm conditions (lower speeds), that the AFE's performance was not up to par with the other two contenders. However, for Top End power, AFE not only made up for lost ground, but was actually the top horsepower performer.

Does this indicate that the ATS and CFM would be better for comparitively low-flowing engines, and the AFE would be suited for high cfm flows? Or, in other words, those having a stock turbo or 62 mm turbo would see the most benefit from the ATS or CFM, while someone running a large single (66 mm +) or twins would see better results with the AFE?

It's hard to tell from one test on one truck, but my initial thought would be that the vane technology exhibited by the AFE does not really begin to shine until higher flow rates are achieved... and then, for those wanting to push a lot of air, it may the intake of choice.

What do you think?

--Eric

 

[BHolm]

I think those results show that all three are essentially the same on the top end. The differences are so small, just 3hp top to bottom, that it could be nothing more than statistical error.

 

[Erik@LCD]

I don't think they are significantly better than each other up top. I would suspect that the vanes (given their thickness) are pretty restrictive up top.
My truck is pretty mild, with the stock turbo still in place.

 

[MKenison]

Intake test on a stock Truck

I will do it! I will test the intakes on my stock cali 04. Gas mileage has become a real issue with most large vehicle owners. I have resorted to driving 63 mph on the highway and have seen my mileage go from 14. 5 to about 18, with both highway and town driving. Taking your foot out of it, can really help.



Now if a dealer or manufacturer would like to send me their intake. I will add it my stock truck and report back the results. A friend runs Dune Guide.com and would probably be interested in adding the results to his site. Many towing Diesels over at Dune Guide.



Let me know,



Mike

 

[CToney]

Stainless

check out these stainless intake horns made by Tworline. Look in his photo gallery. He makes them for first gen, second 12v, and second gen 24v trucks. He is working on a CR model for the newer trucks. All mandrel bends with a decent looking radius. Laser cut flange and a lip so the boot won't come off. I think stainless would work well. It doesn't conduct heat as well as aluminum.

 

[Bob4x4]

check out these stainless intake horns made by Tworline. Look in his photo gallery. He makes them for first gen, second 12v, and second gen 24v trucks. He is working on a CR model for the newer trucks. All mandrel bends with a decent looking radius. Laser cut flange and a lip so the boot won't come off. I think stainless would work well. It doesn't conduct heat as well as aluminum.

Despite popular opinion,the horns do not get hot... ... ... ... ... .



Bob

 

[nickleinonen]

Despite popular opinion,the horns do not get hot... ... ... ... ... .



Bob

well, as hot as the charge air temperature is. . makes for nice eye candy and gets rid of one choke. .

 

[Bob4x4]

well, as hot as the charge air temperature is. . makes for nice eye candy and gets rid of one choke. .

I agree with that... ... ... ..... the material of the horn makes little diff. That was my only point



Bob

 

[BHolm]

Despite popular opinion,the horns do not get hot... ... ... ... ... .



Bob

There was another thread about a PSMbuick intake. This was a cold air intake not an air horn but what got my attention was the huge hp and torque differences associated with only a 50 degree temp change. I don't agree with how they came to their conclusions but my point is, maybe the air horn doesn't have to get HOT, is it possible that a 10-20-30 degree difference is enough to greatly effect power?



The claim was 55hp and 100lb/ft based on a 50 degree difference in intake air temp.



So after a hard dyno run, has anybody taken the temp of these various intakes? If one gets 50 degrees hotter than another, is there a power loss?

 

[p-Bar]

I know that outside air temp greatly changes your HP. Scenario, friend is engineer for Los Angeles county Fire his station is up a long hill. He says when coming back from a run in the evening 15-20 degrees lower he can take a extra gear going up the hill.

 

[Bob4x4]

There was another thread about a PSMbuick intake. This was a cold air intake not an air horn but what got my attention was the huge hp and torque differences associated with only a 50 degree temp change. I don't agree with how they came to their conclusions but my point is, maybe the air horn doesn't have to get HOT, is it possible that a 10-20-30 degree difference is enough to greatly effect power?



The claim was 55hp and 100lb/ft based on a 50 degree difference in intake air temp.



So after a hard dyno run, has anybody taken the temp of these various intakes? If one gets 50 degrees hotter than another, is there a power loss?

I tried the Psm kit when it first came out. On a common rail truck running the edge with attitude there was no measured performance gain in the 1/4 mile,no noticable egt change either. I am sure 50 hp would have shown an improvement on the strip.



Dynoing my 3rd gen and immediately after putting my hand on the intake horn it was Not hot to the touch.



The best way to do any of this testing would be using full blown data aqquisition equiptment... ... ... ... ..... slightly out of my budget :-laf



Bob

 

[Gary - K7GLD]

There was another thread about a PSMbuick intake. This was a cold air intake not an air horn but what got my attention was the huge hp and torque differences associated with only a 50 degree temp change. I don't agree with how they came to their conclusions but my point is, maybe the air horn doesn't have to get HOT, is it possible that a 10-20-30 degree difference is enough to greatly effect power?



The claim was 55hp and 100lb/ft based on a 50 degree difference in intake air temp.



So after a hard dyno run, has anybody taken the temp of these various intakes? If one gets 50 degrees hotter than another, is there a power loss?

Here's a pointer on a calculator that can be used to test values like changing altitude, OAT, and such - it takes a LOT of intake air temperature change to get a very high HP percentage change - regardless of common assumptions to the contrary...



Relative Horsepower Calculator

 

[BHolm]

Here's a pointer on a calculator that can be used to test values like changing altitude, OAT, and such - it takes a LOT of intake air temperature change to get a very high HP percentage change - regardless of common assumptions to the contrary...



Relative Horsepower Calculator

I fooled around with that calculator some. On a 400hp engine, going from 85F to 135F, the numbers used by PSM, all other things unchanged would yield about a 30hp difference.



I definately cried foul at the 55/100 numbers they came up with, but according to the calculator, a 50 degree rise does rob a substantial amount of power.



I am not saying the intakes are getting that hot but who knows, hot day, hood down:-laf long grade, seems plausible that there would be an advantage to being cooler. The chances of it being much different though is pretty slim. We are talking about air fresh out of the intercooler too.

 

[Gus's 03]

well after about 20 pulls today...

blade runner vs stock, peek hp changed by as much as 10 hp, torque peek was up about 25 ft/lbs.



the thing is peek #'s arnt where this is shining. its the area below the curve. its a fatter curve.

WOT runs you probably wont se much change, light throtle is where these shine.



under boost you can overcome huge restrictions, but when the motors not on the boost and has to draw it in it makes a huge diferance!



i drive the same back rodes almost every day, light throttle transitions are now much stronger than before.



i think where it would realy shine is for the guys with a big single that lave alot of low end lag, i can see that the improvemet for them would be much better than a fast spooling stocker.

give it a month or so and ill put that to the test!

 

[ENafziger]

Maybe I'm missing something, but it doesn't seem to me like thermal conductivity of the material of the intake horn would matter at all. The resident time of the air passing through the horn is very short; thus, there's not much time for the air to heat up as it passes through.

Furthermore, I'm not convinced that the air outside the horn would be hotter than inside the horn... except possibly if driving in very cool conditions with an upgraded charge air cooler.

We do alot of engine dyno testing here at work, and from memory, it seems like 53° C (or 127° F) for the intake charge is what most engine manufacturers shoot for at a B50 point, or similar.

Since the intake horn is on the opposite side of the exhaust/turbo/downpipe/etc, and would not imagine the surrounding air being much hotter than this.

Anyone with firsthand information?

--Eric

 

[CToney]

I agree the intake temp should be higher than ambient air temp under hood. On the air filter side cooler air would help. It would be denser for the turbo to ingest. The different manufacturer have to sell the sizzle as well as the steak.

 

[Bob4x4]

Maybe I'm missing something, but it doesn't seem to me like thermal conductivity of the material of the intake horn would matter at all. The resident time of the air passing through the horn is very short; thus, there's not much time for the air to heat up as it passes through.





Anyone with firsthand information?



--Eric

I have gotten that very response from a fluid dynamics engineer... ... ... ...

that's good enough for me



Bob

 

[JDerbedrossian]

How much boost can the cfm+ handle compared to the aluminum intakes?

 

[BHolm]

How much boost can the cfm+ handle compared to the aluminum intakes?

Mine see's 40 psi several times everyday