Hi,

I have the superchip on my 4.6l auto 3.55 4x4 and am thinking of doing the other two recommended mods; the air force 1 and magnaflow cat back exhaust.

Question for Mike or anyone else with these mods:
I know they will add horsepower but I'm wondering if they'll add a significant low end torque gain that will benefit me towing my boat.

Thanks for the help, I love this forum.

Randy

 

Hi Randy,

That's an excellent question, and the very short answer is actually "Yes."

The Air Force One will certainly help, intake kits in general do well to match their horsepower gain numbers with an equal torque gain in these gas-engine F-150's, I.E., usually it's about a 15-18 lbs./ft. gain and a 17.9 HP gain on a 5.4 motor with the Air Force One, for example. So yes, the Air Force One will help.

The Magnaflow exhaust will help more, as it's the only cat-back system we've tested that actually shows positive torque numbers at literally every throttle position, load, or vehicle speed tested, no other cat-back system has ever done that for us & we spent 23 months testing virtually every "name" system out there for the F-150. The Magnaflow shows the best torque results, and also shows the highest peak hp gains, even over tru-dual setups like the Spintech, for example (which causes noticeable torque loss below 3000 rpm even though the HP gain was second only to Magnaflow at 18-19 hp versus 21-22 horsepower for Magnaflow).

Nobody else comes close to matching Magnaflow's flow engineering over the past few years, they are managing to keep the exhaust gas velocity very high even at low rpms while opening up the flow capacity significantly, not easy to do.

It's far too common to get a horsepower gain above 3000 rpm but to actually *lose* torque below 3000 rpm with almost all cat-back exhaust systems, we found only a couple that did not cause torque loss below 3000 rpm. But with Magnaflow you will get the best results possible, and a solid improvement in any kind of performance, from just plain cruising around to towing a heavy load literally all the way up to drag racing. You don't lose *anywhere* with Magnaflow's cat-back systems, which is why we're so hot on them and made them the exhaust system we use in our Stage 1 kit.

Like I said at the beginning, "Yes."

Give us a shout if you'd like to go over this in more detail.

 

Thanks Mike,

I think I'm going to save and do both those mods, then for absolute sure (yeah right) I'll not do another thing, except those electric fans sound like a good idea too....

Take care,

Randy

 

Hi Randy,

You're very welcome, & I know what you mean by it'll be the last things you do "yeah right," as once the mods bug bites, it's hard not to do most or even all of the simpler bolt-ons.

The 4.6 in particular has signficantly less torque and makes it at higher rpms compared to the 5.4, so making more torque is more of a challenge in the 4.6 by comparison. But it can be done, the same intake & exhaust that does the best job on the 5.4 motor also holds true for the 4.6 motor as well.

Here we're talking about increasing the efficiency with which the cylinders are filled and then evacuated of the air/fuel mixture, and in this case, with the Magnaflow system you can not only avoid the typical "gain hp at high rpms but lose torque everywhere else" results that the vast majority of cat-back exhaust systems cause.

Our Performance Products Electric Fan Kit does indeed make a lot of sense, especially when more torque is required, as you're completely eliminating one cause of parasitic loss. Getting rid of the single mechanical fan means that the engine no longer has to expend energy to accelerate that 10 lb. dead mass up to engine rpms every time you touch the throttle anymore, and that is always a nice torque gaining modification as well as a mileage improver, in addition to another 14-15 horsepower being added.

Have fun,

 

Hey Mike,
One last question on the exhaust topic (I did actually try this question in that forum but...). How does magnaflow sound inside the cab? I'd like to keep a nice quiet truck still, is that still possible?

Thanks,
Randy

 

Hi Randy,

Yes, actually, the Magnaflow is *not* for somebody who wants a LOUD exhaust system, as it's much quieter than it's power gains would tend to indicate.the Magnaflow is about the same volume at idle , about 2 Db louder at cruise (but no "droning" inside the cabin), and then when you nail it, it talks to you, & nobody will have any doubt that a healthy V-8 lives under your hood.

The SuperCrews will always be a bit louder because of muffler positioning under the right rear seat, but even they don't drone (except for the 2002 Harley model, which *does* drone even with the factory stock exhaust!) with the Magnaflow.

So in terms of volume, the Magnaflow won't be a problem, I think it's a near-perfect compromise of low V-8 rumble with lower volume than you would expect. When you nail it, it barks out, but even then isn't LOUD, it's just strong.