Mocked up my X-pipe kit and duel flowmasters dumped before the axles.... Ran everything tight to the floorboard all the way back and turned the dumps at a 45 towards the bottom of the tires before the axles.... Went to lower it down and the damn flowmasters hit the ground!!! didn't take into account the 2 inchs i lowered the car. So now i am trying to sell the mufflers and go with a diff setup.. Anyone got any ideas.. Bullets off the headers dumped? single chambers dumped?

 

Don't dump. Run the duals back and have 2 bullets in the back.

 

Depends on the diameter of his exhaust. 3" pipe is very difficult, if not impossible, for most people to run all the way back.

 

Might have to run a Y-Pipe..
I am goin to have to run the 3" Y-ed into a 4" back, then reduced into a 3" over the Axle into something..

 

Pointless to have the 4", unless you're using it for a sound chamber. You can only flow as much as the smallest pipe (3") allows. 6 miles of 4" wont help if it only has a 3" opening. Unless you plan to bring physics into play and make some sort of a vortex to help bring the exhaust along lol Or 4" over the axle so when bent, it's still at least 3-1/2"

Plus, I thought for true duals on a SBC (under X amount of HP of course) that 2-1/2" is all that's needed. We need SOME back pressure right?

 

I have my true duals in 3" pipe with the Moroso mufflers exiting at the rear end with no dumps.

 

I have LT's to an X-setup with bullets dumped with the tips pointed at the tires like your saying. Its all 3"... In this picture I still had stock SS springs and shocks in the front. The back is a tad higher (changed the setup for the stereo weight). It works for me... especially since I got new suspension stuff in the front now.

 

Pics in here, 3" from collector to exhaust tip and I'm lowered with strano springs, 1.2-1.3". I'm running moroso spiral flow mufflers...
http://s86.photobucket.com/albums/k1...n24/?start=all

 

i'm on 2" drop and realy wanted to go true duals because i'm @ the point where my 3" is @ max flow with the hp the motor makes. I am going to a Mufflex 4" mandrel bent set-up with a 30- series top ten race muffler. Ground pounding muscle car sound. I LOVE the sound the 2 chamber flows make with 4" pipe(Old style NOT Delta Flow).

I'd find some bullets or sweet thunders.

 

I beg to differ on that one..

Read this, this can help alot of us out..This is from a Guy named Patrick G, he does alot of research. He just got a Heads/Cam LS1 with Stock Bottom to put 500's at the Wheels with this Exhaust. This guy does alot of research, also the one that recommended my Cam.


Exhaust selection:

To make big power with a street motor, you need an exhaust that sucks...literally (David Vizard quote). When running a cam with lots of overlap, backpressure is not your friend. But when building a daily driven street car, too free flowing of an exhaust often means too loud. Not in my case.

You want the best headers you can find. For an LS1 F-body, it would be QTPs or Kooks in 1 3/4" size. For a Vette, the LG Pro Long tubes reign supreme. A high velocity merge collector on the header collector is typically worth some nice gains in the mid-range and is known to squeak out a few extra ponies up high as well.

Merging the twin pipes coming off the headers is a critical item for power and sound quality. Vettes have it easy because an x-pipe easily fits and the sound quality is awesome. F-bodies are handicapped because of space constraints. For 500 rwhp, you want to run dual 3" pipes after the headers and you'll want them to merge into a 4" intermediate pipe. Anything smaller will run the risk of flow loss. Most y-pipes on the market slam the 2 pipes together like this:



When the pipes meet at close to a 90 angle, the flow is going to be lower and the sound is going to rasp and drone at 2000-2300 rpm. By using a Flowmaster merge collector or better, your sound quality will improve since the gasses meet side by side as opposed to ramming into each other. Here are a few pics of my exhaust.









Notice the dual 3" pipes merging into a 4" intermediate pipe, then a 4" cutout. After the cutout, the pipe is reduced to a 3" SLP dual dual catback. Compared to open headers with 20" extensions, my motor lost 1 hp with this y-pipe, but gained 10 rwtq in the 2500-4000 rpm range. From a sound standpoint, the rasp/drone is gone with the better y-merge collector. The difference between running with an open cutout and closed exhaust through the tail pipes is 9.5 rwhp. Not bad at all.

 

or just 4" all the way OTA with no HP loss.

 

All the shops around here can't bend 4". How is everyone getting 4"? Am I just in a deficit area?

 

Tomorrow I am goin to get some 3" and try to locate a 16" section of 4", and make that Y-Pipe. I am going to have to bring it in tighter at the Y area cause of the Torque Arm that I have.

 

I like the oval drivers side section of 3" for ground clearance, that exhaust is something most shop could not even come close to replicating. Nice....

 

That is a nice lookin setup, hopefully I can get some gains out of it.

 

One thing I have noticed about exhaust is you bout have to have all your suspension and chassis done cuz one change and the exhaust is in the way.

 

Mufflex sells 4" kit's and i am getting some of mine from Semi Truck parts stores.

 

Another vote for the 4" set-up... Here's a pic of mine when it had a 4" one chamber flowmaster... It now has a spintech super stock race muffler, love it...

 

^^^ I had a similar setup to that until I went to true duals. I bought a 4" Borla and found out no one could bend 4" pipe. So I put a reducer on it and run 3" and stuck out on the driver side like that. I'm saving the 4" Borla for the turbo LS1.

 

I'm just not happy when I see how much a 4" catback costs. That info on the ypipe is interesting though......

I hear it about the chassis/suspension. Every time I asked a shop about true duals they cringed when seeing the spohn suspension parts and slp subframe connectors. I finally gave up on the TD idea.