6.2 with afe intake = 36hp!

Rawyzf · January 25, 2017

I only used crank hp in the first post because my first thought when I saw the results is that the intake is the missing link between lt1 and the l86. I've been trying to figure out where the lt1's get 40hp since I bought my truck.

Well....look what you started ;).

Lets start over.

SILVER SLED · January 25, 2017

I only used crank hp in the first post because my first thought when I saw the results is that the intake is the missing link between lt1 and the l86. I've been trying to figure out where the lt1's get 40hp since I bought my truck.

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The diff is in the intake manifold, the part that GM actually spends time and money trying to match with a particular engine and vehicle is different, and the exhaust manifolds are diff. Those are the two items that actually affect air flow. The exhaust manifolds for a 355hp 5.3 are the same as a 420hp 6.2. Meaning the exhaust manifolds aren't much of a restriction for a 5.3 since they can flow at least 420hp...not to start another argument.

truckguy82 · January 25, 2017

The diff is in the intake manifold, the part that GM actually spends time and money trying to match with a particular engine and vehicle is different, and the exhaust manifolds are diff. Those are the two items that actually affect air flow. The exhaust manifolds for a 355hp 5.3 are the same as a 420hp 6.2. Meaning the exhaust manifolds aren't much of a restriction for a 5.3 since they can flow at least 420hp...not to start another argument.

That is not where the difference is. Thats what I thought for awhile, and even argued it with JonA. JonA, who is actually an engineer and did dyno's with different manifolds, intakes, and exhausts was telling me the lt1 intake offers little benefit and the power is made up in the actual intake before the manifold and the exhaust after the manifold. I did not believe him at all, and I actually called bullshit on him. I can even find the thread if you like.

Then a couple weeks later we get a BB dyno test with a whole bunch of CAI's making big power.

Look I hear you, all of my automotive knowledge suggests it must be the intake manifold. I mean the l86 has these long runners and it seems more than obvious that's why it's choking up top compared to the lt1. I've been looking into this for months.

I have plenty of evidence now that I can confidently say it's the intake and not the manifold. JonA was correct.

truckguy82 · January 25, 2017

Here is the thread where JonA makes me look like an idiot and I am completely wrong about the intake manifold.

http://www.gm-trucks.com/forums/topic/194700-intake-manifold-swap/page-1

Add his findings to the backbear dyno's, as if the blackbear dyno's weren't enough.

We have pretty much undeniable evidence that the intake before the manifold is a big restriction on the l86. I mean JonA even found the increased vacuum at WOT compared to the lt1. Vacuum is the opposite of boost and indicates a choke, and the l86 has more of it.

SILVER SLED · January 25, 2017

That is not where the difference is. Thats what I thought for awhile, and even argued it with JonA. JonA, who is actually an engineer and did dyno's with different manifolds, intakes, and exhausts was telling me the lt1 intake offers little benefit and the power is made up in the actual intake before the manifold and the exhaust after the manifold. I did not believe him at all, and I actually called bullshit on him. I can even find the thread if you like.

Then a couple weeks later we get a BB dyno test with a whole bunch of CAI's making big power.

Look I hear you, all of my automotive knowledge suggests it must be the intake manifold. I mean the l86 has these long runners and it seems more than obvious that's why it's choking up top compared to the lt1. I've been looking into this for months.

I have plenty of evidence now that I can confidently say it's the intake and not the manifold. JonA was correct.

The intake manifolds are diff though. I ran across an article a while back about what they did to make the Corvette engine more suitable for a heavy truck. The diff's were stated as the intake manifold and exhaust.

truckguy82 · January 25, 2017

The intake manifolds are diff though. I ran across an article a while back about what they did to make the Corvette engine more suitable for a heavy truck. The diff's were stated as the intake manifold and exhaust.

I know they are different, but hardly any different when it comes to HP.

Every gear head on planet earth would come to the conclusion thats where the power difference is. It's not though.

This blackbear test seals the deal.....a bottle neck has been discovered. It's officially a fact that l86 owners have an amazingly easy and substantial increase in power by simply upgrading the intake.

15_silverado · January 26, 2017

I know they are different, but hardly any different when it comes to HP.

Every gear head on planet earth would come to the conclusion thats where the power difference is. It's not though.

This blackbear test seals the deal.....a bottle neck has been discovered. It's officially a fact that l86 owners have an amazingly easy and substantial increase in power by simply upgrading the intake.

So would you expect the same 8.6% increase for the 5.3L

5.3L. 355 x 8.6% = 30.53 @ the crank

Does that sound possible with the 5.3L or is it not as restricted as the 6.2L

I know it's hard to answer without some data, but what are your thoughts. Thanks.

Sierra706 · January 26, 2017

So would you expect the same 8.6% increase for the 5.3L

5.3L. 355 x 8.6% = 30.53 @ the crank

Does that sound possible with the 5.3L or is it not as restricted as the 6.2L

I know it's hard to answer without some data, but what are your thoughts. Thanks.

It's not going to be exactly so but you can imagine that there would be a few hp to gain at the top.

Sent from my iPhone using Tapatalk

Jason Patterson · January 26, 2017

An engine is an air pump

You have an amazing v8 at your disposal and you want to move it from a sports car to a truck. Whats the easiest way to reduce top end power and keep your torque curve to the left.....an air restriction. In a further effort to reduce power but not decrease towing capacity, they left the torque managment and throttle input on fun kill mode. It's very possible that during testing they ended up with a truck more like an srt-10 when really they just wanted a comfortable truck with towing power. It's clear that they purposely tried to zap the fun out of these trucks. Whether its for insurance reasons, fuel economy, or the warranty, who knows, but there is no denying they did do it intentionally.

Not to mention, these trucks run a bit rich from the factory. I've seen plenty of black smoke coming out of my tailpipe at WOT before my tune. It's also possible freeing up the air restriction leaned out the fuel mixture a bit further increasing the power. But as you can see from the timing, it didn't run too lean.

Speaking of SRT, I have been a Viper owner and forum member for many years and a similar situation arose quite a few years ago. There were certain claims that a simple intake (Vipair) created about the same increase in power as the subject at hand. Fast forward many discussions and follow up tests and it is now the running joke for nearly every Viper performance mod discussion. 2,000hp dyno videos always include the obligatory "All stock except Vipair!" That was a 30hp claimed increase on a 500 cu engine.

I am in no way saying that Black Bear did anything nefarious, I'm on many boards and they have a stellar reputation. I've purchased from them and will in the future. However, if you're wife leaves the house an A cup in the morning and comes home a solid C and tells you she's been eating extra veggies, it's probably too good to be true.

Silver ice 6.2 · January 26, 2017

420+36= 456... anybody want to do a group buy custom AFE 456 badges?

truckguy82 · January 26, 2017

Speaking of SRT, I have been a Viper owner and forum member for many years and a similar situation arose quite a few years ago. There were certain claims that a simple intake (Vipair) created about the same increase in power as the subject at hand. Fast forward many discussions and follow up tests and it is now the running joke for nearly every Viper performance mod discussion. 2,000hp dyno videos always include the obligatory "All stock except Vipair!" That was a 30hp claimed increase on a 500 cu engine.

I am in no way saying that Black Bear did anything nefarious, I'm on many boards and they have a stellar reputation. I've purchased from them and will in the future. However, if you're wife leaves the house an A cup in the morning and comes home a solid C and tells you she's been eating extra veggies, it's probably too good to be true.

I don't know how long ago that was, but I've been frequent participant on automotive forums since '02. Back then nobody had what we had at our disposal. 90% of automotive enthusiast still had no idea what they were talking about. They didn't have access to the wealth of information and sharing of ideas we had today. I am very confident BS like that doesn't exist nearly as much.

We have a lot of real evidence at our disposal, and you can't disregard it because of the typical bullshit marketing from the likes of k&n commercials and inexperienced enthusiast. Yeah you're right, most of the time a CAI does jack shit. Infact this is probably he best performance I've ever seen.

We have

-dyno's from a reputal source

-the same exact engine in another vehicle making 40 more hp

-tons of dynos of this engine making big power from simple bolt ons

-vacuum readings from the factory intake vs camaro intake

-Dyno's the show a gradual increase in torque in the upper rpm band indicative of removing an air restriction and not altering the sensor readings.

I challenge anyone calling bullshit to propose valid data, or even solid logic supporting otherwise.

"I've never seen an cold air intake do this" is not data or logic

F4Gary · January 26, 2017

Do the LT1 and the L86 both use the same cam?

Also, has anyone measured the areas of the fender intake hole, the airbox inlet and outlet holes, the MAF sensor and the throttle body (not sure it that is what it is called)?

Also the air velocity at wide open throttle and various rpm?

truckguy82 · January 26, 2017

Do the LT1 and the L86 both use the same cam?

Also, has anyone measured the areas of the fender intake hole, the airbox inlet and outlet holes, the MAF sensor and the throttle body (not sure it that is what it is called)?

Also the air velocity at wide open throttle and various rpm?

Yes same cam

To the rest not that I'm aware of

IOMike · January 26, 2017

I don't know how long ago that was, but I've been frequent participant on automotive forums since '02. Back then nobody had what we had at our disposal. 90% of automotive enthusiast still had no idea what they were talking about. They didn't have access to the wealth of information and sharing of ideas we had today. I am very confident BS like that doesn't exist nearly as much.

We have a lot of real evidence at our disposal, and you can't disregard it because of the typical bullshit marketing from the likes of k&n commercials and inexperienced enthusiast. Yeah you're right, most of the time a CAI does jack shit. Infact this is probably he best performance I've ever seen.

We have

-dyno's from a reputal source

-the same exact engine in another vehicle making 40 more hp

-tons of dynos of this engine making big power from simple bolt ons

-vacuum readings from the factory intake vs camaro intake

-Dyno's the show a gradual increase in torque in the upper rpm band indicative of removing an air restriction and not altering the sensor readings.

I challenge anyone calling bullshit to propose valid data, or even solid logic supporting otherwise.

"I've never seen an cold air intake do this" is not data or logic

People are going to believe what they want to believe. I used to race a buddies modified G8 with my (stock at that time) 2005 GTO, both auto's. I always lost by a noticeable amount, everytime. By just putting in a OTR (over the radiator) intake we were dead even. We had both modified multiple vehicles and were amazed by how much of a difference a intake made.

An intake can be a considerable difference if the oem one was not designed correctly and the aftermarket one is actually done right (most have little to no development into them). This won't apply to all vehicles obviously.

Thanks BB for doing the testing.

BigBlueLB756 · January 26, 2017

Having just installed a MIT and Green drop-in filter on the 5.3 in the Hoe, I've noticed NO additional intake noise at all from this combination. It really makes me wonder what all of that flat black plastic in the stock intake piping does. It was a nice place to lay tools while installing the catch can, though.

Guess I'm just happy with the cleaner under hood looks.