I recently built my LT1 to a mild 383. Here are the relevant details:

SLP Fender Well Intake
Aluminum Intake Elbow
58MM Professional Products Throttle Body
Loyd Elliot Ported Intake Manifold
LE2 Heads - Comp beehive springs
LE2 Billet Cam 236/236 @.050"
Comp Chromoly pushrods
Comp 1.6 NSA RR 7/16" Stud
LS7 Lifters
Eagle Cast Crank
Eagle Forged I Beam 5.7" Rods W/ARP Capscrews
Speed Pro Hyper -12CC Dish Forged Pistons (11.8:1)
Widebad O2 Sensor - AFR Gauge
Gutted Cat
Unknown Series Flowmaster Catback
Pacesetter Mid-Tube Headers & Pacesetter Y-pipe



I have always had problems reeving past 5000RPM. I bought a new optispark but did not install it yet.

So I have about 1,500miles on the motor and for the most part I was happy with it. Not overly impressed but happy. Well today I decided to pull the Y pipe off (A friend who helped me put the motor back in said it felt a lot more powerful with the exhaust off, and it did) So were running open headers and holy Fu** what a difference. My misfire went away completely, she revs to the limited flawlessly every time and never misfires. And best off all it feel so much more powerful and quicker revving. I did a bit of research and asked around and its pretty accepted that Flowmaster sounds nice but hold back HP. Apparently its holding back a whole lot more than I ever imagined!.


So I need to get rid of this setup. I have part of a SLP Loudmouth setup. I have the rear portion. I lost the resonator. So If I were to weld this in I would have straight pipes. I need to add something to make it quiet without killing flow.

I have the pacesetter midtube headers with the pacesetter Y pipe, going into the stock pipe/cat (cat is gutted) then the flowmaster 3" pipe is bolted to that, with straight pipes back to the muffler. I want to put the SLP loudmouth rear potion in place of the muffler and tips (the part I have will leave the inlet just over the axle. I will use the flowmaster 3" pipe to complete it, then I would like to put somehting in place of that straight pipes between the cat and the axle hump.

How about a Cherry-bomb glass pack?.. some some kinds of resonator. Will it kill a decent amount of sounds?.. recommendations?.. I don't want to spend more than $100 on this.

Thanks for any advise.

 

Magnaflow part#14419 3"in/out, 4"dia., 14"case length.
PM Sent.

 

that is perfect, and the price is right, and its sexy. Thanks for your response. part number and all.

How does it sound?.. I know you said its loud if u dump before the axle, but I will not be doing that. How loud is it oustide the car? ever get pulled over?..

Thanks for the advise! :-)

 

Not very loud until you get into the "GO"pedal!
Haven't got pulled over, at least not yet!
It's not loud enough to get you pulled over if your just cruising around at a low engine rpm. It's also not any louder than the flowmaster super 44 I had on it before at idle to light throttle, but louder at full throttle.

 

That is perfect. I ordered one off eBay. $72 with free shipping. I will get it installed next Tuesday at my buddy's shop. Thanks

 

Resonator will be loud as Hell. Hence loud mouth.

If you want to tone it down with little loss get a straight through muffler catback like GMMG, Borla. Blowmaster sounds great but chokes big power.

BTW I noticed only less than 8 RWHP gain by pulling the Y-pipe connected to my old Borla and slipping 18" torque tubes directly on the collectors. This means the Borla flows real good.

I know have home-built TD's with a magnaflow straight through muffler.

 

to be honest. Im not huge on how the car sounds. I just want to have the ability to drive threw town semi quietly, just enough to not get pulled over. as long as it pulls like a raped ape I could care less what it sounds like at WOT. I think this magnaflow will fit me well.

 

How did you get 11.8:1 comp with -12 cc dish pistons? Just curious.

 

Bore = 4.030"
Stroke = 3.75"
Head Gasket = .026" (Victor Reinz)
Deck Clearance = .010"
My LE2 Head Combustion Chamber= 51.9CC

This all calculates out to 11.97:1

 

so I just searched around my shed good and deep and I found the SLP resonating chamber from my loudmouth kit. Its quite short. I think I will have room to put both resonator on the car, make make it a little quieter yet

 

no they will not both fit.

do you think the magnaflow resonator will be quieter, louder, or equal to the SLP resonator?

Thanks

 

same

 

I had exh respnance problems @ 2k rpm. App... 97ss 383-D1 MM6 AFR heads + Seimens 72# Inj. I have slp headers and Mufflex 3 1/2 modded exh system. I added a CCI insert to atenuate noise and resonance with a SpinTech 3 1/2" muffler. I also use a 3 1/2" Qtp cutout when flow is needed. They are available @ Summitracing.com. Small and easy to install with a MIG welder. B.

 

Here is a link to what mzgp5x is referring to:
http://www.summitracing.com/parts/CC...R/?image=large

Personally I would have to imagine that it would cause some restriction and MINOR power loss regardles of what the maker says. Sounds like a trade-off to me.

 

I used these with the head/cam you have , longtubes, no cat thru the loudmouth. http://www.summitracing.com/parts/DTC-72-32520/

Idle and light part throttle was ok but at WOT it sounded like all hell bustin loose.
I am not sure there is an exhaust louder than the loudmouth.