Patrick G

iTrader: (14)

Since I've been making one bolt-on change at a time, this bolt-on shows the American Racing 1 7/8" headers with dual cats and their gains on my 2009.5 G8. Keep in mind, my G8 already had an x-pipe with the deletion of the rear two post cats and mid-muffler so the gains weren't as high as if I was swapping from stock unmodified exhaust. Since I gained 31rwhp and 22rwtq over the previous setup shows the strength of the American Racing headers by themselves. Here's the overlay of my mods to date. The previous run had Vararam CAI, ASP UD pulley, Yella Terra 1.85 ratio rockers with Comp 26918 springs and 7.450" pushrods. Previous power was 361/367 rwhp/rwtq. Power after headers was 392/388 rwhp/rwtq. The next mod will be a Stage 2 ported intake manifold. It looks like 400rwhp with bolt-ons alone is within reach!

I plan on dynoing the ported intake this week.

Cold Zero

iTrader: (1)

Great results PG
This prove that 1 7/8 is the headers to go even with bolton
hope to see the 400rwhp with ported intake

BrianC98Z28

iTrader: (11)

who is porting the intake for you Patrick?

Patrick G

iTrader: (14)

Jeremy Formato from Fasterproms. It's his stage 2 ported LS3 intake.

allngn_c5

iTrader: (3)

Very good information. I'll be so happy when the money situation is right and I can pick up one of these in a couple/few years. I'd love a daily driver with some style, real punch, and still get good gas mileage. The 93 gran prix is great but everything is broke, lol why am I complaining it runs. Gotta get that 3.8 rebuilt for the coma esque 99.

Thanks again Pat for the update. Every time you post about your G8 I want to go out and get one of these things and start modding. Please give a fuel economy update when you have one.

htownws6

iTrader: (1)

nice gains

SUPER_CHEVY

Great number for a bolt-ons!!

I think it will reach the 400rwhp easily after you drop the intake.

Good luck.

MikeG

iTrader: (33)

Roller rockers aren't considered a bolt-on, at least not on this forum. Solid numbers regardless though.

Patrick G

iTrader: (14)

We're not class racing here. Bolt-ons is a subjective term. Most people consider adding high ratio rockers an easy bolt-on for adding power. Changing rockers is easier than swapping intake manifolds. My thread on the Yella Terra 1.85 rockers from several months back detailed this out. Hopefully, people have appreciated my methodical approach to disclosing which mods gained power and what you need to do to make them work properly.

6.0monsta

iTrader: (7)

Good stuff Patrick. I didn't catch the previous threads but did you gain any power with just the YT rockers?

PowerShift408

iTrader: (44)

I got in a debate on here the other day about roller rockers and whether or not they're a bolt. I'm on your side though, I believe they're a bolt-on.

Link to your thread with the RR install and results? I'm curious to know how much you picked up.

Patrick G

iTrader: (14)

Here's the thread on the Yella Terra 1.85 ratio rockers: https://ls1tech.com/forums/dynamomet...o-results.html

zigroid

iTrader: (22)

results like this make me excited for my LS3 headed 6.0L LQ9 build.

nice job patrick.

panterx1

iTrader: (22)

Any plans for a cam or any work on the heads?

Patrick G

iTrader: (14)

My next mod after the ported intake will be a DOD/AFM cam. After that, it will either be added cubes with ported heads (dead reliable) or a supercharger (more power potential).

I have lots of race car projects in the works so this G8 doesn't have to be super fast at the expense of degrading its wonderful street manners. I love driving this car everywhere. Loud exhaust, loose converter, and lopey cam will ruin its exceptional manners. Gotta be careful with the parts selection because up to now, nothing I've done to this car has made it less enjoyable to drive. It's only gotten better.

panterx1

iTrader: (22)

I hear you there. My wife drives our G8 (for now, eventually I will inherit it) so I have been looking into modifying it, but still being able to drive it somewhere nice withought turning too many heads by sounding like a race car when she pulls in. Will probably end up doing mods similar to what you have done thus far. You're not too far away, may even drive out there to get a tune when we are ready.

Sofls1

iTrader: (16)

AMEN!

Congrats on the results, and thank you for posting the data. I have been on the fence about switching to the 1"7/8 headers, but this is just solid data to prove what you and others have told me in private conversations.

ScreaminRedZ

iTrader: (3)

Great gains! I've been printing out your progress with the G8 as I plan on using it for a template when I start modding mine

At what point did you put the UD pulley on the car? Did you dyno it then?

PewterScreaminMach

iTrader: (7)

Damn, awesome gains. All these post-LS1 bigger cube GM motors make me sad when I look at my H/C LS1.

Larry

iTrader: (4)

Your G8 is a great car Patrick! Thanks for the ride and all the help yesterday. I could sure use that G8 for hauling my grandkids.

When you get ready for a cam I'm buy those Yella Terras from you.

Guys, Patrick knows his tuning. Give him a call if you want your tune right!