Back pressure missing, how much I'm I loosing?

[drakesdad]

I have the trickflow trackheat set up H/C/I with bbk shorties. I am running just the four cats. I know I need more back pressure for optimal performance. Just curious if I will notice any performance once I go flowmasters?

 

[S/CBlack95GT]

If you have cats then you have way too much back pressure. Just the headers, an off road pipe, and mufflers is perfect.

 

[CManT1914]

lol, the stock system gives too much backpressure, especially for a h/c/i 5.0. Flowmasters aren't gonna give you much if any performance gains. Matter of fact, most mufflers don't give hp gains, just sound variances. The power comes from the headers and mid-pipe.

 

[drakesdad]

I'm actually on ebay now looking at off road pipes.

 

[HISSIN50]

Back pressure and exhaust scavenging are often confused. The latter is MUCH more important - with proper exhaust tuning, one wants as little backpressure as possible.

 

[The Green GT]

On my '94 I took the mufflers off, just the cats. You can feel the loss of power up to about 2500 RPM, but after that it kicks in nicely.

 

[drakesdad]

That's about where I lose the power now.

 

[black94gt50]

well I've read a couple little articles and seen some tests where it is actually better to have a good mid pipe and set of mufflers, no mufflers is not the way to go. Maybe try doing a search on here I believe i seen where someone posted a big chart of what mufflers made the most power on the same motor. I've also seen a couple tests in hotrod mag where they have ran open long tube headers on a couple of their motors and then tried a nice set of mufflers like dynomax bullets or something of the sort, and made more horsepower with the mufflers on, so the whole " you want no backpressure at all" is a myth. Like hissin50 said you want the least amount of backpressure you can get, but you want to make the least backpressure with a full exhaust : nice headers(which i hear that our stock headers on the 5.0 are good up to 300 horse or so), a good midpipe, and a nice set of mufflers. Just my opinion on the matter.

 

[Grn92LX]

You do NOT want back pressure. An offroad h pipe and a 2.5" cat back are fine.

 

[mo_dingo]

You do NOT want back pressure. An offroad h pipe and a 2.5" cat back are fine.

Common misconception. I don't know how it started either. There is a reason dragsters run open headers.

And using the SOTP meter is not an effective tool, in all honesty.
Scott

 

[xkuntrycowboyx]

i'd like to throw something in .... people keep saying... MAKES HP... exhaust does not MAKE HP proper exhaust flow frees up HP that's already there but needs direction on exit. it allows the engine to breath properly.

...and im not trying to pick on anyone in particular, just hear MAKES HP alot, and its not the right way to say it i don't think.

 

[1SLO306]

i'd like to throw something in .... people keep saying... MAKES HP... exhaust does not MAKE HP proper exhaust flow frees up HP that's already there but needs direction on exit. it allows the engine to breath properly.

...and im not trying to pick on anyone in particular, just hear MAKES HP alot, and its not the right way to say it i don't think.

:Word: well put!