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This spring I will be adding a Chrs1313, a Fast 102 and some PRC 225s to my car so this will be the setup
-Chrs1313 non AC
-FTP 104
-LS7 MAF with a 4" housing
-Nick Williams 102mm TB
-Fast 102
-PRC 225 heads
-Torquer V2 cam (232/234 .600/.600 112 lsa)
-TSP 1-7/8' headers
-electric cutout
-Magnaflow 3" catback
So I'm wondering about the Y-pipe, right now I have a TSP Y which I cut and welded to stay 3" instead of 2.75", shown below.
So I'm trying to decide what to do, do I cut the TSP Y again and weld in a 3.5" piece? Or should I go with the Flowmaster merge? Or is there another option?
It would certainly be easiest to cut and weld the TSP Y, then upsize my cutout to 3.5" and neck back down to 3" for the cat-back, also this allows me to keep it all stainless steel which I like. Would a Magnaflow merge with a 4" cutout be worth a significant amount more power? Are there other merges out there made of stainless steel that would do the job well?
Multiple good ways to do this.
1: dual cutouts at each end of the Y.
2: flowmaster merge into 4" into cutout reduced to 3" towards muffler
3: x pipe setup out the back so you dont have exhaust aiming at your rear tires.
Yes it makes more power and will be just as efficient as an x pipe up to ~600hp. More then that you need dual 3".
A good Y pipe will save power. A good X pipe makes power.
I assume your talking about scavenging and not flow. Would a properly built Y with pipes merging parallel not increase scavenging just as much as a x pipe? Especially if there is a 3" to 4" expansion chamber at the merge? It is true that an x pipe and duals will allow more flow and therefore support higher hp applications but this guy will only be making ballpark 420 wheel.
So the consensus is basically 3.5" is not enough is what I'm seeing.
I would love to have an X-pipe, but I want to maintain the ability to make it relatively quiet. The area I live in is pretty quiet, and I don't want to always be grabbing everyone's attention when I'm out driving country roads, what matters more than that is keeping it quiet enough that I don't wake my neighborhood when I leave for work at 4:45 am.
So I have 2 different thoughts, one of them is kinda out there.
1) Dual 3" cutouts before the Y like Bspeck suggested
- Would this lose power down low vs a Flowmaster merge with a 4" cutout because of scavenging?
- Can this cause tuning issues if they're too close to the O2 sensors?
2) X-pipe / Single hybrid (I might be crazy)
- Texas Speed x-pipe, (see picture below) connect #2 to the existing intermediate pipe, leave the existing cutout where it is. Add a cutout at #1 and add a pipe behind that to match the length to the existing intermediate pipe cutout.
- would this retain the benefits of the scavenging effects of and X-pipe?
- Google is failing me and I can't seem to find a good picture of the underside of a car with the TSP x-pipe installed, is it even possible to connect the intermediate pipe to the X? Or will it require some serious pipe bending and fabrication?
- tuning issues? Is it going to run badly with the cutouts closed because of how much it will change exhaust flow?
The x pipe does not align with stock location I pipe. Not even close and usually for a good fit you need to fab some brackets to really get those duals up tight. If you want quiet and good flow I would get a good y pipe like the texas speed y pipe or a mufflex which has the flowmaster merge already fabbed. Anyways, get a flowmaster merge. From that merge run it 4" to the pass rear. You will see where the bucket of the floor pan is and there is a handy little spot there that seems like it was made for a cutout to turn there. Well yes but the cutout there and then add a 4" to 3" reducer after the cutout. Run that back into a quiet catback like the hooker aerochamber or dynomax super turbo. You can add high flow cats to make it even quieter and cats seem to make straight through style muffler sound better imo. More like a new corvette sound.
I have a true dual dumped before the axle with super 10s. Kinda sucks to drive on the freeway. Doesnt drone at all because I cruise above that 2100rpm drone range but you really have to crank the radio to hear it. I'm going to do exactly what I just told you with the hooker catback no cats. Got all the parts already.
A properly built Y scavenged just fine. Its just science. The issue people were having is those cheap pacesetter y pipes and early tsp y pipes ran the gasses perpendicular to each other causing scavenging loss as well as rasp. This has been reconized and resolved. Running those glasses parallel allow each gas pulse being followed by a pressure wave to help suck the following pulse put at a faster rate. Merging 2 3" pipes into a single 3" was fine for most bolt on cars but your really benefit from merging into a 3.5" or 4" pipe for better flow from higher hp applications. I'd wager you'd be fine with a 3.5" merge but might as well do 4" anyways in case you change something and push over 600 or so crank in the future.
Will the Mufflex Y fit up with my TSP headers? It says it's made for Hookers, does anyone know if they are positioned close enough to work? It kind of looks like the pipe coming off the driver side header is at a different angle than my TSP Y.
Stick with your TSP merge, it’s efficient and effective enough, but at minimum increase the outlet size up to 3.5” with a 3.5” cutout downstream before necking back down to the 3” catback.
If you can work in a 4” outlet and cutout, this will be worth a few more ponies, and will give more room to grow down the road...only downside with 4” is clearance...make sure it’s tight to right side of tunnel, or removing driveshaft will be a bitch if need be, especially if you go bigger driveshaft later.
Food for thought...when I was H/C/I on my stock LS1, I started with ARH 1-3/4” LT’s and 3” catted Y pipe with the standard 2-3/4” or 3” outlet and a 3” cutout before SLP CME catback.
Put down 446whp, not bad.
I stepped up to 1-7/8” ARH primaries with 3” catted Y pipe, but this one I had them make the Y merge with a 4” outlet, then ran out a QTP 4” cutout before necking down to the 3” SLP CME.
Put down 470whp!
I gained 20-25rwhp between systems.
Bigger primaries probably accounted for 5-10whp of that, and I attribute the rest due to the increased Y merge outlet and cutout size.
Stick with your TSP merge, it’s efficient and effective enough, but at minimum increase the outlet size up to 3.5” with a 3.5” cutout downstream before necking back down to the 3” catback.
If you can work in a 4” outlet and cutout, this will be worth a few more ponies, and will give more room to grow down the road...only downside with 4” is clearance...make sure it’s tight to right side of tunnel, or removing driveshaft will be a bitch if need be, especially if you go bigger driveshaft later.
Food for thought...when I was H/C/I on my stock LS1, I started with ARH 1-3/4” LT’s and 3” catted Y pipe with the standard 2-3/4” or 3” outlet and a 3” cutout before SLP CME catback.
Put down 446whp, not bad.
I stepped up to 1-7/8” ARH primaries with 3” catted Y pipe, but this one I had them make the Y merge with a 4” outlet, then ran out a QTP 4” cutout before necking down to the 3” SLP CME.
Put down 470whp!
I gained 20-25rwhp between systems.
Bigger primaries probably accounted for 5-10whp of that, and I attribute the rest due to the increased Y merge outlet and cutout size.
it cant be that easy for a shop to cut the 3" merge and just weld on a 4" pipe right? Can visualize how that would work, but if it does it may go ahead and do that and sell the flow merge
it cant be that easy for a shop to cut the 3" merge and just weld on a 4" pipe right? Can visualize how that would work, but if it does it may go ahead and do that and sell the flow merge
you mean can’t be that hard?
no it wouldn’t be hard, just need a nice transition to 4” made up off the outlet, or even 3.5” would be a hell of a lot better than the 2.75” outlet most companies make their Y pipe with.
That’s designed for a 3” catback to slip over it, and will barely be enough flow for a bolt on car.
Once you dig into the motor, true duals or a larger I pipe/catback with a good merge is required if you wanna get all the power outta the combo.
I think I'm going to go the Flowmaster merge route, I'll probably take my merge off and use it as a template to get the angles of the pipes correct so that it will slip right in place of the TSP merge.
I already have a 3" cutout on the intermediate pipe so I won't have to re-wire anything, and it will dump a little bit behind the driver instead of right underneath.
I think I'm going to go the Flowmaster merge route, I'll probably take my merge off and use it as a template to get the angles of the pipes correct so that it will slip right in place of the TSP merge.
I already have a 3" cutout on the intermediate pipe so I won't have to re-wire anything, and it will dump a little bit behind the driver instead of right underneath.
the flowmaster merge will work well, but make sure the piping downstream of that and including the cutout is the same size as your merge outlet...if it necks right back down to 3” after the merge, that will be a bottleneck...you want it nice and free flowing up to the cutout, and then you can neck it back down to the 3” before it goes over the axle
the flowmaster merge will work well, but make sure the piping downstream of that and including the cutout is the same size as your merge outlet...if it necks right back down to 3” after the merge, that will be a bottleneck...you want it nice and free flowing up to the cutout, and then you can neck it back down to the 3” before it goes over the axle
Yup, that is my plan. I already have a QTP 3" cutout by that little notch in the body, so I'll swap it out to a 4" and re-use the existing wiring.
Does anyone make a 4" turn down? I have a QTP turn down on the end to direct the exhaust away from the body, I was hoping they would make the same thing but in 4", I can't seem to find a nice stainless steel turn down anywhere though. It looks like I'm going to have to buy an SS pipe with a bend and cut one myself.
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Y-pipe for HCI car 
