magnaflow cat back

[camaroz87]

i have a magnaflow cat back and i just had it installed not too long ago but i never got the 3" s bend or a CAI or WHISPER LID so idk if im robbing my car of power it is a 3" cat back i feel less power and idk wat i should do ...also its quiet its not loud at all

[pcgame4life]

Re: magnaflow cat back

CAI will definitely help... the amount you exhale is limited by how much you inhale. :p as for the whisper lid, I don't know, not familiar with 98+. I'd invest in a good intake setup and a hi-flow cat, that should open up your sound quite a bit.

[odw777]

Re: magnaflow cat back

Well the guy at the exhaust shop said that 3" would be too big for me and that the air would start to tumble or something and that would acctually be worse then a smaller pipe. I don't know...
I have 2.5" catback with a 3" flowmaster dual.

Did you keep the original cat? Because I put in a 2.25" magnaflow cat but now I'm really regretting not using a 3" since the damn ses light is on anyways.

[pcgame4life]

Re: magnaflow cat back

Imo, throwing sizes around like that is giving you a power cut. 2.5, 2.25, and 3" in random places throughout your exhaust is bound to be bottlenecking your power, if you hadn't spent so much money on it already, i'd suggest on size all the way back. I've got 3" Magnaflow hiflow cat, 3" S pipe, 3" TSP rumbler all the way back... sitting in my room waiting for the shops to open back up after this damn holiday.

Since you've got an SES light, I'd suggest getting a new cat, sell your old one, a 3" with an O2 sensor hole in it, that'll eliminate your SES light, as well as increase sound and performance.

[odw777]

Re: magnaflow cat back

I know that 3" to 2.25" going from the header to the cat is a bottleneck.
But I just had the magnaflow cat put in. The code is for an oxygen sensor no transmission or something. The old cat was bad.
I thought a 2.25 cat wouldn't cause any problems cause its the factory size, I should have checked on here before doing anything. lol

But I really like thse sound it's really deep and loud. I don't know if it's the high flow cat, the 2.5 piping or both, but there's a definite improvement in the sound and it runs pretty good right now.

I don't want to hijack the posters thread though but he was talking about a performance loss from a 3" catback. I'm curious as well if a 3" is too big if it's done without any mods to the motor.

[pcgame4life]

Re: magnaflow cat back

I'll let you know wednesday when I have mine installed, SLP CAI, 3" s pipe, 3" hiflow cat, and 3" tsp rumbler ( no tips yet)

[CamaroBoy]

Re: magnaflow cat back

I have magnaflow catback exhaust, whipser lid, slp cai & K&N air fliter and those mods go together great. I suggest you buy slp cai & whipser lid. There easy mods to install and can notice a difference.

[CamaroBoy]

Re: magnaflow cat back

hey where at in PA r u some of us on the board r starting to meet up in the philly area.

[loser]

Re: magnaflow cat back

hey where at in PA r u some of us on the board r starting to meet up in the philly area.

he's closer to philly than i am, but im like 4 hours from philly.

[99v6cam]

Re: magnaflow cat back

The arguement for 3" exhaust being "too much" is just as stupid as the one that says that headers for our cars are useless. We just proved that heads alone (no other mods whatsoever) boasted a 10rwhp gain so just stop with random accusations without proof.

Back on topic: You need to at least get the 3" s-pipe, that's a crazy bottleneck you got going on there.

[camaroz87]

Re: magnaflow cat back

The arguement for 3" exhaust being "too much" is just as stupid as the one that says that headers for our cars are useless. We just proved that heads alone (no other mods whatsoever) boasted a 10rwhp gain so just stop with random accusations without proof.

Back on topic: You need to at least get the 3" s-pipe, that's a crazy bottleneck you got going on there.

i know im a damn retard i wasnt thinkin when i brought it to get done i just wanted to have it on quick you know how it is... but yea im gunna order it from summit tomorrow but that should def give me some better air flow rite?

[odw777]

Re: magnaflow cat back

The arguement for 3" exhaust being "too much" is just as stupid as the one that says that headers for our cars are useless. We just proved that heads alone (no other mods whatsoever) boasted a 10rwhp gain so just stop with random accusations without proof.

Back on topic: You need to at least get the 3" s-pipe, that's a crazy bottleneck you got going on there.

I don't know 3" is huge for a 3.8 v6.
The guy at the exhaust shop was talking about the air starting to tumble and creating restriction if the pipe was too big.
When I had my cat clogged and the stock 2.25 piping I could acctually spin the tires up just by hitting the gas quickly. That's with 3.08 rear and 245 tires and no mods.
But it would completely die when you were going at speed and didn't want to rev up.
So you have to be giving up torque to get that little extra topend.

[borispeed]

Re: magnaflow cat back

I don't know 3" is huge for a 3.8 v6.
The guy at the exhaust shop was talking about the air starting to tumble and creating restriction if the pipe was too big.

The mufller shop guy said 3" was not worth when he installed my flowmaster. It seems like all of them are agree. Probably they have not drive a 3.8 with 3" . Magnaflow guys think more or less the same:
As a general rule, you can enlarge the pipe diameter of your OEM exhaust system by 1/4- to 1/2-inch to increase your horsepower. However, any additional increase in pipe diameter is likely to decrease your performance; specifically, low end torque.
http://www.magnaflow.com/wideopen/performdata.asp

So the shop guy made me not to replace the OEM tubing. After reading different threads, I thinking to do a general 3'' replacement: Tubing, headers, catalyc and muffler. I want more air flow, but the quietest sound possible. What do you recomend?

[odw777]

Re: magnaflow cat back

Quietest sound possible? Well I don't know about it being that quiet but I'm happy with the 80 series flowmaster, though mine is 3" in dual 3" out. And then my tubing's 2.5 and cat 2.25 yeah I know random sizes throughout. lol

If you're doing headers I would get a 3" magnaflow cat because where those pipes met it turns to 3" and gets squished down. And then I would just run 2.5". Because an all out 3" along with headers just seems like too much for a stock 3.8. I don't know that's just what I think.

But I would really try to get that mandrel bent because crush bending's going to make it more restricitive in the bends.

Maybe if it was cammed rebuild and modified that wouldn't be the case. I know there's one guy here that rebuild his motor with performance parts and he's getting like 260hp out of it now, he can probobly benefit from a 3" all out.