Motormouth

iTrader: (44)

ok, so I had a custom single exit mandrel bent piping exhaust fabbed up.

specs:

test pipes - 2.5 in/out
y pipe - 2.5 in 3.0 out
muffler (vibrant) - 3 inch straight-through design

so there are no resonators... OMG it is the loudest exhaust I have ever heard. it is louder than my friend's LS1 Camaro with straight pipes I think!

but, my real concern is the layout the exhaust shop came up with. I basically told them what I wanted but left it up to them to layout and fab up as they do this on a daily basis. I took a quick peek under my car (it should be on the lift Thursday and I should have my camera back by then as well) and the welds looked decent, but the Y pipe is extremely long, from the test pipes to about the rear axle almost (like y and b pipe area)... is this a good design, or can it cause problems because the exhaust flows are not equalized for so long?

I made a mspaint illustration of the exhaust and what the stock layout was. please if you have any REAL exhaust experience let me know what you think. I need to take it back and have some resonators welded in, so I can have some changes made then...

characteristics:
my idle is very jumpy, going from 600-500 then up to 1000 and back again. Also, when accelerating part throttle, it is very sluggish until just about 3k then it pulls hard... any idea if that is related to lack of back pressure or a bad design?

Motormouth

iTrader: (44)

and once I get my camera back and can get it on the lift, I'll post some Vid of the sound and pics of the layout.

it sounds to me like a sport bike, it's THAT loud.

Hydrazine

iTrader: (53)

Its a bad design...
I tried a custom y-pipe like that and the car ran like complete $hit. Jerky, lumpy, acceleration. It seriously F'ed up the throttle response. Dyno testing showed a significant loss of power too.

Sorry for the bad news bro. Been there, done that in early exhaust research.
Merge the exhaust gasses together ASAP.

Motormouth

iTrader: (44)

that is what I thought as well. I was going to ask him to change it to a more 'stock' Y pipe design.

thanks for the input.

Motormouth

iTrader: (44)

here is a clip of what this exhaust sounds like right now

http://www.projectforwardmotion.com/...1/100_0519.MOV

have fun. turn the volume up.

ISMSOLUTIONS

WOW! Open headers sounds better than that! Has to be the worst sounding exhaust ever...sorry man!

The design is horrible. Almost seems like the company knows how to bend pipe, but absolutely nothing about a 6 cylinder - especially these cars.

Save your money - DO NOT go back and have resonators put on..it really wont help. That system is going to RASP like hell, drone and hurt your performance.

Balancing the system in the back isn't the worst thing, but usually done as a secondary balancing spot, and what you have isn't balancing the system anyway. You have a single exhaust there - no balancing really to begin with without at a Y segment that is about 8" long - minimum.

BUY something aftermarket...please!!!! Anything! With all of the options out there, using them as samples, I can't believe the system was built like that and even accepted by you based on how it sounds. Did you ask them for wide open pipe and a crappy muffler?

There is SO MUCH research and samples available on these boards....wow again...I can't believe that video...just WOW!!

Rick

Motormouth

iTrader: (44)

thanks but actually, I LIKE the sound

And no offense, but all you do is take off the shelf components and bend up some piping... congrats on making an exhaust the same way I did and then jacking the price up. Your exhaust sounds boring as anything anyway, so your opinion on the sound quality of my exhaust is worthless and wasn't solicited.

The 'crappy' muffler I used is the same ones that AAM uses on their popular exhausts as well, so you just called another vendor's product crap, good job.

ALSO, if you bothered to read this thread you would see I am going back and having it redesigned (moving the Y pipe, etc) so... thanks for your waste of a post and unnecessary attitude. This is a trial and error thing. I'm sure your first exhaust design wasn't perfect and forgive me for trying to do something myself. I learned and am moving forward and improving my design. I didn't ask the Y pipe to be designed like that, but he followed my instructions for materials and components. I did not ask for resonators to begin with, hence why it is so loud. this exhaust cost me about 450 to make, compared to 1k + for an aftermarket exhaust. I could've taken him a picture of a JIC single exhaust and had him replicate it but my intention wasn't to rip off anyone else's product.

If I would have known you were going to give me your asshole opinion I wouldn't have asked you to give me a hand.

thanks for taking the time to read the thread though...

ISMSOLUTIONS

Get your mind straight, first of all.

Don't ask for opinions and advice, and then hate on people for giving it to you...you asked for other's opinions and advice...and you got it...LIVE WITH IT! Dont' look potentnial gift horses in the mouth!

Also, I never tried to sell you another exhaust system....EVER!!! The Fast Intentions system isn't for everyone...duh!!! However, super raspy drone over 100db exhaust isn't for just about ANYONE!!

The system is an extremely poor design - by simple evidence of massive loss of power, poor vehicle running and the massive sound you want to accept...and sound is all subjective, so take that with a grain of salt as well.

I would definitely think twice about going to an exhaust shop that takes a completely inexperienced owners advice on how to design a system, and still goes with it. Did they not know it was a bad design? Did they give you warnings, etc? If they did - then perhaps you should have listened, however, if they didn't and were surprised in any way - I'd not go back there.

I'm not bashing any vendor - just the design and sound and obvious negative impact on performance.

BTW - other than the perforated x-pipe on the Fast Intentions exhaust, everything else is custom deigned by them, for this application..specifically.

Post some pics of that exhaust though..woudl love to see the workmanship.

Rick

Motormouth

iTrader: (44)

again, I did not design the layout of the exhaust.. it was miscommunication. they did warn me how loud it was and he said as soon as I picked it up that I would be back shortly to get some resonators put in. maybe he thought I wanted it that loud, and honestly I WAS looking for a loud exhaust... but 'loud' compared to stock, not a harley And what potential gift horse? you offered me no help other than to scrap it. thanks I guess?

second, I asked for opinions on the layout, NOT the sound quality. I appreciate your attempting to guide me in the right direction, but instead of just giving advice on how to improve the design you keep pushing 'buy aftermarket'. I DONT WANT TO. if I wanted to I would have. that isn't what I asked.

all I wanted was tips to improve the design, which I got. that is all that was necessary. I'm sorry I reacted this way but when I asked for your advice, I was expected something different... lesson learned as well.

just leave it at that. I am not really interested to hear anything more from you. Tony from motordyne helped, immensely so I am set to go.

again, thanks for taking the time to help me out.

ISMSOLUTIONS

OK - I understand where your coming from, and thanks for posting a little more info about the situation...that helps, and another lesson learned - divulge everything so crap like this doesn't happen

Also - have you researched most of the aftermarket designs out there? If you haven't, you should. There isn't a single exhaust for these cars built the way yours was built, that should tip you off that it's likely not a great idea.

Also - you wanted loud, and didn't want to spend $1000 on a system. There are some pretty loud systems out there, for a lot less than $1000, that actually work and do what a system should - gain power. Some do work better than others.

Systems like the HKS knock off system (X02), doesn't really sound like the HKS, but I think is actually louder, and that is one loud exhaust. The Magnaflow system - loud and controlled at the same time. The gains on these aren't quite the same as others, BUT they cost under $600. You can always add testpipes or HFC's as well for sound augmentation, once your initial catback design is in place.

I know you don't want to copy another companies design - but as you go forward, you will soon find out that what you end up with will undoubtedly be very similar to something that is already out there, and you could have likely saved money and time, but perhaps not learned as much as the process will yield you in the end.

The advice you've asked for has been given. Do yourself a favor, save money, and don't try to redesign what's already been done. Look at similar exhaust designs that you are making - singles, before you go back and just add resonators or move the y back to where it should be - you'll save time and money that way, even though I know you don't want to copy.

Just out of curiosity though, who's idea was it to move the Y to the back of the car? If it was the exhaust shop - I would question that pretty well. you want to mix/join the sides while the exhaust is as hot as possible, hence up front. By the time the exhaust cools at the end of the 8FT of pipe...it's too late to balance/scavenge the gases in any way to be helpful.

Rick

helldorado

iTrader: (4)

Couple things I want to add since I've been around for all of this and was the one who couldn't hold the camera steady.

In regards to the sound, the sound quality is actually very mean in person. Its just so loud, it clips on the microphone levels which is why it sounds so bad in the video. Its not like we had great sound recording equipment, just quickly grabbed the camera and it in video mode. Other than the volume levels, its very aggressive and sounds awesome when you get on it.

Also, motormouth knew going in that this would be a learning curve. He wanted something a little different than what was out there and knew he might have to get some things redone as this is a header back setup. The big mistake was lack of clear communication on the y-pipe design and the fabricator took a shorter, more direct pathway where as we invisioned a pathway more like the stock y-pipe.

But we're learning from our mistakes and are going back to the drawing board and the car is going back under the knife next week. New y-pipe design, probably an inline resonator and we'll see what the results are.

We're going to get the car up on the lift tonight and take some photos of the work done. See how clean the welds are and the overall quality of it all. He's done some custom downpipes and other work some of our guys and the work has been pretty clean.

And motormouth was our guinea pig. There's a handful of us who are contemplating doing some custom exhaust work with the fabricator if it turns out well in the end. We're learning from his mistakes and moving forward. We're just going this route as none of us have really fallen in love with any of the exhausts some our other guys have or they won't even work with our setups; Greddy EVO 2; FI Intimidator, HKS Ti; Stillen true dual, etc...

Motormouth

iTrader: (44)

I am discussing this in so many places I guess the info is spread out, but I thought I was clear from the get go i did not think the Y pipe was optimal design hence this thread.

thanks.

Motormouth

iTrader: (44)

yeah I mean, the ONLY exhuast I like is the JIC Ti or Nismo and it's super expensive. I mean, for a B pipe back it is over 1k!

Sean needs it because most exhuasts are routed for a stock rear sway setup while he has a different layout requiring a change in piping design.

thanks Sean

helldorado

iTrader: (4)

Well that, and I'm going to go modular with the design so I can make changes to it depending on need (track, street, show, winter) and how I'm feeling for the day.

Besides, once you and I get our exhausts finally complete, some of the fence-sitters might hop off!

Nexx

iTrader: (41)

i like your effort and understand why you are wanting to get custom exhaust done but honestly very few have managed to fab up a system they actually liked both from sound and performance gains stand point. in the end most people have ended up regretting going in that that direction. i just hope you dont spend an arm and a leg trying to perfect this system. i actually looked into getting a custom setup done but after going to some of the better exhaust shops and getting quotes, it made more sense to just buy a good aftermarket exhaust. in any case, good luck to you and i hope you get a finished product you are looking for.

Motormouth

iTrader: (44)

thanks man, I'm only in the hole for 450 so far, and the test pipes are a keeper (stock layout, so no problem)

part of the issue is a handful of test pipes I didn't like the angle the o2s came out at and some didn't have brackets like the stock cats have. and the muffler I have is great and I love the look and sound it has.

I can't imagine the refabrication costing more than 300.. but we will see. cause 450 was with parts.

I felt the same thing ('will I be happy with this') which is why I went custom. I haven't heard more than two or three exhuasts I like and that varies with cat/header setups... I didn't want to risk it. I figure I can cut this up and move it around without feeling as bad as if I bought a JIC

the ONLY problem so far is that I was remiss in clearly spelling out exactly what I wanted in the design. if I had designed it it would have basically mimicked stock layout just with larger piping and less bends/muffling.

helldorado

iTrader: (4)

Basically we can afford to screw it up at least 1 more time, before its more expensive than buying most of the aftermarket setups anyway.

Motormouth

iTrader: (44)

well no, the aftermarket setups don't normally come with test pipes so 1 1/2 more times!!!

Zridder19

iTrader: (14)

Sorry to hear that, I went with an Ebay y pipe back in the day, and ran straight 3" single I fabbed up with an HKS Ti can, I know how loud it is!! lol

Definatly get that y pipe they made outta there and merge the exhaust like factory.

Motormouth

iTrader: (44)

thanks for you experience! it sounds soo good at WOT though. if I could drive around like that and not get in trouble I'd be in heaven!!!