Doug@C&L

Hey guys,

John's is an auto, please let's try to keep this post on track.

Thanks, Doug.

metroplex

Doug,

Is the stock air intake truly a restriction? I desire using the paper panel filter for maximum filtration efficiency, and I see the C&L flows about twice as much as the stock air intake. Does the engine actually need more air than the stock intake can flow?

The cotton-gauze style filters do not filter as well as paper (the military doesn't use K&Ns in Iraq and for good reason).

karman

The "good reason" is that the K&N is an OILED filter. Ever see how much sand sticks to oil. That is the reason they don't use them in Iraq. They get enough sand in the stuff WITHOUT oil.

Boomer

Was there a tailwind... downhill...towards a magenet factory

And is stock stock....
I hate reading 'I'm stock except for the ______'
well..thats not stock

metroplex

His GT was bone stock (no mods). Well, his weatherstriping was about to fall off...

SteelTownStang

Who shot JR? Where are you JR? You seem to have fallen off the face of the planet?

Doug@C&L

I think this question can be easily answered by looking at every aftermarket CAI on the market and the improvements made by them. Even using the K&N air intake I've seen excellent results without a tune, of course even better with. Also from the flow numbers posted in the first post you'll see that the aftermarket intakes require less effort for the airflow to flow through them therefore improving Hp.

If the stock box couldn't be improved upon then the kits from Ford or Steeda wouldn't make any difference as they just replace the box and not the intake pipe.

Thanks, Doug.

V8Mike

Here Here!! Great post!

downwithwallmart

metroplex

Having more products on the market can also show there is a demand for buying aftermarket parts, not necessarily that the stock airbox is a restriction.

Having an intake flow 10,000 cfm isn't going to do much if the engine is only capable of 500 cfm. I'm not sure Ford powertrain engineers would spec out a restrictive airbox/MAF combination. A simple glance at the stock MAF air transfer function will show what Ford intended for tthe stock airbox and filter.

The factory Ford 2003-2004 Mercury Marauder MAF has a peak flow rating of 54 #/min and the stock intake is used on 400-450 hp supercharged applications.

m05fastbackGT

Hummm and I wonder why that could be ???

Doug@C&L

I guess what I'm saying here is that if there were not any gains to be had from a Aftermarket air intake then the stock airbox would make the same Hp numbers as one of these kits, it doesn't. I invite you to run your stock Mustang air intake against one with a aftermarket unit and I can guaruntee you'll see improvements.

Also the flow numbers of the stock airbox as compared to the C&L/GMS aren't even close. You are still looking at the high flow, like I've said the low flow numbers would still be higher at 5 inches of vacuum as well as 20 inches, in the same proportion.

I haven't done a Marauder so I don't know about these airbox systems but Saleen uses the stock air box as well as Roush. BUT, if you want to flow MORE air and make MORE power then you upgrade to a different style and when you do you have to retune to ensure the proper transfer function on the MAF. Ask Justin, he'll be happy to explain everything I've said to you.

m05fastbackGT

Doug? is your e-mail address still www.bamachips.com? or has it changed? I know it's been 7 months since my last message, anyway, let me know when you have a free moment... Rocky!

metroplex

I may have missed this in some of the other threads, but what type of hp/torque gains are we talking about when comparing a dynotuned stock intake setup with a dynotuned aftermarket intake setup (GMS, C&L, JLT, Steeda/FRPP, etc...)?

Doug@C&L

Ask me in another thread, this thread isn't the place for this...

m05fastbackGT

I believe another reason Ford designed the stock airbox was for emission purposes, which may also be the reason for it's limited airflow capacity or restriction

Doug@C&L

Yes, BamaChips@gmail.com or info@Bamachips.com

Thanks Doug.

Justin00Stang

I know Doug very well and I believe that his article is accurate, based on the facts presented by him. I would never attempt to tune a car with a jumper box and some kind of so called calibrated maf sensor as granatelli trys to do. Pro-Ms calibrated MAFs never really worked right.

Justin00Stang

To add some more information. The stock GT intake is horribly restrictive, even when used on a V6 mustang that only makes ~200rwhp. On V6's I see gains of 6-7rwhp with a good intake, and double that gain on a GT.

SilverHorse-----Racing

To add another couple data points - our car was the one used by Superchips in the design of their 1755 tuner last year, and had a month of dyno and tuning time on it as they got through the software for the first time. The power gains were 15 hp and 15 lb/ft of torque with no modifications to the mechanicals whatsoever - however this requires the use of 91 octane fuel. Attached is a dyno plot from those runs. A proper CAI builds upon that, but was not used because we wanted 100% stock #'s to be measured on the car at the time. In the interest of full disclosure, they are one of our sponsors of our racing program, but if I didn't believe in their products and capabilities, I wouldn't work with them the way I do.

To reinforce further the CAI viability, look at the #'s posted on K&N's own site regarding Hp numbers for their various intakes. The drop-in filter gives you ~5Hp, the Typhoon (ricer piece) doesn't do much better, and it takes you to the FIPK to get 12Hp. Obviously if the filter were the only difference and the intake tube didn't matter, the drop-in would produce the same #'s, but it doesn't.

Another thing to consider when asking what the reasons for the difference are - there is more to building power than just peak flow rates. Just because the stock intake flows sufficient air to cover the pumping requirements of the engine does not mean it will be as efficient as a better designed intake. Any pumping losses you can minimize (ie the engine has to exert energy to pull in the fresh charge) will also help to add to the RWHP measured by the dyno. Also, the factory has to design for certain standards, meeting a long list of internal and external requirements. The aftermarket has a lot more liberty in their design specifications, and can also tailor specific pieces for specific customers, unlike the factory that has to supply pretty much a "one size fits all" part for the job.

As to the cotton vs. paper - I firmly believe that a proper paper element will trap better than the cotton gauze products available - that said, the performance gains of a lower restriction filtering medium outweighs the increased filtration for many customers. If I were running in an extremely dusty environment with small particles everywhere, I might not go the cotton route, but for most of our customers, the use of the aftermarket filter is not an issue, even in long-term use. Heck, I remember the days when my 302 with a velocity stack on top of the carb only had a foam element to keep out things in the mosquito-sized and up range !! Not that I'd recommend that today, but that engine survived and is still around today..

The same can be said about aftermarket exhaust systems, but that is a discussion for another thread.

ski

Good article.
Here's my reference:
http://www.auto-ware.com/combust_bytes/eng_sci.htm