Wicked4u2c

iTrader: (6)

THAT SOUNDS HORRIBLE!!! Sorry bro, I have to say its sounds BAD! But hey if your happy that's all that matters...

FLY BY Z

It sounds a lot better with the cats in (that is why I put them back in - they are staying). And I hope you aren't reffering to my exhaust leak when you say how bad it sounds. Otherwise, I don't think it sounds much different from the Injen just little louder. Once I get the leak fixed I am hoping that it is a little better, too. Otherwise, I like it just fine! Plus, for 300 bucks it sounds just fine compared to 1000 plus.

Gsedan35

iTrader: (10)

I dunno, even with the cats it still doesn't have a very pleasing idle sound wise. And as you rev it, it does get better, but it's no Injen, not close enough to justify the price gap. Your really making me worry about my plans. I think your muffler place location is really hurting you. I think the long run's from the mufflers to the tips is allowing sounds resonate. God I hope my using resonator's and 6" vs your 4" mufflers improve's thing drastically. Make me wonder if I should do everything possible to stuff 2 Injen muffler side by side on my sedan.

BTW, your crimp bends are allot more of a liability than your thinking. Corners are not flow friendly, add in a reduction in pipe diameter at that point, that's gonna hurt flow. That's why mandrel bend's are used. If I were you I'd change the muffler location and see if that helps the sound quality. As you know, your shop works for a respectible rate, so moving them shouldn't cost much and it can't hurt.

Gsedan35

iTrader: (10)

BTW, I wanna thank you for the video. You put allot of work into it and it show's. Being able to hear your system is a valuable resource to me. Thanks

FLY BY Z

Hey what if I just cut the tailpipes off and ran the mufflers as the end of the exhaust but just let them dump before the rear end. No tailpipes, no bends, no resonation? Also, I really hope you guys aren't referring to the exhaust leak. It really affects the sound and sounds pretty bad. What do you think? This is as much experimentation as anything else.

I just noticed that you mentioned not pleasing at idle. That is definitley the leak you are hearing. I will make another vid when I get that welded up. Then you can see pre and post leak vids!

Gsedan35

iTrader: (10)

I wouldn't do that for 2 reason's. One, the muffler will be dumping their sound much closer into the cabin of the car. Also, with as much work that has been done areodynamically on these car's I think their might be a issue of the exhaust gases not being able to make a clear break away from the car. Certainly Idling at a stop with the window's down for a very long time likely would have the interior filled with exhaust. Just my 2 cent's. I still say your best bet it so put the mufflers near the bumper and if that doesn't work trade them for 6" one's. I'm sure you could sell your 4" one's as resonator's to someone else.

Your sound quality had me so worried, I bailed on the idea of using Magnaflow mufflers, I ordered a pair of Injen SES universal's today. I'll still use a pair of 4" by 22" Magnaflow mufflers as resonator's however.

lsdunique

iTrader: (3)

He is right about the concern with dumping the mufflers out before they exit the rear. When we used to do custom air suspensions on cars/trucks we had tried several times cutting the exhaust just before the rear axle.

This led to several problems because sometimes even though the car may be traveling down the freeway at 70mph, the exhaust gases don't necessarily get pulled out from under the car and sometimes they can get concentrated on certain areas under the car. We found on a couple cars that the gases were in fact beginning to melt some of the factory wire harnesses that ran under the car.

It is also true that you may get unwanted resonance in the cabin.

FLY BY Z

Thanks for the advice guys. The car sounds MUCH better with the leaks fixed. I had three!!! Anyways, it sounds a little bit smoother but there is def. less extraneous noise. I think that the back half of the system needs to be redone and I probably will sometime soon. I just don't drive it enough to warrant another replacement immediatley. The only reason I didn't use 6 inch mufflers was because they would not fit where I put these 4 inchers. Also, they did not want to cross them in the back because the bend would be too tight. I will probably do that and just buy some mandrel bends. Thanks again!

Eric1h

looks god, but the design is oddly familiar.



hehehe
yours does sound extremely raspy and high pitched, maybe its because there are no cats, my design has a much deeper tone

FLY BY Z

Hey cool! I bet your X pipe makes it smoother than the H. Well, the second half of the vid has the cats back in so it is not so gross sounding. A 6 cylinder really does sound bad with an open exhaust. Anyway, yours looks better going over the sway bar. I think mine needs to be redone. It touches the sway, too.

Eric1h

yeah we did a double X pipe, there is another X just before the tips, check out more pics on www.extremespeedonline.com under the gallery and then Eric1H if you want any other pics.

Gsedan35

iTrader: (10)

2 x pipe's trying to pull off the benefit's of the X pipe twice doesn't make sense. That would hurt rather then help. The first X pipe would have done it's thing of scavaging off of the alternating pulses coming from each bank. I avoided Magnaflow's dual in and dual out muffler for this reason, it use's a internal X crossover that would have been a liability vs benefit. Curious, what muffler's did you use?

This is the X pipe I created for my system. It is a copy of stillen's design.

Eric1h

My contradicting X pipes gained me 13+hp and torque

When R&Ding the exhaust we did it both ways, with a single X pipe, and the added the second, the second isnt full X but merely 2 pipes merged, the best sound/tone and HP's #'s were gained from the system I have now. The second merge REALLY toned and evened the sound out. And of the 15-20 Z members who have seen and head and have the exhaust, its a work of art!

Gsedan35

iTrader: (10)

2nd X not a full X, gottcha. I don't know if I'd class it as a work of art, I see crimp bends, radias's that could have been smoother and the bends leading into and out of the first X crossover could also be smoother.

Eric1h

FLY BY Z

Well, I have redone my exhaust entirely and will post pics next week. I will say that it is VERY smooth sounding and much quieter. I don't know if I will be able to say the same when I get the XERDs. Anyways, it comes off the cats, goes into an X-pipe (much smoother sounding than the H) and goes into the same Magnaflow mufflers, then into some small resonators right before the tips. Sounds really good and all the welds are secure and the bends are as smooth as they are going to get.

Pics to follow in a week.

For those in DFW, I highly recommend LorentZ Automotive in Lewisville, TX. Just call them and ask for Jason in the muffler shop. Tell him Cody with the silver Z sent you. He will give you a great deal for awesome work. I couldn't be happier.

Eric1h

sweet!! Post some pics, i liked the X-pipe sound much better than the other options we tried.

Gsedan35

iTrader: (10)

Finally got my sedan system done.

100% mandrel bends, Acosta Racing Y-pipe with high flow Magnaflow cats converted to true dual. My copy of stillens X-pipe. Dual 18" Magnaflow mufflers as resonators and 2 Injen SES mufflers. I have no idea how much I gained yet, but if feels significant. Cost me between what a Stillen system and a Injen system sell for, but I have the best of both and high flow cats to.

Eric1h

very nice!

Dissolved

You guys know that Stillen, Invida and Borla made exhaust systems for the 350z right? Sorry, I don't understand paying $30k+ for a new car, then hacking up a half a$$ exhaust system to save a few bucks.