silverBFGXP

Hey guys. This is my second post here - looks like a great forum! (had to comment on that throttle body thread first)

I got my 08 GP GXP about a year and a half ago and I'm ready for an exhaust . Only mod so far is a drop in K&N, which was actually surprisingly effective.

After watching a million youtube exhaust videos I picked up a couple SLP powerflos because those things sound amazing. See here:
The thing is, I want to go either cat back or DP back with 2.5" piping instead of just half assing it and welding them to the stock pipes. I'm having a hell of a time finding 2.5" piping that will fit the 08 GXP. It shouldn't be that hard right? But I'm sure spinning my wheels a lot here searching over and over online.

Can anyone point me in the right direction for some 2.5" pipes that I can swap on? Thanks!

batboy

iTrader: (6)

SLP has drone issues. Magnaflow makes a catback for the GXP. Summit Racing has them in stock.

91parkave

iTrader: (4)

3' mandrel bends on eBay just have it welded in at a muffler shop

silverBFGXP

Oh trust me I've seen/heard the magnaflow a number of times. Not a big fan of it when compared to the SLP. It sounds good sure, but that SLP is exactly what I'm looking for.

So what I'm hearing is that my best bet is to just pick up various pipes off ebay (a few bends, a long straight or two) and weld them up? My cousin recently opened up a garage so welding is not a problem, though he cannot make bends.

xxtheshockerxx

maybe its the video but my magnaflows sound much louder.

TheMonteMan

i guy posted this link on another forum im on. the pic looks like it might be right but i havent really looked at it that hard. http://www.mandrelexhaustsystems.com...E-CARLO/Detail

91parkave

iTrader: (4)

What a rip off just buy the mandrel bends on eBay and have shop do the welding/cutting you'll save and you'll have it the way you want it

silverBFGXP

Nice exhaust shocker.

Thanks MonteMan that looks like exactly what I was looking for! Now I'll have to compare that to the cost of piecing my own together off eBay and see what I think abut the cost/benefit.

xxtheshockerxx

thanks. It is the catless downpipe and hacked up magnaflow kit. resonator delete. so I imagine you could get the pipe you have a link for with the downpipe and get the same results

99corvette

iTrader: (12)

Man your car sounds good! Every other magnaflow catback ive heard on youtube sounds quieter than the stock mufflers. It must be the catless down pipe.

baltsk8er69

iTrader: (1)

From far away our car sounds like a flock of geese. Just saying lol

baltsk8er69

iTrader: (1)

From far away your car sounds like a flock of geese. Just saying lol

99corvette

iTrader: (12)

Bahahaha^^^^

xxtheshockerxx

thanks. yea the downpipe really livened it up and I deleted the resonator too. Has just a little big of cackle over 4500 rpm. I am really liking it. Sounds really aggressive to me.
hahaha yes I scared the **** out of them when I took off. they were in the field across the way.

99corvette

iTrader: (12)

Had any problems with your tranny?

xxtheshockerxx

I do have an issue right now with what seems to be the converter holding on too long and the rpms dip way down

99corvette

iTrader: (12)

I'm about to buy a gxp on Saturday and I'm a little worried about this.

The_Madcat

If you are talking about the trans, you are in the right to be worried. But we have all been through it at one point or another so you will have knowledgeable folks that can help get you around it. If you are planning on getting an LS4 powered car, your first mod (and one you should plan on before buying the car) should be the transmission. TripleEdgePerformance.com has a lot of good info and the owner, David, is tops. We know how to make these things reliable and able to take bunches of power, as well as what parts are inherently flawed in the 4T65e-HD.

99corvette

iTrader: (12)

Well to me your first mod shouldn't have to be a transmission in a car haha! The one I'm getting has already had the converter replaced so I might be good. I'm immediately getting the car/trans tuned which should help it and also a tranny cooler. Don't these things have trans temp on the info center?

The_Madcat

Yes they do. I also agree you shouldnt have to, but you asked, and I answered. I doubt you would get many different responses from other LS4 owners Trans is really the first thing you should do, if you don't like being stranded that is.