450rwhp?
Also, this is probably a silly question (and the wrong forum, I'll put up a topic there if necessary) but I'm planning my bolt-ons at the same time. I was planning on a set of pacesetter 1-7/8"s with either TSPs y-pipe, or a custom one with a flowmaster merge. At this much hp, am I going to see any kind of restriction sticking with the single pipe setup? (Catback is a Magnaflow, btw)
There was an exhaust flow chart somebody posted. I want to say 2.5" duals flowed with almost no loss at the 450 mark, but not 100% sure.
Also I just saw an older thread where someone posted 12 horsepower difference between a 3" cat back and open cutouts on their 4xx horsepower car. Hope that helps
Also I just saw an older thread where someone posted 12 horsepower difference between a 3" cat back and open cutouts on their 4xx horsepower car. Hope that helps
Not sure if your interested but I am selling my old setup to move onto my 408 turbo build. My heads and cam will be for sale soon aswell as my ls1 alum block 6.125 scat h beams and mahle forged lightweight Pistons. I'm re using my crank for my new build. I made 459 to the tire at 22 degrees of timing on 93 octane. I'll also won't be needing my injectors either they are the red top 36 pound injectors. I'm just now disassembling the old block and can send you some pics of the rotating assembly if you would like. They still look new.
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TECH Resident
Joined: May 2011
Posts: 752
Likes: 2
From: Leander TX
my buddies car MS4 Ported ls6 heads ls6 intake and 1 7/8 longtubes custom mandrel y pipe with flowmaser merge and a sinister 4" catback made 460rwhp the exhaust was worth 30hp over an slp header y pipe and loudmouth combo
I don't have a Flowmaster merge but I do have a single pipe. I think it does just fine with my setup. In my opinion, until you reach a certain amount of horse power the difference between a good Y pipe setup and a good X pipe setup will be little to none. The reason I chose the exhaust setup that I did was the weight factor.
Thread Starter
Staging Lane
Joined: Aug 2014
Posts: 73
Likes: 0
@Poltergeist If i'm reading your sig correctly, you're running a 4" pipe after the y, that's dumped before the axles?
I was thinking of going with a good y, and doing a cutout instead of TDs. Seems to me to be much cheaper. Opinions on that?
I was thinking of going with a good y, and doing a cutout instead of TDs. Seems to me to be much cheaper. Opinions on that?
If you have a 3" Y pipe to start with, it can be cheaper. The vibrant merge was $100, I think the vibrant muffler was about the same, then I used a 4" stainless diesel stack for the rest of the piping and turndown which cost $40 (ebay). I chose the vibrant merge over the Flowmaster cause it is stainless as well and the construction of this piece is really nice. The ONLY down side of doing this is it's loud. I have had multiple exhaust setups (pacesetter Y with hooker cat back, pacesetter Y with 3.5" mufflex, custom 2.5" duals with an H pipe out the back, custom 3" duals with an X pipe out the back) and the setup I have now. For a lower horse power car like mine I feel the custom single 4" setup is superior to the rest for MY application. Not only is it lighter but I would bet at this power level it would be within 2hp of a decent dumped X pipe setup on my car. Here is what most people don't realize, the area of a 2.5" pipe is 4.9087385212341, the area of a 3" pipe is 7.068583470577 and the area of a 4" pipe is 12.566370614359.
Used AFR 205's @ 59cc (GM MLS ghead gaskets .051 compressed)
BTR Platinum springs w/ titanium retainers
Unported Fast 92
NW 92mm TB
Powerbond 25% UDP
SLP lid (it's a 4" neck... screw a flimsy FTP 98 or 104)
Stock rockers w/ trunion upgrade
BTR Platinum springs w/ titanium retainers
Unported Fast 92
NW 92mm TB
Powerbond 25% UDP
SLP lid (it's a 4" neck... screw a flimsy FTP 98 or 104)
Stock rockers w/ trunion upgrade
Thread Starter
Staging Lane
Joined: Aug 2014
Posts: 73
Likes: 0
I've read that you "shouldn't" use stock rockers with AFR heads because it would cause premature wear on the valve guides. This is the only thing shying me away from AFRs or other heads with bronze guides. I have similar goals as the OP. I already had CHE upgrade my stock rockers as I had planned to go with a ported LS6 head so I could keep stock like reliability and longevity.
Thanks!
Hmmm. I guess I should probably mention that (after a brief discussion with Tony) I'm going with his new MMS 220's. Though I'm sure that's the same thing. I did just buy a set of rockers with the trunion upgrade already installed... I'll ask Tony. Worst case scenario is I turn around an sell them.
Thanks!
Thanks!
You and I are going to end up with very similar rides, it looks like. I just made the same decision. I'm pretty much going all in for an optimized build so I know I haven't left anything on the table. good luck with your build. It'll be interesting to compare numbers.
Also, this is probably a silly question (and the wrong forum, I'll put up a topic there if necessary) but I'm planning my bolt-ons at the same time.
I was planning on a set of pacesetter 1-7/8"s with either TSPs y-pipe, or a custom one with a flowmaster merge. At this much hp, am I going to see any kind of restriction sticking with the single pipe setup? (Catback is a Magnaflow, btw)
I was planning on a set of pacesetter 1-7/8"s with either TSPs y-pipe, or a custom one with a flowmaster merge. At this much hp, am I going to see any kind of restriction sticking with the single pipe setup? (Catback is a Magnaflow, btw)
This was with stock 243's, 227/235 cam and a FAST 102. Not that wild of a combo and quite a bit of a gain. Dyno sheets in the link:
https://ls1tech.com/forums/dynamomet...stage-2-a.html
Thread Starter
Staging Lane
Joined: Aug 2014
Posts: 73
Likes: 0
Tony will definitely want you to go with YT's.
You and I are going to end up with very similar rides, it looks like. I just made the same decision. I'm pretty much going all in for an optimized build so I know I haven't left anything on the table. good luck with your build. It'll be interesting to compare numbers.
You and I are going to end up with very similar rides, it looks like. I just made the same decision. I'm pretty much going all in for an optimized build so I know I haven't left anything on the table. good luck with your build. It'll be interesting to compare numbers.
And hey, once we get our builds done, we'll have to run against one another. I think my gf has some family in AZ, so we might go on a road trip.
But, the heads are the foundation. Once they're done, everything else is relatively easy. Down the road, I'll throw a set of duals on and go with a carbon twin disc, which will make a difference.
