Thread: GXP Exhaust

So I'm getting readt to throw on a 3" dp, hi-flo cat, and cat back from hoganperformance. My problem is my exhaust manifolds. Is there such a thing as porting them and about what does that run. Is it even worth it? I know they dont make headers.

I'm getting the DP, Magnaflow cat, and bypass pipe (for after inspection) for 300. The tbs is from Airaid but I got it through summit racing. Can the exhaust manifolds be ported just like heads. And if so about how much would I be looking at? Get those holes opened up more but then consider the exhaust port on the head...hopefully someone can school me on this heh.

Originally Posted by Cableguy

I'm getting the DP, Magnaflow cat, and bypass pipe (for after inspection) for 300. The tbs is from Airaid but I got it through summit racing. Can the exhaust manifolds be ported just like heads. And if so about how much would I be looking at? Get those holes opened up more but then consider the exhaust port on the head...hopefully someone can school me on this heh.

300? thats a good price, I was thinking about doing a custom set up, mufflers, possibly resonator removal and a DP. Havin a hard time as well getting pricing info on the DP, but I dont know if it would be cheaper to just get mufflers, remove the resonator and throw on a DP. vs buying a whole kit. input?

Honestly...I am a L67 guy, don't know too much about the LS4...but I took out any imperfections from my stock manifolds with a high-rpm dremel tool and A LOT of sanding bits LOL You might give that a shot if you got time and patience

As for exhaust...depending on where you live...I'd take out the cat...plus they sound *****ing here is a link to a "converter" you V8 guys might look into to fool some noobs

I posted it elsewhere...but I'll give it to you guys incase you don't ever check out the L67 section

Catalytic Converter

Hope this helps ya at all

sweet man thanks for the info! good stuff!!

Yeah, emmissions in AZ can be pretty picky...so i think that will come in handy for me. I guess the only thing to do is start piece by piece and see what sounds like **** and what sounds good, I KNOW i want a DP, and mufflers...just gotta figure out the whole cat thing.

Anyone find out or know the inlet piping on the GXP (for my muffler swap), cant find out any of these specs online anywhere...hhm

Well I was gonna say since you are gonna run a 3" DP, that fake converter would be great to put in while it was off the car since or when it is being installed...personally my GTP sounds great with Flowmaster 40's...I'd tell ya the mufflers I am getting ready to buy but I don't want to kill the surprise...after I get them in I'd think they would sound pretty damn sexy on a GXP...with that V8 and all

Originally Posted by bluegtp91

Well I was gonna say since you are gonna run a 3" DP, that fake converter would be great to put in while it was off the car since or when it is being installed...personally my GTP sounds great with Flowmaster 40's...I'd tell ya the mufflers I am getting ready to buy but I don't want to kill the surprise...after I get them in I'd think they would sound pretty damn sexy on a GXP...with that V8 and all

40's are too loud. Magnaflow sounds real good and everyone likes the tone it has. It has a 70's Dodge sound about them. I plan on putting on a 3" DP from Hogan later this summer. You have to make sure you tune when you put on the larger DP so the computer won't code.

Just thinking and knowing the principle theory about it, you definitely will through a code. I'm trying to learn more about the HP Tuners program and when I get better at it I'll probably be doing a lot more mods. I'm ol' skool. Give me time to catch up. we ol' men are like fine wine. We might not be as quick as we used to be, but we're still fast enough to kick your A _ _! Well, you know what I mean.

It set me back $600.00. So far I like it. I haven't broken anything yet. I make small adjustments at a time.

Me and my youngest son split the cost. He has a '05 GTO. He's wants to go fast, but in a hap-hazard way. Like all kids, he don't listen, but he's learning (the hard way). I keep tellin' him, "I told you so." When he gets tired of spending and wasting money, he'll listen.

Originally Posted by Panther427

LOL i want one but tooo much money for me right now.

They give you enough credits to do two (2) cars and some stuff you can use for Wide Band before you have to buy more credits. Can't use it with a 64 bit OS (Operating System) Laptop. My wife is constantly screaming at me when her laptop turns up missing, even though I'm the one that bought it for her. You would think that she would be more accommodating. Her laptop has a 32 bit OS on it. She don't like using mines, but I need hers to tune.

I tuned the car one day going to church and let me tell you, she almost put me out of my own car. That didn't go well.