I ordered this exhaust before reading this thread and mine arrives tomorrow. I'll post pics and video once installed with my thoughts on the fit and finish.

 

I know where you could've got the ISIS with a y-pipe for cheap...

In all seriousness, I want to make a recommendation. When you install the system I want to give you a heads up. I don't know your experience, so let me be descriptive without being insulting.

If you read through the whole thread, you'll see that I had some issues with driveshaft contact. I don't know if I have a non conforming exhaust or they have extremely close proximity to the driveshaft.

Install the full system with hand/lightly tighten hardware so that you can articulate the position of the pipes. When everything is in place on their hangers, try twisting the mid section away from the driveshaft and tighten the hardware at the y-pipe. You can preload the postion away from the driveshaft.

Follow that by tightening the hardware of the other flange. This should further help by providing decent clearence from the driveshaft. It's not perfect but, that's my two cents.

You may have better luck than I did. The clearence I have is only about 1/8 on an inch when the engine is off. That means you couldn't even fit a USB connector through that gap.

 

I'll say my experience is much more than most. I've been building, racing and repairing cars for 20 years and have ran my own auto repair/modification business for the past 12. Thank you though for the great information as I know it will help others.

 

Oh snap! I'm sure we've crossed paths before. What's the name of your shop? I've been up your way a few times for some SCCA events. I really wish I could be at RA this weekend for the IMSA event. The local mazda team speedsource competes in the prototype class. It's nothing too impressive.. They broke down at Sebring while I was rooting them on...

Yeah, I'm sure any of the open discussion we make here will help someone. I try not to direct my replys right at one person but, more so as open information or advice.

 

Well my shop is technically my garage and I'm way past outgrowing that space so I'm currently shopping for an actual shop to buy. I'll actually be at Road America next Sunday for my second Autocross. I've helped customers race on the big track but this will be my first experience on the Go Kart track. I was into drag racing mostly and have just started competing for purely fun and learning this year with my 350Z. Next year I'll look to run a full season with the Madison Sports Car Club. I'll just say I'm hooked on turning and breaking.

That's the perfect attitude. I love teaching and sharing information to fellow enthusiasts.

 

Right on, man! It's great to see so much involvement and enthusiasm. I like autoX but, it's so hard on the cars. Then again, you came from drag lol.

I look forward to your experience with the ISIS single. Your feedback will be great for this thread.

 

Just got confirmation that the exhaust is sitting at my house and I am off of work in 30 minutes. Ill be taking pics as I go and am going to see how comparable the 2012 G37 Y-pipe I have laying around is to the 03 350Z Y-pipe.

 

I don't want to take this thread on a tangent with another subject but, considering the circumstances I faced with the ISIS exhaust, it seems fair. I wanted to share some observations with the Gemini since I have related experience with manufacturing and avaliable equipment.

Pros
-SU304 stainless steel; Confirmed.
-Very well done, hand TIG welds. (Equal to acceptable aerospace grade welds)
-Very nice fabrication. It's just imperfect enough to show it's hand/semi-hand made, while retaining good details.
-Expansion joint (gap). That is a VERY good detail and shows there was thought put into the design. In short; without that gap, as the material expands and contracts with heat, the joint would put compromising stress on the weld causing it to crack.

Cons
-Poor packaging. (parts flying around in a big box with some bubble wrap.)
-Casted flanges (looks to be investment casting). That's not really a big deal for this application. That process is plenty strong but, it would have been nice for them to be completely machined from a cold-rolled plate. No biggy.
-Metal burrs. They could have taken 30 seconds to deburr the damn joints.
-Grease inside the pipes. Every pipe that has a bend in it has residual grease that I assume is from the mandrel bending. That should have been cleaned.

This information isn't something I've come across in reviews. I figured I'd just include it as a contrast to my previous input.

 

From top to bottom
-An example of a decent TIG weld with tight beads, straight tow lines and good fusion.
-Inside picture of the X-pipe, burrs can be seen on the intersection of the two sides.
-The pen is pointing at the expansion joint.
-x-ray fluorescence analyzer shows the x-pipe as "304-exact".
AKA, it is exactly 304 stainless steel.

 

That is very good information!

I received and installed the Isis Exhaust today. My fitment may be slightly different than others as my Z has an unkown to me brand of headers on it and it has given the cats and Y-pipe slight down angle. This was noticed when I first bought the car and had to replace the entire exhaust with a stock setup.

The packaging was decent and I would have liked to see foam on all sides of the exhaust instead of just on the bottom. The exhaust took around 45 minutes to install including taking pictures and the rear bumper tuck and I did this on the ground with just a jack and jack stands.

Fitment was good everywhere except for over the frame brace which it just rested on. My solution to this was to install 1/2 inch spacers between the brace and frame. I initially used 1/4 washers but when driving the car the exhaust would hit the brace on larger bumps.

The sound is exactly what I wanted as my goal was slight noise increase with weight loss.

Pictures are being uploaded and I will update this with them but here is a video to hold everyone over.

 

On to the pictures.

 

 

Wow, great feedback. You gave a ton of detailed pictures, including one of those silly "TIG" welds. I'm curious to see how long that will hold up. You should be able to show us one day since you may be taking your 350z on the track. I'm digging those brembos . I need to install my akebonos!

The video is a good representation of the exhaust. How is the drone noise while cruising? I was never able to record the driving sound inside the car with it accurately representing the sound. It sounds way better outside the car than it does inside.

What do you think?

 

I love the invidia Gemini you bought. Your invidia is definitely a better quality exhaust. This Isis should serve my purposes just fine, and I really do love the way it sounds. With the stock cats there is zero drone in the cabin and the sound isn't intrusive at all. I must note that the headers appear to give the exhaust a deeper tone. I recorded a full throttle video on the GoPro this morning that I just need to edit and upload. The sound isn't the best straight from the GoPro but it'll work. I will be AutoXing the Z this weekend and I will give more feedback than.

 

Thanks man! The Invidia is more of a daily usable exhaust for my preference. It's super smooth. It sounds just like it looks.

I'm curious how your headers effect the drone. For me, it was horrible. It had a rice sound while im cruising. Although, I dont think it sounds rice from the outside.

The ISIS gave a really good gain at 5k rpm. My car just screamed with that set-up and that is something I would use for a track set-up but, thats what my 240sx is for . There is no doubt it freed up HP with the ISIS/megan. It did tone down after about 500 miles. It was still too much for modest driving. Im a spirited driver and don't need the attention.

Im curious how PPE long tube headers would go with this invida...

 

Here's an acceleration video.

 

Very nice. I actually like the sound, not loud and not too quiet. I never really like the single exhaust until I started looking into the bumper tuck mod. Where did u order yours? I'm still waiting to hear back from Concept Z for the $325 shipped price.

 

I ordered mine from concept z. My advice on the bumper tuck is to use a heat gun to warm up the paint on the bumper. I didn't and noticed cracking in the paint where the bumper gets bent during the tuck.

 

Thanks for the tip. Mine should be here today! If I have enough time I'll get it installed tomorrow and see how it sounds. I can't wait.

 

Very nice. It does get deeper and cleaner sounding as it breaks in so give it a few days if you don't like it right away.