I got my AEM CAI really cheap used from a member here, hang tight, one might show up here again.

oh, can you explain to me why a custom tune would make less power from a intake than the stock?

I mean if you get say 15 from just the intake and then the custom tunes cuts the power gain from a intake like mine to say 7.5 but you pick it back up else where, ( I just confused my self ) is that not self defeating?

I guess I would like to see the numbers for my self

Stock tune 5.4L 3V
Stock intake
CAI
Gotts mod



Custom tune 5.4L 3V
Stock
CAI
Gotts

I know with out major upgrades the engine can only use or need X amount of air, but you confused me when you said you would loose power gained by a CAI with a custom tune.

So basicly what I am getting here unless I am wrong and you are right, and I don't doubt that you are right is this.

Made up numbers

Stock 5.4l 3v
300hP
Gotts modd 305HP?
AEM intake say 310

Custom tune 93
Stock, 330?
Gotts 335?
AEM 338?

I made those up but you get the point.

 

YES! That's why, when asked our opinion, we generally recommend that customers skip the CAI if they are purchasing a programmer. $300 for 8hp just doesn't seem like a good bang for your buck!

(I know Bill has some dyno graphs illustrating what I'm talking about. I will see if he can find some time today -- or in the next few -- to either post in this thread or tell me where I can find them on our server so that I can post. My explanation, however, won't be NEARLY as good as his. )

 

Good, because if what you said is correct, I have been misinformed and repeating wrong information. I was under the impression that with a stock program, you got about 7 to 8 hp from a CAI and with a custom tune, you got 14 to 16 out of it.

 

I think I paid $150 for mine, but even at only 8Hp, the much cleaner and nicer looking bay is worth it, not counting the sound and drone that i love so much.

That said, I would love a set of e-fans but I don't want to pay that much for them, and I am to be honest, scared of them failing me.

 

 

Don't be afraid. Done correctly they are superbly reliable, clean up the engine bay, and reduce some of that parasitic loss.

And if you piece together the proper, quality components yerself, it's actually reasonably priced. Try searching for the recent threads on e-fans for more info ...


MGD

 

I've also seen some CAI's that have an open element in the engine bay. Unless your CAI can pull cooler air outside of the engine bay with the hood closed, your engine is going to draw in heated air and report higher temps by the ACT, which could result in the PCM pulling some timing out of the engine. Hoods are usually up on dyno pulls, but in the real world this could have a pretty significant effect on engine output.

 

Jim, I think it MIGHT be the other way around. On stock you MIGHT get an HP gain in the teens, but since a programmer can add between 25-35 HP, you're not going to get an additional 14-16 HP out of the CAI. So, between the two, the programmer gives more "bang", and in combination, the CAI simply can't add as much since the power has already been improved.

And, I know YOU know all that, but I'm saying this because I don't want people to somehow think that a programmer somehow "detunes" a CAI. It's just reduced the additional gain due to the fact that the program has already provided such a significant increase. (At least this is MY take on it.)

- Jack

 

Ok, then I think we are saying the same thing just in a different manner.
What I understand takes place:

1. Add a CAI to stock tune, you get an increase of about 7 HP
2. Add a custom tune and you pick up another 7 HP, due to having a CAI, so that with a custom tune, the CAI is worth about 14 HP

I have been saying that without a custom tune, you get only about half the potential from the CAI. Is that a fair statement or is that totally wrong?

 

It's not how I understand it - heck, maybe we're both out to lunch? I thought adding a CAI to a stock tune gave a possible gain of ~14 HP. But, adding it to a custom tune would only give an increase of ~7 HP, since the custom tune has already provided a big increase and you reach a point of diminishing returns.

Of course these HP gains are all RPM dependent, since HP is a derived quantity based on torque and RPM, and is calculated at WOT.

Oh well, I'm sure some expert will set us both straight.

- Jack

 

You may very well be correct. Hopefully, Bill will answer the question.

 

Simply put the 'power adders' are not 'additive'. Rather, well-designed intakes and even exhausts (refer to the Exhaust thread where Phil & Jim Allen posted recently), facilitates power production that a good tune produces and allows same to be maximized/optimized for a given vehicle.

Depending on the intake - and they are not all equal - CAI's, on their own, will add the most gain at high rpm's / high loads ( large throttle openings) where engine breathing is required most. Whatever that actual number is depends on the design of same. Bernoulli being who he is, often intercedes at lower rpm for a large-tube intake and provides no gains (or in a few cases undermines them by a degree due to a loss of flow velocity).

Note - The above has a caveat - as per Justin's statement ( which I've referred to a couple times before):

"Any aftermarket intake that flows well and puts the slot-style MAF sensor into a larger less restrictive housing is going to REQUIRE a tune for the vehicle to run properly. Intakes that do not require a tune are often just as restrictive as stock and do not result in large power gains".

Now - take that programmer - a good custom tune will add gains almost everywhere under the curve - which is one reason why you need to see dyno plots - so at say, 4,000 rpm+, the gains from the tuning 'mask' the gains from the intake.

The differences in the curve(s) would help highlight where that well-designed intake (or exhaust) facilitated/optimized the tuning results compared to what they'd be with just a tuner, or just an intake, alone.

HP numbers are meaningless in real-world terms without rpm data - and on a truck I'd be a lot more concerned with torque production anyway, and keeping it robust down low for most daily-driver's needs.

Just a couple NOS, SlowMaster, or K&N stickers and yer golden ...

Confuded yet? I am!

 

This is strange! Says MGDfan has posted, but when I open the thread, it is not there. I wonder if my computer just knows I want to ignore him!! LOL

 

?

Hmmm ... Strange. I've noticed BJ's posts to be empty of any real content ...

 

Damn, says he posted again. I'm sure it was something good. His posts are ALWAYs of value and so informative.