wont changing pulleys and flywheel make it a bitch to drive tho

How so? Can you elaborate on what you think might happen that'll make it hard to drive? Not enough torque off the line or something?

nah semtex, I already mentioned this in the other thread.

let me find it for you...

EDIT: Here you go

On UD Pulley

This is only a problem for UD pulleys which aren't well designed for the car. I am 100% sure this won't be an issue with the STILLEN pulley.

On having both lighter pulley and flywheel

I have a feeling this isnt going to be a problem with the 370Z. I think we can do both pulley and flywheel.

I had a horrible experience with Pulleys on the 350.. Not sure if it was the install or the bad pulley out of the batch.. A year of wobbling caused my crankshaft to almost strip the thread off - leading to a new crankshaft for what a couple horsepower a little better response? In and out of shops not knowing what was wrong. Put a stock pulley back on it and bought a new crank bolt and got rid of the car after a couple thousand miles.

If your in need of horsepower that badly Id skip all the bolt-ons and go FI for a couple thousand more..

Somethings arent meant to change.. Something connected to the main component of your motor is one of them IMO.

I disagree...how about you make sure things are installed right and enjoy the benefits of a more responsive engine and a some hp?

If we are going to be afraid of things because they aren't installed properly, then you would be insane to think that a FI setup is less risky, and that is by your own logic, don't you think?

This is a good mod, but like anything else, if you don't install it right then you can't expect good results. Also let me tell you, you got off easy..that could have been SO much worse.

Who's pulley was it?

A pulley is NOT something you want to take a chance on with a sub-par vendor. Don't go thinking you're going to save $$ and find one on ebay, you are opening yourself up to potential problems.

Not all pulleys are the same.. by any means. Thanks zeebra, you bring up a good point.

I have had pulleys on all of my cars. However, the gain you get from what you risk is not worth it.

Ok I'm re-hijacking my thread back for a bit.

Just got the Stillen cat-back installed. I raised the "center" section at the spot indicated in the instructions with a floor jack to try to get the system clear of the chassis crossmember, but in the end after I torqued everything down, it still dropped in a bit and came to rest on that crossmember. So clearly, I'll have to go back and loosen all the bolts and tweak this some more to get it to sit right.

However, I went ahead and fired it up for a short test drive. Words cannot describe how awesome the full exhaust setup sounds, and when I make an audio recording later, I'm sure it won't do justice to the live thing. Whoever was worried about the headers making it too high-pitched, I don't think you have anything to worry about. It's a really nice low growl (at low rpms), and changes predictably with load and rpms.

All that said, on the test drive I still had an odd rasp/buzz/whatever sound at certain RPMs under acceleration load on the road. Although the sound characteristics of the exhaust have completely changed, I recognize this as a sound that was bothering me before, ever since the cats/headers went in. I'm starting to think I must have a leak issue somewhere up in the area of the cats/headers still, which I'll also have to sort out. I may just run down to an exhaust shop sometime tomorrow and have someone who looks at this stuff every day listen around under the car and try to find it.

Anyways, minor install issues that are undoubtedly my fault aside, it's awesome. I think the catback really let loose a lot of pent-up gains from the headers and cats, I could definitely feel a real difference on the road. And the sound is amazing, although it borders on the territory of too loud, in a "My neighbors are all going to hate me now" sort of way. Not loud like a fart can on a civic, loud like standing in the pits at a NASCAR event.

Audio soon...

Awesome wstar!

The rasp you're hearing is most likely from the HFCs, and it's sort of par for the course. You want the increased horsepower, but it will add some rasp (although seemingly far less than previous year Z's).. Test pipes take that to another level..

But it will absolutely not hurt to run everything through and make sure their are no leaks, that will definitely add to the noise, and not in a good way.

The cat-back can take some adjustment, and a lot of people have asked us why there is adjustment in our exhaust systems. The answer, unfortunately, is back to Nissan, in that the stock exhausts don't always line up, and rarely are on spot. The cars are just built slightly differently. Most people don't notice because they aren't staring at the brand new part they just installed, the entire car is new. We go the extra step in allowing for minor adjustments to compensate.

Congrats on the new exhaust! Glad you're feeling the results others have been documenting..

Josh is correct. The OEM's test individual components on a jig. The jig has plus/minus tolerances. If on one side the tolerances stack to the plus side while the other stacks to the minus side you will have issues.

Well I think I know what you mean about the cat rasp, and I don't really mind that sound at all. I think I have something else going on too, some weak spot that doesn't really leak at idle or even revving under no load, but adds a pronounced buzzy sound to the exhaust note at certain rpms under accel. I've noticed also that if I engine-brake back through that same range, the buzz is replaced by a hiss like pressurized air leaking, which I'm guessing is also a good sign of a leak.

In any case, I've got a short vid from this evening so people can get some idea about the sound. The ugly buzz I'm talking about doesn't really come through on the video (odd). Then again, neither do the low frequencies either (I guess my mini-dv's mic sucks). You may think it sounds low and grumbly rolling around the parking lot at the start of the video, but the video is really missing most of the even lower frequencies. It's even more beastly in person. Under acceleration the audio track sometimes seems like the car gets quieter as it passes through certain RPM ranges - again that's the low frequencies the mic can't handle, seems to kinda mute the rest. There's no full-throttle runs in this, mostly light throttle just rolling up and down the rpms a bit. There's one good 3/4 throttle run through a couple of gears near the end though.

-- bleh youtube "processing" is taking forever this evening...
[YOUTUBEHQ]YS98sdExjz4[/YOUTUBEHQ]

Dude that sounds awesome! When will you be getting a dyno? Recall that RelentlessRY said he saw a loss of torque in the mid-range with these headers, but we suspect that it's because he had the stock cats & cat-back, and that this issue goes away when the headers are combined with HFCs and a good cat-back. Now all we need is a dyno to confirm once and for all (which is why I'm so eager). Still, thanks for the video, as it at least puts to rest the 'high-pitched sound' concern. +rep.

Sounds great! Rep added.

It sounds a little more hollow but that is to be expected.

Yeah, I think I need these headers. *sigh* I'm going to have to take the wife shopping. Again.

wstar--I'm having the same hissing sound with my cat/exhaust set-up. I'm taking mine to a muffler shop next week to get them to check for leaks and do some seam welding. I noticed there's very little room for error in the small pipe going to the exhaust from the x-pipe. I'm almost positive that's where my leak is coming from. Nothing a quick hit from a torch won't fix!