Shenlon

iTrader: (4)

So I've been reading the threads about PatG's Y-pipe merge taking two 3" into a 4" merger and then 4" I pipe and have a few questions. I read that because the X-pipe can't be put in the "correct" location on an F-body (because they weren't designed for them) that this Y-pipe setup is better than a true dual setup. Can anyone explain this further? What is the ideal x-pipe location? If the primary issue is not "slamming" the air together at a 90* angle, would you not see the same success by running dual 3" pipes parallel together into an x-pipe merge instead of the typical 90* x-pipe entry? Or are the two concepts completely different because of the 2 outlet pipes for a dual exhaust compared to the 1 pipe for the Y-pipe?

I would really like to put a true dual system on my car, but if the exact same, or even better, results can be obtained without going through the hassle of trying to fit dual 3" pipes over the axle it makes a lot more sense to go with the single 3" pipe.

I am not concerned with any aspects of a dumped system, just to get the best flow/power characteristics for an over the axle system. If it matters at all, there is a possibility of a larger CID engine being swapped in down the road (400"+).

Thanks in advance all, just trying to wrap my head around how a single pipe could be a better choice than a true dual setup.

blk99sleekbeak

iTrader: (2)

heres another cool read on the subject. I am biased towards the y pipe

https://ls1tech.com/forums/drag-raci...ep-y-pipe.html

Shenlon

iTrader: (4)

Thanks blk99sleekbeak, that was a good read.

So from what I'm gathering, the only real advantage (quantifiable) to true duals over a properly configured Y-pipe is possible noise reduction if you run two mufflers?

I mean I'm not trying to sound like an *******, every single set of true duals I've ever heard has sounded completely badass, where there have been quite a few non-TD setups that sounded nasty. But, it seems like everything really is pointing in the direction of the Y-pipe with a dual 3" to single 4" merge.

Less weight, less cost, more ground clearance (possibly?)

Hmm, actually this may be a great turning point for me because I've pined over TDs for so long and have yet to find a place that I think can get a NICE setup done, whereas it seems like getting the correct Y-pipe setup done and tucked under the car is less difficult.

BFarrier

u believe you can run true duals with an x pipe if you dont use a short t/a because im running a short t/a and to me i now have no room to run duals but im happy with my single the setup which im going to install in a month or so should scavange the exhaust great andways. good luck

Damian

iTrader: (89)

No. You cannot make a Ypipe, in any way shape or form flow the same amount of air as a true dual system.

I consistantly see 10-15ft lb gains in the midrange going to true dual setups on cammed and heads/cam cars.

Shenlon

iTrader: (4)

The question wasn't whether a Y-pipe CAN flow as much air as a true dual system. That's simple fluid calculations. Obviously 2 3" pipes are going to flow more than 1 4" pipe, the question is given the appropriate setup, which there are more than 1 accounts of, can the Y-pipe perform close enough to the true duals to make the overall package for a y-pipe better than true duals.

Also, from what I've seen, it seems like there are very few Y-pipes that are setup "properly" with the pipes running parallel into the connector instead of perpendicular. I'm not saying that you haven't seen the things you say Damian, but have you witnessed the same things with the y-pipe not making a 90* angle? And with a dual 3" to 4" collector? I DO NOT have the experience here, so I'm just trying to do all the research and understand it all before I throw money down on my car.

I was 1000% all for a TD system until I read the "Recipe to 500 RWHP" by PatrickG and then the other thread linked earlier by blk99sleekbeak. In both of those cases it seems like the right Y-pipe was able to make the real world performance difference negligible between it and true duals. If the performance gain is negligible, then all the other factors like weight, cost, and ground clearance seem to be in favor of the Y-pipe system especially for a primarily street driven car that isn't trying to wring out another .1 at the track.

MeentSS02

iTrader: (11)

Keep in mind that the problem most f-body owners face is routing - especially going over the axle. Even getting two 2.5" pipes over the axle without getting too close to the fuel tank, the axle, or the upper panhard brace is a challenge on these cars. That's why you see a lot of people staying with a y-pipe setup - it is flat out easier IMO to route a single pipe through that area. Most people aren't willing to live with the noise of a dumped exhaust, so running everything all the way to the back is a must. Getting duals out the back so that they don't look like a two-year old made them is not cheap.

To me, another huge area of concern is where the two pipes merge together, whether that is into an x-pipe or a y-pipe. If you are taking two 3" pipes into a single 4" at the merge, that is going to take up a significant amount of room, and that area is typically where people run either a driveshaft safety loop or a body mounted torque arm. Getting those two things to share that small space isn't easy either. My x-pipe fits JUST above my driveshaft loop, and I can guarantee you that a 4" diameter pipe in that same location would not have worked. Granted, there are other options out there for DS loops, but still...

You can sit there and analyze the performance benefits until you are blue in the face, and there will be tons of people backing both sides of this argument. My suggestion is that you look at it from an overall packaging perspective, because that is ultimately what you are facing here. See what fits the best, and just go with that. You may quickly find out that what you have done as far as chassis/suspension work will dictate how big of a sewer pipe you'll be able to fit without losing too much ground clearance.

Shenlon

iTrader: (4)

Thanks for the advice MeentSS02, and I am trying to go with that mentality of looking at the overall package. I guess probably the hardest thing is that I haven't really done anything to the car yet other than SFCs, so I'm still trying to fit all the pieces together prior to purchasing them instead of just making a decision and working with them. As much as I would love to have a true dual system, I haven't found a shop yet that I would feel comfortable forking over the cash to and it seems like the Y-pipe would be "easier".

So, I think that gives me the answer right there, thanks for everyone that threw an input in to this thread.

TA1364

iTrader: (11)

I did the bullets on the collector, it sounded horrible so I put the Y back on. I then put a X pipe on, sounds the best by far and picked up 2 mph at the track over the Y setup. Only downside is grounded clearence isnt the best. As far as price by the time you buy and Y and flowmaster merge then have someone cut and weld everything up, you can probably just buy a X pipe.

dutinsss

iTrader: (2)

i've been running 3'' dumped duals with flowmaster single chambers, but i'm about to swap it for a y-pipe with a flowmaster 3'' into 4'' merge, then put a 4'' cutout, then to a 3'' pipe over the axle. i doubt the power will differ much going from 3'' duals to a 4'' cutout. if your going for simplicity, stock-like fitment, and not much if any power difference from true duals, i'd go to a setup like i'm going to. but if you want good power, the BEST sound, but don't worry as much on fitment, and don't care that they'll be dumped at the axle, i'd go true duals. i just want an exhaust that doesn't constantly rattle the car, and drown out other people talking in my DD. that being said. if there was a competent exhaust shop locally, the perfect set-up to me would be 3'' true duals ran out the back with flowmaster single chamber mufflers. it's just that it's rare to find a shop that can build you that, and it actually be quality work and clear everything.

MeentSS02

iTrader: (11)

This ended up being a big issue for me...I had to go to great lengths to find someone that I could trust to do the work. I ended up driving from Florida to Chicago to have Speed Inc. to do mine. Most exhaust shops will just tell you it's impossible to do on these cars. Horseshit.

Finding someone that can do quality work will make all the difference with this one. Finding someone that knows these cars well and can do quality work would be the best case scenario.

EDIT - being from NC, you might consider Kooks. I know they've done custom exhausts for people in the past, and it looks to be about a 2.5 hour drive away. Probably wouldn't be cheap, but they've done some impressive work for people in the past, and there have been some pics posted on this forum showing that work.

Shenlon

iTrader: (4)

Yea, I have considered Kooks, but the $$ figure is just too high for me right now to do that. I've seen their systems and they look AMAZING. Hopefully in a couple weeks I'll be able to talk to them. For some reason I thought that they were in NY.....thanks for making me realize that they're just down the road!

blk99sleekbeak

iTrader: (2)

I would like to say, since you are on the topic of fitment, i had to cut the driveshaft loop off of my UMI tunnel brace mounted tq arm. Other than that the fitment is PERFECT. But it is a custom one off y pipe

ss454327

iTrader: (10)

I'd like to see some graphs of true duals with an X pipe vs dual 3 Y to single 4". The bends in most X pipes probably reduce the flow more than the reduction of a single 4" pipe. You would definatley pick up some midrange TQ by slowing the exhaust through an X pipe. A properly tuned exahust system should get smaller as it goes to help keep the velocity constant. I think that's why dual 3 Y to single 4" works so well on LSX motors. I'm running that setup on my SSS and the LQ9 LOVES it.

Halon330

iTrader: (7)

Could you post pics of how and where your exhaust system is ran?