Motordyne XYZ + which exhaust?
 

I currently have Berk HFCs and want to replace the OEM Y pipe with the Motordyne XYZ. Since the XYZ exits at 3", I would like to replace the remaining exhaust components to match the increased diameter.

What are my options for the mid pipe and mufflers? Custom?

Tony, feel free to suggest options to match up with your XYZ pipe.

top speed exhaust

I may be wrong, but I believe the Topspeed is 2.75".

the topspeed exhaust is muffler section only? they don't have a mid pipe?

Its mid pipe and muffler

ah, they have mid pipe + muffler for 370Z but muffler only for G37.

on a side note, why does their y pipe exit at 74mm but mid pipe enters at 69mm?

I don't know of the various 3" single "Y-back" exhausts out there but they will all likely perform well on the dyno as long as they are the straight through design. As for the sound, it totally varies and which you like is up to you.

On the XYZ pipe however, I can help you make the modular selection based on what your objectives are.

For a brighter sound, go with the XYZ & Straight pipe module.
For a softer/warmer sound, go with the XYZ & Resonated module. Its also good for resisting rasp.
And since you already have the Berk HFC's, you wont need to bother with the XYZ with HFC module.

Another option is to get the XYZ with HFC and hook it up to ART pipes. You could do this if you wanted more power and a significantly deeper and more aggressive sound while still utilizing a HFC in the system. It would also be slightly quieter at the same time.

Hook that up to your single 3" exhaust and that would work really well. This way you can have the best possible gains and still have a HFC in your system. Then if you want to take it to the track and make a little extra power, remove the HFC from the XYZ and install the straight pipe for track use. The straight pipe or resonator will make 4 more HP than the HFC.

One other detail about the XYZ with HFC. It has a longer life expectancy than other aftermarket metal HFC's that are currently available. Exhaust gas temperature measurements show exhaust gas temperatures are ~1600 deg F' at the inlet of a test pipe. At the outlet of the test pipe the temperature rapidly drops to about 1200' F. As the exhaust gas flows down stream to the Y pipe collector it drops to about 1100' F.

So the temperature drops about 500'F at the inlet connecting point of the XYZ HFC. The XYZ HFC is well above its light off temperature so it is fully operational at warm up, but at the same time, the operational temperature is about 500'F lower than seen by a regular HFC. It is this temperature difference that extends the converters life expectancy.

We have been selling the XYZ converters for years and not a single one has failed. They work well because they run cooler.

Tony, thanks for the response.

I'm planning to stick with the Berk HFCs until they need to be replaced. I want to swap out the OEM Y pipe to your XYZ w/ resonator. The issue is there appears to be no existing mid pipe + muffler options that match the 3" XYZ exit diameter. I believe you stated that any gains in using XYZ would be negated if matched to the 2.5" OEM mid pipe.

There will be gains for sure, but it will do better with a 3" exhaust behind it.

OK, thanks for clarifying.

Btw, I assume that there is no full exhaust in the works for 370Z/G37 like what you have for 350Z/G35?

Yes, there definitely is. A full dual cat back. Its in development now.

eta on the catback? this year?

also, since it is full dual, it will not reuse the XYZ pipe?

No eta but its being worked on now. There are two basic variations of the exhaust. One that uses the XYZ and another that does not.

Tony, is it possible to have the XYZ resonator piece match the oem 2.5" instead of 3" until you release the remaining exhaust components? Or maybe even a separate resonator option in addition to the current 3" resonator?

We don't stock the parts to do that unfortunately. The design is based all the optimized dyno testing. 2.5" didn't work out in that location of the exhaust.

Tony... without doing much looking... the xyz pipe is 3"? and your TP's are not? I have been thinking about all different exhausts, but I thought about the resonated xyz and your TP's with the stock CBE until your's is complete and ready to send out... I have seen some dyno's with the stock cbe with your TP's and cheap y pipe, but nothing with the xyz... I assume it would make at least a little more power.

My other question is... why did you decide to make a 3" xyz pipe? I didn't think on NA cars there were much gains to be made with that extra 1/2"?

Almost all of the aftermarket Y pipes including MD XYZ are 60mm or 2.5in at cat side and 70mm or 3in at mid pipe side. The only one that's not is the ED Y pipe which is dual 2.5in to single 2.5in.

OEM Y - 1.75in + 1.75in -> 2.5in
MD XYZ - 2.5in + 2.5in -> 3in
Tanabe Y - 60mm + 60mm -> 70mm
ED Y - 2.5in + 2.5in -> 2.5in

This thread has some discussion that may answer some of your questions:

Motordyne XYZ-Pipe (Pilot Production) - MY350Z.COM Forums

oh ok cool then, thanks.

hmmm ok.. so getting a 3" cbe to go along with this really wouldn't make much power difference from a 2.5 then? Tony?

Go with 3in if it is available.

The design of all the Motordyne exhaust parts was established by comprehensive dyno testing. All the diameters were tested in various locations and the diameter selected produced the best dyno results.

it depends on what you are comparing it against. Assuming a straight through design for both diameters, a 3" single makes more power than a 2.5" single.

Oh ok, i'm just trying to figure out what all the parts I want to get and like I had said before... I did want to see what you guys had to offer as far as your CBE is going to produce in both gains, obviously quality would never be in question, but tone, loud or soft, etc.

I do like the Exotic Speed A LOT, but I just feel it may be worth it to wait... just wish I know what sort of time frame we are looking at before you all get your cbe's finished and in stock.

Thanks for all of the info though... I think right now for me it will be the XYZ pipe with the ART test pipes and stay with the stock CBE. How loud do you think that set up would be? Just PM me what I would need whether is XYZ with a resonator with the the ART TP's, etc etc. I'm just looking for no drone or rasp, quiet at cruise, but the least restriction possible lol.. I feel like i'm asking for a miracle.

ARt pipes and resonated XYZ connected to the stock exhaust will be louder than stock for sure but it won't be all too loud.