2009.5 G8 GT X-Pipe mod (photos)

[Fatdaddy]

Nice gain for such a small investment. you used 2.5 tubing and Fatdaddy used 2.25. do you think it matters which size is used? Is one size easier to install?

Are there different sizes of MF Tru-X? If so, which did you use?

Care to speculate what you might get from this mod with Kooks 1 7/8 mids and high-flow cats?

Grrrr8 job. Thanks.

I used the 2.25 x 12 tru-x and the 2.25 ss tubing. One end of the tubing has to be expanded to fit over the existing pipe. I also installed my X as far forward as I could get it.

My objectives do not include power adders. I only wanted to optimize what I have. Based on my past experience, I think the 2.25 pipe is the correct size and good to about the 425 chp level. My current dyno curve looks very similar to the one Patrick posted with peaks of 347/357. I think that puts me around the 400 - 415 chp level.

At this point, I don't think I have much exhaust breathing room left. A set of headers would improve flow but I might not be able to get max utility out of them due to the exhaust size limitation. I would be right on the line. I think I could get another 10 - 15 hp is all and 1 3/4 would be sufficient to get that. My guess is that if Pat and I both installed the same header setup, he would net more from it than I would.

As a secondary and useless (to me) point, I think the GXP absolutly needs a full 2.5 inch exhaust the second you make any power mods. I think the factory setup is maxed where it sits and will dilute additional power gains.

[johnbell2]

I think they reduced the size to get the flow rate high enough in DOD node so that the resonators would be effective.

Normally I would give some benefit of a doubt, but as Patrick has mentioned there is no change to speak of in exhaust noise/drone characteristics with this mod. That, and he has kept his DOD.

[G8V8]

The x-pipe must be helping get rid of drone. With resonators, if the velocity of air passing through them gets too low, the air does not expand outward into the bdy well enough to get any cancellation effect. That is probably why GM reduced the pipe diameter before and through the resonators. Not good for V8 flow rates but needed for 4 cylinder.

I'm looking at x-pipes and SS tubing. I see another mod in my future.

[98aggie]

Glad I could help ya out Patrick - nothing like having access to a dyno at 10pm.

So when do I need to plan on installing the next mod?

[johnbell2]

Boy, you fellas are out in the boonies aren't ya... I had to go to Victoria's GIS database to find you.

[98aggie]

Boy, you fellas are out in the boonies aren't ya... I had to go to Victoria's GIS database to find you.

Depends on how you look at it.

We are pretty much just a 1.5hr away from Houston/Austin/San Antonio/Corpus.

[Fatdaddy]

Boy, you fellas are out in the boonies aren't ya... I had to go to Victoria's GIS database to find you.

Depends on how you look at it.

We are pretty much just a 1.5hr away from Houston/Austin/San Antonio/Corpus.

It's the boonies alright. In fact Kurt (98aggie) is so far out there you dang near need a passport and a visa to get back to civilization. But he has nice toys.

[Speed6]

If drone was there with this setup like Pat did, i wonder if puting (Dynomax Ultra-Flo X Muffler) would be even better for drone ? X mufler and pipes..Insted Xpipe and no res..or mid.....

[johnbell2]

Depends on how you look at it.

We are pretty much just a 1.5hr away from Houston/Austin/San Antonio/Corpus.

Yahoo maps has you but Google doesn't... been a long time since I've seen that. When in doubt, city GIS

[johnbell2]

It's the boonies alright. In fact Kurt (98aggie) is so far out there you dang near need a passport and a visa to get back to civilization. But he has nice toys.

Y'all need another 2009.5 G8 customer as a data point? I'm game.