01Blk*SS*

iTrader: (4)

Anyone have 3" ypipe merged to a 4"ipipe over the axle to a muffler? If so, can you please post pics/reviews? Im going to do this pretty soon and want to get an idea on the best setup for clearance/ sound.
thanks!

STREET99

iTrader: (3)

I am doing a similar setup w/o the merge. Mine is just LT Headers into 3inch ORY into a I-pipe into a 3inch Dynomax Bullet Muffler w/ Turndown.

01Blk*SS*

iTrader: (4)

does anyone know the disadvantages/advantages of the 3" y to 4" merge before the I pipe?

-98-Z28-Darkness-

iTrader: (7)

my tsp ypipe looks like it ends in a 3 1/2'' merge( not 100% sure) then goes down to 3'' inlet. looks like all you have to do is chop the piece that minimizes the pipe. plus its a great merge!...i think othe then that you will need to get it custom made ypipe to fit a muflex 4inch catback.

brian_rs/ss

pretty soon here i am goin to be taking my TSP o/r y and doing the flowmaster 3"/4" merge with a 4" i-pipe run as far back as possible into a 3" spintech cat back. i haven't really found too much on the 3" spintech but it looks pretty legit, all 3" piping and has a real deep tone. so hopefully this will kill the rasp, fingers crossed.

Z28_LT1

iTrader: (2)

why do you want a 4" anyway?

brian_rs/ss

https://ls1tech.com/forums/generatio...heads-cam.html

read post #9


i would love to go with the mufflex 4" cat back but damn they are expensive

01Blk*SS*

iTrader: (4)

What Im gonna do is get a flowmaster 4" merge and a magnaflow muffler with singe 4" inlet with dual 3" outlets. To reduce turbulence in your exhaust you want to keep the same cross-sectional area throughout the exhaust system. going from 2 3" pipes into a single 4" pipe will reduce the turbulence.

brian_rs/ss

turbulence=rasp?

i know for sure turbulence is bad for flow, is it also bad for sound? because i know my TD's sounded AMAZING, and i'm sure they couldn't have had much turbulence.

Twotonefreak

iTrader: (11)

I run a 3" mandrel bent Y with a 3" Flowmaster merge that is 4" outlet and necked down to a 3" I pipe, 3" electric cut out. 3" over axle into a Magnaflow muffler and 3" mandrel tailpipes. I pick up right at 10 with the cut out open.

brian_rs/ss

u pick up 10hp with the cut out open? see thats why i really want a mufflex 4" cat back. i dont want a cut out, and i want to be able to get as much flow as possible out of a cat back. i guess i'll be saving up.

blue99fbody

iTrader: (5)

when my builds done im gonna be cutting my old tsp y pipe and putting in a 3" to 4" flowmaster merge into a dynatech 4" race muffler and 4" turn down before the axle. i wont know how it will fit till i get the motor back in but i know its gonna be tight bc my car sits pretty damn low.

brian_rs/ss

^ a tip for the turndown, take a grinder and shave off the bottom edge of turndown. that way if you scrape it wont bend up/smash that part of the pipe. i ran into that problem with the turn downs on my TD's. but a big set of pliers and grinder fixed it.

1969mach1

this looks like Pat's merge.
a Dr. Gas Exhaust.
http://drgas.mybisi.com/products/street-performance

Twotonefreak

iTrader: (11)

Honestly, I bet you'd still pick up 10 with a cut out, even with the Mufflex system. I've installed a few, they aren't any better flowing than a magnaflow IMO.

brian_rs/ss

not that i doubt your experience, but a 4" cb > 3" cb. it has to be, just like a 4" merge > 3" merge. it's the same concept.

^and thats where the problem lies, it's your opinion and not based on actual testing or actual hp/tq/cfm #'s.

now i would love to see a dyno comparison between 3" y-pipe with 3" merge and a 3" cb with 2.5" tails vs. a 3" y-pipe with a 4" merge with a true 3" cb vs. a 3" y-pipe with a 4" inch merge with a 4" cb with 3.5" tails.

01Blk*SS*

iTrader: (4)

I would say turbulence is higher pitched at faster velocity (speed). So it would depend on what sound you prefer, deep or high. I currently have tsp true duals on my car and would say its a little raspy. Just think of the true duals xpipe merge and a y pipe merge. the flow in the TD's stays parallel and the streamlines of the flow do not collide at as big of an angle as the ypipe streamlines.

01Blk*SS*

iTrader: (4)

I agree with you Brian, you basically want to get the exhaust out as fast as possible without too much resistance.

brian_rs/ss

yeah i would say my TD's were pretty deep until you hit the higher rpm's and it would be a little raspy. but NOTHING near as raspy as my TSP exhaust.

FirebirdSS

iTrader: (7)

You do not need 4" exhaust. You wont gain anything from it over a well designed 3". Unless you plan on going over 500rwhp. If you look at the recipe 500rwhp, he only last 10hp with a 3 inch exhaust after y-pipe through a muffler. Compared to 4 inch dump after ypipe. You would never notice 10hp.

IMHO Larger pipe sounds like ****.
And sometimes a 4" pipe will flow worse then a 3" pipe. Heat, volume, air speed, turbulence it is all effected.