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6.2 with afe intake = 36hp!


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As for the intake gaining 36 hp.

Here's my experience:

I've put intakes on several cars I've owned.

Most of them by themselves have done little to nothing, at most 10 hp.

 

For my Hellcat AFE advertised the same 36 (or so) hp with an intake alone, dyno tests/sheets and all.

Many of us bought them as soon as they were released in a group buy.

Several independent people took their Hellcat's to a dyno and did before and after dyno testing of the AFE intake and got zilch for power gains.

I did my usual road/track testing and got zero performance gains. Because of my tests and the couple people who independently dyno tested it, most of us sent the intake back for full refund.

 

I'm sure and feel confident saying Blackbear didn't manipulate their intake dyno testing. But here's my issue. Dyno tests vary so greatly they are hard to fully substantiate. Take the MIT tube. Apparently just a couple years ago the MIT tube did the best on the GM motor in BB dyno tests. This time around hardly a gain at all. Maybe they'll test the MIT tube again in a year and it splits the difference.

There are lots of variables on the dyno.

Here's my two main issues with what I often see on a dyno:

 

1. Hood up testing. Especially with open element CAI, testing with an open hood isn't realistic as it has the ability to take in air that wouldn't be able to do while driving. It also allows the hot air from the engine to escape instead of building up the heat under the hood more like would be the case on the road. Dyno tests should always be done with the hood down.

This is not to say that BB did the test with the hood up (they'd have to reply to that) but I have been to many shops and have walked in to see a dyno going where the hood is up on the car.

 

2. Fan speed and direction of air. When driving on the road, you have a consistent area of air being pushed into the front of the vehicle. The air is not directional like on a dyno using fans. Further, on the road, the amount of air coming in increases with the speed of the vehicle. On the dyno with the fans on, the amount of air that is directional is also static, the speed of the air doesn't increase with the speed of the engine.

And on the dyno you are testing in 4th or 5th gear on most cars, going to redline. This would equate to well into triple digit speeds, often times 140+ mph. On the road you'd have 140+ mph of air smashing against the front of the car, on the dyno with the fans most shops have, you are lucky to have 50 mph winds hitting the front of the car, and again with little uniformity and directional based on where the fans are pointed, if there is not multiple fans evenly covering the front of the vehicle.

So when the dyno starts at 40 mph you have the proper amount of wind hitting the front of the car, but as the dyno runs go on, the fan speeds don't increase to replicate the increase in engine speed correlated to what you would be doing on the road.

 

Now I'm no scientist, but to me, logic would dictate their are going to be some inaccuracies because of this.

 

An interesting test on the dyno for BlackBear to do would be to do a baseline dyno again, get 3-4 runs in with 5 minutes of cool down between each run. Strap on the AFE intake again, then do 3-4 runs with 5 minutes in between again. See if the test results are the same or similar with the same or similar gains this time around. If it's within 1-3 hp of the last test, it would be safe to say the intake is picking up a fair amount of power.

 

I believe the stock intake probably is restrictive, due to GM's desire to have a vault quiet truck.

I do question that if this engine is essentially the exact same engine as the LT1, how is it that the LT1 is rated at 35 hp more (455) with better intake air flow, better exhaust, and different tuning, if you can get that exact same 35 hp gain on this engine with simply an intake, no need for a freer flowing dual exhaust system or a tune? Maybe even the "restrictive" stock exhaust on the trucks, with it's smashed down cross over section, 4 into 2 into 1 exhaust system, and large mufflers and cat still flows well enough to suffice if you strapped it onto a 455 hp LT1 too.

And maybe the tune difference is purely where the power is made and nothing for improved power. If that was the case, then it's possible the 35 hp difference is solely in the intake. An air flow test would probably tell us that.

 

Maybe it's time for another one of my road/track tests for some real world empirical data. :D But I have a 2017 and supposedly AFE intake only supports up to the 2016 truck. Didn't think their was any difference between the 16 and 17's intake?

Edited by Driver72
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You don't have a tune but your truck got 103+ mph?

I thought after 2014 model year they limited them to 99 mph?

I have a 2015 silverado 6.2... I can hit 112 from the factory... again I have no tune. Just afe intake and a borla muffler Edited by Silver ice 6.2
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Looking for more HP for a hellcat, I'd be saving money for back tires and maybe tickets.

 

No I didn't feel the Hellcat needed more power, just wanted to give the AFE intake a test. And if it honestly did make the 35 hp increase they claimed it would of been a bonus. Pretty much knew it wouldn't. You don't make a 714 SAE certified (707 rated) engine and not have an intake that adequately gulps air.

So I was 99% sure it would do nothing, and that's what the AFE Momentum intake did for the Hellcat.

There are 800+ Hellcat's running around on the stock intake, pulley and tune only.

I don't remember which tuner I read it from, maybe HHP, but on the Hellcat forum I remember one of them stating they didn't find any intake restrictions on the Hellcat in their tuning and modding, so felt it was completely unnecessary to change it until you get into quite high power.

Edited by Driver72
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That's awesome for

 

I have a 2015 silverado 6.2... I can hit 112 from the factory... again I have no tune. Just afe intake and a borla muffler

That's awesome for you.

Seems GM has no rhyme or reason to the speed limiters on these trucks either, like the control arms being aluminum or steel.

Don't know WTF is up with GM and their seemingly random decisions on so many things.

From what I read the 2014's were limited to 110, then in 2015 it went to 99 mph.

Edited by Driver72
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That's awesome for

 

 

That's awesome for you.

Seems GM has no rhyme or reason to the speed limiters on these trucks either, like the control arms being aluminum or steel.

Don't know WTF is up with GM and their seemingly random decisions on so many things.

From what I read the 2014's were limited to 110, then in 2015 it went to 99 mph.

Well stomping on it regular I can only hit 99... but if I stomp on it and activate the kick down mode I can hit 112..
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As for the intake gaining 36 hp.

Here's my experience:

I've put intakes on several cars I've owned.

Most of them by themselves have done little to nothing, at most 10 hp.

 

For my Hellcat AFE advertised the same 36 (or so) hp with an intake alone, dyno tests/sheets and all.

Many of us bought them as soon as they were released in a group buy.

Several independent people took their Hellcat's to a dyno and did before and after dyno testing of the AFE intake and got zilch for power gains.

I did my usual road/track testing and got zero performance gains. Because of my tests and the couple people who independently dyno tested it, most of us sent the intake back for full refund.

 

I'm sure and feel confident saying Blackbear didn't manipulate their intake dyno testing. But here's my issue. Dyno tests vary so greatly they are hard to fully substantiate. Take the MIT tube. Apparently just a couple years ago the MIT tube did the best on the GM motor in BB dyno tests. This time around hardly a gain at all. Maybe they'll test the MIT tube again in a year and it splits the difference.

There are lots of variables on the dyno.

Here's my two main issues with what I often see on a dyno:

 

1. Hood up testing. Especially with open element CAI, testing with an open hood isn't realistic as it has the ability to take in air that wouldn't be able to do while driving. It also allows the hot air from the engine to escape instead of building up the heat under the hood more like would be the case on the road. Dyno tests should always be done with the hood down.

This is not to say that BB did the test with the hood up (they'd have to reply to that) but I have been to many shops and have walked in to see a dyno going where the hood is up on the car.

 

2. Fan speed and direction of air. When driving on the road, you have a consistent area of air being pushed into the front of the vehicle. The air is not directional like on a dyno using fans. Further, on the road, the amount of air coming in increases with the speed of the vehicle. On the dyno with the fans on, the amount of air that is directional is also static, the speed of the air doesn't increase with the speed of the engine.

And on the dyno you are testing in 4th or 5th gear on most cars, going to redline. This would equate to well into triple digit speeds, often times 140+ mph. On the road you'd have 140+ mph of air smashing against the front of the car, on the dyno with the fans most shops have, you are lucky to have 50 mph winds hitting the front of the car, and again with little uniformity and directional based on where the fans are pointed, if there is not multiple fans evenly covering the front of the vehicle.

So when the dyno starts at 40 mph you have the proper amount of wind hitting the front of the car, but as the dyno runs go on, the fan speeds don't increase to replicate the increase in engine speed correlated to what you would be doing on the road.

 

Now I'm no scientist, but to me, logic would dictate their are going to be some inaccuracies because of this.

 

An interesting test on the dyno for BlackBear to do would be to do a baseline dyno again, get 3-4 runs in with 5 minutes of cool down between each run. Strap on the AFE intake again, then do 3-4 runs with 5 minutes in between again. See if the test results are the same or similar with the same or similar gains this time around. If it's within 1-3 hp of the last test, it would be safe to say the intake is picking up a fair amount of power.

 

I believe the stock intake probably is restrictive, due to GM's desire to have a vault quiet truck.

I do question that if this engine is essentially the exact same engine as the LT1, how is it that the LT1 is rated at 35 hp more (455) with better intake air flow, better exhaust, and different tuning, if you can get that exact same 35 hp gain on this engine with simply an intake, no need for a freer flowing dual exhaust system or a tune? Maybe even the "restrictive" stock exhaust on the trucks, with it's smashed down cross over section, 4 into 2 into 1 exhaust system, and large mufflers and cat still flows well enough to suffice if you strapped it onto a 455 hp LT1 too.

And maybe the tune difference is purely where the power is made and nothing for improved power. If that was the case, then it's possible the 35 hp difference is solely in the intake. An air flow test would probably tell us that.

 

Maybe it's time for another one of my road/track tests for some real world empirical data. :D But I have a 2017 and supposedly AFE intake only supports up to the 2016 truck. Didn't think their was any difference between the 16 and 17's intake?

Dyno'ing an engine via the wheels is definitely not an exact science.

 

If this was just a stock dyno, and then a dyno with an afe intake making 25whp (like most people do when testing a particular part) I would probably conclude there were variables effecting the test and in the real world there is no way the intake actually makes 25whp.

 

But when you factor in that there are several dyno's all pretty consistant, it really points to it being the real deal.

 

The truely amazing thing about these motors is, lt1 guys are making close to 100whp on bolt ons and e85. So our 6.2's are down like 40hp stock, and then another 100+hp without even touching the engine internally. It's amazing how you can uncork these things. I've never in my life heard of a naturally aspirated engine that responds so well to bolt ons.

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  • 2 years later...
On 2017-01-14 at 11:01 AM, SkiDooNick700 said:

Interestingly the aFe website is only showing about half the gains of what BB showed. They used a 5.3L truck though. Maybe the 6.2L has a lot more to be gained from this kind of mod?

Yes. There is no way a 6.2 puts down 291 hp and loses 31% 

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My 2015 6.2 rolled over and stopped making power just over 5000 rpm with the factory intake on the dyno.  You could even feel it on the street.  I cut my air box and fender, which were incredibly necked down as well as adding the MIT tube and that roll over raised over GMs 5600 rpm rating.  I would not doubt it picks up that much just letting it make it to the proper 5600 rpm without going flat or losing power lol.  The 5.3 draws significantly less air so its gains would be minimal if any at all without some major mods.

Edited by SierraHD17
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