Intake....What's Best?

#1

What are you guys doing about your air boxes or the lack of, air filters etc? Is there a performance advantage of one over another?

Thanks

#2

Stock box is best and if I recall correctly the rules are going be mandating it.

#3

Stock box - K&N OEM replacement panel filter. From what I read, there is Zero benefit to a cone filter on a dyno - actually - the opposite. I think the theory is the AFM is the bottleneck.

#4

I got 3hp by removing the box and running open on the dyno. I lost 6 by removing the plastic funnel on the front of the AFM.

#5

Does anyone have a spare airbox tube they’d be willing to part with? I just have the hole on the front of the box and it sucks in hot, underhood air.

#6

Part Number: 13-71-1-713-128 Air inlet tube $9.16
Part Number: 13-71-1-284-612 Duct $9.36

You need both - one is the tube, and the other looks like the bell of a trumpet. $18.52 total from www.trademotion.com. With gas what it is, cheaper than driving to the junkyard!

#7

scottmc wrote:

Good thing I found this in time. I’m heading down to Korman to get some stuff. Part of the “stuff” might have included an aftermarket box. Saves me some cash.

#8

OriginalSterm wrote:

Might not be worth worrying about. And I say this as the SepcE30 guy that’s most likely to be obsessed with things. But even I can’t get worked up by this one.

Well, ok, I was obsessed by this, but I got over it. I did a bunch of research on this last year. A consensus emerged that our airbox design was pretty good, and the filter design was very good. It’s hard to find good data tho, because Marketing dept. types stretch the truth a lot.

In reference to heat, at 100mph there’s likely a lot of airflow in our engine compartments. When folks talk about getting cold air to the intake, they’re talking about a static situation where the car isn’t moving. It be just as useful, and much more amusing, to put on a faux hoodscoop.

#9

I can’t help but keep Korman’s air intake kit in mind. I take your word for it when you say the stock intake is pretty good, but seeing as how Korman’s been building their own stuff for their own race cars for the past 20 years, I get the feeling that it must have made some difference. I just don’t know how much and if it’s worth it. Their reputation is what keeps me from dismissing it so easily.

#10

One answer… Dyno. And don’t keep the results to yourself. There is a local guy down here that gave me 4 runs for less than $100 bucks. I agree with Korman beinging around the block on this stuff for a long time.

Also - don’t miss Scott’s note up top- there is a good chance the stock box will be mandated in the near future, which makes your purchase and testing money out the window.

#11

you also have to look at how they applied it - for example, maybe on their cars they made a headlight intake to bring lots of air to the cone filter. We can’t do that.
cheers,
bruce

JeepinMatt wrote:

#12

leggwork wrote:

[quote]you also have to look at how they applied it - for example, maybe on their cars they made a headlight intake to bring lots of air to the cone filter. We can’t do that.
cheers,
bruce[/quote]

From what I can tell it just drops in. Didn’t see any additional ducting

#13

does Korman claim any benefit? because I’ve yet to hear of a benefit in a BMW application.
thanks
bruce

#14

leggwork wrote:

[quote]does Korman claim any benefit? because I’ve yet to hear of a benefit in a BMW application.
thanks
bruce[/quote]

Beats me. Doesn’t say much on their website. I talked with the guy in charge of the racing applications for a while a couple weeks ago. I didn’t mention the intake, but based on everything else, it makes me wonder. I doubt they’d change it out if it didn’t help, but I’ll mention it and ask about their power increase claims when I’m at their shop in the near future. If they are planning to make the stock intake required, I’ll just leave mine in. Nothing wrong with it and it’s not a bad intake by any stretch.

#15

Ummmm. Doesn’t this rule prevent using an aftermarket box?

9.3.1.1.2. Stock air intake and air box assemblies may be replaced with an aftermarket filter that attaches directly to the airflow sensor housing. If the stock air intake assembly is used, it may not be modified in any way.

9.3.1.1.3. Heat shielding is permitted around an aftermarket air intake/air filter assembly, if used.

The way I read that, your only choice is a filter on the end of the AFM housing. As the rule stands, the grey area is in the “heat shielding” part.

Steve D.

PS - If I did it right, I attached a “heat shield” picture.