Terry, Question about exhaust

[scott015]

Terry... got a question about my exhaust. I plan to EVENTUALLY get a full long tube setup from you.... but dont have $1500 right now...

so I was thinking... right now I currently just have a dual flowmaster setup... if I were to get you to install some high flow cats and remove my factory 4 cats.... would that make a big difference to me? I mean, would i be able to considerably notice the differnce?

also, i would like new tips on mine... the first person who did my truck (before i bought it) did a crappy job, the tips are not centered up very good and are also a little smaller than I would like...

also, can i install an X or H pipe with system i have, or have to wait until the headers?

so here is what I want a price on:

1. high flow cats + tips + labor
2. high flow cats + tips + X or H pipe + labor

[L8 APEX]

Hi flow cats will probably slow your truck down. Hi flows are 350 installed, Tips fixed is 150 installed, X pipe may or may not fit depending on the system 150 installed.

[PoorSvtman]

Hi flow cats will probably slow your truck down. Hi flows are 350 installed, Tips fixed is 150 installed, X pipe may or may not fit depending on the system 150 installed.


why will hi flows slow a truck down?

[L8 APEX]

Lightnings love some back pressure. A few years ago at OnTrack the engineer challenged anyone to surpass the power curve on his stock system. Most get a touch more at peak but lose bottom end. When you remove the stock cats you loose to much back pressure and low end power. The only time you gain with hi flow cats is with long tube headers, KB, or pulleys over 6#. At that point you are moving enough air to benefit from the cats. A 4# is not enough for hi flow cats.

[Alpine]

Lightnings love some back pressure. A few years ago at OnTrack the engineer challenged anyone to surpass the power curve on his stock system. Most get a touch more at peak but lose bottom end. When you remove the stock cats you loose to much back pressure and low end power. The only time you gain with hi flow cats is with long tube headers, KB, or pulleys over 6#. At that point you are moving enough air to benefit from the cats. A 4# is not enough for hi flow cats.Yep, I am ready for the two # upper:evil

[PoorSvtman]

Lightnings love some back pressure. A few years ago at OnTrack the engineer challenged anyone to surpass the power curve on his stock system. Most get a touch more at peak but lose bottom end. When you remove the stock cats you loose to much back pressure and low end power. The only time you gain with hi flow cats is with long tube headers, KB, or pulleys over 6#. At that point you are moving enough air to benefit from the cats. A 4# is not enough for hi flow cats.


Ahh that means i need a 6# instead of my 2# :burnout:
Thanks for the info on that

[03LightningRocks]

Lightnings love some back pressure. A few years ago at OnTrack the engineer challenged anyone to surpass the power curve on his stock system. Most get a touch more at peak but lose bottom end. When you remove the stock cats you loose to much back pressure and low end power. The only time you gain with hi flow cats is with long tube headers, KB, or pulleys over 6#. At that point you are moving enough air to benefit from the cats. A 4# is not enough for hi flow cats.He isn't shittin ya!!!! I watched this phenomena on the dyno in Florida as they did my mods piece by piece. I started to get ticked until they put the 6lb lower on it and then I got to see a guy get his L dynoed with a six pound lower and stock cats....mine did better than his.

We then put the 4lb lower back on and he did better than me with his 4lb lower and stock cats on his truck. These mods only work right if you do the proper combos. Doing one without the other can be real disapointing.

I had long tubes...He did not. But with a 4lb he dynoed a bit higher than me. It wasn't alot better...my memory is faded but I am thinking around 10-12 H.P. I just thought of something else. With the 4lb comparison, his torque was around 12-15 higher....if I am rembering right, the torque was where the high flow cats screwed me most on the 4lb.


Rocks:tu: