Hi all. I have been reading a lot trying to get as much info on catback exhaust systems as I can but there are still some holes.

Magnaflow is using a straight flow design, and they (and Mike Troyer) claims there are ZERO low-end torque losses. I am under the impression that less backpressure usually means less low-end torque. How then did they design an exhaust system that is better flowing, which equals less back pressure, and does not cause any low-end torque losses.

On the flip side: If Magnaflows catback does not lose low-end torque, how does another exhaust system, such as Gibson or Mac which is also a better flowing exhaust than stock, lose low-end torque?

Thanks,
Glen

 

BTT...

Anybody??

 

Delete "exhaust backpressure" from your vocabulary. The only thing that matters is exhaust flow. Design an exhaust system that keeps the speed of the exhaust gases high, and you'll have good torque at any engine speed.

 

Thanks APT. That's the kind of clarification I was looking for. So then I suppose I should assume Magnaflow has designed a cat-back system that flows better at all rpm's compared to their competitions systems.

 

Borla and Magnaflow single 3" systems IMHO are the two best for performance. There are others that are better than stock, but compromise in one way or another.

 

Thanks again APT.

With all that information out of the way let me ask this. I currently have a cat back system from www.macperformance.com Unfortunately there is practically zero information on their site. Here is what I do know (from their tech line): mandrel bent pipes, high-flow muffler using some special reflective design. I believe the pipes are 3", however when I put it on I did not notice that any of the pipes were larger than stock.

It has a great sound, but I don't like that I can't break my tires loose from a dead stop (unless it's raining ). Do I frequently do that? No, it is just indicative of a low-end torque loss.

Is there anything I can do to remedy this? Preferable something that does not cost too much. Weld in a magnaflow, keeping all the other pipes?

Maybe I should just forget about it and move forward with some other mods like efans or a FT valve body.

 

You say you can't break the tires loose from a stop, could you before the exhaust modification? I don't really know what to say, because I can't break my tires loose, but then again they are taller, wider, heavier, softer compound, and I'm still running 3.55 gears.

I will tell you this though, Fords (at least my truck) make lots of low end compared to Chevys. I have a SCMT running 93 performance, AF1 intake, and Spintech truedual x-pipe exhaust. I raced a GMC (aka Chevy clone) with the 5.3, 245's and 3.73 gears and whooped him from a dead stop until I hit 30 (stupid Durango in the way), though she was catching up quickly. I wish I would have held the brakes and launched at 2k instead of mashing the gas (like she was) I would have proved to 8 Chevy fanatics that Fords kick major ***.