how much did you spent on parts and labor total? Under $300(total) = win Over $300 (total) = loss IMHO
I gained 17rwhp 7 wtq just on a tune w/ osiris.

 

The labor for the install of headers, cats, y-pipe was $495. Parts were $409, all used and all stock from the HR engine.

I didn't take any video/sound clips of the exhaust because it sounds almost exactly like stock, except a little louder. There was no change in the tone.

 

Yes, these are the stock HR cats. I didn't want to deal with any issues if I were to be pulled over or when I need to get my car smogged.

Another potential bottleneck is that I still have the stock exhaust, which is only a single exhaust. On the 2008 HR engine, these parts are used with a dual exhaust setup.

The main reason why I'm keeping the stock exhaust is because I like the way it sounds. I still think it sounds better than the exhaust on the current G37.

 

Headers are worth it, but I wouldn't bother with anything that wasn't a 'long tube' type. PPE is making (or made?) a set that looked promising.

But you could have made that power without the HR bits, not worth the cost or time to install, even if it were free.

 

That's funny because for the HR engine, Infiniti touted the new exhaust components as one of the main factors for the power increase. I wonder why they went through the trouble to redesign the headers, cat length, and y-pipe. Maybe there are other things that the VQ35DE is missing that would help it take greater advantage of these component upgrades?

 

From what I've read headers are a valuable modification provided you upgrade your cams... which this guy evidently did.

 

i remember the hype over the HR y-pipe and it was a hot commodity. I don't ever recall hearing about the headers and cats. maybe the headers was redesigned, but they were never a cost effective mod, even with aftermarket headers, so i can't imagine anythign coming from the factory doing much. Cats, unless hiflow, i'd assume are like any other cats. There's only so many bends from that simply pipe to 'improve' upon. You definitely got the parts and labor at a great rate, but at the end of the day, you went from stock to stock. It's the tune that netted you most of the gains. The money would have been better spent on spacer or mrev and hiflow cats.

 

You picked up your HP and TQ from your tune. The exhaust mods did nothing for you.

 

Other than high flow cats, I have done all of the typical bolt-on mods. The only thing left to do is to build the engine, upgrade the suspension, tire width, and brakes, and go FI.

 

The biggest weakness on the DE is the intake manifold and on the non-rev the camshafts.
Otherwise, I stand by what I stated before - long tube headers, a good intake and exhaust and a great tune will put you at 280whp+ easy. Don't bother with the HR stuff, as they are only marginally better than the DE parts.

And the biggest gains in the HR are in the intake manifold sysyem.