m05fastbackGT

Bill ! I was strictly referring to the other post, in which Bob was referring to the stock exhaust as an airflow restriction, and from a performance point of view only ! Therefore, I didn't miss anything, being that sound wasn't brought up in his post, to begin with..However on the other hand I definitely agree with you, as to why most people do upgrade lol. In fact I've just recently upgraded to Pypes Violators, because of the stock axle backs sounding way too quiet..Although, if just running the Violators still isn't loud enough ? then you can be assured, that my next mod will be an off road H-pipe, or Mac off road prochamber

GT Bob

Thanks guys. Just started posting over here, tho I am a regular on Mustangforums for a while. I work on the side as a tuner so I have a pretty good grasp on how this stuff works, but am just now moving over from the LSx world into the Ford mod motors 2nd Ford I have owned, and this stang blows away every one of the 14 F-bodies I have had. Anyway, if ya don't mind.. I've picked a couple of pieces apart above that I am going to pick at a bit if ya don't mind (in the name of friendly conversation/debate)... Keep in mind also, my initial reply was somewhat simplified, just so I didn't loose anyone in it, especially the OP who has no background in this stuff.

1. Now, I can't say that my approach has been super scientific, but I've yet to find the stock airbox restrictive. It's opening is MUCH larger than ther MAF (in the high 90's to 100 mm range compared to the 80 mm of the MAF) and I've yet to find any increase in ET's by doing any kind of change to the box (i.e. remove the filter, remove the lid, remove the whole box), which to me, HAS to indiciate that it's flowing better than the most restrictive part of the intake, which has to be the MAF or the intake pipe. Since the intake pipe only adds like 5 or 8 hp on the Steeda CAI (which is the only intake I have seen that can use the stock intake pipe), that basically rules out the everything but the MAF. The second benefit of the larger MAF is that you can meter more air with introducing less turbulence into the intake path.

2. I agree 100% on the exhaust being high flowing, except for one part. The exhaust manifold... While it may flow on a bench as well as the rest of the exhaust, a flow bench will not simulate the pulses and pressure waves that an actual header/manifold goes thru, nor will it show any kind of scavenging capabilities. Now, I understand your point about the shorties, and agree 105%. They don't make power on the Mods, however, shorties are historically known for not making good power, simply because of the resonance and scavenging tuning that you can't do with them. There is just not enough length in them to pull it off. Long tubes however, can be tuned for both of these things and regularly are. I suspect (and have yet to find it in writing, but I really think its the case) that it's this very scavenging tuning that gives the long tubes their additional Horsepower, above and beyond what the shorties/manifolds give. I also think that the reason this gain from scavenging is so substantial, is that it overcomes some of the limitations designed into the stock heads/cam (which are incredibly well matched to what the rest of the car desires) to keep HP levels and durability well within what Ford considers safe.

The other reason I list it as the 2nd biggest restriction is simply, it's the second largest HP gain you are going to get from a car without forced induction or opening the engine case up. CAI/tune being the first, most guys are reporting in the 20 hp range from what I have seen. And beleive me.. with the bet I have with my brother, I am tracking gains on peoples mods like it's my job.. lol.


And Lastly, Bill, your car is the reason I have a Torch red 07 GT sitting in my garage right now You've made my marriage worse, and my drive to work SO much better..LOL!

m05fastbackGT

So you claim to have a pretty good grasp on how this stuff works huh ? well I suppose that tuners such as Brenspeed who btw, have specialized in Ford modular motors for 10+ years, who also R&D every product they sell, doesn't have any background either right ? And while you're at it ! why don't you also ask every CAI designer such as Lee Bender, from C&L along with Steeda Autosports, as to which component of the factory intake system, restricts the most airflow ? And I guarantee time and time again, the answer will always be ! the stock airbox..The reason ? other than for the very small opening in the fenderwell ! there's no other place for air to be pulled into the stock airbox to reach the throttle body, thanks to both the bottom and side sections of the airbox, being completely sealed off from the corner grille opening..As for the exhaust manifolds ? Lidio from Alternative Auto Performance, also conducted an independent test comparing the factory exhaust vs MAC 1 3/4 mid length headers, along with a custom high-flow catted H-pipe, and Flowmaster Delta 50 series axle backs..After all was said and done ! his dyno results confirmed just 10-15 RWHP over the stock exhaust, and only at the very peak RPM's..And although, I personally don't have any background as a tuner ! my posts are the results of extensive research from tuners such as Brenspeed, Bamachips, and also from Mike at Powerhouse Automotive, who dyno tested my Steeda CAI and Bamachip's tunes personally, all in which have been in the performance industry for over 15 years..Therefore, the bottom line is this ! when CAI designers such as, Lee Bender from C&L maintain the stock airbox along with the ribbed S curved intake tube, as the main culprits behind it's airflow restriction, not only do I take his word for it ! but he also has the dyno results, to back it up as well..That being said, I personally could care less, as to how much of a grasp you claim to have ! unless you have proof on the dyno, to back it all up ? you're claims don't mean a thing, as far as I'm concerned..And finally ! here's a direct quote, from Lidio at Alternative Auto Performance, concerning the stock exhaust manifolds..Even the exhaust manifolds have a header like shape cast into them unlike older 4.6L manifolds which were essentially a tube with 4 tubes leading into one log. The ‘05 manifolds basically have a 4 into 1 header design..

LBJay

Not really, a bigger MAF tube causes the air to have a lower velocity past the sensor (at any flow rate) then it is calibrated for.

Being calibrated for a smaller tube the ECM interprets the lower velocity as less air and therefore commands less fuel to the injectors causing the car to run lean.

2006muzzy

Gonna pull the trigger on getting the C&L mass air. Anyone have any input on this system. C&L will also provide the 93 oct tune for the preditor for me if I buy through them.

GT John

m05fastbackGT

Hey Tony ! The C&L racer intake is an excellent choice..However, you would be much better off, if you purchase both the intake and tuner from either Bamachips or Brenspeed as their custom e-mail tunes, will give you much better throttle response, by getting rid of that nasty throttle lag and also provide better overall performance, over the Predator's canned tunes as well..That being said ! you definitely won't be disappointed

TacoBill

Thanks Bob!

Welcome to the car vs wife club!

Be sure to post up your pic here in the TR section.



And Rocky, lighten up a bit, I know you get pretty passionate in your posts, but try not to scare the new guy away (just yet)!

m05fastbackGT

Who me Nah, the last thing that I'd ever want ! would be to scare anyone away Bill..However, when it comes to defending Doug, Brent, Lidio, Lee, and Mike ? then yes ! you're absolutely right on the money..I get extremely passionate

metroplex

When you run an aftermarket intake assembly upstream of the MAF sensor, you will NEED to get a tune, just like when you install a Marauder airbox and MAF on a non-Marauder Panther.

If you modify your stock box, it will skew the air transfer function (which is what the tune changes to account for more air going in with aftermarket CAIs). It's best to get the car dynotuned rather than depend on a canned tune.

My opinion is to stick with stock unless you are trying to squeeze every bit of hp to win at the track. The aftermarket CAIs aren't tested as well as the OEM airbox and intake assembly. The OEM spends more money than what these CAI vendors are worth, just to evaluate the airboxes (NVH, thermal, water jet spray, etc...)

LBJay

True, but also remember that Ford and the aftermarket manufactures have different sets of criteria for evaluating their intakes. The aftermarket is simpling looking to supply some increase in HP to the customer. Ford has to look at a system that meets their NVH standards, will tolerate all production variances and function properly in the dead of an Alaskan winter to the heat of a Nevada summer for at least 80,000 miles. Oh, and also come in on budget.

Hey, Powerball is up to 161 million. If I win I can buy a dyno shop and play around for a year or so. (Wish me luck. If I win everybody gets free pulls for life)

JonW

Remember, also, that the OEMs have to meet intake noise standards.

JonW

Actually, I'm not modding the stock air box except to remove the rubber snorkel. All I'm doing is providing a path for cooler air to reach the airbox. I know I'll still need a dyno tune because of the "different" air going into the airbox. I'll probably get a 'Bama or Bren tune, then drive the car to Kansas City and get it dyno'd.

metroplex

I already said that (NVH).

The OEM intakes are superior because they are designed to handle a variety of conditions. A conical filter might work well for a limited number of applications, but superior filtration and durability isn't one of them. I have yet to see any type of K&N-style oiled cotton gauze filters used in Iraq. I trust the OEM a lot more than I trust some of the aftermarket vendors that depend on customers/beta testers with deep wallets. Saleen's HID kit is a good example of this.

JonW

If I remember right, K&N claims a 93% effectiveness on their filtering ability. AEM claims a 99% effectiveness on their dry filter. I don't know what percentage the OEM filter is, but I would suspect it would be very close to 100%. The factory doesn't want to pay any more warranty claims than they have to. I'd give up a little bit of flow and a horsepower or two to have the better filtering capacity.

metroplex

Your stock paper panel filter will flow more than enough air for your engine. The GT500 paper panel filter has comparable dimensions as well. We've done studies on filters and found that the K&N-style filters can filter very well if you keep them well oiled. However, too much oil will contaminate the MAF sensor. Stick with paper for the best overall solution. Large OEMs have spent millions doing research and testing on these things.

I've "been there, done that" with nickel and dime mods and other more expensive mods.

m05fastbackGT

The airbox itself ! has nothing to do with the air transfer function..As long as the MAF housing remains the same size as stock ? the air transfer function remains the same, therefore NO re-tuning is necessary..Case in point ! C&L street intake w/no tune insert along with the Airaid/Roush CAI

metroplex

Incorrect. Anytime you modify the airbox assembly upstream of the MAF, you must adjust the air transfer function. Drilling a hole in the box will skew the air transfer function.

LBJay

For my own edification... please explain how its happens. I've head this stated and repeated several times and can't seem to figure out how an upstream modification screws up the MAF sensor readings.

Seems to me that would be saying the minute an air filter gets even the slightest bit dirty the A/F ratios will be totally messed up.

m05fastbackGT

Exactly what do you mean, by modify Upstream of the MAF ? are you referring to before the MAF housing or after ? my understand is ! as long as the MAF itself, remains the same size as stock ? it doesn't matter how large the intake tube is afterwards, the air transfer function remains the same..However ! if it does not ? then explain how the Airaid/Roush and C&L intakes with their no tune inserts, don't require any additional tuning. As not only are their airboxes modified ! but are really nothing more, than just heat shields