Next on my list is a new intake for my Expy 03 4.6l. Troyer really likes the AF1, and it does seem to have some neat innovations. There is also one by Trueflow - a foam filter that uses the stock airbox. So here are a few questions:

In the AF1, there is no airbox. So it beggs the question about sucking in hot engine air. They have an inverted filter that can draw air from the fender and, the inlet tubing diameter is reduced to induce a venturi effect (low pressure) which they claim cools the air a few degrees and thus eliminates the need for an airbox. Is that true?

Also, I've read that the gauze filters allow a lot of air - and consequently more dirt (sort of make sense). The true flow foam filter makes a good point about trapping dirt and allowing air to move around the dirt through the foam media. How does that sound.

Any thoughts or details would be appreciated. I'm mostly looking for performance, not looks or sound. I want to boost hp and mpg a little.

thanks,

John

 

I use the AF1 and like it and I do believe all the claims made by the manufacture based on R&D that TP did for 9 mo. or so before they were even for sale for the 04 3-valve

 

HI John,

All of this is very simple - Also, just FYI for future reference any time you want to know something - use the SEARCH feature and you will immediately find hundreds of posts about this exact topic and any other.

In short, you are "not* sucking in "hot underhood air" - that is a myth perpetrated by some of the intake manufacturers & others who really have not done properly isolated & controlled testing - and this whole mindset really comes from the days when carbs were used, prior to fuel injection. Take one look at where the air filter element is placed on the AF1 (and many other) intake kits - you will see it's nowhere near the engine itself.

In short, the reality is that at speeds below about 30-35 mph, it does not hatter what type of intake kit you have, there is going to be a little bit of "heat soak" - however, we have found that this is less with the AF! than with any other intake kit we have tested, including all the ones who claim plastic is colder, scoops are better, ram air this, that, etc. What matters is the air density getting into the motor, and by the time you hit 30-35 mph, there is so much air circulation under the hood that the temperature of the air entering the engine is roughly the same as ambient air temps.

We have tested this very thoroughly with many different intake kits, and one of the things that is important is how quickly a material takes on heat and how quickly it sheds it after a heat soak - because no matter what intake you use, from stock to every other kit in existence, at very low speeds and at stationary, you are going to get a bit of heat soak - so then it really becomes a matter of how quickly the IAT's come back down to ambient & how much power the engine is actually making.

We prefer the AF1 simply because it does a better job - just as everyone who has ever come to one of our public dyno day events (which we just held another one of this past weekend) clearly sees, the AF1 intake kit makes more power than the K&N, the Volant, and every other kit we have tested.

So I wouldn't start worrying about all the stories of how you are breathing "hot underhood air" - it's mostly myth and/or unavoidable (meaning it's unavoidable at stationary to the very low speeds I pointed out above) once you actually test those inlet air temperatures, and especially once you actually test power & performance levels, which is what it's all about.

The bottom line is, getting more air into the motor without killing intake air velocity is what it's all about, and what the Air Force One excels at, which is why we recommend them and use them on all of our vehicles (well, except one that is currently wearing a K&N because we wanted to test it's 30 RWHP gain claim - which turned out to be more like 10 RWHP instead).

We understand your concern over this, but it's considered one of "the basics" around here, and thus has been covered for years and years over literally hundreds upon hundreds of posts.

Please feel free to give us a call if you'd like to go over this in more detail, we'll be happy to.

 

Mike. I like the AF1 - the inverted cone filter that abutts the fender hole is a good idea. I am interested in the physics of the venturi effect - neckking down the tube a little to induce low pressure. That I get. They indicated that this also reduces the air temp a little. I was just curious about how that worked.

All in all, it looks like a good piece - well thought out and deigned. I appreciate the thorough testing you have done too.

Two questions -

1.. How about posting some pics and data of your "dyno days" events

2.. Are my tunes coming soon? it's been about 6 weeks!

Best Regards,

John

 

Unless mine is not installed correctly it does NOT abutt the fender hole. There is a several inch gap between the end of the filter and the hole in the fender.

Tom

 

Anybody know how to contact AF1? The number on there web site doesn't work and the email bounce's back

 

could be... I was basing my comment on an installation pic I saw on the AF1 website (I think- i've looked at so many I've lost track of what is what) and, the filter desgin is an inverted cone. I believe the AF1 website mentions that it is designed like that to take advantage of the fender hole, "if so equiped".

guess I will have to wait and see for myself!

Regards,

John

 

Hello John,

We do not post our dyno plots, that is considered proprietary info - the *only* dyno plots we hand out are to those who come here to be tuned in person.

We used to publicly post dyno plots, and unfortunately, people always immediately got out of hand, demanding a dyno plot for this, another one for that, and so on, endlessly clogging these boards with demands for all kinds of dyno plots - so years ago we made a firm policy of not doing that. We'd have to hire another dozen or more people just to keep up with all of those requests, as well as the fact that this also aids our competition, many of whom merely attempt to tide our coattails, as we are the first company to specialize in this vehicle platform's performance, and thus we help develop a number of products for other manufacturers.

People who schedule to come in for our dyno day events get a chance to see exactly what we do here, in person. So if you want to see data from us, I suggest making an appointment to attend one of our dyno day events.

Regarding anything about order status, Tech Support, or anything else that is of a nature that is between vendor & customer, as everyone should already know because of the reminder in big bold red type at the top of the page any time anyone makes a post here, it is against the rules here to discuss those matters here on the boards - so you will need to contact us privately for anything such as order status, Tech Support, or anything else regarding an order placed with us - and thanks in advance for your understanding on that, it's greatly appreciated!

Now with that said, chances are it's probably already done, as I do not have any orders that have been waiting that long since fully completed CPW's were presented sitting on my desk - so it might be a good idea to give us a quick call just to make sure we got your CPW's and they have all the info needed, etc., so our people can give you correct status, or take care of anything right away if there is any kind of delay or problem, OK? Thanks once again, very much, for your understanding!